Ball joint

In an automobile, ball joints are spherical bearings that connect the control arms to the steering knuckles, and are used on virtually every automobile made. They bionically resemble the ball-and-socket joints found in most tetrapod animals.
A ball joint consists of a bearing stud and socket enclosed in a casing; all these parts are made of steel. The bearing stud is tapered and threaded, and fits into a tapered hole in the steering knuckle. A protective encasing prevents dirt from getting into the joint assembly. Usually, this is a rubber-like boot that allows movement and expansion of lubricant. Motion-control ball joints tend to be retained with an internal spring, which helps to prevent vibration problems in the linkage.
The "offset" ball joint provides means of movement in systems where thermal expansion and contraction, shock, seismic motion, and torsional motions, and forces are present.
Theory.
A ball joint is used for allowing free rotation in two planes at the same time while preventing translation in any direction, including rotating in those planes. Combining two such joints with control arms enables motion in all three planes, allowing the front end of an automobile to be steered and a spring and shock (damper) suspension to make the ride comfortable.
A simple kingpin suspension requires that the upper and lower control arms (wishbones) have pivot axes that are parallel, and in strict geometric relationship to the kingpin, or the top and bottom trunnions, which connect the kingpin to the control arms, would be severely stressed and the bearings would suffer severe wear. In practice, many vehicles had elastomeric bearings in the horizontal pivots of the trunnions, which allowed some small amount of flexibility, however this was insufficient to allow much adjustment of caster to be made, and also introduced compliance where the suspension designer may not have desired it in his quest for optimum handling. Camber angle could generally be adjusted by moving both inner pivots of either the upper or lower control arm inwards or outwards by an exactly equal amount. But compliance of the control arm inner pivots, typically due to the use of elastomeric bearings, would again cause the trunnions to be stressed. The suspension designer's freedom was limited, it was necessary to have some compliance where it might not be wanted, and very little where more would have been useful in absorbing the fore and aft impact loading from bumps.
The introduction of ball joints top and bottom allowed 3-axis articulation and so removed all the constraints on the control arm axes being exactly parallel, so caster could be freely adjusted, typically by asymmetric adjustment of the position of the control arm inner pivots, while camber was adjusted by the symmetric adjustment of these same pivots.
The arrangements for adjusting the toe angle are not changed by introducing ball joints in the suspension, although the steering linkage itself must use 4 or more pivots, also usually ball joints, and in almost every vehicle ever made, some of these have been adjustable by having a threaded end and locknut, to enable the toe to be set precisely.
This ability to fine-tune ball-jointed suspension allows manufacturers to make the automobile more stable and easier to steer, compared to the older kingpin style suspension. It may also be quieter and more comfortable, because lateral and fore and aft compliance in the suspension can be introduced in controlled amounts at the control arm inner pivots without compromising the integrity of the steering axis pivots, which are now ball joints instead of a king pin and trunnions. The smoother ride may also increase tire tread life, since the ball-joint suspension allows better control of suspension geometry and so can provide better tire-to-road contact.
Purpose.
On modern vehicles, joints are the pivot between the wheels and the suspension of an automobile. They are today almost universally used in the front suspension, having replaced the kingpin/linkpin or kingpin/trunnion arrangement, but can also be found in the rear suspension of a few higher-performance autos. Ball joints play a critical role in the safe operation of an automobile's steering and suspension.
Many currently manufactured automobiles worldwide use MacPherson strut suspension, which utilises one ball joint per side, between the lower end of the strut and the control arm, with the necessary small amount of articulation at the top of the strut being usually provided by an elastomeric bearing, within which is a ball bearing to allow free rotation about the steering axis. So, there are commonly only two ball joints in the suspension, however there will be at least four (track rod ends and rack ends) in the steering linkage.
In non-MacPherson strut automobile suspension, the two ball joints are called the "upper ball joint" and "lower ball joint". Lower ball joints are sometimes larger and may wear out faster, because the fore and aft loads, primarily due to braking, are higher at the bottom ball joint. (Torque reaction and drag add at the bottom joint, and partly cancel at the top joint.) Also, lateral cornering loads are higher at the bottom joint. Depending on the suspension design, the vertical load from the suspension spring may be handled entirely by the top ball joint, or entirely by the bottom ball joint. The damper load, (which is low in normal conditions, zero when stationary, but in peak bump or rebound rate may be almost as large as the spring load) is usually, but not always, taken on the same ball joint as the spring load. The anti-roll bar loading is often, but not always, taken on the bottom ball joint. It may be taken by the top ball joint, or directly from the steering knuckle by ball-jointed drop links.
If one of the ball joints does not carry spring load, it may be fitted with an internal anti-rattle spring to keep the ball preferentially in contact with one seat. This was the case in the BMC Mini of 1959 and its many derivatives, where the lower control arm carried no vertical loading, so the joint needed and anti-rattle spring, while the top joint, comprising identical parts, was always in compression due to spring (rubber cone) and damper loads, and so was not fitted with a spring.
Other vehicles of the 1960s era, including some Vauxhalls, had lower ball joints with considerable end float, because the joint was always in tension as the spring and damper loads were applied via the lower control arm and were always non-zero.
Another example is the Ford Focus, which uses MacPherson struts, and the anti-roll bar is connected directly to the strut, so the lower ball joint is only carrying fore and aft traction/braking and lateral cornering loads.
Front-wheel drive.
Unlike a kingpin, which requires an assembly in the center of the wheel in order to pivot, joints connect to the upper and lower end of the spindle (steering knuckle), to the control arms. This leaves the center section open to allow the use of front-wheel drive. Older kingpin designs can only be used in a rear-wheel-drive configuration.
Lubrication.
Sealed ball joints do not require lubrication as they are "lubed for life". Formerly most ball joints had grease fitting (sometimes called a "grease zerk") and were designed for periodic addition of a lubricant, however almost all modern cars use sealed ball joints to minimise maintenance requirements. The lubricant was usually a very high-viscosity lubricant. It is commonly believed that standard ball joints will outlive sealed ones because eventually the seal will break, causing the joint to dry out and rust. Additionally, the act of adding new lubricant pushes out old and dry lubricant, extending the life of the joint. This was supposed to be done at intervals of 1000 to 2000 miles on many vehicles, which is incompatible with the service interval on modern cars, often 12000 miles or more, and in any case was rarely attended to by owners, resulting in severe wear and possible ball joint failure, which can result in serious accidents. For this reason, almost all ball joints on modern European or Far Eastern cars are the sealed for life type. New technology especially applied to the internal bearing design has allowed ball joints to meet these longer service intervals. The special designs incorporate sintered metal bearings which replace OEM sealed polymer/plastic version and improved dust boot seals that work much better at retaining the grease.
Spherical rolling joint.
A spherical rolling joint is a high-precision ball joint consisting of a spherical outer and inner race separated by ball bearings. The ball bearings are housed in a spherical retainer and roll along both the inner and outer surfaces. This design allows the joint to have very low friction while maintaining a large range of motion and backlash as low as 1 μm. SRJs are often used in parallel robotics applications like a Stewart platform, where high rigidity and low backlash are essential.
Most SRJs are designed with an offset housing, allowing for higher compressive loads in a smaller space. Alternatively, the joint can be assembled backwards for higher tensile load capability but less range of motion.
An alternative to the SRJ is the universal joint, which consists of two revolute joints. By using spherical rolling joints instead of universal, designers can reduce the number of joints to achieve the same result. Using a spherical joint as opposed to a universal joint also eliminates the problematic possibility of a kinematic singularity. Plain spherical bearings can be used in place of SRJs at the cost of increased friction, but offer an opportunity to preload the joint further.
Failure.
While there is no exact lifespan that can be put on sealed ball joints, they can fail as early as in modern vehicles, and much sooner in older vehicles. Signs of a failing ball joint may start with a sudden burst sound as a result of ball joint dismantling. Then it keeps on with clicking, popping or snapping sound when the wheel is turned and eventually turn into a squeaking sound at the end of a stop, when the gas pedal is used and/or also when hitting bumps. Another symptom could be 'thud' noises coming from front suspension when going over bumps. Dry ball joints have dramatically increased friction and can cause the steering to stick or be more difficult.
If a ball joint fails, the results can be dangerous as the wheel's angle becomes unconstrained, causing loss of control. Because the tire will be at an unintended angle, the vehicle will come to an abrupt halt, damaging the tires. Also, during failure, debris can damage other parts of the vehicle.
Other uses.
While in automotive parlance the term "ball joint" usually refers to the primary ball joint connections at the ends of the control arms, this type of joint is used in other parts as well, including tie rod ends. In these other applications, they are typically called tie rod ends or, when they are an inner tie rod end on a rack-and-pinion steering system, they are called inner socket assemblies. These joints are also used in a number of other non-automotive applications, from the joints of dolls to other mechanical linkages for a variety of devices, or any place where a degree of rotation in movement is desired.


Engineer Special Brigade

Engineer Special Brigades were amphibious forces of the United States Army developed during World War II. Initially designated engineer amphibian brigades, they were redesignated engineer special brigades in 1943. The 1st, 5th, and 6th Engineer Special Brigades were assigned to the European Theater of Operations. The 1st Engineer Special Brigade participated in the landings in Sicily and Italy before joining the 5th and 6th Engineer Special Brigades for the invasion of Normandy.
The 2nd, 3rd and 4th Engineer Special Brigades were assigned to the Southwest Pacific Area, and participated in the campaigns in the Bismarck Archipelago, New Guinea, Leyte, Luzon, the Southern Philippines and Borneo campaign. The 1st Engineer Special Brigade fought in both theaters of the war, participating in the Okinawa campaign near the end of the war. The 2nd Engineer Special Brigade remained active after the war, and served in the Korean War before being inactivated in 1955.
Concept.
At the onset of direct American involvement in World War II, it became apparent that the United States would need a large strategic and tactical amphibious warfare capability. In 1941, the amphibious forces were divided into two corps: one in the Atlantic, and one in the Pacific. Both were combined United States Army and United States Marine Corps commands, administered by the United States Navy. The Amphibious Corps, Atlantic Fleet, consisted of the 1st Infantry Division and the 1st Marine Division, while the Amphibious Corps, Pacific Fleet, consisted of the 3rd Infantry Division and the 2nd Marine Division.
In April 1942, the United States and United Kingdom agreed on plans for an emergency invasion of Northwest Europe in the late northern summer of 1942 (Operation Sledgehammer) that would be conducted in the event of signs that the Soviet Union was on the brink of collapse, or that the Germans were withdrawing from Western Europe, possibly due to an internal coup or collapse. This would be followed by a full-scale crossing of the English Channel in mid-1943 (Operation Roundup). These were envisaged as shore-to-shore operations. The US Navy's policy at this time of only taking volunteers meant that it was short of manpower, and those personnel it had available were mainly allocated warships and the amphibious ships required for ship-to-shore operations. This meant that the landing craft for Sledgehammer would have to be operated by the British and the US Army.
Amphibious Training Center.
The Joint Staff then considered the issue of amphibious warfare training. Very large scale operations were contemplated in both Europe and the Pacific, which the Army would have to conduct. To have the Marines carry out all amphibious operations was impractical, as there were limitations on its size, and joint Army-Marine amphibious operations would involve problems of coordination in view of their different organization, doctrine and procedures. The Joint Staff planners therefore felt that the Army should conduct amphibious training. This meant that the Army would have to establish its own amphibious training establishment.
The Joint Staff hoped to have twelve Army divisions (eleven infantry and one armored) trained in amphibious warfare by 1 February 1943. Another two infantry divisions and one armored division would receive training overseas. This did not include the 1st, 3rd and 9th Infantry Divisions, which were already undergoing training, the 3rd on the West Coast and the 1st and 9th on the East coast. In addition, the Army would train enough boat crews to move eight divisions. These would also be available by 1 February 1943. The Joint Staff intended to create three amphibious training centers. The plan was to train four divisions at Camp Edwards, Massachusetts, six at Camp Carrabelle, Florida, and two at Fort Lewis, Washington. It was intended that training at Camp Edwards would be conducted between July and November 1942. The Army Ground Forces was given responsibility for the development of amphibious warfare doctrine and the conduct of unit training.
The Army activated its Amphibious Training Center at Camp Edwards on 22 May 1942, with Colonel Frank A. Keating, the chief of staff of the 2nd Infantry Division, assigned to command it. It became active on 15 June 1942. The 45th Infantry Division underwent training at Camp Edwards from 15 July to 20 August 1942. Training concluded with major amphibious maneuvers from 17 to 19 August, during which the division conducted a shore-to-shore operation, embarking from Washburn Island, Massachusetts, and crossing Vineyard Sound to land on Martha's Vineyard, about away. It was followed by the 36th Infantry Division, which arrived on 22 August, and completed its training on 3 October. The final three days saw a repeat of the shore-to-shore exercise the 45th had conducted.
The Amphibious Training Center moved to Camp Carrabelle in October 1942. The first formation to undergo training there was the 38th Infantry Division, which commenced its amphibious warfare training there on 23 November 1942. The final shore-to-shore amphibious maneuver was conducted on 17 to 19 December, but performance was not considered satisfactory by the Amphibious Training Center staff, and it was repeated on 28 to 30 December. Camp Carrabelle was renamed Camp Gordon Johnston 13 January 1943. The 28th Infantry Division commenced training on 28 January 1943, and conducted its landing exercise on 7 to 9 March. This was the last division to be trained by the Amphibious Training Center, although three separate battalions, the 81st Chemical Battalion, 61st Medical Battalion and 462nd Anti-Aircraft Artillery Automatic Weapons Battalion, received training there in May 1943.
On 10 March 1943, the Chief of Staff of the United States Army, General George Marshall, and the Commander-in-Chief, United States Fleet, Admiral Ernest King, entered into an agreement that amphibious training would henceforth be a Navy responsibility. The Army Ground Forces was relieved of responsibility for the Amphibious Training Center on 16 March, and it was closed on 10 June.
Engineer Amphibian Command.
In addition to training combat units in amphibious warfare, the Army also had to train personnel in the operation and maintenance of landing craft. Operating the necessary landing craft was estimated to require 48,000 men, organized into 18 boat operating regiments and seven boat maintenance battalions. Each boat regiment had three battalions, each of three boat companies. It was agreed with the British that boat units deploying to the UK would receive their initial training in the US, and final training in the UK. A consequence was the amphibian engineers' adoption of the British Combined Operations shoulder patch, but with the colors switched to gold on blue. The War Department also authorized the wearing of a pocket patch showing a scarlet seahorse on a white background, these being the colors of the United States Army Corps of Engineers.
The Engineer Amphibian Command was created on 10 June 1942 at Camp Edwards, Massachusetts under the command of Colonel Daniel Noce, with Lieutenant Colonel Arthur Trudeau as his chief of staff. Noce was answerable to Brigadier General Clarence Sturdevant, the Assistant Chief of Engineers for training. Additional training facilities were established at Cape Cod. The beach south of Buzzards Bay was selected for shore facilities, and Washburn Island was leased as a training site. Some $1.6 million was spent on dredging and the construction of roads, camps, piers and utilities.
Noce and Trudeau considered how the boat units would operate in combat, and noted the importance of well-trained shore parties to load and unload the boats, and establish supply dumps on the far shore. Since combat engineers were not specifically trained for the task, and would in any case have their hands full dealing with obstacles and fortifications, they felt that a permanent organization was required. They drew up a structure for an engineer shore regiment that would combine the functions of a Navy beach party and the Marine Corps shore party. About half the size of a boat regiment, a shore regiment would consist of three battalions, each with a near shore company and two far shore companies. Each shore regiment would be grouped with a boat regiment, a boat maintenance battalion, and support units to form an engineer amphibian brigade capable of moving an entire infantry division. The proposed organization was approved, and authority was granted to form eight engineer amphibian brigades.
The table of organization and equipment for an engineer amphibian brigade provided for 349 officers, 20 warrant officers, and 6,814 enlisted men. The Army searched its personnel records for men with appropriate marine experience. Arrangements were made to train ships' carpenters and marine mechanics at the Gray Marine Motor Company in Michigan, Higgins Industries in Louisiana, and Evinrude Outboard Motors and the Manitowoc Shipbuilding Company in Wisconsin. In all, 3,368 personnel were trained by these companies. Another 1,481 were trained at the Army Ordnance School at Aberdeen, Maryland, the Naval Operating Base at Toledo, Ohio, and the Army Motor School at Fort Holabird, Maryland. The majority, some 33,627 men, were trained at schools run by the Engineer Amphibian Command. Instructors were obtained from the British Army, Royal Navy, and the United States Coast Guard, Marine Corps and Coast and Geodetic Survey. Of the 37,651 enlisted men assigned between 10 June 1942 and 31 December 1943, 20,244 came from replacement centers, 11,898 from reception centers and 5,509 from other units; of the 2,899 officers, 634 came from other units, 825 from the Officer Reserve Corps, 965 from Officer Candidate Schools, and 475 through direct commissioning from civilian life.
The Engineer Amphibian Command estimated that it required 1,000 landing craft and 225 tank lighters, but it was soon discovered that this exceeded the number available. The Navy agreed to turn over 300 36-foot craft from new production in June and July. Initially the Engineer Amphibian Command used whatever landing craft were available: the 36-foot landing craft, personnel (LCP); landing craft, ramp (LCR); landing craft, personnel (ramp) (LCP(R)); and landing craft, vehicle (LCV); and a small number of the 50-foot landing craft, mechanized (LCM). Some were petrol-, and some diesel-powered. The 36-foot boats were later superseded by the landing craft, vehicle, personnel (LCVP), which combined their attributes.
The shortage of landing craft meant that enough were available for only one boat battalion at a time. The practice of allocating the boats to one battalion at a time, while the only way that all battalions could be trained, annoyed the Amphibious Training Center, as it meant that its ground units were always training with inexperienced boat crews. Tests were carried out with the newly-developed DUKW, and it was decided that each brigade should be equipped with three of them. An important organizational change as a result of experience with training occurred on 5 September, when Noce decided to group the boat and shore engineers into three boat and shore regiments, each with one boat and one shore battalion. Each boat and shore regiment could work with one of the three infantry regiments in an infantry division.
While the Navy was still willing to allow the Army to operate landing craft, it reserved the right to operate ocean-going landing ships. A dispute arose over which category the larger Landing craft, tank (LCT) belonged to. The LCT was powered by the same Gray marine diesel engine as the LCVP and LCM, so no special training was required to operate or maintain it. The Engineer Amphibian Command was informed on 21 May 1942 that the Navy had agreed that the Army could operate LCTs, but the British then decided that the LCT was a landing ship after all, and on 29 June the Navy announced that it would be operating the LCTs. This came as a blow to the Engineer Amphibian Command, as it meant that it was dependent on the Navy to transport its larger pieces of equipment like the D8 bulldozer.
The Navy also announced that it would take over the operation of all landing craft as soon as possible. The reason for this was that Sledgehammer had been abandoned in favor of an invasion of French Northwest Africa (Operation Torch), a ship-to-shore operation, and plans for the 1943 cross-Channel invasion operation were scaled back on 1 July from twelve to eight divisions. The number of engineer amphibian brigades was cut from eight to five; on 17 August it was reduced to just three. Given the additional time, the Navy now believed that it could train all boat crews, but the absorption of the engineer amphibian brigades into the Navy was precluded by the fact that they contained draftees, which the Navy was still refusing to accept.
Uncertainty about the future became acute as the year wore on, as Camp Edwards was unsuitable for boat operations in winter. The Amphibious Training Center moved to Camp Carrabelle, Florida in October, taking the 2nd Engineer Amphibian Brigade with it, but left the 3rd Engineer Amphibian Brigade at Camp Edwards. Up to this point, all plans had revolved around operations in Europe, as the war against Germany had priority, although in planning for amphibious training for twelve divisions, the War Department had also been providing for operations in the Pacific. In the wake of the US victory in the Battle of Midway in June 1942, plans were advanced for offensive operations in the Pacific, particularly in the Solomon Islands.
Amphibious operations in the Southwest Pacific Area (SWPA) depended on the availability of landing craft. The Navy intended to ship only 60 per month to the theater, as they had to be sent deckloaded on ships bound for Australia, as they were too large to fit into ships' holds. Trudeau proposed shipping them as components. In this way hundreds could be carried in a ship's hold. They could be assembled in Australia by the 411th Base Shop Battalion. The decision to ship the 2nd Engineer Amphibian Brigade to Australia freed accommodation at Camp Carrabelle for the 3rd Engineer Amphibian Brigade, although it meant that yet another cycle of training would be conducted with inexperienced boat crews. On 27 November, General Douglas MacArthur asked for two more brigades. He also recommended that their name be changed from "amphibian" to "special".
Voluntary enlistment in the Navy of men aged 18 to 37 ended on 5 December 1942; henceforth men in this age group could be obtained only through the draft. This cleared the way for absorption of the Army boat crews into the Navy. On 8 March 1943, the War and Navy Departments agreed that landing craft should be operated by the Navy, but exempted the three engineer special brigades allocated to SWPA. The 4th Engineer Special Brigade completed its training at Camp Edwards in August 1943, and then moved to Camp Gordon Johnston, where it conducted joint training with the 4th Infantry Division. After it departed for Australia in December 1943, the Engineer Amphibian Command provided instruction to replacement crews before being disbanded in April 1944.
1st Engineer Special Brigade.
The 1st Engineer Amphibian Brigade was activated at Camp Edwards on 15 June 1942. Some 2,269 men were transferred from existing units, the 37th Engineer Combat Regiment providing the nucleus of the boat regiment, and the 87th Engineer Heavy Ponton Battalion that of the shore regiment. Brigadier General Henry C. Wolfe was assigned as commanding general on 7 July 1942. The brigade trained until 15 July, when it was assigned to the Amphibious Training Command.
The brigade was pulled from the Amphibious Training Center early and sent to England to participate in Operation Sledgehammer, departing from the New York Port of Embarkation on 5 August, and arriving on 17 August. Elements of the brigade participated in the Operation Torch. The 531st Shore Regiment and 286th Signal Company acted as the shore party for the 1st Infantry Division, while the 2nd Battalion, 591st Engineer Boat Regiment was reorganized as a shore battalion, and operated in support of Combat Command B, 1st Armored Division. Brigade headquarters departed Glasgow on 24 November, and landed in North Africa on 6 December. Wolfe became chief engineer at the Services of Supply on 22 February and Colonel R. L. Brown of the 531st Engineer Shore Regiment acted as commander.
Wolfe rejoined the brigade on 22 March 1943, but on 25 May he became S-3 at Allied Force Headquarters, and was replaced by Colonel Eugene M. Caffey. On 10 May 1943, the brigade was redesignated the 1st Engineer Special Brigade. The 591st Boat Regiment was detached, as was the 561st Boat Maintenance Company, which remained in England working on Navy landing craft, but the 36th and 540th Engineer Combat Regiments were attached for the 10 July Allied invasion of Sicily (Operation Husky), bringing the strength of the brigade to over 20,000. The brigade then participated in the Allied invasion of Italy at Salerno (Operation Avalanche) on 9 September.
In November 1943, the headquarters of the 1st Engineer Special Brigade, along with the 531st Shore Regiment, 201st Medical Battalion, 286th Signal Company, 262nd Amphibian Truck Battalion and 3497th Ordnance Medium Automotive Maintenance Company, returned to England to participate in the invasion of Normandy (Operation Overlord). This nucleus of 3,346 men was built up to a strength of 15,000 men for Overlord. During Exercise Tiger, a rehearsal for the Normandy operation on 28 April, German E-Boats attacked a convoy of landing ships, tank (LSTs) of the XI Amphibious Force carrying troops of the brigade. Two LSTs were sunk, and the brigade lost 413 men dead and 16 wounded. The exercise was observed by Lieutenant General Omar N. Bradley, who, unaware of the sinking of the LSTs, blamed the resulting poor performance of the brigade on Caffey, and had him temporarily replaced for the Normandy landings by Brigadier General James E. Wharton.
The brigade participated in the D-Day landing on Utah Beach, and operated as Utah Beach Command until 23 October 1944, and then as the Utah District of the Normandy Base Section until 7 December 1944. Under the command of Colonel Benjamin B. Talley, the brigade headquarters returned to England, and embarked for the United States on 23 December. It arrived at Fort Dix, New Jersey, on 30 December. After four weeks leave, it reassembled at Fort Lewis, Washington. Part of the brigade headquarters went by air to Leyte to join the XXIV Corps for the invasion of Okinawa, while the rest traveled directly to Okinawa on the . The brigade was in charge of unloading on Okinawa from 9 April to 31 May. It then prepared for the invasion of Japan. This did not occur due to the end of the war, and the brigade landed in Korea on 12 September 1945. Its final commander was Colonel Robert J. Kasper, who assumed command on 1 November 1945. The brigade was inactivated in Korea on 18 February 1946.
On 30 September 1986, the brigade was reformed at Fort Leonard Wood, Missouri, as the 1st Engineer Brigade, and was assigned to the United States Army Training and Doctrine Command.
2nd Engineer Special Brigade.
The 2nd Engineer Amphibian Brigade was activated at Camp Edwards on 20 June 1942, with the 532nd Engineer Shore Regiment and 592nd Engineer Boat Regiment assigned. Colonel William F. Heavey, who was appointed its commander on 6 August 1942, and was promoted to brigadier general on 10 September, led the brigade for the rest of the war. It quickly expanded to 6,000 men, but lost 1,500 in September to the 540th Shore Regiment. On 1 October, the brigade was reorganized; the 532nd and 592nd became engineer amphibian regiments and the 542nd Engineer Amphibian Regiment was formed. The brigade, less the 542nd Engineer Amphibian Regiment, moved by rail to Camp Carrabelle on 15 October. On 7 November, the brigade moved to Fort Ord, California, where it was joined by the 542nd Engineer Amphibian Regiment the following day. In January and February 1943, the brigade embarked from the San Francisco Port of Embarkation on a series of vessels bound for Australia.
In Australia, the brigade was based at Cairns, although its headquarters was co-located with that of I Corps in Rockhampton, away. The brigade helped the 411th Base Shop Battalion establish a landing craft construction facility, which produced its first finished LCVP on 7 April. In May, elements of the brigade began moving to New Guinea. A detachment of ten LCMs of the 592nd Engineer Amphibian Regiment went to Port Moresby, where it moved supplies to the Lakekamu River. They were followed by detachments of the 532nd and 542nd, which moved to Milne Bay, Oro Bay and Samarai. On 30 June, the brigade participated in its first amphibious operation, the landing at Nassau Bay. On 4 July, the brigade was renamed the 2nd Engineer Special Brigade, and its three regiments became engineer boat and shore regiments.
The 2nd Engineer Special Brigade trained at Cairns with the Australian 9th Division in June and July 1943. The 532nd Engineer Boat and Shore Regiment then moved to New Guinea, and landed part of the 9th Division at Red Beach near Lae on 4 September. On 22 September, it landed elements of the 9th Division at Scarlet Beach near Finschhafen. On 11 October, four Japanese barges attempted to land on Scarlet Beach. They were defeated by men of the 532nd Engineer Boat and Shore Regiment, including Private Junior Van Noy, who was posthumously awarded the Medal of Honor.
Over the next few months, units of the 2nd Engineer Special Brigade participated in the landings at Arawe, Long Island, Saidor, Sio, Los Negros, Talasea, Hollandia, Wakde and Biak. On 20 October 1944 it participated in the amphibious assault on Leyte in the Philippines. Over the following months it participated in a series of amphibious operations to liberate the Philippines. Nine of the 2nd Engineer Special Brigade's units were awarded Presidential Unit Citations.
The 2nd Engineer Special Brigade arrived back in San Francisco on 16 December 1945, and returned to Fort Ord. It later moved to Fort Worden, Washington, where it was stationed when the Korean War broke out in June 1950. The brigade moved to Yokohama, Japan, and participated in the landing at Inchon in September 1950. Afterwards it operated the ports of Suyong and Ulsan. The brigade was redesignated as the 2nd Amphibious Support Brigade on 26 June 1952. In December 1953 it moved to Camp McGill in Japan, where it was inactivated on 24 June 1955.
The brigade was reactivated at Fort Belvoir, Virginia, on 13 November 1956, and inactivated at Fort Story, Virginia, on 25 August 1965. It was reactivated as the 2nd Engineer Brigade at Joint Base Elmendorf-Richardson, Alaska, on 16 September 2011. Although no longer an amphibian brigade, it wore the World War II-era seahorse emblem until inactivated there on 15 May 2015.
3rd Engineer Special Brigade.
Commanded for almost the entire war by Colonel David Ayres Depue Ogden, who was promoted to brigadier general on 18 September 1942, the 3rd Engineer Amphibian Brigade was activated at Camp Edwards on 6 August 1942 with the 533rd Engineer Shore Regiment and 593rd Engineer Boat Regiment assigned. On 9 November they became engineer amphibian regiments, and the 543rd Engineer Amphibian Regiment was assigned to the brigade. The brigade moved to Camp Gordon Johnston by rail in November. In April 1943 it relocated to Fort Ord, where it prepared to move to Australia. Due to shipping shortages and changes in priorities, this took six months. The brigade was redesignated the 3rd Engineer Special Brigade on 25 May 1943, and the amphibian regiments became engineer boats and shore regiments.
The first unit of the brigade to reach New Guinea was the 563rd Engineer Boat Maintenance Battalion, which arrived at Milne Bay on 14 October 1943; the rest of the brigade followed in December 1943 and January 1944. The brigade became widely scattered, and never operated as a single unit, but Ogden retained control using a special radio net. It participated in the landings at Talasea, Aitape, Lingayen, and Borneo and Mindanao. The brigade returned to the United States on 20 December 1945, and was inactivated two days later.
4th Engineer Special Brigade.
The 4th Engineer Amphibian Brigade was activated at Fort Devens on 1 February 1943, with the 534th, 544th and 594th Engineer Amphibian Regiments assigned. The brigade moved to Camp Edwards, where it was redesignated the 4th Engineer Special Brigade on 10 May, with the three regiments becoming engineer boat and shore regiments. The brigade moved to Camp Gordon Johnston in September 1943, and then staged at Camp Stoneman, California, on 21 April 1944, before departing the San Francisco Port of Embarkation for New Guinea on 28 April. Its commanding general throughout its lifetime was Colonel Henry Hutchings, Jr., who was promoted to brigadier general on 15 January 1944.
The 4th Engineer Amphibian Brigade arrived at Oro Bay on 18 May 1944, where its headquarters opened on 23 May. Most of the rest of the brigade arrived in the area over the next few weeks, and participated in amphibious training with the 31st Infantry Division. The Boat Battalion of the 534th Engineer Boat and Shore Regiment was sent to the Bulimba Boat Yards in Brisbane, where it was engaged in assembling landing craft. It participated in the assaults on Morotai in the Netherlands East Indies on 15 September 1944, and Lingayen Gulf on Luzon in the Philippines on 9 January 1945. It was inactivated in Japan on 15 April 1946.
5th Engineer Special Brigade.
The 336th Engineer General Service Regiment was activated at Camp Rucker, Alabama, on 25 July 1942, under the command of Lieutenant Colonel William D. Bridges. On 7 April 1943, it was redesignated the 1119th Engineer Combat Group, with its 1st and 2nd Battalions becoming the 336th and 234th Engineer Combat Battalions respectively. The 1119th Engineer Combat Group moved to Fort Pierce, Florida, on 15 April, where the 348th Engineer Combat Battalion was assigned as the third battalion of the group on 21 April. The group moved to Camp Pickett, Virginia, on 16 June. The 234th Engineer Combat Battalion was detached on 15 August, and replaced by the 37th Engineer Combat Battalion on 22 August. The group staged for overseas movement at Camp Myles Standish, Massachusetts. It left the Boston Port of Embarkation on 21 October, and arrived in the UK on 1 November. It was redesignated the 5th Engineer Special Brigade on 12 November 1943 at Swansea, Wales. The following day, Colonel William M. Hoge assumed command of the brigade.
Unlike the brigades in the Pacific, those in the European Theater had no boat units, although they did have additional service units to handle cargo over the beaches. When Hoge stepped up to command the provisional Special Brigade Group, he was replaced by Colonel Doswell Gullatt. For the invasion of Normandy, the brigade had a strength of 6,756 men. It landed on Omaha Beach, where it was responsible for the eastern beaches, Easy Red, Fox Green and Fox Red. Gullatt was hospitalized due to illness in July 1944, and Bridges assumed command on 31 July. The brigade operated Omaha Beach until it was closed on 19 November 1944. On 4 January 1945, the brigade was transferred to the Seine Section of Paris, where it supervised construction activities. It returned to the United States on 11 July 1945, and was inactivated at Camp Gordon Johnston on 20 October of that year.
6th Engineer Special Brigade.
The 146th Engineer Combat Regiment was activated at Camp Swift, Texas, on 25 January 1943. On 1 April 1943 it was redesignated the 1116th Engineer Combat Group. The group moved to Fort Pierce, Florida, for amphibious training on 16 August, and then to Camp Pickett, Virginia, on 10 October. It staged at Camp Kilmer, New Jersey, before departing the New York Port of Embarkation on 8 January 1944. It arrived in the UK on 17 January, where it was redesignated the 6th Engineer Special Brigade on 15 May.
The brigade participated in the invasion of Normandy, operating the western end of Omaha Beach, the Charlie, Dog and Easy Green beaches. The brigade lost its commander, Colonel Paul W. Thompson, who was seriously wounded on D-Day, and he was replaced by Colonel Timothy L. Mulligan. It operated Omaha Beach until it was closed on 19 November. The brigade then became responsible for the security of the western coast of the Cotentin Peninsula. On 29 December the brigade was assigned to the Advance Section (ADSEC), where it was responsible for construction and road maintenance. On 28 March 1945, it was made responsible for coal mining. On 14 July the brigade headquarters, without any troops, embarked at Le Havre for the United States. The brigade arrived in the United States on 23 July 1945, and was inactivated at Camp Gordon Johnston on 20 October.
Other amphibian units.
Provisional Engineer Special Brigade Group.
The Provisional Engineer Special Brigade Group was formed at Penllergaer, England, on 17 February 1944 to control Omaha Beach. It was commanded by Brigadier General William M. Hoge. Its main components were the 5th and 6th Engineer Special Brigades, and the 11th Port. For the D-Day landing it had a strength of 30,000 men. On 26 June it became the Omaha Beach Command.
540th Engineer Combat Group.
The 540th Engineer Shore Regiment was activated at Camp Edwards on 11 September 1942, and was rushed to Europe to participate in Operation Torch. The 3rd Battalion was inactivated at Camp Edwards on 3 October; thereafter it had only two battalions. It staged at Camp Kilmer, New Jersey, and departed the New York Port of Embarkation and the Hampton Roads Port of Embarkation on 23 October 1942. It was redesignated the 540th Engineer Combat Regiment on 25 October 1942, and assaulted French Northwest Africa on 8 November. It subsequently participated in the assault landings at Licata, Sicily, on 9 July 1943, at Salerno and Anzio in Italy on 9 September 1943 and 22 January 1944 respectively, and the invasion of Southern France on 15 August 1944. It was redesignated the 540th Engineer Combat Group on 15 February 1945, with its 1st and 2nd Battalions becoming the 2832nd and 2833rd Engineer Combat Battalions. It was inactivated on 25 October 1945. The 2832nd Engineer Combat Battalion returned to Camp Kilmer on 13 November 1945, where it was disbanded two days later. The 2833rd Engineer Combat Battalion returned to Camp Kilmer on 26 November 1945, and was disbanded on the following day.
411th Engineer Special Shop Battalion.
The 411th Engineer Base Shop Battalion was formed at Camp Edwards on 17 August 1942. A composite platoon from the battalion went to England with the 1st Engineer Amphibian Brigade. It departed the San Francisco Port of Embarkation on 17 January 1943, and arrived in Australia on 30 January. It moved to Cairns where it operated an assembly plant for LCVPs. On 5 June 1944 it moved to Milne Bay, where it operated a facility that assembled the larger LCMs. It was redesignated the 411th Engineer Special Shop Battalion on 1 November 1944. On 16 December it moved to Batangas in the Philippines, where a new LCM assembly plant was established. It returned to the San Francisco Port of Embarkation on 4 February 1946, and was inactivated at Camp Stoneman, California, two days later.
692nd Engineer Special Shop Battalion.
The 692nd Engineer Base Shop Battalion was formed at Camp Edwards on 15 May 1943. It was redesignated the 692nd Special Shop Battalion on 12 August. It departed the New Orleans Port of Embarkation on 10 February 1944, and arrived at Milne Bay on 25 February, where it assisted the 411th Engineer Base Shop Battalion in the operation of the LCM assembly plant there. It followed it to Batangas on 17 June 1945. It returned to the Los Angeles Port of Embarkation on 25 January 1945, and was inactivated at Camp Anza, California, two days later.


Tongue (footwear)


Holbrook/Randolph station

Holbrook/Randolph (also signed as Randolph/Holbrook) is an MBTA Commuter Rail station in Randolph, Massachusetts. It serves the Middleborough/Lakeville Line. It is located at the junction of Union and Center Streets near the border of Randolph and Holbrook.
From 1984 to 1988, the Cape Cod & Hyannis Railroad stopped near the current station site. Holbrook/Randolph station opened in September 1997; it is located on the Middleborough Main Line, opened in 1846 as the Fall River Railroad.


George Lailey

George Lailey (1869–1958) was a craftsman from the United Kingdom, noted as the last professional practitioner of the traditional craft of bowl-turning using a pole lathe.
Life.
Lailey lived in Miles Green, near the Berkshire village of Bucklebury Common, near Newbury. Both his grandfather, George William Lailey (1782–1871) and his father William (1847–1912) were also bowl-turners, specialising in the production of bowls and plates from elm wood using a pole lathe. George Lailey was particularly noted for his exceptional skill of turning bowls in a 'nest', one inside another. After being mentioned in Henry Vollam Morton's popular 1927 book "In Search of England", Lailey's work became increasingly desirable, and he began signing and dating his pieces.
George Lailey was unmarried, had no children to pass his skills to, and was unable to find anyone who wanted to continue his business. By the time of his death in December 1958 he had for many years been the last practitioner of his craft, and his equipment and tools were given to the University of Reading's Museum of English Rural Life.
Working techniques.
Lailey's workshop, on Bucklebury Common, had the form of a "Grubenhaus" (a sunken-floored building of early mediaeval type), though it dated from the nineteenth century. He did not install an electricity supply, though one was available.
Lailey made a variety of items (including wooden ladles) but concentrated mainly on bowls, produced in a variety of sizes. For this, elm logs were seasoned for at least two years, sawn with a crosscut saw, and then trimmed using a side axe; the blanks were then roughly turned, stored for a further short period and finished on the lathe, applying a polish of beeswax and turmeric root. Most of the specialist tools used would have been made by Lailey himself.
Lailey charged a relatively modest amount for his services, although he and his father had also supplied leading London stores, including Harrods, with their work around the turn of the twentieth century, when there was a fashion for craftsman-made items. He told Morton that "Money's only storing up trouble, I think. I like making bowls better than I like making money."


Christian Zell

Christian Zell (or Zelle) (c. 1683 – 13 April 1763) was a German harpsichord maker.
He was probably a pupil of harpsichord maker Michael Mietke. The first mention of him is in 1722 in the register of citizens of Hamburg, the city where he was to spend the rest of his life. In that year, he took over the workshop of instrument maker Carl Conrad Fleischer after marrying his widow; they had three children.
There are three of his harpsichords surviving: a 1728 instrument in the Museum für Kunst und Gewerbe Hamburg; a 1737 instrument in the Museu de la Música de Barcelona; and a 1741 instrument in the Museum of the Organeum in Weener, Lower Saxony. They are noted for the richness of their decoration, with lacquered chinoiserie typical of Hamburg harpsichords, and most significantly, their 'matchless tone'.
The harpsichord played by American singer-songwriter Tori Amos on her 1996 album Boys For Pele and the subsequent Dew Drop Inn Tour is a replica of the 1728 Christian Zell harpsichord although without the elaborate paintings. It was made by Robert Goble & Son.


257th Tunnelling Company

The 257th Tunnelling Company was one of the tunnelling companies of the Royal Engineers created by the British Army during World War I. The tunnelling units were occupied in offensive and defensive mining involving the placing and maintaining of mines under enemy lines, as well as other underground work such as the construction of deep dugouts for troop accommodation, the digging of subways, saps (a narrow trench dug to approach enemy trenches), cable trenches and underground chambers for signals and medical services.
Background.
By January 1915 it had become evident to the BEF at the Western Front that the Germans were mining to a planned system. As the British had failed to develop suitable counter-tactics or underground listening devices before the war, field marshals French and Kitchener agreed to investigate the suitability of forming British mining units. Following consultations between the Engineer-in-Chief of the BEF, Brigadier George Fowke, and the mining specialist John Norton-Griffiths, the War Office formally approved the tunnelling company scheme on 19 February 1915.
Norton-Griffiths ensured that tunnelling companies numbers 170 to 177 were ready for deployment in mid-February 1915. In the spring of that year, there was constant underground fighting in the Ypres Salient at Hooge, Hill 60, Railway Wood, Sanctuary Wood, St Eloi and The Bluff which required the deployment of new drafts of tunnellers for several months after the formation of the first eight companies. The lack of suitably experienced men led to some tunnelling companies starting work later than others. The number of units available to the BEF was also restricted by the need to provide effective counter-measures to the German mining activities. To make the tunnels safer and quicker to deploy, the British Army enlisted experienced coal miners, many outside their nominal recruitment policy. The first nine companies, numbers 170 to 178, were each commanded by a regular Royal Engineers officer. These companies each comprised 5 officers and 269 sappers; they were aided by additional infantrymen who were temporarily attached to the tunnellers as required, which almost doubled their numbers. The success of the first tunnelling companies formed under Norton-Griffiths' command led to mining being made a separate branch of the Engineer-in-Chief's office under Major-General S.R. Rice, and the appointment of an 'Inspector of Mines' at the GHQ Saint-Omer office of the Engineer-in-Chief. A second group of tunnelling companies were formed from Welsh miners from the 1st and 3rd Battalions of the Monmouthshire Regiment, who were attached to the 1st Northumberland Field Company of the Royal Engineers, which was a Territorial unit. The formation of twelve new tunnelling companies, between July and October 1915, helped to bring more men into action in other parts of the Western Front.
Most tunnelling companies were formed under Norton-Griffiths' leadership during 1915, and one more was added in 1916. On 10 September 1915, the British government sent an appeal to Canada, South Africa, Australia and New Zealand to raise tunnelling companies in the Dominions of the British Empire. On 17 September, New Zealand became the first Dominion to agree the formation of a tunnelling unit. The New Zealand Tunnelling Company arrived at Plymouth on 3 February 1916 and was deployed to the Western Front in northern France. A Canadian unit was formed from men on the battlefield, plus two other companies trained in Canada and then shipped to France. Three Australian tunnelling companies were formed by March 1916, resulting in 30 tunnelling companies of the Royal Engineers being available by the summer of 1916.
Unit history.
257th Tunnelling Company was formed in 1916. From June that year until March 1919 it served under Reserve (later Fifth) Army.
The Company was active in the Neuve Chapelle area in April 1917. It left No 4 Base Depot in Rouen in June 1917, and moved to the Bethune area. After this, the unit assisted the 5th Gloucesters in repelling a German attack near the Ducks Bill, Givenchy. The same month, the company moved to Nieuwpoort to construct subways for Operation Hush. While serving in the coastal sector, it was involved defensive actions during a German attack – Operation Strandfest – in July 1917. The 256th and the 2nd Australian Tunnelling Companies were also involved in this part of Operation Strandfest.
References.
An overview of the history of 257th Tunnelling Company is also available in Robert K. Johns, "Battle Beneath the Trenches: The Cornish Miners of 251 Tunnelling Company RE", Pen & Sword Military 2015 (), p. 229 see online


William Rich Hutton

William Rich Hutton (March 21, 1826 – December 11, 1901) was a surveyor and artist who became an architect and civil engineer in Maryland and New York in the latter half of the 19th century. His sketches of the pueblo of Los Angeles and diary of his life as a surveyor in California were published by the Huntington Library.
Early life and California.
William Rich Hutton was born on March 21, 1826 in Washington, DC. He was the eldest son of James Hutton (d. 1843) and his wife, the former Salome Rich, sister of bibliographer Obadiah Rich and botanist and explorer William Rich. He studied mathematics, drawing and surveying at the Benjamin Hallowell School in Alexandria, Virginia. Hutton traveled with his uncle William Rich to California in 1847 as a payroll clerk for the US volunteer forces in the Mexican–American War, accompanied by his younger brother James D. Hutton, also an artist and surveyor. William Hutton remained in California for six years before returning east in 1853. His diaries and drawings record his travel west via Panama and his six years in California, including a surveying expedition to Los Angeles in June 1849 with Lieutenant Edward O.C. Ord. Ord and Hutton mapped Los Angeles in July and August 1849. Lieutenant Ord surveyed the pueblo; Hutton sketched many scenes of the pueblo and drew the first map from Ord's survey, recording street names in both Spanish and English for the first time. In July 1850, Hutton was appointed county surveyor of San Luis Obispo County, a position he held until resigning on August 4, 1851.
The Hutton's vireo is named after him.
Engineering career.
Returned to Maryland, Hutton became the assistant engineer for the Metropolitan Railroad in 1853. He was an assistant engineer to General Montgomery C. Meigs on the Washington Aqueduct and Cabin John Bridge from 1855, succeeding Meigs as Chief Engineer in 1862-63. He later served as Chief Engineer for the Annapolis Water Works (1866), the Chesapeake & Ohio Canal, and the Western Maryland Railroad (1871).
He played a significant role in the later years of the Chesapeake and Ohio Canal. He served as Chief Engineer from 1869-1871, and as a consulting engineer until 1880. Under him, the canal was widened to its full prism width, and had augmented the banks to resist flooding. He also worked on macadamizing the towpath, dredging the Rock Creek basin, and the Georgetown inclined plane.
Hutton also practiced as an architect, working in partnership with his youngest brother Nathaniel Henry Hutton (1834–1907) between 1873 and 1880, but little is known of his work in this field. He relocated to New York in the 1880s, serving as Chief Engineer for the Washington Bridge in 1888 and 1889 and the Hudson River Tunnel from 1889 to 1891. He consulted on projects including the New Croton Aqueduct and designed the locks on the Kanawha Canal. Hutton died on December 11, 1901.
In the 1930s, his daughters sold a selection of his personal letters and diaries and ninety-five drawings of California to the Huntington Library. Papers related to his engineering career are housed in the Division of the History of Technology at the National Museum of American History.
Publications.
Hutton published "The Washington Bridge Over the Harlem River, at 181st Street, New York City: A description of its construction" in 1891.
In 1942, the Huntington Library published "Glances at California 1847–1853: Diaries and Letters of William Rich Hutton, Surveyor" and "California 1847–1852: Drawings by William Rich Hutton".


Cycloidal drive

A cycloidal drive or cycloidal speed reducer is a mechanism for reducing the speed of an input shaft by a certain ratio. Cycloidal speed reducers are capable of relatively high ratios in compact sizes with very low backlash.
The input shaft drives an eccentric bearing that in turn drives the cycloidal disc in an eccentric, cycloidal motion. The perimeter of this disc is geared to a stationary ring gear and has a series of output shaft pins or rollers placed through the face of the disc. These output shaft pins directly drive the output shaft as the cycloidal disc rotates. The radial motion of the disc is not translated to the output shaft.
Theory of operation.
The input shaft is mounted eccentrically to a rolling-element bearing (typically a cylindrical roller bearing), causing the cycloidal disc to wobble in a circle. The cycloidal disc will independently rotate around the bearing as it is pushed against the ring gear. This is similar to planetary gearing. The direction of rotation of the disc and output is opposite to that of the input shaft.
The number of pins on the ring gear is larger than the number of pins on the cycloidal disc. This causes the cycloidal disc to rotate around the bearing faster than the input shaft is moving it around, giving an overall rotation in the direction opposing the rotation of the input shaft.
The cycloidal disc has holes that are slightly larger than the output roller pins that go inside them. The output pins will move around in the holes to achieve steady rotation of the output shaft from the wobbling movement of the cycloidal disc.
The reduction rate of the cycloidal drive is obtained from the following formula, where P means the number of the ring gear pins and L is the number of lobes on the cycloidal disc.
Single-stage efficiency approaches 93% and double-stage approaches 86%. Single stage reductions are available commercially up to 119:1 and double stage up to 7,569:1.
The cycloid disc is usually designed with a "shortened cycloid" in order to minimize the eccentricity of the disc and the associated unbalance forces at high speeds. For this reason, two cycloid discs are often mounted offset by 180°.
Many modern precision drives provide the eccentric motion through multiple shafts that also transmit the output force, typically 2 to 5 shafts arranged in the same circular pattern as the output rollers of the most basic design. The shafts are driven through planetary-like gears by a central input shaft. Since these shafts are always aligned by the input gears this allows the output to be transmitted through roller bearings rather than intermittent surface contact. Due to the planetary input this is effectively a two-stage drive and may be designed to be directly driven by a high speed brushless motor. This type is often used in robot actuators.
Disadvantages.
Due to the eccentric nature of the drive, if the cycloidal disk is not balanced by a second disk or a counterweight, it will generate vibrations which propagate through the driven shafts and the body. This increases wear on the exterior teeth of the cycloidal disk and the component bearings. With two discs the static imbalance is corrected but a small dynamic imbalance remains. This is generally considered acceptable for most applications. To reduce vibration, high-speed drives use three or more discs to correct the imbalance; the outer discs move in unison, in opposition to the middle one, which is twice as massive.
Advantages.
Cycloidal drives can feature zero backlash and high torque capacity while being compact in size, unlike Involute gearboxes. They are useful in situations where low speed with high torque is required. Cycloidal drives may be designed with significantly higher contact areas for their size than any gear-based transmission such as epicyclic gearing. They apply force through many of the teeth at once, allowing very high torque output relative to size at the cost of requiring sliding contact.


Garter spring

A garter spring is a coiled steel spring that is connected at each end to create a circular shape, and is used in oil seals, shaft seals, belt-driven motors, and electrical connectors. Compression garter springs exert outward radial forces, while extension garter springs exert inward radial forces. The manufacturing process is not much different from the creation of regular coiled springs, with the addition of joining the ends together. Like most other springs, garter springs are typically manufactured with either carbon steel or stainless steel wire.
Types of Springs.
Compression Springs.
Compression garter springs are a type of coiled spring that exerts outward radial forces away from the center. They are typically made up of a thick steel wire with large coils; compression springs need to be able to handle very large loads while being able to return to their natural extended position. Compression springs store potential energy when they are compressed (length of spring decreases), and exert kinetic energy when released. Compression garter springs use this principle to withstand forces acting on it from outside. They may be placed inside a circular object to maintain the object's circular shape. This is similar to squeezing a rubber ball; the ball will contract when squeezed but will return to its natural state once the external pressure is released.
Extension Springs.
Extension garter springs are on the opposite side of the spring spectrum. Although they are also a type of coiled spring, extension garter springs exert inward radial forces that move toward the center. Extension springs store potential energy in their extended form and want to contract. Thinner wire and a greater number of coils allow extension springs to be able to contract quickly, which is essential when dealing with pressurized fluids and gases. Extension garter springs act against forces from the center, so they may be placed on the outside of a circular object to maintain the object's circular shape. They act similar to a bracelet, which is extended to fit around the hand and then snaps back into shape on the wrist. Extension garter springs are more common than compression garter springs because they use less material (smaller circumference and thinner wire) and they respond to changes quicker and more efficiently.
Manufacturing.
Process.
There are four main stages for the production of steel garter springs. The first step is to cut and coil reels of steel wire to produce normal coiled springs. The strength of the spring is proportional to the thickness of the wire. Compression springs are coiled in such a way that the coils are more spaced apart, while extension springs have no space between the coils.
The second step is to join each end of the spring to form the garter spring's unique circular shape. This can be accomplished through a few different ways:
The third stage is heat treating, which prevents the spring from being too brittle to function. Heat treating involves placing the spring in an oven at high temperature for a predetermined amount of time, and then letting it cool slowly.
The fourth stage is applying the finishing touches to the spring, which may include grinding (flattening the ends of the spring), shot peening (shooting tiny steel balls at the spring to harden the wire further), setting (permanently fixing the length and pitch of the spring), coating (electroplating or applying paint or rubber to the surface to prevent corrosion), and packaging.
Materials.
Carbon steel wire is typically used for garter springs due to its affordable price and usability, in comparison to stainless steel. Carbon steel springs tend to have very high yield strengths, and are able to return to their original shape when temporarily deformed. The carbon content in carbon steel wires range from 0.50 to 0.95 percent. This relatively small amount of carbon is enough to improve the toughness of the spring. The close proximity to oil and high-pressure engines mean heat treated garter springs are essential for enduring temperatures over 100 °C (212 °F). However, carbon steel is not suitable for highly corrosive environments; stainless steel would be a more viable option. Stainless steel differs from carbon steel in the amount of chromium present; stainless steel has between 10.5% to 11% chromium by mass, while carbon steel has about 1%.
Applications.
Most garter springs are used for oil seals and shaft seals. Since they are able to withstand forces from all directions, garter springs are effective at handling changes in volume, pressure, temperature, and viscosity.


Anna Ben-Yusuf

Madame Anna Ben-Yusuf was a German milliner and teacher based in Boston and New York City. She wrote The Art of Millinery (1909), one of the first reference books on millinery technique. She was the mother of the portrait photographer Zaida Ben-Yusuf.
Early life.
Born Anna Kind in Berlin in around 1845, she married an Algerian man, Mustapha Moussa Ben Youseph Nathan, who lived in Hammersmith, London. They had four daughters - Esther Zeghdda Ben Youseph Nathan, better known as Zaida (1869-1933), Heidi (c.1873-1915), Leila (c.1877-1967) and Pearl (c.1878-1940), before the marriage fell apart. Anna and her daughters moved to Ramsgate, where she supported her family by working as a governess. Her ex-husband remained in London, occasionally giving lectures on Arab culture for the Moslem Mission Society. In 1891, he and his second wife Henrietta Crane, had a daughter, also called Zaida (1891-1967) and a son, Mussa, who died in infancy in 1893.
Career.
During the late 1880s, Anna Ben-Yusuf emigrated to the United States, where by 1891, she had established a milliner's shop on Washington Street in Boston. Her eldest daughter Zaida also emigrated to the US in 1895, setting up a milliner's at 251 Fifth Avenue, New York City before becoming a successful portrait photographer. Zaida published occasional articles on millinery for Harpers Bazaar and the Ladies Home Journal.
From September 1905 to June 1907, Anna Ben-Yusuf was an instructor in millinery at the Pratt Institute in Brooklyn, New York. She resigned in 1907 to set up a school of her own on West 23rd Street.
Her book, "The Art of Millinery: Practical Lessons for the Artiste and the Amateur" was published in 1909. It was one of the first reference books for teaching the art of hat-making in all its aspects, and remains a useful resource for leading contemporary milliners such as Stephen Jones. It was formatted as a series of lessons, each dealing with a particular aspect of constructing a hat, treating the fabric, or creating different types of trimming. On a more practical note, it also advised on correct storage, renovating fabrics, and the business side of millinery, and included a glossary of terms used in millinery. In 1992, a revised edition was reprinted as "Edwardian Hats: The Art of Millinery".
Death.
Anna Ben-Yusuf died in New York on 8 December 1909.


Valley Line (Edmonton)

The Valley Line is a future , low-floor urban light rail line in Edmonton, Alberta, currently under construction. It will be part of the Edmonton Light Rail Transit. It will run southeast to west from Mill Woods to Lewis Farms, crossing through downtown. The line will be constructed in phases, with phase 1 being the , 12-station portion between Mill Woods and 102 Street (Downtown) allowing passengers to connect with the Capital Line and Metro Line at Churchill station. Construction began on April 22, 2016, with completion of phase 1 set for 2021. Upon completion of the entire line, the Valley Line is expected to serve more than 100,000 commuters daily, nearly matching the current Capital Line and Metro Line in terms of capacity and ridership.
Unlike the other trains in the system, the Valley line will operate low-floor Bombardier Flexity Freedom trains, which were first designed for Toronto's Line 5 Eglinton line.
Valley Line Southeast (Downtown to Mill Woods).
Planning studies for an LRT route from downtown to Mill Woods began in early 2009. In December 2009, Edmonton city council approved a new low-floor train route that would leave a new ground-level station at Churchill Square on 102 Avenue between 100 and 99 Streets before stopping in The Quarters redevelopment on 102 Avenue between 97 Street and 96 Street. From here the route enters a tunnel and travels beneath 95 Street descending into the river valley to cross the North Saskatchewan River on the new Tawatinâ Bridge, which is being constructed east of Louise McKinney Park. The route then proceeds to climb the hill adjacent to Connors Road then proceed east along 95 Avenue and southbound at 85 Street. The route will travel southbound along 85 Street crossing the intersection north of Bonnie Doon Mall and shifting to 83 Street, continuing south and east. Just north of Argyll Road, the line is lifted onto an elevated guideway over Davies Industrial. Finally, the line will proceed south along 75/66 Street until it reaches Mill Woods Town Centre. Within this line the proposed stops are: Quarters, Muttart, Strathearn, Holyrood, Bonnie Doon, Avonmore, Davies (to include a bus terminal and park & ride), Millbourne/Woodvale, Grey Nuns, and Mill Woods Town Centre. The maintenance and storage of vehicles for the line will be at the new Gerry Wright Operations and Maintenance Facility, at Whitemud Drive and 75 Street.
On June 1, 2011, Edmonton City Council approved $39 million in funding to proceed with preliminary engineering for the Valley Line. In November 2011 City Council voted to allocate $800 million to the project, with the hopes of starting construction by 2014 and an expected completion date of 2018. A funding plan was approved in October 2012 in which the city would contribute $800 million into the project with the remaining $1 billion coming from the provincial and federal governments.
On February 15, 2012, city council approved the Downtown LRT concept plan. The Downtown LRT Project became part of the Southeast to West LRT project. The city hoped to have money in place by the end of 2013 for the $1.8-billion LRT line from downtown to Mill Woods to start construction in 2016. City council committed $800 million, the federal government invested $250 million, and $235 million would come from the provincial government, leaving a $515 million funding gap delaying the project. On March 11, 2014, it was announced that the project would be completely funded with an additional $150 million from the federal government and $365 million from the provincial government.
Land procurement began in 2011 and utility relocation began in 2013, completion of the first stage is expected in 2020. The official groundbreaking of the new LRT "Valley Line" occurred on April 22, 2016.
As of September 2019, this segment of the line is a year behind schedule of its projected December 2020 opening date. The 2019 construction season posed a challenge to crews due to frequent rain.
In December 2019, completion of the line was pushed back until 2021 after TransEd found a car-sized piece of concrete underneath the North berm of the Tawatinâ bridge.
Trains are being tested on an ongoing basis, on tracks between the Gerry Wright OMF and the Mill Woods stop. This testing will gradually be expanded north until the entire line is completed, at which-point line-wide testing will occur before it opens to the public.
Valley Line West (Downtown to Lewis Farms).
A planned expansion to Lewis Farms, with the West Edmonton Mall en route, is in the engineering phase as part of the 27-kilometre Valley Line.
The option approved by Council in 2010 has the west LRT extension run from downtown along 104 Avenue and Stony Plain Road to 156 Street, then south on 156 Street to Meadowlark Health And Shopping Centre, and then west along 87 Avenue to West Edmonton Mall and beyond. Proponents of this route cited opportunities for transit-oriented development.
In 2016, the Valley Line West received funding through the Government of Canada’s Public Transit Infrastructure Fund (PTIF) to review the preliminary design that was completed in 2013. The funding covers work to determine the most appropriate project delivery method (P3, for example) and to develop a business case for construction funding.
The Government of Canada is providing approximately $948 million for the Valley Line West expansion, and the Government of Alberta has committed approximately $1.04 billion for the project. The expansion is projected to cost approximately $2.67 billion in total. Edmonton has selected Marigold Infrastructure Partners to build the western section of the Valley Line. Preparation work, such as the relocation of underground utilities and clearing of land along the route, has already begun. Construction of the expansion is scheduled to commence in 2021, and it is expected to open in 2026 or 2027.


Involute gear

The involute gear profile is the most commonly used system for gearing today, with cycloid gearing still used for some specialties such as clocks. In an involute gear, the profiles of the teeth are "involutes of a circle." (The involute of a circle is the spiraling curve traced by the end of an imaginary taut string unwinding itself from that stationary circle called the base circle.)
The involute gear profile was a fundamental advance in machine design, since unlike with other gear systems, the tooth profile of an involute gear depends only on the number of teeth on the gear, pressure angle, and pitch. That is, a gear's profile does not depend on the gear it mates with. Thus, n and m tooth involute spur gears with a given pressure angle and pitch will mate correctly, independently of n and m. This dramatically reduces the number of shapes of gears that need to be manufactured and kept in inventory.
In involute gear design, contact between a pair of gear teeth occurs at a single instantaneous point (see figure at right) where two involutes of the same spiral hand meet. Contact on the other side of the teeth is where both involutes are of the other spiral hand. Rotation of the gears causes the location of this contact point to move across the respective tooth surfaces. The tangent at any point of the curve is perpendicular to the generating line irrespective of the mounting distance of the gears. Thus the line of the force follows the generating line, and is thus tangent to the two base circles, and is known as the line of action (also called "pressure line" or "line of contact"). When this is true, the gears obey the "fundamental law of gearing":"
The angular velocity ratio between two gears of a gearset must remain constant throughout the mesh."
This property is required for smooth transmission of power with minimal speed or torque variations as pairs of teeth go into or come out of mesh, but is not required for low-speed gearing.
Where the line of action crosses the line between the two centres, it is called the pitch point of the gears, where there is no sliding contact.
The distance actually covered on the line of action is then called "line of contact". The line of contact begins at the intersection between the line of action and the addendum circle of the driven gear and ends at the intersection between the line of action and the addendum circle of the driving gear.
The pressure angle is the acute angle between the line of action and a normal to the line connecting the gear centers. The pressure angle of the gear varies according to the position on the involute shape, but pairs of gears must have the same pressure angle in order for the teeth to mesh properly, so specific portions of the involute must be matched.
While any pressure angle can be manufactured, the most common stock gears have a 20° pressure angle, with 14½° and 25° pressure angle gears being much less common. Increasing the pressure angle increases the width of the base of the gear tooth, leading to greater strength and load carrying capacity. Decreasing the pressure angle provides lower backlash, smoother operation and less sensitivity to manufacturing errors.
Most common stock gears are spur gears, with straight teeth. Most gears used in higher-strength applications are helical involute gears where the spirals of the teeth are of different hand, and the gears rotate in opposite direction.
Only used in limited situations are helical involute gears where the spirals of the teeth are of the same hand, and the spirals of the two involutes are of different "hand" and the line of action is the external tangents to the base circles (like a normal belt drive whereas normal gears are like a crossed-belt drive), and the gears rotate in the same direction, such as can be used in limited-slip differentials because of their low efficiencies, and in locking differentials when the efficiencies are less than zero.


Richard Orchard

Richard Beaumont Orchard CBE (14 October 1871 – 24 July 1942) was an Australian businessman and politician. He was a successful watchmaker and jeweller, with premises on George Street, Sydney. He served in the House of Representatives from 1913 to 1919, representing the Division of Nepean, and was an honorary minister in the Fourth Hughes Ministry.
Early life.
Orchard was born at Cockatoo, near Maryborough, Victoria, to Cornish parents John Henry Orchard, a blacksmith, and his wife Alicia, née Thomas. In the 1870s he moved with his family to Sydney. He spent four years as a travelling jewellery salesman in rural New South Wales. In 1895, when he married Maria Annie Austen, he was a photographer living in the Sydney suburb of Ultimo. He later became a watchmaker and established a jewellery store in George Street, Sydney in 1901, which became a public company in 1913 as "R. B. Orchard Ltd".
Parliament.
Orchard ran unsuccessfully for the Sydney Municipal Council in 1909 and the New South Wales Legislative Assembly seat of Hawkesbury in 1911. He won the Australian House of Representatives seat of Nepean at the 1913 election for the Commonwealth Liberal Party. He joined Billy Hughes' Nationalist government in 1917 and was appointed an Honorary Minister with responsibility for recruiting from March 1918 to January 1919. He retired from politics at the November 1919 election.
Later life.
Orchard was appointed as a Commander of the Order of the British Empire in 1920. He ran unsuccessfully as a Nationalist for the seat of East Sydney at the 1925 election, and for the Senate in 1928 election. He was a commissioner of the Australian Broadcasting Commission from its foundation in 1932 until 1939. He died in the Sydney suburb of Darling Point survived by his wife, a son and three daughters.


AT-8 (Cuban mine)

The AT-8 or Cuban anti-tank mine is a square green plastic cased anti-tank mine. It is a scaled-up version of the Cuban anti-personnel mine. The mine consists of a plastic ribbed hinged upper case which rests on the fuzes placed into the lower plastic case. When enough pressure is placed on the upper lid the strikers are released from the fuzes. This triggers the main charge, which consists of up to twenty 400 g blocks of TNT. The mine is fitted with MUV or RO-1 type fuzes.
The mine is found in Angola, Nicaragua and possibly Cuba.


Edwin Samuel Crump

Edwin Samuel Crump CIE (born 6 July 1882, died 5 March 1961) was an English civil engineer specialising in hydraulics.
Early life and education.
Crump was born in Wolverhampton, Staffordshire, England, the youngest child of Charles Crump and Clara Annie Crump (nee Gittoes). His father Charles Crump was Chief Clerk, Northern Division, Great Western Railway Company, prominent football legislator and administrator, and committed Methodist. Edwin Crump was educated as a civil engineer at the Department of Engineering, Imperial College.
Personal life.
Crump married Helen Elizabeth Jefferis in 1913 and had two sons, Anthony Jefferis Crump (born 1914) and Colin Edwin Crump (born 1916).
Career and accomplishments.
Crump joined the Indian Service of Engineers in 1906 and was based in Punjab Province, British India. Here he was engaged in irrigation projects of the Punjab Water Station. During World War I Crump served as an engineer in South Africa. Crump retired from the Indian Service of Engineers in 1937. After returning to England, Crump joined in 1949 the newly established Hydraulics Research Station at Wallingford, Oxfordshire, part of the Hydraulic Research Organisation, Department of Scientific and Industrial Research. In 1952 he was promoted to Senior Scientific Officer, retiring in 1956.
Honors and recognition.
Crump was made Companion of the Indian Empire (CIE) at the King's Birthday Honours of 1936 for his work with the Indian Service of Engineers as Superintending Engineer, Public Works Department (Irrigation Branch), Punjab Province.
Edwin Samuel Crump was the inventor of the Crump weir that is named for him. The Crump weir is a two dimensional triangular weir with a horizontal crest in the transverse direction and a triangular crest shape in the stream-wise direction. Crump weirs are used as measuring structures in open channels.
Publications.
Crump published a number of seminal papers in the field of hydraulics, including methods to accurately measure stream flow by means of the Crump weir, design of steeply graded pipelines, and vortex-siphon spillways.


Victoria Cross railway station

Victoria Cross is a future underground rapid transit station, to be located beneath the central business district of North Sydney, Australia. The station forms part of Transport for NSW's Sydney Metro City & Southwest scheme. It is scheduled to open in 2024.
A station at Victoria Cross was proposed in 2001 as part of Co-ordinator General of Rail Ron Christie's "Strategic Plan for Rail", as a stop for trains travelling to the north-west, Northern Beaches, Cronulla and Macarthur. The new station – a block away from the existing station in Blue Street – was designed to take pressure off the constrained interchange, which dates from 1932. The NSW Government incorporated many of Christie's ideas in its Metropolitan Rail Expansion Program (MREP) in 2005, including Victoria Cross station as part of a future Redfern to Chatswood railway line. When the MREP was cancelled in 2008, the idea of a station at Victoria Cross was dropped as well.
The concept of a Redfern to Chatswood line was partially revived by the NSW Government as part of the "Sydney's Rail Future" plan in 2012, this time as a metro stop. A detailed concept plan, including a station at Victoria Cross, went on public exhibition in 2015. The station entrance will be on the eastern side of Miller Street between Berry and Mount Streets.
In June 2017 changes were announced including an additional station entrance on McLaren Street. The second entrance is notable for being the first lift-only entrance to a passenger train station in Australia, and consists of 4 lifts capable of carrying 27 people each.


John Widman

John Widman is an American luthier who makes high-end, hand-built guitars.
He grew up in the Asheville, North Carolina area. After graduating from North Carolina State University (1984) and working as a photographer and graphic designer, he turned to building high-end electric guitars under the name Widman Custom Electrics, from Arden, North Carolina. Woods and hardware are specified by the customer. Besides vintage-styled guitars, he also builds electric banjos.


Zagreb rocket attacks

The Zagreb rocket attacks were a series of two rocket attacks conducted by the Army of the Republic of Serbian Krajina that used multiple rocket launchers to strike the Croatian capital of Zagreb during the Croatian War of Independence. The attack killed seven and wounded over 200 Croatian civilians and was carried out on 2 May and 3 May 1995 as retaliation for the Croatian army's offensive in Operation Flash. The rocket attacks deliberately targeted civilian locations. Zagreb was the largest of several cities hit by the attack. It is not the only instance in the war in Croatia that cluster bombs were used in combat.
The International Criminal Tribunal for the former Yugoslavia (ICTY) characterized the attack as a crime against humanity and convicted Croatian Serb leader Milan Martić of ordering the attack.
Introduction.
During the early part of the war, the Croatian capital Zagreb was spared from devastation, as it was far from the frontlines. Serb General Milan Čeleketić announced to the press on 24 March 1995, more than a month prior to the attack, that should a Croatian offensive be launched, he expected to respond by targeting the "weak points," that is, "the parks of the Croatian cities" and added: "We know who the people in the parks are; civilians."
In May 1995 Croatia launched Operation Flash, which recaptured the area of western Slavonia (UNPA sector West) that had been under Serb control since 1991. In neighboring Bosnia, the leader of the Republika Srpska, Radovan Karadžić, threatened to send help to the Serbs in Croatia. Following the rapid collapse of the Serb defence in the area, Serb leader Milan Martić ordered Serb rocket artillery units in the self-proclaimed Republic of Serbian Krajina to fire missiles on the capital of Zagreb. Karlovac and Sisak were also subjected to retaliatory attacks.
The Yugoslav-produced "Orkan" 262 mm Multiple rocket launchers (MRL) fires M-87 non-guided missiles. The ones fired against Zagreb were armed with aviation cluster bomb warheads (called "cassette bombs" or "Jinglebell"), each of which contains 288 "bomblets" (smaller ammunition) which are ejected at a height of 1,000 meters above the target area. Upon impact, each bomblet explodes and releases 420 pellets, the lethal range of each of which is ten meters. This means that each rocket releases around 120,000 of these pellets, which have been characterized as designed specifically to kill or maim local infantry.
Strikes.
On 1 May, a meeting was held between leaders of the RSK. Although negotiations were on-going, Martić and Čeleketić were not in favor of a peaceful solution. At 1 pm on 1 May, Milan Čeleketić ordered, with Martić present, an artillery barrage on Sisak which was opened at 5 pm that day. On the same day, an M-87 "Orkan" rocket artillery unit from Knin was redeployed to Vojnić (about 50 km south of Zagreb).
The first attack occurred on 2 May, at 10:25 in the morning. At the time, many civilians were in the streets. The targets hit included the Strossmayer promenade, Petrinjska street and Vlaška street where a tram full of passengers was hit. The Classical Gymnasium in Zagreb located in the city centre was also hit, as were Pleso and its airport. In total, five civilians were killed and 146 injured.
The second attack occurred the following day, at 12:10 in the afternoon. The children's hospital in Klaićeva street, the Croatian National Theatre building (which housed Russian, Ukrainian and British ballet dancers at the time, some of whom were wounded) and the Courthouse at Nikola Šubić Zrinski Square were among those hit.
Two civilians were killed that day and 48 injured, which were less than the day before due to many people avoiding public areas following the first attack. Most of the missiles targeted the city center and surrounding streets, which were most likely to be filled with civilians in the morning. In total, seven people were killed and about 200 injured (of which about 100 seriously) from these attacks.
Aftermath.
On 3 May, Slobodan Milošević, President of Serbia at the time, instructed Yugoslav Army Chief of the General Staff Momčilo Perišić to call Čeleketić and forbid further strikes against Zagreb.
After 4 May and the end of Operation Flash, United Nations Special Envoy Yasushi Akashi met with Martić and condemned him for the attack. Martić then threatened to resume the attacks and spoke of "massive rocket attacks on Zagreb which would leave 100,000 people dead."
On October 10, 2013, a cluster bomb which failed to detonate was discovered on the roof of the Klaićeva children's hospital, 18 years after the attacks. After surgery on several patients had been completed, the Zagreb police bomb disposal squad was given clearance to detonate the ordnance. No one was injured in the detonation.
In May 2013, city mayor Milan Bandić opened a museum in Petrićeva St. dedicated to the tragedy.
War crimes charges by the ICTY.
Immediately following the attacks, Martić appeared on Serb television and publicly boasted about ordering the attacks. This video was later used against him during his trial at the International Criminal Tribunal for the former Yugoslavia (ICTY) after he was indicted for war crimes. The attack on Zagreb was one of the main points of the indictment against him, to which he confessed, but claimed it was a "legitimate action against the enemy". On June 12, 2007, he was sentenced to 35 years in prison.
Perišić, was also indicted for his role in the rocket attack. He was sentenced to 27 years in prison because the judges ruled that he had effective control over the SVK commanders since he issued orders to them and initiated disciplinary proceedings against them; therefore he was responsible for the failure to punish those who launched the rockets on Zagreb. In February 2013, Perišić was acquitted on all counts and released upon appealing his conviction.


Robert Wynne-Edwards

Sir Robert Meredydd Wynne-Edwards CBE, DSO, MC and bar (1 May 1897 – 22 June 1974) was a British civil engineer and army officer. Wynne-Edwards was born in Cheltenham and educated at Giggleswick School and Leeds Grammar School before being commissioned into the Royal Welch Fusiliers at the outbreak of the First World War. He served on the Western Front in France where he received a Mention in Despatches, Distinguished Service Order and a Military Cross and bar for his gallantry and leadership. Following the war he studied engineering at Christ Church, Oxford from which he graduated with second class honours in 1921.
Wynne-Edwards emigrated to Canada working on several contracts in Vancouver including the Detroit–Windsor Tunnel. He returned to Britain in 1935 following a slump in the Canadian building industry and joined John Mowlem & Co. where he was given the task of constructing the William Girling Reservoir. The newly constructed dam later collapsed and Wynne-Edwards enlisted the expertise of the Building Research Station and Karl von Terzaghi to prove that he was not at fault. During the Second World War Wynne-Edwards was seconded to the Ministry of Works where he became their director of plant.
After the war Wynne-Edwards was managing director of Richard Costain Ltd, specialising in pipelaying and also served on several boards and committees for the British Government. For this latter role he was appointed Commander of the Order of the British Empire. Wynne-Edwards was also involved with the Institution of Civil Engineers serving on many committees and being elected their one hundredth president in 1964. He was knighted in the Queen's Birthday Honours of 1965.
Early life.
Wynne-Edwards was born on 1 May 1897 in Cheltenham to Reverend John Rosindale Wynne-Edwards, canon of Ripon Cathedral and schoolmaster (later headmaster) of Leeds Grammar School, and his wife Lilian Agnes Streatfield Welbank. Robert was the eldest of their four sons and two daughters. Robert was educated at Giggleswick School and Leeds Grammar School.
First World War.
At the start of the First World War in July 1914 Wynne-Edwards joined the Royal Army Medical Corps, obtaining a commission in the Royal Welch Fusiliers in October 1914. From December 1915 he served on active duty in France and was Mentioned in Despatches. Wynn-Edwards was awarded the Military Cross on 1 January 1917. He received the Distinguished Service Order on 11 January 1919 for conspicuous gallantry and devotion during an assault in which a neighbouring company was in some difficulty. He reorganised it and captured its objective before returning to his own company of just 35 men and retaking a fortified position from the enemy which had been lost that morning.
Wynne-Edwards was awarded a bar to his Military Cross on 15 February 1919. The award was made for gallantry on the night of 7 October 1918 at Northo Wood. Having located two gaps in the German barbed wire he led his company through them and three belts of uncut wire. The company forced back the enemy and took over a position 400 yards ahead of any other troops on the front. Wynne-Edwards held the position for three hours, though being attacked from all sides. He then single-handedly crawled to an enemy howitzer and removed the sights before returning with some of his men and capturing the gunners.
Wynne-Edwards was seconded from his regiment on 21 December 1918 and attained the rank of temporary major before his demobilisation in January 1919.
In Canada.
Upon leaving the army Wynne-Edwards became a student of engineering science at Christ Church, Oxford from which he graduated in 1921 with second class honours. In July of that year he moved to Canada where he was apprenticed to Andrew Don Swan, the consulting engineer to Vancouver Harbour Board. In 1923 he joined Sydney E. Junkins Ltd, a contracting firm in Vancouver, where he assisted in the construction of a reinforced concrete wharf for the Canadian Pacific Railway. Whilst working there Wynne-Edwards trained as a diver so that he could undertake underwater inspections of work.
In 1924 he married Hope Elizabeth Day Fletcher the daughter of Francis Fletcher, a surveyor from Nelson, British Columbia. They had one son and three daughters. He became a member of the American Society of Civil Engineers whilst in Canada and an associate member of the Institution of Civil Engineers (ICE) in 1926. In 1928 he submitted a paper on the wharf at Vancouver to the ICE and was awarded a Telford Medal. From 1929 he maintained his position at Junkins whilst working with the Northern Construction Company on the shield-driven sections of the Detroit–Windsor Tunnel and a water tunnel in Vancouver.
Return to UK.
Following a downturn in building during a 1934 economic slump in Canada Wynne-Edwards returned to the UK in 1935 where he joined John Mowlem & Co.. He was given the task of building the William Girling Reservoir near Chingford in Essex, this was constructed using the first fleet of newly developed American earth moving equipment to reach Britain. In 1937 a recently constructed part of the dam embankment collapsed and it was shown by the Building Research Station (BRS) that the fault was due to a patch of soft clay which Wynne-Edwards had asked to be allowed to remove but was overruled. When this theory was ignored by more senior consultants Wynne-Edwards traced Karl von Terzaghi, the famous geologist and soil mechanics expert, and persuaded him to represent Mowlem. Terzaghi supported the BRS's theory and redesigned the bank to accommodate his findings. The publicity surrounding this event and Wynne-Edwards lectures at universities led to the popularisation and acceptance of the relatively new science of soil-mechanics in the UK.
Second World War.
After the outbreak of the Second World War Wynne-Edwards worked as a deputy agent for Mowlem in the construction of a shell factory in Swynnerton, Staffordshire. This so impressed the Ministry of Works that he was seconded to it as the director of plant for the remainder of the war. In this role he excelled as a chairman, especially during several difficult Anglo-American committees. In recognition of this fact he was appointed as an officer of the Order of the British Empire on 2 June 1943.
Post-War.
Following the war's end in 1945 Wynne-Edwards joined Richard Costain Ltd as a director and became managing director in 1948. Here he concentrated on the oil and chemical industries, in particular pipelaying. This included the laying of a pipeline for the Anglo-Iranian Oil Company from their Abadan Refinery to Tehran at the rate of three miles per day. In 1957 he was elected a first class member of the Smeatonian Society of Civil Engineers Wynne-Edwards served chairman of both the Building Research Board and the Road Research Board from 1960-5, a role for which he was rewarded with his appointment as a Commander of the Order of the British Empire on 1 January 1962. In 1965 he served as a member of the advisory committee to Harold Wilson for the Queen's Award to Industry.
Institutions and honours.
Wynne-Edwards was a keen supporter of the Institution of Civil Engineers and served on many of its committees and being elected to its governing council in 1950. He was elected as president of the Institution in 1964, the 100th president and the first to be elected whilst still working as a contractor. He became the founder-chairman of the Council of Engineering Institutions for 1964–6 a role he was rewarded for with a knighthood in the Queen's Birthday Honours on 12 June 1965. Wynne-Edwards was also
an honorary member of both the Institution of Structural Engineers and the American Society of Civil Engineers and was made an honorary fellow of the University of Manchester Institute of Science and Technology in 1965. He received an honorary Doctor of Science degree from Salford University in 1966 and was elected president of the Manchester Technology Association for 1969.
Personal life.
Wynne-Edwards found time to hold an interest in natural history, bee-keeping, gardening and reading. He also kept horses which he occasionally used for fox-hunting with the Old Surrey and Burstow hunt. He retired to Blandford Forum, Dorset and died at the Promenade Hospital in Southport, Lancashire on 22 June 1974.
References.


AutoCAD DXF

AutoCAD DXF (Drawing Interchange Format, or Drawing Exchange Format) is a CAD data file format developed by Autodesk for enabling data interoperability between AutoCAD and other programs.
DXF was originally introduced in December 1982 as part of AutoCAD 1.0, and was intended to provide an exact representation of the data in the AutoCAD native file format, DWG (Drawing). For many years Autodesk did not publish specifications making correct imports of DXF files difficult. Autodesk now publishes the DXF specifications online.
Versions of AutoCAD from Release 10 (October 1988) and up support both ASCII and binary forms of DXF. Earlier versions support only ASCII.
As AutoCAD has become more powerful, supporting more complex object types, DXF has become less useful. Certain object types, including ACIS solids and regions, are not documented. Other object types, including AutoCAD 2006's dynamic blocks, and all of the objects specific to the vertical market versions of AutoCAD, are partially documented, but not well enough to allow other developers to support them. For these reasons many CAD applications use the DWG format which can be licensed from Autodesk or non-natively from the Open Design Alliance.
DXF coordinates are always without dimensions so that the reader or user needs to know the drawing unit or has to extract it from the textual comments in the sheets.
File structure.
ASCII versions of DXF can be read with any text editor. The basic organization of a DXF file is as follows:
The data format of a DXF is called a "tagged data" format, which "means that each data element in the file is preceded by an integer number that is called a group code. A group code's value indicates what type of data element follows. This value also indicates the meaning of a data element for a given object (or record) type. Virtually all user-specified information in a drawing file can be represented in DXF format."