GB2187681A - Apparatus for launching a boat - Google Patents

Abstract

Apparatus for launching and retrieving a boat from a motorised land vehicle comprises a frame-like structure of boat width which tapers in the stern region (10.1), and comprising transverse members (11, 12, 13) connecting longitudinal members (10), supports (16, 17, 20, 21) for the boat in the conveying position disposed at the ends of the boat. Also it comprises a tilting device (23, 24, 25) for the frame, a cable gear (4, 26, 27, 28) and a gantry crane device (18) with a cross-beam (19). Inclined guide struts (21, 17) are disposed in the bow and stern regions. The support at the bow end comprises beams (20) for lowering and raising the bow of the boat. Slide rails (14) are mounted under the longitudinal members (10) and co-operate with corresponding rollers on the vehicle. Guide pulleys (28) are provided halfway up the gantry (18) and allow guidance of the cable (4), if required, which exerts a greater leverage on the frame. Lashing chains (32, 33) serve to secure the boat to the launching frame. <IMAGE>

Description

SPECIFICATION Apparatus for launching a boat The invention relates to apparatus for launching a boat, for example a military tug boat, from a motorised land vehicle such as a lorry into water and for retrieving it.

The apparatus is of the type comprising a frame-like structure which is substantially composed of two longitudinal members, transverse members connecting the longitudinal members, supports for the boat in the conveying position disposed atthe stern end and at the bow end of the boat, a crane device at the bow end, a tilting devicefortheframe and a cable guidance with a cable winch.

Numerous types of apparatus for conveying boats over land andfortheirsubsequentlaunching,that is letting the boat into the water, are known and are commonly used. Frequently, a special single-axle trailer pulled by a towing vehicle is used. For example, a frame comprising two longitudinal members is mounted on this trailer. The frame can betilted. Either rollers are mounted on the longitudinal members, on which the keel of the boat is supported and rolls thereon and/or a slide to which the bow ofthe boat is secured and which, operated by way of a cable winch, lowers the boat into the water or removes it therefrom once more.

Whereas in the arrangement just described, as illustratedforexample in DE Patent Specification No.

2843966, a ramp is formed along which the boat is pulled by means of rollers or a slide, other types of launching apparatus take the form of a downwardly open tubularframe with its own chassis. In these types of launching apparatus, as illustrated for example in DE Utility Model No. 7013928, the boat is suspended beneath the frame. For launching purposes the apparatus has to be manoeuvred right into the water. Therefore, if the boat is heavy, a special ramp has to be prepared in the region ofthe shore.

For military purposes, special motor boats, known as tug boats, are employed to tow pontoons, used for building pontoon bridges, inthewaterandto hold them stationary in the current. Whereas the pontoons are now conveyed on special lorries and these lorries directly let them into the water or remove them from the water, the associated tug boats are conveyed partly on individual lorries, partly on special single-axle trailers. In this case the bow ofthe boat is secured to a special slide which can slide on a ramp, the ramp itself being movable on a track device mounted on the lorry. Thistrack device can be raised and lowered hydraulically; the ramp can be tilted freely relative to the track device. A cablewinch is usedfor moving the ramp and slide with the boat, the cable being fastened to the slide.

The multiplicity of moving parts of the known types of launching apparatus and the complicated sequence of movements necessitated thereby means that the launching operation is a relatively lengthy procedure. Moreover, to find shore zones with a sufficiently flat and firm embankment, which offer suitable access to lorries is not always easy.

The known types of apparatus do not usually permit launching to take place on steep banks, or only to a very limited extent, so that special apparatus, for example the above-mentioned single-axle trailers must be used.

The present invention is based on the object of devising an apparatus for launching heavy boats, for example military tug boats, which enables launching to take place directly from the vehicle both on flat and steep shores, which is of simple construction, has only a minimum of moving parts and allows boats to be launched very rapidly.

According to the invention the distance between the two longitudinal members corresponds substantially to the width of the boat and narrows in tapered fashion in the stern region, the crane device is in the form of a gantry with a cross-beam, inclined guide struts are disposed in the bow region and stern region, the support at the bow end is intheform of beams for guiding and raising the bow of the boat, slide rails are mounted underthe longitudinal members and co-operate with corresponding rollers on the vehicle, locking devices are provided which locate the frame in its extended-out and, optionally, tilted position, lower and upper guide pulleys are provided on the gantry for a cable for moving the boat and simultaneously the launching apparatus, and lashing chains are fastened to the gantry and to laterai guide spars in the vicinity of the supports at the stern region.

In the apparatus according to the invention the launching frametogetherwith the boat securely lashed thereto is let down rearwards using the cable winch until the boat becomes buoyant in the water and floats. In this casewhetheror not at this instant the end of the frame is resting on the ground does not matter. Only now are the front and, optionally, rear lashing chains between the frame and boat released, whereupon the boat floats out of the launching apparatus under its own power. The frame is then hoisted back on to the vehicle by means of the single cable winch. No other mechanical or hydraulic lifting or tippling devices are required.

Preferably another guide pulley is provided approximately halfway up the gantry, to which the cable coming from the cable winch can be guided round if required. Atilting moment can thereby be appiied to the frame, so that the frame remains in a predetermined angular position even on a steep bank. This is particularly advantageous and importantwhen the boat is to be removed from the water. Here the boat floats into the launching frame under its own power, is initially loosely connected to the frame by means of the lashing chains and is pulled into its final position in the frame afterthe hauling cable has been attached. As soon as the boat has reached its position, the frame with the boat mounted thereon is pulled out of the water on to the vehicle.The entire procedure can thus be effected in a single hoisting operation and at high speed.

Preferably this continuous sequence of movement is assisted by the provision of a locking device,for example in the form of pins, which prevent any displacement ofthe frame in its extended-out position. This locking action is only released when, in the course of picking up the boat, the boat reaches its final position on the frame by means ofthe hoisting cable.

Preferably two cables are controlled by the single cable winch, namely one cable forthe right side of the gantryand oneforits left side andforthe guide pulleys provided thereon.

Preferably, the cable ends are guided on a separate lifting cross-beam which is provided with a type of crane hookto which the bow of the boat can be attached.

In the accompanying drawings: Figure 1 shows a launching apparatus in a perspective view; Figures 2 to 7 show separate stages in the use of the launching apparatus on a flat shore; and Figure 8shows the launching operation on a steep bank.

Figure 1 shows an apparatus 1 for launching a boat, such as a militarytug boat, from the loading area of a lorry. The apparatus substantially comprises two longitudinal members 10 on the bottom side which are joined to one another by cross-members 11,12 and 13. In the stern region portions 10.1 of the longitudinal members 10 are bent at an angle to one another so that, when placed on uneven ground, the tilting moment resulting therefrom is kept as low as possible.

Rails 14 are disposed under the longitudinal members 10 and they co-operate with corresponding rollers on the loading area ofthe lorry, whereby the entire launching apparatus 1 is rendered displaceable by rolling.

Lateral guide spars 15 are arranged in the stern region, which together with inclined guide struts 17 ensurethata boat can be floated into position so that it is seated centrally on supports 16 situated atthe stern region.

Agantry 18with a cross-beam 19 is provided at the bow end. Heretoo, inclined guide struts 21 and guide struts 22 on the bottom ensure that a boat is automatically floated into the correct position. On each side of the centre, beams 20 are arranged obliquelyforthe actual guidance and support ofthe bow of a boat. On the these inclined beams 20 the boat can slowly slide down from its support atthe bow end and be pulled up again.

Two parallel cable lines4,which are operated bya common winch, serve to displacethe launching apparatus 1 as well as for releasing and taking up a boat. After leaving the winch, the cable lines 4 initially pass over lower guide pulleys 26 to upper guide pulleys 27 and theyterminate at common lifting cross-beam 29; finally, the bow of a boat is hooked to a loop 30 of the cross-beam 29. This cross-beam 29 is only required if two parallel cables 4 are used. A simple cable hook suffices if a only single, centrally running cable is used.

Additional guide pulleys 28, over which the cables 4 can pass when so required, are provided approximately halfway up the gantry 18. This cable guidance is used whenever a tilting moment is to be applied to the launching apparatus 1. This is always the case when launching is to take place on a steep bank where the ends 10.1 ofthe longitudinal members 10 cannot be supported on the ground. By passing the cables 4 over the guide pulleys 28, the launching apparatus 1 can be maintained in the desired angular position and/or let down slowly until the boat floats.

The lifting cross-beam 29 can be temporarily suspended from a hook of the cross-beam 19 ofthe gantry 18 by means of a further loop 31, so that its own weight does not load the cable lines 4when they are guided by hand round the guide pulleys 28.

To enable the launching apparatus 1 to be secured on the loading area of a lorrywhilst being transported by road, without precluding its capacity for longitudinal displacement, the longitudinal members 10 are provided with vertical retaining means 23 which co-operate with corresponding counterparts on the lorry. To enable the launching apparatus 1 to be locked in longitudinal direction, corresponding horizontal retraining means 24 are provided. Locking pins 25 are provided so asto prevent any possibility of longitudinal movement of the launching apparatus 1 in the extended-out rear, end position, thereby facilitating the manoeuvring of a boat by means of the cables 4.

Lashing chains 32 and 33 are provided so as to effect a sufficiently secure connection between the boat and the launching apparatus 1 both for transportation by road and forthe launching operation.

Figures 2 to 7 illustrate a launching operation using the launching apparatus 1.

In Figure 2 a lorry 3 with a launching apparatus 1 and a boat 2 lashed thereto is being reversed along the shore region 6 into the water 5 until it approximately reaches the position shown in Figure 3. The rear lashing chains 33 have already been released sothatthe rear end of the boatcanfloat freely.

Thelaunching apparatus 1 and the boat2 are let down rearwardly by means of the cable 4, which is operated by a cable winch 8 and is secured byway of the lower guide pulley 26. As soon as the centre of gravityofthe launching apparatus 1 and the boat2 has exceeded the rear limit of the loading area ofthe lorry 3, the apparatus 1 tilts without requiring any special hydraulic equipmentforthis purpose.

FigureS shows the launching apparatus in its end position. The ends 10.1 ofthe longitudinal members 10 rest on the 9 round.

In Figure 6 the front lashing chains 32 between the lauching apparatus 1 and the boat 2 have been released and, by further slackening of the cable 4, the boat is let down from its support atthe bow end by way of inclined beams 20 until it is completely floating.

Afterthe hoisting cable 4 has also been released from the bow of the boat 2, the boat can float away from the launching apparatus 1 under its own power, as illustrated in Figure 7. By winding upthecable4 by means of the cable winch 8 the launching apparatus 1 is hoisted back on to the loading area of the lorry 3, whereupon the lorry can then be driven awayfrom the shore region.

Figure 8 shows a position during the launching procedure corresponding to Figure 5 but at a steep bank7wheretheends 10.1 ofthelongitudinal members 10 cannot rest on the ground. Additional care has to be taken here to ensure that the rear lashing chains 33, which in this procedure are not immediately lossened, can be disconnected during subsequent unhooking.

Upon paying out the cable 4 by means ofthe cable winch 8, the stern ofthe boat 2 and the launching apparatus 1 are together lowered slowly into the water 5 until the boat floats; at this pointthe launching apparatus 1 is temporarily secured to the boat 2 by means ofthe rear lashing chains 33 and is thereby prevented from being tipped over. Firstlythe lashing chains 32 at the bow end are then released and the bow is lowered on to the surface ofthe water by paying out more of the cable 4. After relasing the cable 4from the bow of the boat, the cable 4 is then drawn back up to the gantry 18.

Afterthecable4 has been guided roundthe additional guide pulleys 28, the launching apparatus 1 is tilted slightly upwards, the rear lashing chains 33 are released and the boat 2 floats away from the launching apparatus under its own power.

To retrieve the boat from the water and replace it on the lorry, the above-described operations proceed in corresponding manner both on a steep bank7 and on a flat shore 6. Here too, the boat 2 is floated under its own power into the launching apparatus 1, is raised by means ofthe cable 4 initially at the bow end into its finai position and, finally, is pulled together with the launching apparatus 1 out of the water on to the loading area ofthe lorry 3. This continuous sequence ofthe operation for launching and retrieving can be quite rapid.

Claims (6)

1. Apparatus for launching a boat, for example a militarytug boat, from a motorised land vehicle such as a lorry into water and for retrieving it, comprising aframe-like structure which is substantially composed of two longitudinal members, transverse members connecting the longitudinal members, supports for the boat in the conveying position disposed at the stern end and at the bow end ofthe boat, a crane device at the bow end, a tilting device fortheframe and a cable guidance with a cable winch, wherein the distance between the two longitudinal members corresponds substantially to the width of the boat and narrows in tapered fashion in the stern region,the crane device is in the form of a gantry with a cross-beam, inclined guide struts are disposed in the bow region and stern region, the support atthe bow end is in the form of beams for guiding and raising the bow ofthe boat, slide rails are mounted underthe longitudinal members and co-operate with corresponding rollers on the vehicle, locking devices are provided which locate the frame in its extended-out and, optionally, tilted position, lower and upper guide pulleys are provided on the gantry for a cable for moving the boat and simultaneously the launching apparatus, and lashing chains are fastened to the gantry and to lateral guide spars in the vicinity of the supports at the stern region.

2. Apparatus as claimed in Claim 1, wherein another guide pulley is provided approximately half way up the gantry.

3. Apparatus as claimed in Claim 1 or 2, wherein two cables are guided in parallel.

4. Apparatus as claimed in Claim 3, wherein both cables are guided on a lifting cross-beam for attachment to the bow of the boat.

5. Apparatus as claimed in Claim 1,2,3 or4, wherein the locking device is in the form of pins.

6. Apparatus substantially as herein described with reference to and as shown in the accompanying drawings.