GB2099397A - Fire fighting equipment - Google Patents

Abstract

A fire fighting tower is intended to be mounted on a floating vessel for fighting a fire on an offshore production platform and comprises an access tower having a gangway (30) to enable personnel to be moved to the vicinity of the mouth of the well. Not all drilling platforms are of the same height and the desired height of the access tower will vary with the tide. The gangway (30) is built of telescopically collapsible sections (32,34) and is mounted on a carriage (20) which is movable by a lifting mechanism up and down a vertical tower (10). The gangway (30) is pivotable relative to the carriage about both vertical and horizontal axes. The gangway (30) thus has several degrees of freedom and a working platform (38) at the end of the gangway (30) can be positioned with accuracy to place fire fighting personnel at the desired location. <IMAGE>

Description

SPECIFICATION Improvement in fire fighting equipment The present invention relates to a fire fighting tower to be mounted on a floating vessel to assist in fighting a fire on an offshore production platform.

A serious risk in the operation of offshore production platform is the possibility of a well blow-out. It has been proposed to construct on a semisubmersible service vessel an access tower with a gangway to allow personnel to be moved in safety to the vicinity of the mouth of the well.

There is however a problem that not all the drilling floors are at the same height as each other and furthermore, as the access tower is on a floating vehicle while the oil rig is tied to the sea bed the relative height of the drilling floor will vary with the tide.

According to the present invention, there is provided a fire fighting tower intending for mounting on a floating vehicle such as a semi-sumbersible vessel which comprises a gangway built of telescopically collapsible sections and mounted on a carriage which is movable by a lifting mechanism up and down a vertical tower, the gangway being pivotable relative to the carriage about both vertical and horizontal axes.

The gangway thus has several degrees of freedom and the end of the gangway can be positioned with accuracy to place fire fighting personnel at the desired location.

Preferably, the tower further includes a supply pipe to enable water to be sprayed onto fire fighting personnel on the gangway and to provide a high pressure flow of "mud" to allow the fire to be fought.

In the particularly preferred embodiment of the invention, the tower comprises three vertical columns interconnected by struts, two of the columns serving to guide the gangway carriage and the third being of larger section than the first two.

The use of a tower having this construction enables the required strength to be obtained while minimising the weight of the structure.

If desired, a second lift mechanism may be provided on the tower for raising fire fighting materials.

Conveniently, there is placed at the top of the fire fighting tower a control cap from which an operator may control the lifting and tilting of the gangway.

The invention will now be described further, by way of example, with reference to the accompanying drawings in which: Figure 1 is an elevation showing the gangway in an extended position, and Figure 2 is a plan view of the fire fighting tower in Figure 1.

In the drawings, there is shown a fire fighting tower which comprises a tower 10 which as seen in Figure 2 is formed ofthree columns 12, 14 and 16 arranged at the corners of an equilateral triangle.

The column 16 may if desired be of larger cross section than the remaining two. The tower is fixed at its lower end in a suitable fashion to a semisubmer siblevessel. In order to provide a suitable anchorage of the tower to withstand the considerable stresses it is invisaged that the columns may be extended through more than onefloorofthesemisubmersible vessel. The tower 10 serves to guide a carriage 20 movable up and down the tower and supporting a telescopically collapsible gangway 30. The carriage 20 incorporates a swivel mechanism to allow the gangway to be pivoted about a vertical axis the movement being effective by means of a motor (not shown) mounted on the carriage 20.The telescopic gangway 30 may additionally be pivoted about a horizontal axis relative to the carriage 20, this movement being controlled by a jack 22 fed with hydraulic fluid through a pipe 24. The gangway is formed of a first section 32 formed with tracks on which are guided wheel secured to a second section 34 of the gangway. Further tracks on the two sections of the gangeway 30 serve to guide a sliding trolley 36 for supplying materials to personnel standing on a platform 38 on the end of the gangeay 30.

The carriage 20 can move up and down the tower 10 the movement being effected by a lift mechanism (not shown) which may either be mounted on the carriage 20 or on the tower 10. The operation of the lift and the gangway is controlled from a cab 40 at the top of the tower. Also arranged at the top of the tower is a fire monitor 42 which is supplied with water from the semisubmersible vessel and sprays water constantly along the gangway for the protection of personnel. A mast 44 carries warning lights for aircraft.

On another side of the tower, a second lift mechanism 50 is provided comprising a hoist 52 and a platform 54. The platform is guided on rails 56 and is intended to carry fire fighting materials to the personnel on the gangway 30.

In use, it is necessary to supply various fluids, such as mud, for use by the fire fighters and these may either be fed through pipes accomodated within the tower or preferably passing through the columns 12, 14and 16.

A staircase 60 is provided to enable access to the cab 40. The advantages offered by the tower of the present invention reside in the fact that a single semisubmersible vessel can be used to carry fire fighting equipment for a variety of offshore production platforms having wells at different heights. The fire fighting personnel can be positioned with safety and accuracy and are offered protection from the fire by the telescopic gangway which is constantly cooled by the fire monitor. The semisubmersible will first be manoeuvred alongside the production platform and the gangway raised and tilted employing its many degrees of freedom until the working platform 38 is at the desired position. The platform 38 will then be brought to rest and the gangway will be supported at both its ends and will define a bridge between the offshore production platform and the semisubmersible vessel.

The invention offers the particular advantage of minimising the weight of the tower by utilising a construction employing only three vertical columns which nevertheless is capable of withstanding the considerable stresses applied to it by the cantile vered gangway.

CLAIMS (Filed 13 Apr 1982) 1. A fire fighting tower intended for mounting on a floating vehicle such as a semisubmersible vessel which comprises a gangway built of telescopically collapsible sections mounted on a carriage which is movable by a lifting mechanism up and down a vertical tower, the gangway being pivotable relative to the carriage about both vertical and horizontal axes.

2. A fire fighting tower as claimed in Claim 1, wherein the tower further includes supply pipes to enable water to be sprayed onto fire fighting personnel on the gangway and to provide a high pressure flow of mud to allow the fire to be fought.

3. A fire fighting tower as claimed in Claim 1 or 2, wherein the tower is constructed of three vertical columns interconnected by means of struts, a first and a second of the columns serving as means for guiding the said carriage.

4. Afire fighting tower as claimed in Claim 3, wherein the second and the third columns serve to support a second lifting mechanism for raising and lowering fire fighting materials to the level of the gangway.

5. A fire fighting tower as claimed in any preceding Claim, wherein a cab is provided at the top of the tower from which an operator may control the position of the gangway.

6. A fire fighting tower as claimed in Claim 5, wherein a staircase is provided to allow access of personnel to the control cab.

7. A fire fighting tower constructed substantially as herein described with reference to and as illustrated in the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (7)

**WARNING** start of CLMS field may overlap end of DESC **. vered gangway. CLAIMS (Filed 13 Apr 1982)

1. A fire fighting tower intended for mounting on a floating vehicle such as a semisubmersible vessel which comprises a gangway built of telescopically collapsible sections mounted on a carriage which is movable by a lifting mechanism up and down a vertical tower, the gangway being pivotable relative to the carriage about both vertical and horizontal axes.

2. A fire fighting tower as claimed in Claim 1, wherein the tower further includes supply pipes to enable water to be sprayed onto fire fighting personnel on the gangway and to provide a high pressure flow of mud to allow the fire to be fought.

3. A fire fighting tower as claimed in Claim 1 or 2, wherein the tower is constructed of three vertical columns interconnected by means of struts, a first and a second of the columns serving as means for guiding the said carriage.

4. Afire fighting tower as claimed in Claim 3, wherein the second and the third columns serve to support a second lifting mechanism for raising and lowering fire fighting materials to the level of the gangway.

5. A fire fighting tower as claimed in any preceding Claim, wherein a cab is provided at the top of the tower from which an operator may control the position of the gangway.

6. A fire fighting tower as claimed in Claim 5, wherein a staircase is provided to allow access of personnel to the control cab.

7. A fire fighting tower constructed substantially as herein described with reference to and as illustrated in the accompanying drawings.