Submersible observation vessel
FIELD OF INVENTION 
     This invention relates to a submersible observation vessel, and more particularly a submersible which comprises a transparent acrylic hull having an integral cradle. 
     BACKGROUND AND SUMMARY OF THE INVENTION 
     Conventional submersibles are made of 4 inch steel walls which have poor insulation qualities, lack sound absorption properties, and readily condense water on its interior surface. In addition, these submersibles were not designed for sightseeing, but for research, therefore the quarters are uncomfortable and cramped and view ports are small and provide a restricted view of ocean environment. Through these small view ports, a person can sample only a small portion of the beauty of the ocean and its variety of inhabitants. 
     The purpose of an excursion submersible is to provide every tourist a view of the surrounding ocean in a comfortable manner. Currently a new type of submersible is being designed which features transparent acrylic hulls that can provide a panoramic view of the ocean environment. The acrylic hulls must overcome many hurdles such as being designed to sustain substantial water pressures and meeting or exceeding the rigorous design criteria and regulations dictated by the American Bureau of Shipping. All designs must be reviewed and approved by the American Bureau of Shipping before the submersible can be manufactured. 
     One design developed by Hyco Technologies of Vancouver, British Columbia, utilizes three acrylic spheres sandwiched in a stainless steel fiberglass framework. The drawbacks of this submersible are (1) a limited passenger occupancy (2) small passageways between acrylic spheres and (3) the cost. Hyco Technologies also has a design for a submersible utilizing acrylic cylinders for a vessel which can accommodate 46 passengers. This design requires the hull be reinforced with wide steel ribs which obstruct and limit the view of the ocean. A further discussion of these designs can be found in the article &#34;Touring the Deep&#34; by Jeff Mangiat, Popular Mechanics, Oct. 1988, beginning at page 68. 
     An important design criteria for the hull is that the seals properly prevent the passage of water and air into or out of the hull. Another hurdle is that the shape of the hull should be able to provide room, comfort, accessible viewing, and easy ingress and egress for passengers/tourists. 
     The object of the present invention is to provide a submersible observation vessel that is safe, comfortable and provides a panoramic view of the ocean environment. 
     It is a feature of this invention to have a transparent acrylic hull for the submersible observation vessel which allows for seated passengers to view the ocean not only laterally out side windows but vertically above their seats through the acrylic hull. 
     It is another feature of this invention to have seals that meet or exceed the design criteria of the American Bureau of Shipping for providing a water and air-tight hull. 
     It is another feature of this invention to have a cradle apparatus to support the hull and to provide a means to lift the submersible out of the water. 
     It is an advantage of this invention to provide an air-tight, water-tight submersible observation vessel having a transparent acrylic hull to transport people, who can not swim or are afraid to dive into deep waters, down into the deep waters to explore the ocean environment. 
     Other objects, features and advantages of the invention will be apparent in the following description and claims in which the principles of the invention are set forth with details to enable persons skilled in the art to which the invention pertains to practice the invention all in connection with the best mode presently contemplated for the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Drawings accompany this disclosure and the various views thereof may be described as follows: 
     FIG. 1 is a perspective view of a submersible observation vessel having an exemplary but preferred embodiment of a hull of this invention. 
     FIG. 2 is an end elevational view of the submersible of FIG. 1 with a front hatch. 
     FIG. 3 is a sectional view taken along line 3--3 in FIG. 1. 
     FIG. 4 is a fragmentary side elevational view of the hull of FIG. 1. 
     FIG. 5 is a fragmentary and enlarged sectional view of a forward hatch and seal of FIG. 4 embodying this invention. 
     FIG. 6 is a fragmentary and enlarged sectional view of a rear seal of FIG. 4 embodying this invention. 
     FIG. 7 is an enlarged sectional view of an intermediary seal of FIG. 4 embodying this invention. 
     FIG. 8 is a perspective view of a cradle apparatus. 
     FIG. 9 is a fragmentary and enlarged perspective view of an upper cradle frame of FIG. 8 embodying this invention. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The preferred embodiment of the present invention is illustrated by way of example in FIGS. 1-9. With reference to FIG. 1, a submersible observation vessel 10 has a transparent hull 12 coupled to an ogive unit 14 and has along the lower portion of the hull a pair of battery pods 16. Attached to the sides of the hull 12 are a pair of propulsion housings 18, which move the vessel through the waters. 
     The transparent hull 12 has 3 defined areas, forward 20, central 22 and rear 24 sections as shown in FIGS. 1 and 4. A tie-bar unit 26 holds the sections into a water and air-tight hull 12. An integral cradle 28 is fitted to the underside of the hull 12 to provide support for and a medium to lift the hull in and out of the water. 
     As shown in FIG. 2, the forward section 20 of the hull 12 includes a front hatch 30 pivoted on a pair of hinges 34 attached to a first end or forward seal 32. Hatch 30 is held against forward seal 32 by a latch 36, 180° from hinges 34 so that no water may pass between the hatch 30 and seal 32. Front hatch 30 has a generally hemispherical shaped member 38, a holddown ring 40 and a hatch ring 42. Hemispherical shaped member 38 is preferably made of a 31/2 inches thick translucent acrylic having a reference radius of 40.1875 inches and an arc of 1211/3°, which meets or exceeds the minimum physical properties detailed in the ASME/ANSI Specification PVHO-1. The ASME/ANSI Specification is a safety standard for pressure vessels for human occupancy sponsored and published by the American Society of Mechanical Engineers. 
     To assemble the front hatch 30, acrylic member 38 has its edge 44 abut a lower portion 46 of the forward face of hatch ring 42 as shown in FIG. 5. Hold-down ring 40 goes over hemispherical acrylic member 38 and has its inner circumferential surface 48 pressed down onto a neoprene gasket seal 50 adjoining the entire perimeter portion of outer surface 52 of member 38. 
     Hatch ring 42 is a circular steel band with threaded bores 56 spaced equally around the perimeter, preferably every 60°, of an upper portion 54 of the hatch ring forward face. Lower portion 46 of the forward face slants inwardly at an angle that allows contact with the entire surface of circumferential edge 44 of hemispherical acrylic member 38. Rear face 58 of hatch ring 42 is beveled slightly with an annular groove 60 midway on face 58 to seat a seal 62 such as an O-ring. 
     Hold-down ring 40 is a circular band having bores 64 on the perimeter to align with the threaded bores 56 of the hatch ring 42. Hold-down ring 40 has its inner circumferential surface 48 arcuate shaped so that the inner surface 48 can apply a uniform pressure on gasket seal 50 which has conformed its shape to the outer surface 52 of acrylic hemispherical member 38. Bolts 66 are passed through bores 64 of the hold-down ring 40 and are received in threaded bores 56 of hatch ring 42 (FIGS. 2 and 5). As bolts 66 are tightened down, hold-down ring 40 presses against neoprene gasket seal 50 which bears down on hemispherical member 38 to force edge 44 into tight abutment with forward face lower portion 46 of hatch ring 42. Rear face 68 of hold-down ring 40 presses against forward face upper portion 54 of hatch ring 42 with neoprene gasket seal 50 preventing any leakage (FIG. 5). This front hatch 30 acts as both the viewport for the pilot and the front entrance for the vessel. 
     Forward seal 32 is a circular band having a forward face 70 that is inwardly slanted and clad in monel. A rear face 72 of seal 32 is flat and has an annular groove 74 cut throughout. Forward seal 32 has a shoulder 76 extending radially outward of the forward and rear face. Shoulder 76 has a plurality of through bores 78 preferably spaced every 60° on the periphery. At a plane halfway between the top and bottom of the forward seal 32 is fixedly attached a latch 36 and equally spaced from this plane and opposite the latch 36 are a pair of hinges 34 that support front latch 30. A neoprene bearing gasket 80 lines a bottom wall 82 and inner diameter wall 84 of the annular groove 74 and a neoprene external gasket 86 is adjacent to the outer diameter wall 88 of the annular groove 74. 
     As shown in FIGS. 1 and 4, the mid-section 22 of the preferred embodiment 10 comprises of a pair of intermediary seals 90, 90a and three transparent cylinders 92a,b,c. These transparent cylinders 92a,b,c are preferably made up of 31/2 inch thick acrylic having an inner diameter of 641/2 inches and a length of 90 inches, which exceeds the minimum physical properties ASME/ANSI Specification PVHO-1. 
     As shown in FIG. 7, intermediary seal 90 is a steel circular band having a flat front and rear face 94, 96 each with an annular groove 98, 100 throughout. This intermediary seal 90 has shoulder 102 between both faces 94, 96. Shoulder 102 has through bores 104 equally spaced, but preferably 60° apart, and in alignment with the forward bores 78. Lining the bottom wall 106, 108 and inner diameter wall 110, 112 of the annular groove 98, 100 is a neoprene bearing gasket 114, 116 and adjoining an outer diameter wall 118, 120 of annular groove 98, 100 is a neoprene external seal 122, 124. 
     The rear section 24 (FIGS. 3, 4 and 6) includes a second end or rear seal 130 and a bulk head 132. Rear seal 130 is a steel circular band having an annular groove 134 cut in its flat forward face 136 and a rear face 138 perpendicular to the outer circumferential surface 140. Seal 130 has a shoulder 142 radially outward from the front face 136. There are a plurality of bores 144 spaced equally, but preferably 60° about the periphery and through shoulder 142 and in alignment with forward and intermediary seal bores 78, 104. A neoprene bearing gasket 146 lines bottom wall 148 and inner diameter wall 150 of annular groove 134 and a neoprene external seal 152 is adjacent outer diameter wall 154 of annular groove 134. Welded to the flat rear face 138 of rear seal 130 is ellipsoid shaped bulk head 132 having hinged to it an aft hatch 156 for alternate entrance/exit from submersible 10. 
     To construct hull 12 into an air-tight and water-tight configuration, first cylinder 92a has its forward edge 158a fitted into annular groove 74 of forward seal 32 and is contiguous with neoprene bearing gasket 80 along inner diameter wall 84 and bottom wall 82 of annular groove 74. Neoprene external gasket 86 is snugly fit between outer diameter wall 88 of annular groove 74 and outer circumferential surface 160a of cylinder 92a. The other end of acrylic cylinder 92a is placed into annular groove 98 of first intermediary seal 90 in a similar fashion as forward edge 158a whereby the acrylic cylinder rear edge 162a is contiguous with neoprene bearing gasket 114 along inner diameter wall 110 and bottom wall 106 of annular groove 98 and neoprene external seal 86 is snugly fit between outer diameter wall 118 of annular groove 98 and outer surface 160a of acrylic cylinder 92a. The second acrylic cylinder 92b is placed into rear face annular groove 100 of the first intermediary seal 90 and into the front face annular groove 98a of second intermediary seal 90a. The third acrylic cylinder 92c is placed into annular groove 100a of second intermediary seal 90a and into the annular groove 134 on front face 136 of rear seal 130. 
     A tie-bar unit 170 is utilized to hold the hull in an air and water tight configuration. In this preferred embodiment 10, there are six tie-bar sets, each set comprises of three rods 172, 174, 176 each having both ends threaded to receive a nut or a turnbuckle. All sets are arranged as follows, the first rod 172 has its threaded end 178 introduced into bore 78 through shoulder 76 of forward seal 32. As shown in FIG. 5, once through bore 78, a nut 180 is screwed onto the end 178 to prevent the rod 172 from slipping back through the bore 78. On the other end 182 of the rod 172 is a nut 184 screwed onto the threads. Threaded end 182 is then placed through intermediary seal bore 104 and is received by a turnbuckle 186 which draws the rod 172 through the bore 104 of the intermediary seal 90 and forces nut 184 against shoulder 90. Second rod 174 which is shorter than rods 172, 176, has the front end 188 screwed into the open end of turnbuckle 186. Rear end 190 of rod 174 is then screwed into another turnbuckle 191. Third rod 176 has a nut 194 screwed down on its forward threaded end 192. This threaded end 192 is introduced into second intermediary seal bore 104a and is received into the open end of turnbuckle 190. Rear end 196 of third rod 176 is passed through bore 144 of rear seal 130 and a nut 198 is screwed onto the end to be flush against rear face 138 of rear seal 130. To provide air and water tightness, turnbuckles 186, 190 are rotated so as to draw first and third rods 172, 176 towards second rod 174 and in doing so nut 180 forces forward seal 32 onto acrylic cylinder 92a into intermediary seal 90. Nut 184 forces intermediary seal 90 onto acrylic cylinder 92b and acrylic cylinder 92b into intermediary seal 90a. Nut 194 forces intermediary seal 90a onto acrylic cylinder 92 b and acrylic cylinder 92b into intermediary seal 90. Nut 198 forces rear seal 142 onto acrylic cylinder 92c and acrylic cylinder 92c into intermediary seal 90a. Assembling all six sets of tie-bars in the same fashion provides symmetrical pressure on the seals onto the acrylic cylinders and prevents water leakage into the hull 12. 
     A cradle apparatus 200 as shown in FIG. 8, is necessary to lift hull 12 out of the water. Apparatus 200 comprises a spreader bar 202, an upper cradle frame 204 and a lower integral cradle 28. Integral cradle 28 has a pair of laterally spaced apart and longitudinally extending side rails 206 which extend past forward seal 32, intermediary seals 90, 90a and rear seal 130. Side rail 206 has holes 208 which are in the same plane as the seals of the hull. Under each seal is a cross support member 210, which is a modified I-shaped beam having a concave top surface 212 shaped to provide uniform contact to the side of each circular seal. Cross support member 210 has a flat lower surface 214 as the base and an upright or rib 216 which bisects the width of surface 214 and extends up to support concave top surface 212. As shown in FIG. 7, a plurality of clips 218 are welded to the top surface 213 to prevent the seals from moving transversely off of the cross member 210. This lower cradle portion 28 allows the lifting of submersible 10 out of the water without any pressure or force directly acting on any acrylic cylinder or member. 
     Spreader bar 202 is an I-beam preferably 8 inch and having a length of 22 feet. Two eye bolts 220 are provided, each of which is secured, preferably welded, to opposite ends of the top of spreader bar 202. A steel sling 222 has each thimbled end attached to eye bolts 220 by a shackle 223. Spreader bar 202 has a rib 224 having a pair of holes 226 located on each end of spreader bar 202. Upper cradle frame 204 is made up of 6 inch channel having two sides 228 preferably a length of 25 feet with four cross supports 230 having a length of 90 feet. Cross supports 230 are equal distance from each other and each has a pair of eye bolts 232 welded to the top and a pair of eye bolts 238 welded to the bottom surfaces along the sides 228 (FIG. 9). 
     To move the submersible 10 from dry dock to the water or vice-a-versa, a crane has its a hook 240 attached to sling 222 on spreader bar 202. Slings 242 are pulled through holes 226 of spreader bar 202 and, as shown in FIG. 9, are attached to eye bolts 232 on the top surface of upper cradle frame 204 by shackles 223. Slings 246 are attached to hooks 238 on the underside of cradle frame 204 and to holes 208 of side rails 206 by shackles 223. All slings 222, 242, 246 are preferably made of 3/4 inch plow steel and have thimbled ends to be hooked to shackles 223. The crane raises hook 240 which tensions the slings 242, 246 which act on the side rails and lifts the sub off of the dry dock. The submersible is carefully swung over the water and slowly lowered into the water. Slings 246 are detached from holes 208 in side rails 206 by removing shackles 223 so that the upper cradle frame 204 and spreader bar 202 are returned to over the dock to be removed from the crane. 
     Boarding the submersible 10 may be made through one of two passages. Hatch 250 located in the ogive unit 14 allows passengers to climb down into the ogive unit 14 and then crawl through aft hatch 156. The preferable method of loading passengers onto submersible 10 is through the front hatch 30. Releasing latch 36 allows front hatch 30 to swing open on hinges 34 and provide an entrance whereby passengers do not have to climb or crawl to reach their seat. Instead passengers can comfortably walk down a center aisle and take their seats. While seated, the only obstruction to a passenger&#39;s view may be the narrow steel seals and the traversing tie-rod bar units which hold the hull together. There is no other obstruction to lateral and vertical viewing such as steel ribs or an overhead canopy or roof lining. 
     From the foregoing description and appended drawings, it will now be apparent that the submersible observation vessel of the present invention provides a safe, comfortable and panoramic view of the ocean environment and provides a watertight and air-tight hull which meets and exceeds the design criteria of the American Bureau of Shipping. 
     It is also to be understood that the terminology as employed in the description and claims incorporated herein such as &#34;forward&#34;, &#34;rear&#34;, &#34;upper&#34;, &#34;lower&#34;, &#34;top&#34;, &#34;bottom&#34; etc., is used by way of description and not by way of limitation, to facilitate understanding of the structure, function and operation of the combination of elements which constitute the present invention. Moreover, while the foregoing description and drawings illustrate in detail one successful working embodiment of the my invention, to those skilled in the art to which the present invention relates, the present disclosure will suggest many modifications in construction as well as widely differing embodiments and applications without thereby departing from the spirit and scope of the invention. The present invention, therefore, is intended to be limited only by the scope of the appended claims and the applicable prior art.