WO2016116771A1

WO2016116771A1 - Multifunctional aft door

Info

Publication number: WO2016116771A1
Application number: PCT/HR2015/000001
Authority: WO
Inventors: Vuksan IVICA
Original assignee: Condura Yachting
Current assignee: Condura Yachting
Priority date: 2015-01-19
Filing date: 2015-01-19
Publication date: 2016-07-28
Anticipated expiration: 2017-07-19

Abstract

The innovation reveals a hydraulic aft door which, in addition to preventing the penetration of sea at the stern, also has the function of a tender lifter, gangway, platform for easier access to the water, and for carrying the tender. When mounted onboard, it takes up far less stern space than the currently known solutions. The aft door according to the invention is intended for mounting on sailboats with an open transom.

Description

MULTIFUNCTIONAL AFT DOOR

TECHNICAL FIELD

The invention pertains to a device that is part of the vessel equipment, and may be used as a lift, tender support, gangway, swimming ladder, additional space for marine activities and the aft door. The device is, in principle, intended for all types of sailboats longer than 10 metres, but can also be used on other types of vessels, and other types of coastal structures.

TECHNICAL PROBLEM

The aft of a sailboat is the space at the stern of the vessel which serves various purposes. It is comprised of the cockpit, where, as a rule, the commands and the helm are found, and the transom which closes off the cockpit and prevents the penetration of water into the vessel interior. Various devices are mounted on the transom, for the reason that this does not hinder navigational safety. Such devices include: tender lift, outboard motor rack, gangway, swimming ladder, platform that serves for various aquatic activities, and the aft door. All these devices are, as a rule, necessary, however, due to their number and dimensions, they take up a great deal of space on the transom, and are neither functionally nor visually optimal. The technical problem that this invention resolves is that this is a multipurpose hydraulic device that is installed at the aft of the vessel, and unites several devices, creating a simpler and more reliable solution than the current devices in their individual solutions.

A lift on a vessel intended for entertainment, sport and recreation is used for lifting and transferring cargo to the desired position, so as to ensure its proper and safe storage. The most common cargo lifted is the tender with outboard motor, and in exceptional cases, to raise persons out of the water in the case of an accident. In general, rollers and ropes are attached to two metal davits, most commonly mounted at a slanted angle on the transom. A halyard attached to the mast to which rollers and ropes are attached can also be used as a hoist. The shortcomings of such devices are seen in the following examples:

- the weight of the tender hangs under the davits and there can be a left-right shifting of weight on movement of the stern, which can cause cracking or separation of the davits from the transom. This can cause serious damage to the fibreglass, loss of the tender, or even loss of the vessel if the damage caused leads to a penetration of water into the vessel interior;

- small weight bearing in lifting is most often the result of thin walls of the rods of a maximum to 3 mm, and weak supports or insufficient support points;

- a high physical effort is required in lifting loads via the pulleys caused by the weight of the tender and outboard motor mounted on it. For that reason, the outboard motor is generally removed from the tender, making this task more demanding, as the person removing the outboard motor is required to stand in the tender in the water, which is very unstable, thus risking the chance of a fall into the water, the loss of the outboard motor and the chance of serious injury;

- access and use of the aft platform and passing over onto land are hindered, as the tender is secured laterally across the stern;

- handling the mooring ropes is hindered as the rods of the lift must be installed high over the edge of the transom, and the ropes are often caught up in these rods upon being cast to shore;

- the lift (rods) are visually unacceptable as the stick out vertically, and the pulleys and ropes give an untidy appearance.

The tender support can come in a variety of shapes, and are necessary to ensure that the tender is secured fixed during navigation to avoid hindering navigation. In most cases, these metal rods or V-shaped stands are made from various materials.

Shortcomings in the tender supports made from metal rods are, similar to the hoists, shown in the following examples:

- the load (tender) hangs under these rods and there can be a left-right shifting of the weight on movement of the stern, which can cause cracking or separation of the beams from the transom. This can cause serious damage to the fibreglass, loss of the dinghy, or even loss of the vessel if the damage caused leads to a penetration of water into the vessel interior; - due to the above instability of the structure, it is not possible to store heavy loads at a higher heights, which is very important due to tilting of the sailboat during sailing. In the case the tender is secured at a low point, it will drag along the surface of the water;

- small weight bearing is the result of thin rods and weak supports or insufficient support points;

- the outboard motor generally must be removed from the tender, which is a demanding task, as the person removing the outboard motor is required to stand in the tender in the water, which is very unstable, thus risking the chance of a fall into the water, and loss of the outboard motor and the chance of serious injury;

- handling the mooring ropes is hindered as the rods of the hoist must be installed high over the edge of the transom, and the ropes are often caught up in these rods upon being cast to shore.

The V-shaped stand is usually mounted on the deck under the mast, which presents a problem during sailing. The ropes of the jib, called lines, in the majority of cases when let out will catch under the tender.

If the sail is taut under great wind force, the rope will raise the tender, and there is a high probability it will be lost. When this happens, a crew member is required to untangle and unlatch the line, which is a very dangerous task in choppy seas.

Raising the tender to this position under the mast is also demanding. The outboard motor must first be removed, then the halyard is attached to the mast and ropes and pulleys on its end. This type of raising and positioning the tender requires two persons.

The gangway is necessary for vessels when they dock on the stern. Docking on the stern is the most common form of docking for vessels longer than approx. 20 meters throughout much of the world, due to the greater security of docking this way and a lesser length of dock occupied. Regardless of the type of docking, all gangways take up space on the aft and hinder the use of the aft for other purposes. The simplest solution is a manual gangway which can be folded away in a more complex variation. Another solution is a hydraulic gangway mounted on the exterior of the stern, which is able to be raised and extend the walking surface. The most complex solution (most often under the aft deck) is a hydraulic gangway incorporated in the vessel, which is retracted into the vessel when not in use.

The shortcomings of these devices are shown in several examples:

Simpler gangways are characteristic, above all, for their complexity in their installation. Gangways are typically made of wood and fibreglass and need to be a certain length and weight, and it is not simple to position it on the dock or shore from the aft of the vessel prior to tying the lines. Concretely, these types of gangways can have the following shortcomings:

- uncertain passage over the gangway due to the narrow walking surface and instability of the gangway itself;

- difficulty in opening, installing, folding and putting away. There is not sufficient space on a sailboat for putting away equipment of these dimensions, and the gangway is typically tied onto the rail, which can hinder the use of lines during sailing;

- occupies space on the aft, and hinders use of the aft.

Hydraulic gangways must be mounted onto one side of the transom as the opening is typically in the middle of the transom, which disturbs the balance of the sailboat. Furthermore, shortcomings of hydra lic gangways are as follows:

- mounted relatively high on the transom due to the hydraulic cylinder, and therefore occupies useful space on the platform;

- difficult access from the sailboat to the gangway, as the gangway is set up on the side.

As a rule, the aft railing hinders access to the gangway;

- if the vessel does not have an aft opening, then the gangway is mounted in the middle, and then a large surface of the aft platform cannot be used;

- relatively high complexity and price;

- takes up a significant volume under the aft deck, has a large mass and exceptionally high device complexity.

Aft swimming ladders are necessary for unhindered access to the water and tender during water activities. The current forms of aft ladders do not fully satisfy all needs, and come in a variety of forms, such as straight, folding and telescopic.

The shortcomings of such devices are shown in the following examples:

Straight ladders:

- take up usable space, are mounted on one side of the aft platform with a joint via which they are flipped over the edge of the transom;

- due to the weak profile of the tubes used and the insufficient supports, they can often bend or break when used by heavier persons;

- they are not adapted for children and persons with reduced physical capacities, for the reason that the stairs have a narrow step area and in use stand completely vertical in relation to the platform;

- clumsy to use, when lowering and raising from the water requires the use of lines;

- unsightly.

Folding and telescopic:

- clumsy to use, mounted in a special storage under the lid in the middle of the platform;

- prior to use, the storage lid must be opened to allow the stairs to be unfolded over the edge of the platform, and then the lid is closed. For raising, the same actions are required in reverse order;

- no additional supports, and can often bend;

- for the above reason, telescopic ladders often jam when pulled out;

- load bearing is questionable, and for that reason, manufacturers apply warning stickers of the possibility of such accidents that can cause the sudden drop of a person, which could lead to serious injury.

The aft platform is a lowered area behind the transom that serves for easier access to the water's surface, and is used for additional aquatic activities. There are several types: added-on or built- in.

Add-on platforms are used for older vessels and are made from a combination of stainless steel, and either wood or fibreglass. They are rarely used in new vessels, except in the catch type sailboat, where they are mounted using screws and are not a part of the hull.

Built-in platforms are divided into flat and recessed, and are found on modern sailboats and form a part of the hull.

In both types, the transom often has an opening in the middle for easier access to the platform. In flat platforms, the transom is to the very edge of the stern, and the width and depth of the opening is in fact the platform and as such is, as a rule, insufficient.

With recessed platforms, the transom is pulled forwards, giving a greater width, though the depth may not be high as this causes a loss of space in the cockpit. Therefore, in recent years, folding aft doors are often mounted. This solution has proven to be very good, as such doors fold downwards, and then serve as the aft platform.

The aft doors are mounted in the opening of the transom and serve to prevent the penetration of water from stern waves, and as a barrier that prevents falls of persons and the loss of equipment from the aft into the water. Initially, these were simple single or double doors fixed with hinges at the sides. Naval engineers then came up with a simple solution, and instead of having hinges at the sides of the door, they were mounted along the bottom of the door, and the door was then opened downwards as a ramp which, in that position, could be used as an aft platform. However, this solution has shortcomings that can be seen as follows:

- complicated handling; the aft door is quite heavy, and opening and closing the door requires physical strength, such as an electric winch or electric push cylinder.

- limited function (only additional space);

- inability to mount another device on the middle of the stern such as a hydraulic gangway;

- inability to use the platform if a tender is hanging on the davits

- when approaching the platform from a high dock, a large angle is created, which is dangerous for boarding and disembarking.

The technical problem that this invention resolves is, therefore, a device that is affixed to the aft of the vessel which unifies several individual devices, removes their shortcomings, and improves their function. The multi-purpose aft door, according to this invention, is made in such a way to have the function of a tender lifter, outboard motor carrier, gangway, swimming, and a platform that serves for various aquatic activities, and functions as an aft door that protects from choppy seas.

The multi-purpose aft door serves as a tender lifter. There is a need to use the tender from the sailboat in cases when the boat is not docked, but is instead anchored (or moored) near the shore, for transfer to the shore.

On recreational sailboats, the tender can be towed behind the stern, but not during inclement weather. Tying the tender to the vessel in the case of a sudden appearance of bad weather can be very dangerous. Furthermore, towing the tender can significantly complicate the manoeuvre of docking the boat at the stern. Therefore, the tender on a recreational sailboat is regularly raised onto the boat. On rental (charter) sailboats, the tender is regularly tied on the deck under the mast (and the outboard motor for the tender is regularly affixed to the aft rail of the sailboat), which compromises the use of the deck and front sails, making transport of the tender from the boat into the water and back very complex, and significantly reduces safety due to reduced visibility over the bow for the helmsman. On recreational sailboats used by owners, the tender is regularly tied laterally on the stern, or on special carriers (davits) on the stern, which in both cases can significantly hinder the use of the stern (access to water from the boat, docking at the stern) and demands the mounting of the said carriers (davits). This solution allows relatively rapid lowering of the tender into the water, but is very clumsy and subject to damage and is thus not used on rental sailboats. Furthermore, in tilting of the sailboat during sailing, all the equipment wider than the transom must be affixed at a higher position than the transom to avoid dragging on the water's surface due to the reduced angle.

The procedure of raising and lowering the tender using the multipurpose after door is very simple. The tender is affixed to the carrier of the platform door, and the clasps on the straps are opened, and the tender is reduced from the upper position horizontally to the water's surface, and below until the moment the tender is floating. At that time, persons may descend the ladder into the tender and can begin sailing. In raising the tender, the procedure is carried out in the opposite order: the tender is positioned above the V-shaped platform, and the hydraulics are started to raise the tender to the upper position, where it is ultimately secured using the safety hooks.

Similar devices are made by various manufacturers, such as H+B Tehnic, Besenzoni, and Opacmare, however they are constructed for the purposes of motor boats and are mounted under the water line, and are not suitable for sailboats. In sailboats, there is a similar device by the manufacturer Marine Lift Technology, however that product is intended for closed transoms and therefore does not close the transom, it does not have built in steps, nor can it serve as a gangway or swimming ladder.

The multipurpose aft door, unlike the usual devices, uses a hydraulic system instead of physical force to enable the lifting of heavy dinghies weighing up to 600 kg. With the increase in size in sailboats, the need for heavier dinghies and larger outboard motors is also increasing. One of the main barriers for their procurement is the difficulty in their manipulation.

Thanks to the hydraulic plant, the multipurpose aft door has a high raising and carrying force, and for that reason, it is not necessary to remove the outboard motor. As a rule, the multipurpose aft door can raise a jet tender that has an internal engine and, with petrol, weighs over 350 kg.

We are not aware of any similar device that uses the aft door as a dinghy lifter, sea ladder, and adjustable gangway. They are usually used in a lowered position only as a platform (manufacturers Jeanneau, Bavaria, Hanse).

The multipurpose aft door can raise the tender to a greater height than the usual devices, which is possible as the tender is held on the platform, which in the upper position is raised to the upper edge of the transom, thus allowing for unhindered navigation, without concern that the tender will drag on the sea surface during tilting while sailing.

The multipurpose aft door serves as a support for the tender, and ensures its secure fixation and storage during sailing. The supports upon which the platform is affixed are on the upper part of the door. The width and length of the platform on the multipurpose aft door allows for the installation of a V-shaped stand upon which it is simple to position the keel and to secure the tender using strapping that can be tightened around the tender. The device also features safety hooks that automatically lock the device in the upper position; during lowering, these are automatically opened by a small hydraulic cylinder.

With the use of the multipurpose aft door, the vessel is simply and easily stored on the stern, and therefore, it is not necessary to store it on the bow deck, and it does not obstruct visibility over the bow for the helmsman, and does not occupy any usable space on the vessel during sailing.

In the semi-lowered horizontal position of the multipurpose aft door, it is possible to use a portion of the platform, even when the tender is on the device, which is very useful when docking on the stern, when a person can stand on the door to cast lines towards the dock or shore. .

During opening, the multipurpose aft door extends outwards and serves as a gangway when docking on the stern.

The procedure of use is simple:

- After the docking manoeuvre, the multipurpose aft door is lowered into the water, and the tender is removed. At that time, the multipurpose aft door becomes a gangway. Regardless of the type of execution, every gangway takes up space on the stern of the boat and hinders the use of the stern, while the multipurpose aft door is, simultaneously, a gangway, platform, stairs and other mentioned functions.

SUMMARY OF THE INVENTION

There are many devices that are necessary on the aft of the sailboat; however, none to date offer so many functions in one. This technical solution optimises the simplicity of handling, visual appearance, and security of the use of individual devices.

We also expand the possibilities of its use: - constant horizontal position of the parts of the multipurpose aft door enable unhindered and safe movement,

- it can be adapted to various dock heights unlike other devices, so for high or low docks persons are not required to walk at an angle.

The multipurpose aft door serves for easier access to the water or tender. Upon lowering the device over the edge of the transom, it is lowered into the water. During the movement from the upper to lower position, wide stairs open up, which enable unhindered and safe access to the water or tender.

The multipurpose aft door also serves as a platform. In the semi-open and open position, the aft door becomes an stern platform, which does not obstruct the primary function of the vessel space, but instead expands it. Complete submersion of the platform into the water enables persons with reduced mobility or divers to rise up directly from the water's surface to the upper edge of the transom.

The platform of the multipurpose aft door, when in the water, also serves as a bathing area suitable for small children. The multipurpose after door is primarily a mobile aft door which prevents the penetration of water towards the cockpit, and serves as a barrier that prevents persons from falling or the loss of equipment from the stern into the water.

The multipurpose aft door is a device that when closed, according to this invention, due to its compactness and technical solution, is more visually acceptable that then mentioned individual devices.

STATE OF THE ART

The hydraulic tender platform lift is part of the production programme of various manufacturers, such as H+B Tehnic, Besenzoni, Opacmare, though they are not constructed for the purposes of motor boats and are mounted under the water line and are therefore not adapted for sailboats. For sailboats, Marine Lift Technology makes a similar device, though this is intended for closed transoms and therefore does not close the transom, and it does not have an integrated staircase and therefore cannot serve the function of a gangway or ladder to access the sea.

A tender lift for sailboats exists and is made by the manufacturer Marine Lift Technology, however it is intended for closed transom hulls and therefore does not close the transom, and a further shortcoming is that it does not have an integrated staircase. For that reason, it is not possible to climb up to the deck without activating the hydraulic system, and therefore cannot serve the function of a gangway or sea ladder.

A gangway in a similar form is produced by the company Opacmare {Transformer model), however, this gangway does not have the function of an aft door and due to its large dimensions is intended primarily for large motor boats. The transformer model is constructed to be fully folded away, while on a sailboat, it must stand vertically in order to achieve height.

The aft ladder is produced in a similar form by the company Opacmare {Automatic swimming ladders), though this does not have the function of an aft door.

Aft door - to date there has been no similar device that uses the aft door as a lifter, swimming ladder, and adjustable gangway. They are usually used only in lowered form as a platform (e.g. manufacturers Jeanneau, Bavaria, Hanse).

ESSENCE OF THE INVENTION

The primary intent of the device is to serve as a tender lifter, and when mounted on the vessel it takes up a much smaller area of the stern than the currently known solutions, and with its function, it becomes easier to manipulate with the tender.

The secondary intent of this device is that it can be used as a gangway, tender carrier, swimming ladder, additional space for marine activities and aft door to protect from waves.

The device can also have other intended purposes not described here, and can be used on vessels that have a space intended for carrying the tender, and can be taken apart to combine and use with other structures from where there is access to the water. DETAILED DESCRIPTION OF THE INVENTION

MULTIPURPOSE AFT DOOR or abbreviation (MAD) is the name for this device that serves to raise cargo out of the water, for easier access of persons to water and as a very simple and safe way of boarding or disembarking the vessel. The entire device is constructed to be an integral part of the aft door.

In the past, in small shipbuilding, the sterns of sailboats and motorboats have generally been constructed as a closed unit. The aft door appeared to enable easier access from the cockpit to the aft platform. Initially, these were simple single or double doors affixed to the sides with hinges. Then, naval engineers in small shipbuilding came up with a simple solution, to mount the hinges on the bottom of the door instead of the side, and the door could be lowered downwards like a ramp. This solution brought several advantages over previous versions.

Brief description of the drawings

Figure 1 is the upper position of the aft door, in which is serves as a carrier, e.g. of the tender.

Figure 2 is the position of the aft door in which it becomes the stern platform.

Figure 3 is the position of the aft door in which it takes on the function of a multipurpose lifting ramp.

Figure 4 is the swimming ladder that is built into the aft door. Figure 5 is one type of gear system used to move the ladder built into the aft door. Figure 6 shows of the sections of the device which move the ladder via a hydraulic system. Figure 7 shows the parts of the ladder. Figure 8 is the aft door and ladder in the position in which is serves as a gangway for boarding or disembarking onto raised docks.

Figure 9 is the position of the aft door in which it takes on the function of a multipurpose lifting ramp from another angle.

Figure 10 is another manner of raising and lowering the aft door with hydraulic cylinders in the stern.

Figure 1 1 is the aft door with hydraulic cylinders in the stern - side view.

Figure 12 is the aft door with hydraulic cylinders in the stern - side view with aft door in sea.

Figure 13 is the aft door with hydraulic cylinders in the stern - side view with closed aft door.

Figure 14 is the aft door with hydraulic cylinders in the stern - rear view with closed aft door.

Figure 15 is the aft door with hydraulic cylinders in the stern -view from above with closed aft door.

Figure 16 is the aft door with hydraulic cylinders in the stern - isometric view.

With reference to the relevant Figures 1 through 16, the invention can be described in the following manner.

The aft door (3) is simply raised and lowered and occupies no additional space.

The door (3) with built-in extension arms is activated via mechanical joints (2) installed in the aft of the stern (1) and moves from the upper vertical to the lower semi-angled position. The upper part of the door (3) contains the supports (4) upon which the platform (4') is affixed with the secured cargo in the horizontal position. The tender (5) on the platform with horizontal supports (4) achieves this horizontal position with the lever (6), and the entire system is controlled by hydraulic cylinders (7).

When the vessel is sailing, the tender is secured to the platform which is affixed to the supports (4) as shown in Figure 1.

In the lower position, the door becomes additional space and is used as a stern platform.

The aft door retains its fundamental purpose, and that is to protect against waves, and as a stern wall that prevents undesired falls into the sea from the stern.

Our innovation is an evolution in aft doors into a multipurpose aft device that enables retaining the existing functions of the aft door, and introducing new functions which include the following:

Installation of symmetrical joints (2) on the edge of the transom (1) and on the upper side of the door (9), extension arms (8) and support (4) enables the complete folding of the aft door over the edge of the stern. The aft door in the vertical and horizontal positions retains its primary function, though when it is folded over the edge (10) the door lowers to beneath the water's surface and becomes a multipurpose lifting ramp - Fig. 3

The level of the ramp in the sea for the entry/exit of crew into (from) the tender is shown in Figure 3. Upon entry of the crew, the ramp is lowered further into the sea to allow the tender to be driven with the crew.

The folding of the door towards the water surface is designed as a folding ladder (11), which uses a gear system (15,16,17), transmission shaft (18), sheave (20) and levers (14) to parallely open the ladder steps (12) and to enable easier access to the water, as in Fig. 4 and Fig. 5. The innovation of this device in comparison to existing devices is that by using the aft door as an integral part of the device, the cargo is raised to higher heights, and the support (4) in that position is secured with an automatic safety hook, which is of particular importance. Fig. 4 shows the extension arms (8) with reinforcements (21) of the built-in drive for the ladder in the aft door (3), which are currently not visible.

Figure 5 shows the driving gear (15), which welded to the support (4), and bears the circular motion onto the intermediate gear (16), which turns the driven gear (17,) which is fixed to the shaft (18), and the shaft (18) is connected to the sheave (20) which transfers the torque to the lever (19). The lever (19) transfers via a linear movement to the lever (14) in Figure 4, which opens and closes the ladder steps (12) such that they are constantly in a parallel position in relation to the platform (4).

Figure 5 shows one type of the cogged gears, though the transfer can also be achieved using hydraulics in the aft door. Figure 6 shows a recess (26) in the aft door (3), where the hydraulic device used to control the ladder is housed.

The hydraulic cylinder (22) in Figure 6 is aligned with the angle of movement of the aft door (3) and transfers the linear motion via the lever (14) onto the step levers (23), which are connected to the steps (12) in Figure (7), and circular movement is achieved via the pin (27). The ladder and aft door in the function of a gangway for raised dock positions (24) is shown in Figure 8. The sea is marked with the number 25 in Figure 8.

Here the ladder (12) is used for boarding/disembarking onto raised docks (24). The hydraulic cylinder (7) raises the support (4) using the extension arms (8), which are part of the aft door (3). The lever (6) achieves a constant horizontal position of the support (4) and the platform on it.

Movement of the entire system is made possible by a battery (28), and/or manual mechanism (29), and/or specially installed motor for the hydraulic system (30). It is natural that an expert in the field would imply the existence of a management unit box (31).

The second manner of raising and lower the aft door with the hydraulic cylinders in the stern of the boat is shown in Figure 11. Instead of on the final exterior part as already described, in this manner the movement of the extension arms (8) to which support arms (32) are affixed and connected to the clip of the hydraulic cylinder and the support of the hydraulic cylinder (34) is installed in the stern on both sides of the boat, Figure 1 1.

The lid of the recess (33) allows for rapid access to parts (14, 19, 20 and 22) that move the ladder steps (12) and for the purposes of maintenance. The movement of the ladder steps (12) has already been described: either by cog gears or hydraulics.

The basic parts of the device

1. Stern

The lower part of the stern is the site where the aft door is mounted, which in this solution takes on a multipurpose function

2. Extension arms

Serve to maintain the main support (4) in a constant horizontal position.

The stern platform, according to the invention, is used when the sailboat tilts during sailing, and any cargo in a lower position would catch and drag on the water's surface, hindering safe sailing, and in motorboats, and their use increases the size cockpit as the aft wall can be at the very edge of the stern, while when lowered, the door becomes a usable stern platform.

Claims

PATENT CLAIMS

1. The aft door (3) for sailboats and sailing ships with extendable arms moved via mechanical joints (2), wherein said door closes the transom (1) and the symmetrical joints (2) are installed above the sea surface at the edge of the transom (1) and on the upper part of the door (9), and on the extension arms (8) and support (3) thereby enabling complete folding of the aft door over the edge of the stern, which in the upper position the said door has the function of a support for a tender and/or outboard motor, in a horizontal or near horizontal position has the function of a gangway, and when folded over the edge (10) it is lowered to below the water surface and becomes a multipurpose lifting ramp.

2. The aft door (3) recited in claim 1, wherein the hydraulic cylinder (7) raises the support (4) with the use of the extension arms (8), which are part of the aft door (3), in which a lever (6) achieves the constant horizontal position of the support (4) and platform on it.

3. The aft door (3) recited in claim 2, wherein said door contains a folding ladder (11) whose steps (12) open using a gear system (15, 16, 17), via a shaft (18), sheave (20) and lever (14) thus enabling persons easier access to the water.

4. The aft door (3) recited in claim 3, wherein the driving gear (15) that is fixed to the support (4), transfers the circular motion onto the intermediate gear (16), and said intermediate gear onto the driven gear (17), which is connected to the shaft (18), and the shaft (18) is firmly affixed to the sheave (20), which transports torque to the lever (19), and the lever (19) transfers linear motion to the lever (14) which opens and closes the steps (12) of the ladder (11).

5. The aft door (3) recited in claim to, wherein said door contains a folding ladder (1 1) whose steps (12) open using a hydraulic cylinder (22) which is aligned with the angle of movement of the aft door (3) and via the lever (14) transfers linear movement to the levers (23) of the steps (12) which are attached to the steps (12), and the circular movement of the steps (12) is achieved via the pin (27).