US2478042A - Lifeboat - Google Patents

Description

w. E. ELLING.

LIFEBOAT Filed Nov. 2, 1945 2 Sheets-Sheet 2 Patented Aug. 2, 194-9 UNITED STATES PATENT OFFICE LIFEBOAT William E. Elling, Metuchen, N. J.

Application November 2, 1945, Serial No. 626,226

19 Claims.

This invention is a novel lifeboat, or small boat suitable for life-saving purposes, especially of the kind adapted to be hoisted and lowered or launched by suspensi n ca les or chains carryin ouplin d v c s da ted t be h ok on t the stem and stern ends of the boat, and by which cables the boat may be lifted to suitable resting position or availably stored when not in use, as by mounting upon davits on shipboard. Such lifeboats are customarily equipped with both rowing and sailing equipment, while modern lifeboats are usually also powered by propelling motors, preferably liquid fuel engines, the boats having provision for storage of fuel as well as for equipment articles and with space for supplies of water, food and various other commodities and essentials.

Am n the bjects of the r s nt inve io a d indeed all lifeboats are to ensure safety and endurance by staunch construction, with high longitudinal and transverse resistanc to strains; to provide buoyancy to float safely high even when loaded to capacity and flooded to the gunwale; also to confer stability against capsizir s by having the center of buoyancy well above the center of gravity; and high capacity in persons and goods, with seating and stowing spaces for all. These general objects are well attained in prior pati nts at means o Feb u ry 25,

1941 and No. 2,328, l3'7 of August 31, 1943, over which the present invention is an improvement in certain important aspects, although the features hereof are not confined to utility in lifeboats em, bodying the recited patents. However as in said Elling patents the air or buoyancy chambers hereof are preferably formed between the outer hull and a permanent inner hull which latter is stepped in a manner to provide, at each side within the boat, one or more longitudinal benches or long seats; and with bulkheads or partition walls subdividing the between-hull spaces into built-in individual airtight compartments or chambers.

A special object of the present invention is to provide for the maximum comfort and accommodation of a full load of passengers; and for the convenience and safety of passengers in loading nd disc ar af ord ease a f c li n ing to and from the seating places of the boat with minimum clambering and eifort on the part of the pas n s.

Anoth c al j ct is o ov de ready onvertibility of the lifeboat from a condition with maximum s ating a cit t n whe ein h midships p r on f the b at, for emer nc 11 reses, an ore-: and nobstruc ed QQ space of ample capacity for the accommodation, for example, of a number of ill or injured persons sup: elted in re l i g ost es or n s r che s- Among other objects of the invention is to pro,- vide for the ready and safe stowage of the various necessary long pieces of equipment, oars, masts, pars h use! wi h S perio se n sh w and in emo in h for active h bein one f the r eeen e obl m i lif boat eeri struction. Another object is provision of ads vantageous means of storage of commodities, life sr servers and 1 her t ms in a Snug and protested manner but quickly accessible in case of need.

Another object is to improve seating capacity with maximum comfort, allowing 17 inches in W d 25 -lQ QS i de t P p n- A further objeot is to enhance safety by supplemen ng the ateral Stiffness a an e of ch a boat by a low bracing system of special units placed at longitudinal intervals and located below and, preferably adapted to give support to he a oor- Other and further objects and advantages of the invention will be explained in the hereinafter following description of one or more illustrative embodiments of the invention or will be understood by those conversant with the subject. To the attainment of such objects and advantages the present invention consists in the novel lifeboat and the novel features of structure, arrangement and detail herein illustrated or described- It is of utmost importance that passengers and crew of a sinking ship when boarding a lifeboat w l ind. t eir laces ea o scattered eq pment and reasonably comfortable. Under established practice every lifeboat must be equipped with a sa lm st o a l n h abou ua to oi d the boat length, and with an antenna mast of about the samelength, and with a sail which is attached to a spar of slightly under one-half the oat. len th a d mak n a bulky pa kage wh t-. stowed n the r ul t on as), also it s n to nine cars which are slightly longer than one-half the boat en th T ms J n d t ke a ubstan ial art o the fl space n d r passengers when placed on the thwarts and side seats. It is a special object of this invention to rovid m ns for read ly t ne u items b low the 591) seat level, which result is herein made poss ble b a spec a s u tu f idsh p c oss s ats or b n hes ro d n passages f os tin these elon ed tem do ar l o est upo the be t floor where they ma be 995c or lashed- The accompanying drawings illustrate a representative example of a motor-propelled lifeboat embodying the present invention, as follows. Fig. 1 is a general perspective view of a lifeboat embodying the invention, showing a considerable portion of the exterior and interior of the boat. the stern being at the far end of the figure so that the rudder, propeller and other exterior stern parts are not seen, these forming no part of the invention; while the tiller and certain minor parts and details are omitted from Fig. 1 as unnecessary to a disclosure of the invention.

Fig. 2, on a larger scale than Fig. 1, is a vertical transverse section view taken substantially at the midship center of the boat, looking forwardly, being substantially on the section line 22 of Fig. 4.

Figs. 1 and 2 show the boat in its regular or unconverted condition.

Fig. 3, on about the scale of Fig. 1, is a similar transverse sectional View at midships showing the boat in its converted condition with unobstructed central floor space.

Fig. 4, on about the same scale as Figs. 1 and 3, is a general right hand side elevational view shown largely in central vertical section.

Fig. 5 is a partial sectional view on a larger scale than the earlier figures, taken on the section line 5-5 of Fig. 4, showing details of certain structural elements near the lower central part of the boat.

Fig. 6 is an interior elevational view of a detail, showing an inverted box or housing for accommodating such equipment as life preservers, located beneath one of the passenger seats of the boat; the figure being partly broken away to show the interior construction.

Fig. 7 is a bottom plan view of the stowage housing or enclosure shown in Fig. 6.

Fig. 8 is a vertical longitudinal sectional view showing certain details of hull construction, taken on the section line 8-8 of Fig. 3.

Fig. 9 is a further enlarged sectional detail view showing a manner of joining inner hull walls and partitions.

While modern lifeboats are of various dimensions, usually running from about 18 to 36 feet in length, more or less, for use on seagoing vessels the boat herein illustrated may be considered as representative of a lifeboat, with marine engine installed, of a length of about 28 feet, beam 9 feet YY alloy which is substantially non-corrosive, and

which may be protectively coated or painted if desired. The outer hull, or at least the lower shell-plating thereof, may be of sheet aluminum of No. 10 B. & S. gage or about 0.10 inch thick, while the upper portion thereof and various inside plates and parts may be somewhat thinner, as permissible, but some thicker as necessary. Such a lifeboat, as illustrated, may have a normal capacity of 54 persons or, under more strict wartime regulations, 40 persons. When fully loaded its weight may be of the order of 13,000 pounds, and when completely stripped, or before being equipped and loaded, about 3,500 pounds; or a similar lifeboat without motor about 2,800 pounds.

The lifeboat is shown constructed with elongated air tanks within the opposite sides of the shell which preferably, as in said prior patents, are permanent or built-in, the air space being thus confined between the outer hull or shell and the inner hull, the two interconnected or welded 4 airtightly throughout, and each longitudinal tank being preferably straight at its inner side, and being interiorly partitioned by walls or bulkheads into separate sealed compartments, some of which may be openable to permit, for emergency purposes, the stowing of reserve commodities.

Also like said prior patents the inner hull at each side is preferably composed of a series of formed or bent hull plates which are stepped upwardly from near the keelson to near the gunwale, these separate hull plates being outwardly flanged and thereby sealed to the partitioning bulkheads which subdivide the tank into the individual air compartments or chambers. Such stepped inner hull provides longitudinal benches, with footroom and with support for a removable flooring above a central, longitudinal bottom well.

The stepped inner hull form being employed, with two or more steps between the keel and gun" wale. it is of value, as explained in the prior patents, that the steps at each side are such that an imaginary construction line XX, drawn between the keel and gunwale as applied in Fig. 2, shall intersect the several risers and treads and traverse the low central well or trough which collects the intaken water between the opposite lower risers of the inner hull.

Referring to the illustrated structure by reference numbers, the shell-plating or outer hull l5 of the lifeboat extends, in the form of shaped sheet metal either in a single piece for each side or in strakes or strips, from the stem post it to the stern post I! at each side, the convex opposite sides being preferably straight amidships but converging curvedly to the end posts, between the keel l8 and the gunwale l9, the latter preferably consisting of a heavy or rigid angle iron or aluminum bar riveted upon the top rim of the outer hull. This gunwale carries at its two sides a series of rowlocks 2| for propulsion by cars, and at one or both ends a supplemental rowlock 22 for steering in emergencies when the rudder has been disabled or lost. overhanging the gunwale is shown a conventional system of lifelines 23 having their inner ends engaged in apertures in the bulkhead wall extensions 38 to be described. Conventional grabrails 24 are indicated at the underside of the shell well outwards from the keel.

The boats inner hull basically resembles those shown in said prior patents, comprising at the opposite sides of the central bottom well 25 a pair of symmetrical hull structures 26, composed of sheet metal and united to the outer hull but shaped well inward therefrom so as to afford elongated buoyancy tanks at the opposite sides. Each tank-forming inner hull structure is permanent or built-in, their edges which are continguous to the outer hull being air-tightly riveted, welded or otherwise unitedwith the shell.

Further; as in said prior patents, each inner hull structure is illustrated of stepped formation, having a plurality of enclosing flat step elements trending from a line near the keel upwardly and outwardly to a point on the shell near the gunwale. Thus each inner hull structure is shown formed with a first riser 21, being a sheet metal member secured to the outer hull near the keel, the sheet metal thence extending flatly outwards as a first tread 28, succeeded in turn by a second riser 29, and so forth, in this case the second tread 30 being the top tread of the inner hull and affording an elongated side bench adapted to seat a substantial number of passengers. Each inner hull may consist substantially of a lengthwise series of hull sections, each being of compartment length and comprising its risers and treads either mutually integral and bent to shape or at their corners tightly riveted or welded together; and as a whole the side bench or benches thereby provided may each be substantially straight, at its inner edge and parallel to the boat centerline, but it its ends 3i tapering somewhat Where the outer shell curves and converges into intersection with the bench line. The risers 21, each taper similarly." at 3l--, l.

Instead of seating the passengers directly upon the metal tread or treads or benches of the inner hulls, these are preferably overlaid with rigid mats or wooden planking 32, these extending the full length of the buoyancy tanks; beyond the ends of which planks, and extending substantially to the bow and stern at the two sides are bridging planks 33 laid diagonally, and between the ends of which. are bow and stem end seats 34. Also, in the illustrated example, the boat flooring consists preferably of attachable and removable wooden planking comprising a series of transverse planks or floor sections laid across between the opposite second risers 29 and resting down upon the first treads 28 at the two sides. So also the cross seats, including thwarts, and the longitudinal and other seating accommodations are covered by or consist of planks or seat boards of wood or similar non-metallic material. The side benches 3d, diagonals 33 and end benches 34 may be termed peripheral benches, distin uished from the cross seats.

The air tank space between the outer and inner hulls at each side is subdivided into a. number of subspaces or compartments by means of a series of bulkheads or partition walls 3i set in transverse vertical planes, each such cross wall extending and connected in an air-tight manner to and between the outer hull E5 and the several riser and tread portions 2? to 38 of the inner may be attached to the outer hull by welding or flange-riveting, while the connection to the risers and treads of the inner hull maybe by means of exterior extensions 38 of the bulkhead walls enclosed and air-tightly secured and sealed between adjacent flanges 39 formed at a ri ht angle upon each of the risers and treads of each of the separate sections of the inner hull as shown in Fig. 9. The cross walls 37 at each side also extend upward at 38 to the gunwale, which is attached thereto.

The described arrangement comprising a stout construction of longitudinal air tanks extending at the two sides substantiall the full length of the boat gives added strength against transverse strains because of the opposite arched formations; and this supplements the bracing thwarts and G3, as do also the bottom well structures to be described.

Some or all of the individual compartments 36 may be used for stowin reserve articles and commodities by reason of the circular access openings or handholes as shown, airtlghtly closed by removable rings or flanged covers til.

To refer to certain general apparatus, the drawings indicate a conventional kind of propelling engine 42, preferably a fluid fuel motor, located well aft, and with the control station All of the boat immediately forward thereof. The motor is shown enclosed in a box 33 having a fiat top, and the engine exhaust pipe is shown as enclosed within a housing or covering structure 44, the exhaust delivering through a hole in the outer hull above the diagonal side bench at the port side. In connection with such general matters it is not necessary to describe such common elements as the stern tube, the propeller, the rudder, the tiller and similar parts.

Referring next to the conventional thwarts which give transverse bracing and provide seats for oarsmen, there are disclosed a forward thwart 45 and an after thwart 46, each of these constituting a cross bench suitable for rowing and being mounted as a permanent part of the boat structure, extending across rigidly between the two sides of the hull, and presenting resistance to bending or crushing stresses or pressures upon the sides of the boat. The seat portion of each thwart is preferably a plank composed of wood, with its ends supported by conventional thwart brackets mounted near the inner edges of the topmost treads of the inner hull at each side; the bracing benches constituting the thwarts being substantially at the level of the longitudinal benches 33 or the seating planks 32 restin thereon. The after thwart 46 may be substantially like the forward thwart, or it may be interrupted by the interposition of the motor box 43, as shown, this thwart thus being in two parts each extending transversely between the motor box and the inner hull. In addition to the support of the described thwarts from the inner portions of the inner hull, they may be additionally supported by a pair of permanent stanchions 43, such stanchions or posts being shown for the forward thwart 45, in the form of upright angle-irons, each extending upwardly from the structural unit below the planked floor 35, the stanchions carrying brackets or gussets L 9 upon which the thwart planks 45 rest firmly.

The forward thwart may be utilized for the suitable support of a removable mast, not shown, the mast extending downwardly through an apertured mast step 5 l, at the rear edge of the thwart, and therebelow into a mast seat 52 permanently mounted near the keel.

By way of increasing the interior seating capacity of the lifeboat there is shown, immediately in front of the forward thwart 45 a double width axially positioned seat 54, the front end of which 0 may be rounded and abridged so as to leave ample room to walk the floor between the axial seat, and the nearby peripheral seats, namely, the bow end seat 34, the side seats 30 and the diagonal bridge seats 33. The double width seat 54 is shown as connected by hinges 55 at its after edge to the forward edge of the thwart 45, so that the axial seat may be swung upwardly to vertical position, or over rearwardly and down to an inverted position when the mast is not in use. By this arrangement of hinged axial seat it is possible to provide an underneath box 55, secured to and liftable with the axial seat, this box being adapted for the stowing of various important articles or supplies, which become readily accessible by the upswinging of the seat and box. When the seat is restored to normal position it may have its free end supported above the floor 35, as by the box 56.

The boat may be without the motor 42, 43 shown in Figs. 1 and 4; and in that case the arrangement of hinged axial seat 54 and box 56 shown near the bow end may be duplicated near the stern.

Various other storing conveniences for equipment, supplies, etc., include the following. Below theliftable. flooring are shown a fuel tank 58 and a watertight provision box or tank 59. Beneath the starboard rear diagonal bench 33' is a tank or enclosure 60 for small equipment, while below the opposite bench is a weatherproof enclosure 6| for ready access to such larger equipment as life preservers Y. This is closed at all but the bottom side whereat is a retractible bar E52 with supporting wings 63, all readily pulled out to drop the article upon the floor for emergency use. The near wall of GI ma be transparent.

Attached near the bow and stern posts [6 and I! by means of brackets 64 are the hoisting hooks 65 adapted to receive and hold suspension cables, or eyes provided thereon, and to release the same at will. These suspension hooks 65 may be of any conventional type or make, for example having a cuplike or cylindrical locking member 66 for the swinging hook 55, the locking cup being rotary between locking and released positions and being operated by an upright supporting rockshaft 61. According to the present improvement the rockshafts Bl at the two ends of the boat are operable simultaneously from the control point ii forward of the engine. For this purpose there are shown diagonal end shafts 69, connected to shafts 51 by universal joints, and extending therefrom to a common longitudinal shaft 19, offset to one side of the boat, thus to clear the engine, and near the control point provided with a releasing means or handle ll, which may stand upwardly when the hooks are locked in suspension position, or be thrown inwardly and downwardly to a normal position wherein the two hoist hook locking members 66 are simultaneously shifted to release position, for example when the launched boat has reached the water or even slightly in advance thereof.

Coming next to the midship construction of the lifeboat, it is first pointed out that the thwarts or bracing benches 15, 46 are respectively well forward and aft of the boat center. There may be a plurality of bracing thwarts at one or both ends of the boat, in which case the ones referred to are those nearest to the boat center, and in the present instance are the only true thwarts.

These forward and. after thwarts are spaced well apart from each other thereby leaving the midship space of the boat, and the flooring thereof, free of permanent thwarts or bracin benches. Instead of thwarts at the midship portion of the boat there is a plurality or series of intermediate cross benches 35, extending transversely above the midship floor space and adapted for seating passengers or oarsmen, but not contributing to transverse bracing. By this plan of construction the aforesaid objects are attainable of convertability of the boat to provide a large clear midship floor space, and the abridgment of these intermediate cross benches to facilitate quick access and free movement of passengers within this part of the vessel. By the midship portion of the boat is meant from a third to a half, more or less, of its inside length, about two-fifths or 40 percent, between thwarts 45 and 46 being shown.

The advantage of convertibility is attained by the provision of mounting means for the midship cross benches 75 which permits ready detachment thereof, thus to afford the desired long and wide midship floor space, substantially clear of obstructions, and available for the accommodation of persons on stretchers, or for other special purposes, pertaining to the carriage of special goods or the performing of special operations on board the lifeboat.

The purpose of freedom of walking to and from given seating locations on the boat floor when all the cross benches 15 are in place is attained by the abridging of each of these cross benches, preferably at both of its ends, to an extent well short of the hull structures at the two sides of the boat, for example to the extent of about 8 to 10 inches; in combination with underneath supporting means for these benches, preferably in the form of posts 76. The truncating of the benches thus provides substantial access gaps 11 between each bench and the hull at both sides, these being ample to permit walking around the benches, Without having to clamber over them, when taking or leaving seating positions, or otherwise; a vital point when despatch is of the essence of life-saving. In the particular structure shown, wherein each inner hull structure is of stepped formation, the cross benches may be at substantially the level of the topmost treads or long side benches 30, and the access gaps 1'! may extend between each bench end and the near corner or step where the topmost riser and tread meet. The presence of the gaps, and especially with the rounding of the cross bench ends, materially increases the seating capacity of the side benches, providing improved leg and knee room.

A particular advantage of the described abridged bench arrangement is that the bench supporting posts l5 may be inset somewhat from the ends of the bench, as shown, thus to provide substantial stowage spaces 13 well adapted to receive long items of equipment, designated Z, notably oars, boathooks, masts and spars, which may be readily inserted by Way of the gaps ll of the several cross benches, to rest upon the floor, either loose or lashed, or to be removed therefrom through the gaps when required. Fig. 2 indicates such long articles of equipment stowed in the space l8, wherein they may extend sometimes beyond the end thwarts 45 and G6 to be confined thereby, or the entrance gaps may be obstructed to this end. However, for temporary occasions, as when launching, a few vital articles, as a boat hook and four oars, may be located for ready service, that is, accessibly placed on top of the side benches 30, or laid near the centerline of the cross benches 75.

The specifically illustrated structure attains both of the purposes mentioned, the midship cross benches being so shortened that each of them can be passed around, as around an island, while all of them are easily detachable to afford the convertibility feature. To carry out such complete duplex purpose not only the cross benches 15, but also the supporting posts or stanchions 16 are readily removable and attachable, thus at will either providing the large mid-floor space or providing the cross benches for normal seating and rowing use. In the preferred structure the bench supporting posts are attached to the benches and are removable therewith, the post lower ends being mountable in suitable receiving devices or sockets 19, below the floor lever. The posts may be hinged to fold against the undersides of the benches thereby to permit compact disposal and stowing.

The particular illustrated means for mounting and demounting the removable midship island benches 15 is as follows: Each such bench is supported at the top ends of its cylindrical posts 16, which may be composed of piping, there being triangular braces or gussets at the top of each post to afford solid support for the wooden plank constituting the cross bench. The two supporting posts or pipes for each bench extend downwardly through apertures in the floor 35 and thence into two opposite upright sockets 19, which are elongated or tubular to receive the posts. A stop means or pin 82 may be provided within each socket or upon each post to determine the extent of lowering of the post into position; and lock means 83 may be employed to hold the posts and thereby the bench at the predetermined height, this lock means for example being a pin inserted through bores in the sides of the socket and post. Each socket member 79 may be firmly and permanently secured as a part of the boat structure, for example by being welded to an attaching plate 85 which in turn is riveted, bolted or welded upon a permanent cross member 81, herein called a thwart beam, below the floor, as will next be described.

It remains to describe the below-floor structure or unit, mounted permanently in the central bottom space, in the nature of a trough, well or recess 25 existin between the opposite inner hulls or the riser elements 27 thereof; the stepped formation of the inner hulls being adapted to drain down into this receiving well all water that may enter the boat, which water thus becomes located most advantageously for stability. Within this central well is provided a series of built-up units or framelike bracing structures 86, of open construction, spaced along the length of the boat,

for example one beneath each thwart and one u beneath each cross bench in the midship part of the boat; these well structures giving a strong transverse bracing effect by reason of the solid and rigid manner in which they space apart the opposite inner hull structures, thereby in turn through the alined interior bulk heads transversely bracing the outer hull or shell and contributing to making up for the lack of bracing thwarts at a higher level in the midship portion of the boat. Each of these low units may comprise several bars, interconnected uprights and horizontals being shown.

Across the upper part of the well, each built-up unit or frame 86 comprises a low horizontal bar or thwart beam 81, in the nature of a cross brace between the opposite inner hulls, and centrally attached thereto an upright stanchion 88. These members 81 and 88 may be of conventional structural beam form, such as channels, and the stanchion extends downwardly to where at its foot it receives bottom support through an interconnectin head plate 89, attached to the stanchion, and to which are also attached a cross member consisting of a pair of opposite cross bars 90 extending outwardly to the inner hull structure at each side. These cross bars meet centrally at their lower edges, but thereabove they are shaped, bevelled or cut away to provide a triangular limber hole 9|, by which residue water can flow longitudinally along the bottom well or trough 25 to reach a suitable pumping well or sump. The described structural units 86 may be completed by the provision of upright bars 92 extending from the outer ends of the cross bars 90 upwardly to the outer ends of the thwart beam Bl. All of these parts 8? to 92 may be permanently and rigidly united in a suitable manner, as by rivets or welding. These structural units may be substantially similar at the positions below the true thwarts such as 45 and below the special cross benches l5, excepting that in the latter case each unit is supplemented by provision for the removability of the rod-like bench posts or pipes 16, namely, the tubular receiving sockets l9 therefor, secured to the thwart beam, whereas;

10 beneath each true thwart the posts or stanchions 48 may be permanent, and may in fact be integral extensions of, or be attached to, the opposite upright bars 52 of the structural unit. The bracing units or frames 86 not merely resist side pressure and damaging strain, but protect the bottom part of the outer hull near the keel from gradual bending and damage by the weight of the boat as when resting on its keel, the units 86 acting to distribute the boat weight over an extended hull area through the low crossbars 90, 98, which receive th strain through the uprights 88, 92 from the thwart beam 8i, which in turn is rigid with the inner and outer hulls and the bulkheads.

The described lifeboat thus achieves the advantages already set forth; and it has the important further advantage of being rat-proof. The air tanks are built-in, leaving no concealed crevices as with separate tanks fastened in. Every space and corner is easily inspected and cleaned out. When the floor is lifted out the central bottom well or trough is fully exposed to access, the structures or units therein being spaced well apart and of open construction, facilitating a complete view and ready cleaning. For similar reasons thorough overhauling, repairing and painting of the lifeboat are facilitated.

What is claimed is:

1. In a lifeboat of the kind specified having a sheet-metal outer hull with sides converging to the bow and stern ends between keel and gunwale, and a permanent sheet metal inner hull comprising at its opposite sides stepped structures of risers and treads tightly joined to the outer hull therewith to form longitudinal buoyancy tanks, and so disposed that straight lines tween keel and gunwale intersect every riser and tread while the top treads afford peripheral seating benches; and in combination therewith a series of spaced-apart cross benches at or near the top tread level; those cross benches which are located beyond the midships length of the boat, nearer to the boat ends, being permanent bracing thwarts extending from hull side to side and spaced well apart longitudinally from each other leaving the midship space free of permanent thwarts; and all of those cross benches located within the midships being abridged well short of such top treads thereby providing substantial access gaps between such benches and the inner hull structures, and said abridged cross benches each having underneath supporting posts spaced inwards of the bench ends; and detachable mounting means for said abridged cross benches and supporting posts permitting ready removal thereof from above the floor level for converting the boat to afford a long and wide midship floor space substantially clear of obstruction.

2. A lifeboat as in claim 1 and wherein for each depending post of each abridged cross bench is a permanent upright socket member below floor level to receive such post, and means to position and lock or unlock the post lower end therein.

3. A lifeboat as in claim 1 and wherein, in the space or well between inner hull risers below the top risers is provided a series of hull bracing units comprising thwart beams extending from riser to riser resisting collapse.

4. In a lifeboat of the kind specified having a sheet-metal outer hull with sides converging to the bow and stern ends between keel and gunwale, and a permanent sheet metal inner hull comprising at its opposite sides stepped structures of risers and treads tightly joined to the outer hull therewith to form longitudinal buoyancy tanks and between their lowest risers defining a central Well; and in combination therewith a series of spaced-apart cross benches at or near the top tread level, all of those cross benches which are located within the midships length of the boat being abridged well short of such top treads thereby providing substantial access gaps between such benches and the inner hull structures, and said. abridged cross benches each having underneath supporting means spaced well inwards from the inner hull; whereby passage is provided through such access gaps at least wide enough for depositing oars, spars and the like therethrough into the stowage space between the bench supporting means and the inner hull.

5. A lifeboat as in claim 4 and wherein, located beyond the midships length towards the bow and stern are cross benches constituting bracing thwarts extending from one side hull to the other.

6. A lifeboat as in claim 4 and wherein, along the midships length of the boat, are a series of low cross-bracing units comprising thwart beams located between opposite risers below the top risers and maintaining the hull in effective resistance to lateral pressure.

'7. In a lifeboat of the kind specified having a sheet-metal outer hull with sides converging to the bow and stern ends between keel and gunwale and a permanent sheet metal inner hull comprising at its opposite sides stepped structures of risers and treads tightly joined to the outer hull therewith to form longitudinal buoyancy tanks; and in combination therewith a series of spaced-apart cross benches at or near the top tread level; those cross benches which are located beyond the midships length of the boat, nearer to the boat ends, being permanent bracing thwarts extending from hull side to side and spaced well apart longitudinally from each other leaving the midship space free of permanent thwarts; and all of those cross benches located within the midships having detachable mounting means permitting ready removal thereof from above the floor level for converting the boat to afford a long and wide midship floor space substantially clear of obstruction; together with a series of low bracing units spaced along the midship length of the boat, each including a thwart beam permanently fixed between opposite risers of the inner hull lower than the top treads and risers thereof.

8. In a lifeboat of the kind specified having a sheet-metal outer hull with sides converging to the bow and stern ends between keel and gunwale, and a permanent sheet metal inner hull comprising at its opposite sides stepped structures of risers and treads tightly joined to the outer hull therewith to form longitudinal buoyancy tanks and between their lowest risers defining a central well; and a supplemental permanent bracing means comprising one or more rigid units each mounted in the well or space between two opposite hull risers below the top risers, said unit comprising a thwart beam set crosswise between said two risers to resist compression and stiffen the hull, and associated means holding the thwart beam in place.

9. A lifeboat as in claim 8 and wherein there is a series of such spaced units with bracing thwart beams at the top sides thereof, and a flooring overlying and supported by such series of thwart beams.

10. In a lifeboat of the kind specified having a sheet-metal outer hull with sides converging to the bow and stern ends between keel and gunwale and a permanent sheet metal inner hull comprising at its opposite sides stepped structures of risers and treads tightly joined to the outer hull therewith to form longitudinal buoyancy tanks and between their lowest risers defining a central well; and a permanent hull bracing means comprising a series of unitary rigid structures each mounted in the well; each such structure being a built-up open frame of interconnected structural bars, the top bar being a thwart beam set crosswise between the opposite risers defining the well and resisting compression.

11. A lifeboat as in claim 10 and wherein the bracing frame comprises, associated with said thwart beam set crosswise at the top, a bottom crossbar spanning the well and bearing down on the outer hull bottom and apertured centrally to afford a limber hole, a central upright stanchion attached above to the thwart beam middle and below connected to and bearing down centrally on the bottom crossbar, and side uprights adjacent to the risers defining the well and attached above to the thwart beam ends and below connected to bear down on the outer ends of the bottom crossbar.

12. A lifeboat as in claim 10 and wherein the bracing frame comprises, associated with said thwart beam set crosswise at the top, a bottom crossbar spanning the well and bearing down on the outer hull bottom and apertured centrally to afford a limber hole, a central upright stanchion attached above to the thwart beam middle and below connected to and bearing down centrally on the bottom crossbar, and side uprights adjacent to the risers defining the well and attached above to the thwart beam ends and below connected to bear down on the outer ends of the bottom crossbar; the bottom crossbar consisting of two bars one at each side of the center and bevelled to leave a limber hole; and a headpiece to which said two bars at their inner ends are connected to said stanchion at its lower end.

13. A lifeboat as in claim 11 and wherein by the recited bracing structures the thwart beams thereof brace the inner and outer hulls against compression strains, while the arrangement of uprights extending from the thwart beam down to the bottom crossbar acts through the latter to distribute the weight of the boat over a wide area of bottom, thus protecting the bottom against progressive damage by the bending tendency near the keel when the boat is resting thereon.

14. A lifeboat as in claim 8 and wherein the buoyancy tanks between said outer and inner hulls are subdivided by longitudinally spaced bulkheads, and the bracing thwart beams are spaced apart in positions for each to stand in alinement with a bulkhead at each side of the well.

15. A lifeboat as in claim 10 and wherein the buoyancy tanks between said outer and inner hulls are subdivided by longitudinally spaced bulkheads, and the bracing thwart beams are spaced apart in positions for each to stand in alinement with a bulkhead at each side of the well.

16. In a lifeboat of the kind specified having a sheet-metal outer hull with sides converging to the bow and stern ends between keel and gunwale and a permanent sheet metal inner hull comprising at its opposite sides stepped structures of risers and. treads tightly joined to the 13 outer hull therewith to form longitudinal buoyancy tanks and between their lowest risers defining a central well, the topmost treads constituting longitudinal peripheral seating benches, and a system of cross benches at substantially top tread level, at least the endmost cross benches being bracing thwarts extending between the topmost risers of the stepped inner hull; and in combination therewith an axially disposed seat of substantially double width located between an endmost thwart and the boat end, but so limited in width and longitudinal length as to leave passageway for circulation of occupants between said axial seat and the peripheral seating at that end of the boat, said axial seat having one end of it hinged to the adjacent thwart thereby to be swingable up and over to inverted position above the thwart; and a storage box carried by said hinged axial seat and secured to the under side thereof, whereby the box is swingable upward with the seat and thus rendered easily accessible.

17. In a lifeboat of the kind specified having a sheet-metal outer hull with sides converging to the bow and stern ends between keel and gunwale and a permanent sheet-metal inner hull having each of its opposite sides tightly joined to the outer hull therewith to form longitudinal buoyancy tanks, the topmost portions of which afiord longitudinal peripheral-seating benches, and a system of cross bracing elements including at least one end thwart extending between the hull sides at a location between one end and the midships of the boat; and in combination therewith an axially disposed seat of substantially double width located between said end thwart and the boat end, but so limited in width and longitudinal length as to leave ample passageway for circulation of occupants between said axial seat and the peripheral seating at that end of the boat; said axial seat having one end of it hinged to the adjacent end thwart thereby to be swingable up and over and down to inverted position above the thwart; and a storage box carried by said hinged axial seat and secured to the under side thereof, whereby the box is swingable upward and over with the seat and thus rendered easily accessible; and said box being of such height that in normal position it reaches down to the boat floor and thus gives support to the free end of the hinged bench.

18. In a lifeboat of the kind specified having peripheral and cross benches, a means for stowing life-preservers or like equipment for quick access, comprising, mounted at the under side of a fixed bench having ample open space beneath it, an inverted box having its open side downward, through which bottom the equipment can be inserted and removed; and a retractible support member, slidingly mounted at the under side of the box, the same adapted to be set across the open lower side of the box thereby to confine and give support to the equipment and to be pulled laterally out of supporting position thereby to discharge the equipment by gravity upon the boat floor.

19. In a lifeboat of the kind specified having a sheet-metal outer hull with sides converging to the bow and stern ends between keel and gunwale and a permanent sheet-metal inner hull comprising at its opposite sides stepped structures of risers and treads tightly joined to the outer hull therewith to form longitudinal buoyancy tanks and so disposed that straight lines between keel and gunwale intersect every riser and tread while the top treads afiord peripheral seating benches; and in combination therewith a series of spaced-apart cross benches at or near the top tread level; those cross benches which are located within the midships having detachable mounting means permitting ready removal thereof from above the floor level for converting the boat to afford a long and wide midship floor space substantially clear of obstruction; together with a series of low bracing units spaced along the midship length of the boat, each including a thwart beam permanently fixed between opposite risers of the inner hull lower than the top treads and risers thereof.

WILLIAM E. ELLING.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 277,269 Gray May 8, 1883 658,498 Coston Sept. 25, 1900 1,117,439 Pitt Nov. 1'7, 1914 1,183,647 Joyce May 16, 1916 1,250,560 Chase Dec. 18, 1917 2,328,437 Elling Aug. 31, 1943 FOREIGN PATENTS Number Country Date 13,810 Great Britain June 8, 1914 350,536 Great Britain June 12, 1931

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