US2858055A - Net-type ladders - Google Patents

Description

Oct. 28, 1958 3 5 G, ETAL 2,858,055

NET-TYPE LADDERS Filed May 15, 1956 2 Sheets-Sheet 1 Fig.1

'INVENTORS:

L,e,on B.D,eL,on g, i GeorgpESpdenoLv,

ATTORNEYS.

Oct. 28, 1958 L. B. DE LONG ETAL NET-TYPE LADDERS 2 Sheets-Sheet 2 Filed May 15, 1956 40 SERVICE SHIP L eon B. DLeLpHg/Q 680229111 ,iudez ow,

w wg/ MM ATTORNEYS.

"Unite States Patent fiice 21,858,055 Patented Oct. 28, 1958 NET-TYPE LADDERS Leon 3. De Long, Seattle, Wash, and George E. Surlerow, New York, N. Y., assignors to De Long Corpo ration, New York, N. Y., a corporation of Delaware Application May 15, 1956, Serial No. 584,964

13 Claims. (Cl. 228--40) The present invention relates to new and useful improvernents in net-type ladders adapted to provide access between an off-shore, elevated marine platform and a marine vessel or ship anchored adjacent thereto.

A serious problem existing in the use of off-shore installations is the provision of means for safely transferring men from the platform to a pitching and rolling vessel or ship and vice versa. Numerous methods and structures have been proposed for solving this problem, such as using a cargo net carrying the men, which net is moved between the vessel and the platform by means of a crane on the platform. In this method, if the sea is rough, it is extremely difficult to load or unload the net when it is resting on the pitching and rolling vessel. Another method currently employed is to have a landing platform attached to the legs or columns of the elevated platform whereby men Will jump from the landing platform to the ship and vice versa. It should be readily apparent that this latter method would be extremely dangerous since it requires an accurate judging of the distance to be jumped. Other methods and structures have been proposed but the too, have failed to satisfactorily reduce the dangers incident to transferring men between vessels and platforms at sea.

Accordingly, it is an important object of the present invention to provide a flexible, net-type ladder having front and side rungs and which ladder is disposed between an elevated platform and a vessel at sea to permit men to be safely transferred therebetween.

Another object of the invention is to provide a novel net-type ladder which may be securely attached to an elevated platform to be suspended therefrom, whereby a vessel may be anchored with a side thereof engaging the ladder to facilitate access thereto from the vessel.

A further object is to provide a net-type ladder having the above characteristics and which is also constructed to include a portion functioning as a fender for the vessel and also including weights at the bottom thereof for maintaining the flexible ladder netting in a taut or tensioned state.

A further object is to provide a structure for accomplishing the foregoing objects which will be simple in design and inexpensive to manufacture, yet durable in use.

Other objects and advantages of the invention will become apparent from the following description and accompanying drawings, in which:

Figure 1 is a front, elevational view of a net-type ladder, embodying this invention, secured to and suspended from an elevated platform at sea;

Figure 2 is a vertical, sectional view of the ladder shown in Figure 1;

Figure 3 is an enlarged fragmentary front elevational view of the ladder shown in Figure 1, showing the manner in which certain parts are arranged;

Figure 4 is an enlarged fragmentary, sectional view taken along the line 44 of Figure 3.

Referring now to the drawings, a preferred embodiment of the present invention comprises a net-type ladder or Jacobs ladder, generally indicated at 10, which ladder is suspended from an elevated barge or platform 11, the latter being supported off-shore on piles or columns 13. The ladder 10 includes an upper portion 12 having a single course or ply of netting and. a lower portion 14 having a double course or ply of netting, as seen in Figure 2. The upper portion 12 has vertical coplanar elements or stiles 16 and horizontally disposed elements or rungs 18, coplanar with the vertical elements and perpendicular thereto as seen in Figure 1. The vertical elements 16 and rungs 18 preferably are made of a strong flexible material, such as 3-lay manila rope, chain or cable, and are connected together in any suitable manner. The top of the upper portion 12 is constructed with a transverse, rigid cylindrical member or pipe 20 having the upper ends of the vertical elements 16 suitably secured thereto. The pipe 20 may be provided with lashings 22 for securing the ladder to an appropriate anchoring structure 24 disposed on the barge 11, as seen in Figure 2.

A second transverse cylindrical member or pipe 26 is connected to the netting of the upper portion 12 intermediate the top and bottom thereof and cooperates with the upper pipe 20 to rest against a vertical, side surface 15 -of the barge to thereby space the plane of the upper ladder portion 12 away from the side surface of the platform. This spacing is necessary to enable a person ascending or descending the latter to get a safe and proper foothold or handhold on each of the rungs 18 in this region. Disposed at the bottom of the upper ladder portion 12 is another transverse pipe 28 securely attached to the netting. The pipes 20, 28 may be provided with pairs of washer-like elements 21, spaced longitudinally thereof and enclosing the stiles 16 to retain the latter in proper position on the pipes.

The lower ladder portion 14 preferably comprises two laterally spaced rows or courses of netting 30, 32 as seen in Figure 2. i The rear row 32 preferably includes integral extensions 17 (see Fig. 4) of the vertical elements 16 of the upper ladder portion and horizontally disposed rungs 34 perpendicular thereto and coplanar therewith. It will be noted that the pipe 28 forms the dividing line between the upper and lower ladder portions. The bottom of the lower portion 14 is also provided with a transverse pipe 36 around which the ex tensions 17 of the vertical elements 16 may be wound for securing the pipe 36 to the ladder. Pairs of washerlike elements 21 may also be arranged on the pipe 36 for retaining the stiles in proper position. The front row 32 of the lower portion 14 may also have integral extensions 19 of the vertical elements 17 in the rear row 32. The vertical elements 19 in the front row 30 preferably extend upwardly to the pipe 28 and may be wound on this member and on the elements 16, 17 in the upper and lower portions, as seen in Figures 3 and 4. The front row 30 also preferably includes horizontally disposed rungs 38 connected to the vertical elements in this row and coplanar therewith, It will be understood that the vertical elements in the upper and lower ladder portions 12, 14 may be separate and distinct from each other and need not be integral. However, the integral construction described has been found to be very economical and highly satisfactory.

Disposed between the front and rear rows 30 and 32 of the lower ladder portion 14 are resilient spacers 40. These spacers 40 preferably are arcuate segments of conventional automobile rubber tires, arranged in a uniform and inverted fashion and are connected to the rungs and stiles of the lower ladder portion 14 in any suitable manner, such for example, as by chains or cords 42 connected to the netting and extending through said spacers, as seen in Figure 4. Each side end of the lower ladder portion 14 (as viewed in Fig. 1) is provided with horizontally disposed rungs 48 (see Fig. 2). These rungs 48 preferably are rigid and are suitably secured to the vertical elements 17, 19. These latter rungs 48 lie in vertical planes perpendicular to the vertical planes defined by the coplanar vertical elements and rungs in the front and rear rows 30, 32 of the lower portion 14. Arranged at the bottom of the ladder and secured to the lowermost pipe 36 are a plurality of weights 50. These weights may be connected to and extend from the pipe 36 into the water by means of chains 51, as seen in Figures 1 and 2, and are intended to maintain the suspended ladder 10 in a tensioned or taut condition and to resist any lateral movement thereof.

When it is intended to transfer men from a marine vessel or ship 52 to the barge 11, or vice versa, the vessel 52 is first navigated to a position adjacent the lower ladder portion 14, such as that shown in Figure 2. With the ladder maintained in a tensioned condition by the weights 50, a transfer of men is effected by a direct mounting of the rungs 48' on each side of the lower ladder portion 14 whereby any pitching or rolling of the vessel against the front row 30 of this portion 14 will not injure the men climbing the side rungs 48 since they will be out of the plane of said front row.

In this regard, the resilient spacers 40 will be deformed by movement of the ship 52 against the front row 30 causing little or no deformation or movement of the rear row 32 of the lower portion 14. That is to say, the flexible front row 30 and spacers 40 will be deformed by movement of the vessel thereagainst, whereas the rear row 32 will experience very little or no deformation whereby the major portion of the ladder will remain in a generally upright, substantially stationary position under most conditions. The men climbing the ladder, therefore, will not be disturbed by a rocking movement thereof, which rocking would occur in conventional nettype ladders. It will thus be seen that the spacers 40 in the lower ladder portion 14 function both as a resilient fender for the ship 52 and as a shock absorber for the ladder.

It is intended that the lower ladder portion 14 be of sufficient height to extend above the side of the ship 52 a considerable distance, as shown. It thus will be seen that the flexible ladder structure of the present invention provides a safe and simple method for enabling the transfer of men between an elevated ofi-shore platform and a ship.

In the event that it is intended to increase the rate of departure of men from the ship 52 onto the ladder 10, an accommodation platform or framework 54 may be secured to and behind the rear row 32 of the lower ladder portion 12, as seen in Figure 2. This platform may be constructed of a metal-grating or any suitable material and its rear portion is preferablysuspended from the pipe 26 by ropes 56. By means of this ararngement, the men leaving the boat may move immediately to the accommodation platform 54 and wait on such platform before ascending, until either side of the lower ladder portion 14 is clear of any other men. In this manner, it will not be necessary to wait until each man has climbed the side rungs 48 before the next man can leave the boat; instead, each man may go directly to the accommodation platform 54 which can be accomplished expediently for a number of men, and the ascent may even be delayed until after the ship 52 has actually departed from its position adjacent the ladder, Likewise, in descending the ladder 10, the accommodation platform 54 may be utilized as a safe waiting station for men to be transferred to the ship 52. Additionally, the horizontal elements 34 in the rear row 32 of the lower ladder portion make it possible for the men waiting on the accommodation platform 54 to ascend the rear row 32, if desired, since this row will also be safe from any pitching and rolling of the vessel 52.

It should thus be apparent that the structure described herein completely and effectively carries out the objectives of this invention but it is not intended that the invention be limited to such a structure since various changes in the size, shape and arrangement of the parts thereof will be obvious to those skilled in the art. It is therefore our intention that the invention be measured by the scope and spirit of the appended claims.

We claim:

1. A net-like ladder for the transferring of passengers between an elevated platform at sea and a marine vessel anchored adjacent thereto, said ladder comprising: an upper portion and a lower portion; means for suspending said ladder from the platform; said upper portion of said ladder being defined by a plurality of vertical, flexible coplanar elements and vertically-spaced, horizontal flexible elements arranged between said vertical elements and coplanar therewith; said lower portion of said ladder being defined by two laterally-spaced, coextensive rows of vertical, flexible elements, means arranged in each row for joining together said lastnamed vertical elements and vertically-spaced, horizontal elements connecting the outermost vertical elements in one of said rows to the corresponding vertical elements in the other of said rows, the lower portion of the ladder being adapted to rest against the side of the vessel and extend thereabove.

2. The structure defined in claim 1 wherein resilient spacer means are arranged between the rows of vertical elements in the lower portion of the ladder.

3. The structure defined in claim 2 wherein the ladder comprises a first cylindrical rigid member disposed transversely at the upper end thereof and resting against a side of the elevated platform; and wherein a second cylindrical rigid member is arranged parallel to said first member and connected to the ladder intermediate the ends thereof, said second member resting against the side of the platform, said members spacing the plane of the upper portion of the ladder away from the side of the platform; and wherein the means for suspending the ladder from the platform is connected to said first member.

4. The structure defined in claim 2 wherein the vertical elements of one row of the lower portion and the vertical elements of the upper portion of the ladder are integral and coplanar; the top of the lower portion being provided with a transverse, cylindrical rigid memher; the vertical elements of the other row of the lower portion connecting said last-named rigid member to the vertical elements of the upper portion.

5. The structure defined in claim 4 wherein a tra'nsverse, cylindrical n'gid member is constructed at the bottom of the lower ladder portion; and wherein weights are suspended from said latter member to tension the vertical elements of said ladder.

6. The structure defined in claim 5 wherein the vertical elements in the one row of the lower portion of the ladder are integral with the vertical elements in the other row of the lower portion; the vertical elements being wound around the rigid member at the bottom of the lower ladder portion and extending upwardly to the rigid member at the top of the latter portion.

7. The structure defined in claim 2 wherein the resilient spacing means comprises arcuate segments of inverted U-shaped configuration in transverse cross-section; and wherein means are provided for connecting 5 said spacing means to each row of the ladder.

8. The structure defined in claim 2 wherein a platform is arranged at the rear of the lower portion of the ladder to provide a station for passengers waiting to be loaded onto or unloaded from the vessel.

9. The structure defined in claim 8 wherein the ladder platform is suspended from the upper ladder portion.

10. A net-like ladder for the transferring of passengers between an elevated platform at sea and a marine vessel anchored adjacent thereto; said ladder comprising a plurality of laterally-spaced rows of vertical elements; means for suspending said rows from the elevated platform; means arranged in each row for joining together the vertical elements therein; vertically-spaced, horizontal elements connecting the outermost vertical elements in one of said rows to the corresponding vertical elements in the other of said rows; and resilient spacing means disposed between said rows of vertical elements.

11. The structure defined in claim 10 wherein means are provided at the bottom of the ladder for holding said vertical elements in a tensioned position.

of the lower portion 12. A net-like ladder comprising: a plurality of spaced, coextensive rows of interconnected and flexible coplanar elements, said rows being of generally rectangular configuration; spacer means connected to the elements in said rows and disposed therebetween, said spacer means comprising a plurality of equally spaced resilient members; and rigid ladder rungs connected to said rows at opposite, outermost sides thereof, the rungs on each side of said rows being coplanar.

13. The structure defined in claim 12 wherein at least some of the elements in one of the rows are integral with at least some of the elements in another of said rows.

References Cited in the file of this patent UNITED STATES PATENTS 283,969 Frisbie et a1. Aug. 28, 1883 480,518 Roberts Aug. 9, 1892 732,946 Johnson July 7, 1903 2,343,123 Dahlander Feb. 29, 1944 2,385,824 Margolin Oct. 2, 1945

Images