What are anchor made of?
1004793#4
Modern commercial sea anchors are usually made of cloth, shaped like a parachute or cone, and rigged so that the wider end leads and the narrower end trails. When deployed, this type of sea anchor floats just under the surface, and the water moving past the sea anchor keeps it filled. Some varieties are cylindrical, with an adjustable opening in the rear that allows the amount of braking to be adjusted when deployed.
Sea anchor
18025#26
Longships for the most part used two different kinds of anchors. The most common was a natural wood yoke formed from a tree branch. The weight was supplied by a stone passing laterally through the U of the yoke. The top of the yoke was closed by either a length of hardwood or a curved iron head, which kept the stone in place. One side of the head stuck out so it could dig into mud or sand. In the Ladby ship burial in Denmark, a unique iron anchor has been found, resembling the modern fisherman's anchor but without the crossbar. The cross bar may have rusted away. This anchor—made of Norwegian iron—has a long iron chain to which the hemp warp was attached. This construction has several advantages when anchored in deep waters or in rough seas.
Longship
1735562#2
Somewhat less common are surface anchors, commonly made from surgical implant-grade titanium. A surface anchor has two parts: a base or foot which is inserted under the dermis during the piercing process and which incorporates a stem exposed to the surface, and a decorative disc or ball of jewelry which typically appears flush with the surface of the skin. Surface anchor nape piercings are most commonly found placed symmetrically on either side of the spine at the nape.
Nape piercing
19900609#4
Until the beginning of the 19th century anchors were of imperfect manufacture, the means of effecting good and efficient welding being absent and the iron poor, whilst the arms, being straight, generally parted at the crown, when weighing from good holding-ground. A clerk in Plymouth Yard, named Pering, in the early part of that century (1813) introduced curved arms; and after 1852 the British admiralty anchor, under the direction of the Board, was supplied to H.M. ships, followed by Lieutenant ("afterwards Captain") Rodger's anchor. Rodger's anchor marked a great departure from the form of previous anchors. The arms were formed in one piece, and were pivoted at the crown on a bolt passing through the forked shank. The points or pees to the palms were blunt. This anchor had an excellent reputation amongst nautical men of that period, and by the committee on anchors, appointed by the British admiralty in 1852, it was placed second only to the anchor of Trotman.
Later came the self-canting and close-stowing Martin anchor, which, passing through successive improvements, became the improved Martin anchor made of forged iron. A projection in the center of the arms works in a recess at the hub of the shank; the vacancies outside the shank are filled by blocks bolted through on each side, and are flush with the side plates, which keep the flukes in position.
The introduction of cast steel in 1894 led to the improved Martin-Adelphi pattern, in which the crown and arms are cast in one, and, with the stock, are made of cast steel, the shank remaining of forged iron. A projection in the crown works in a recess (right image), and is secured in its place by a forged steel pin, fitted with a nut and washer, which passes through the crown and the heel of the shank.
History of the anchor
1358#0
An anchor is a device, normally made of metal, used to connect a vessel to the bed of a body of water to prevent the craft from drifting due to wind or current. The word derives from Latin "ancora", which itself comes from the Greek ἄγκυρα ("ankura").
Anchor
5727366#8
The stone anchors have been noticed close to the present lighthouse in inter tidal zone. Being in the high tidal range, the stone anchors that are lying in 5 to 10 m water depth during high tide get exposed during low tide. These stone anchors are found either partially buried or exposed on the gravel bed. The seabed at the finding spot of the anchor consisted of gravel and fine sand. The majority of the anchors are of Indo-Arabia type and one stone anchor falls in the category of composite type. The Indo-Arabia type anchors of typically made from a vertical stone block with often square section with two lower holes are rectangular/ square and an upper circular hole. Two anchors in the group of Indo-Arab type are having uniform vertical deep and wide groove on all the four faces of the anchor. The broken single composite anchor is made of a thin limestone block with two lower holes are square and two circular holes are placed randomly on upper side. The detail measurements and drawing could be completed just of 14 anchors due to tidal time and muddy seabed and hence rest anchors were only photographed. Many stone anchors are fragmented in nature. Majority of the anchors are parted with lower 2 holes and sometimes holes also broken which might have been broken during manufacturing stage. The raw material used for these anchors are hard basaltic, sedimentary and a few of conglomeratic material. A fragmentary anchor is the biggest anchor found from here. Only lower portion is surviving and is very similar to those reported from Mithi Virdi. There is a stone block without any holes noticed similar to the Indo-Arabia type anchor.
Ghogha
1358#8
The ancient Greeks used baskets of stones, large sacks filled with sand, and wooden logs filled with lead. According to Apollonius Rhodius and Stephen of Byzantium, anchors were formed of stone, and Athenaeus states that they were also sometimes made of wood. Such anchors held the vessel merely by their weight and by their friction along the bottom. Iron was afterwards introduced for the construction of anchors, and an improvement was made by forming them with teeth, or "flukes", to fasten themselves into the bottom.
Anchor
19900609#1
The ancient Greeks used baskets of stones, large sacks filled with sand, and wooden logs filled with lead, which, according to Apollonius Rhodius and Stephen of Byzantium, were formed of stone; and Athenaeus states that they were sometimes made of wood. Such anchors held the vessel merely by their weight and by their friction along the bottom. Lashing tree branches to the stone formed teeth or "flukes", to fasten themselves into the bottom. Advances in woodworking and metallurgy encouraged development of improved shapes for more compact, durable, and efficient anchors.
History of the anchor
34795440#4
Crinoid “anchors” were the parts of the crinoid stem that attached the crinoid to a hard surface, such as a rock, to allow the animal to out-compete other filter-feeding animals in its ecosystem. A crinoid would have several anchors that were also made of disks. These are not rare, but are not commonly found in crinoid deposits.
Animals of Devonian Michigan
16200376#7
In the modern era, tie-rods are made of iron or steel, and serve to reinforce vaults, arches, and in general masonry structures. Reinforced masonry walls are strengthened through a tie-rod that connects between parallel walls at the floor-level, which creates a horizontal compression state, thereby increasing the wall's shear strength. While the current literature is very poor, some studies have been done on analysis of anchor plates and tie-rods, for example one study dealing with concrete panels, which, although a thin veneer, may also need anchor plates to help stabilize the wall.
Anchor plate