GB2353259A

GB2353259A - Floating boarding gangway for boats

Info

Publication number: GB2353259A
Application number: GB9919437A
Authority: GB
Inventors: Francis Peter Morrill
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-08-18
Filing date: 1999-08-18
Publication date: 2001-02-21
Also published as: GB9919437D0

Abstract

A boarding gangway comprises a boarding platform (2) having an inflatable and deflatable buoyancy chamber (1) attached to its underside which when inflated is lowered into the water and allows the boarding platform to float. The buoyancy chamber (1) is provided with flexible sides (5), rigid panels (6), guides (7 and 8) and latches (9) which allow the buoyancy chamber to be inflated so as to give the desired shape and to be deflated to provide for stowing.

Description

2353259 FLOATING BOARDING GANGWAY FOR BOATS.

This invention relates to a floating boarding gangway for boarding large yachts and boats.

Boarding gangways which form part of a yachts equipment and are deployed from either the stem or side of the vessel are well known pieces of equipment.

They are used to board the vessel from either the quay side, a tender or from the water. These gangways are generally stowed either on deck, at the stem or within the hull of the vessel. They are deployed manually, mechanically or hydraulically. When deployed they provide either a flat walking surface (a gangplank) or a set of stairs, normally with an upper platform at or near deck level and a lower platform above the water (a boarding or bathing platform).

These gangways have the problem that when deployed as a gangway for boarding from a tender or from the water the lower platform is positioned near the surface of the water and is rigid to and follows the motion of the vessel. A tender (or swimmer) coming alongside the gangway would be experiencing the wave motion or swell. The difFerent motions of gangway and tender (or swimmer) can give rise to a hazardous situation where the tender (or swimmer) can be drawn under the lower platform as the vessel roles and coincides with the trough of a wave.

Also transferring from a tender (or the water) to the gangway can be difficult and hazardous.

An object of this invention is to provide a gangway where the lower platform has attached to the underside an inflatable and deflatable buoyancy chamber. Thus allowing the bottom platform to float making boarding easier and safer. Whilst still providing a gangway which is quick and simple to operate and stows within the minimum amount of space.

The addition of an inflatable buoyancy chamber to a boarding gangway provides several significant advantages:

Improves the motion of the lower platform for boarding.

Prevents the possibility of a tender or swimmer getting under the lower platform.

Maintains the lower platform height relative to the water.

Provides a more stable platform.

Provides a large soft fender around the lower platform.

Reduces cantilevered loads exerted by the gangway on the vessel.

2 Accordingly this invention provides for the addition of an inflatable (and deflatable) buoyancy chamber suitably attached to the underside of the lower platform of a boats boarding gangway.

The buoyancy chamber comprising of rigid panels with rubberized fabric sides suitably attached to form an airtight chamber. Guide means for positioning the rigid panels during inflation and deflation to ensure the rubberized fabric sides attain the correct shape both when inflated and deflated. Means for inflating and extracting all the air from the buoyancy chwnber.

A preferred embodiment of the buoyancy chamber will now be described with reference to the accompanying drawings in which:

FIGURE 1. Shows the side view of a typical gangway arrangement with the buoyancy chamber (1) attached and inflated.

FIGURE 2. Shows a section through the lower platform (2) and inflated buoyancy chamber (1) taken on the centre line.

FIGURE 3. Shows a section through the lower platform (2) and deflated buoyancy chamber (1) taken on the centre line.

FIGURE 4. Shows a section through the lower platform (2) with the buoyancy chamber (1) fully inflated.

FIGURE 5. Shows a section through the lower platform (2) with the buoyancy chamber (1) partially deflated.

FIGURE 6. Shows a section through the lower platform (2) with the buoyancy chamber (1) fully deflated.

When inflated the lower platform (2) and buoyancy chamber (1) would be lowered into the water and allowed to float, while the stairway section (3) forms the transition between the floating lower platform (2) and upper platform (4) or deck of the vessel.

Due to the construction of the buoyancy chamber (1) and the addition of the rigid panels (6) as the chamber is deflated it would automatically retract and stow within the lower platform (2). Means are provided for inflating and deflating the buoyancy chamber.

The buoyancy chamber (1) typically comprises:

Flexible airtight sides of the chamber (5).

Rigid top and bottom panels (6).

Flexible straps between the top and bottom panels (7).

3 0 Folding guide arms between the top and bottom panels (8).

Sprung latches (9) to secure the buoyancy chamber when deflated..

A suitable pneumatic pump to inflate and deflate the chamber (10 not shown).

Suitable pneumatic valves (11 not shown) to retain the pressure in the chamber when inflated and maintain a partial vacuum when deflated.

Suitable piping (12) between the chamber, valves and pump.

The sides (5) of the buoyancy chamber (1) would be made from a rubberized fabric material similar to that used to make inflatable boats. The sides are suitably attached to two rigid panels (6) made from a fiber reinforced plastic material or similar which form the top and bottom of the buoyancy chamber.

Flexible straps (7) are provided which are attached to the top and bottom panels (6) and are of a suitable fixed length such that when the chamber is inflated the top and bottom panels (6) are held by the straps (7) at a suitable distance apart to allow the sides (5) to attain the desired inflated shape.

Folding arms (8) are provided which are attached to the top and bottom panels (6) and ensure correct alignment of the top and bottom panels as the air is withdrawn from the chamber.

Sprung latches (9) are provided suitably attached to the top and bottom panels (6) or incorporated into the folding arms (8) to hold the panels together when all the air is extracted from the chamber.

The buoyancy chamber is inflated and deflated by means of the pneumatic pump (10) and valves (11) which would preferably be located on board the boat and suitably piped (12) to the buoyancy chamber (1).

During deflation of the buoyancy chamber (1) the pneumatic pump (10) would be capable of removing the air from the chamber and creating a partial vacuum. This partial vacuum would act on the internal surfaces of the sides (5) and top and bottom panels (6) drawing them together as the air is removed creating sufficient attraction to engage the sprung latches (9).

During inflation the air pressure acting on the internal surfaces of the buoyancy chamber (1) would be sufficient to disengage the sprung latches (9).

When deflated the sides (5) and panels (6) of the buoyancy chamber (1) would retract into the underside of the lower platform (2) and the sprung latches (9) would engage such that when the buoyancy chamber was deflated the gangway could be used as a conventional gangway or gangplank.

4

Claims

CLAIMS.

1. The addition of an inflatable and deflatable buoyancy chamber suitably attached to the underside of the lower platfonn of a boats boarding gangway. The buoyancy chamber comprising of rigid panels with rubberized fabric sides suitably attached to form an airtight chamber. Guide means for positioning the rigid panels during inflation and deflation to ensure the rubberized fabric sides attain the correct shape both when inflated and deflated. Means for inflating and extracting all the air from the buoyancy chamber.

2. An inflatable and deflatable buoyancy chamber as claimed in Claim 1. Wherein guide means are provided in the form of flexible straps suitably attached to the rigid panels of fixed length such that when the chamber is inflated the rigid panels are held at a suitable distance apart to allow the sides to attain the desired inflated shape.

3. An inflatable and deflatable buoyancy chamber as claimed in Claim 1. Wherein guide means are provided in the form of folding arms suitably attached to the rigid panels to ensure correct alignment of the panels as the air is withdrawn from the chamber.

4. An inflatable and deflatable buoyancy chamber as claimed in Claims 1,2 and 3. Wherein sprung latches are provided suitably attached to the rigid panels or to the folding arms to hold the panels together when all the air is extracted from the chamber.

5. An inflatable and deflatable buoyancy chamber substantially as described herein with reference to Figures 1 to 6 of the accompanying drawings.