GB2236661A - Improvement in or relating to abandonment suits - Google Patents

Abstract

A survival suit, has a weighted lower portion such that in use the wearer's body is inclined at an angle from the vertical as a result of the weight bringing the wearer's legs together and down in the water. The weight may be distributed about the suits' feet at 39 and/or legs at 38, 40 and will preferably be in the region of 2 to 5 kilograms. <IMAGE>

Description

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DESCRIPTION

IMPROVEMENTS IN OR RELATING TO ABANDONMENT SUITS The present invention relates to abandonment suits.

Abandonment suits are survival or immersion suits designed to be donned quickly, in emergency situations, by people who are invariably fully clothed. They are worn in association with life jackets. Existing specifications for life jackets however only require that a life jacket should right, i.e. turn face up, a person wearing standard clothing. The requirements are that a life jacket should:

1. Support the unconscious person in the water in a face-up position; 2. Incline the body at an angle of 20 to SO' from the vertical; 3. Provide a mouth-free board of 120mm or more and provide a reasonable measure of drowning prevention, and 4. Hold the head firmly in alignment with that of the torso of the wearer.

Workers, for example rig maintenance workers, will often be wearing garments that are extremely thick due to the conditions under which they work. Thus, abandonment suits have been made baggy to enable them to be donned quickly under emergency conditions and, according to current theory, to provide added buoyancy.

A report conducted by the Robert Gordons Institute of Technology on behalf of the U.K. Department of Energy found there to be serious shortcomings in the suit/jacket combinations currentlv available.

The results of their tests conducted on current suit/life jackets combinations (worn on mannequins) were designed to simulate an exhausted or unconscious person.

1. None of the twentyfour life jacket and immersion suit combinations were considered as providing an effective survival system for all anticipated phases of survival; 2. None of the twentyfour life jacket and immersion suit combinations proved effective in righting a face-down person so that his airway was clear of the water surface within five seconds; and 3. Whilst all of the life jackets were able to right the simulated exhausted or unconscious person wearing standard clothing, they were unable to function in combination with an immersion suit.

The report recommended that specific life jacket and immersion suit combinations be tested in realistic conditions to confirm that they provided an effective integral survival system.

It has been an object of the present invention to provide an abandornent suit/life jacket combination which overcomes the key problems outlined in that report.

The major problem faced was that of providingan abandoment suit/life jacket combination which would right an exhausted or unconscious person.

The problem faced with current suits was that due to their size. air trapped within the suit provided buoyancy in-unwanted places, and thus, if a person wearing the suit was to land face-down in the water, they would float face-down and the body would take a 11star jump" position, i. e. a position in which the arms and legs were splayed apart.

Current suits have tried to overcome the problem by incorporating air outlet valves into the suits but these require water pressure to force the unwanted air out and prove ineffective since when floating face-down in the water (due in part to the provision of a life jacket and in part to the inherent buoyancy of the suit itself).these valves do not operate.

Other suits have tried to achieve self-righting by adding additional buoyancy. These garments however have excessive bulk which in turn inhibits the wearer's movement.

By conducting studies on abandonment suits, in combination with life jackets, the present applicants have unexpectedly found that a suit can be adapted so that an unconscious wearer of the suit can be righted from a face down position.

They have found that. contrary to current practice, which aims to achieve self-righting by adding buoyancy to the suit, the buoyancy should as far as possible be provided by the jacket and the suit should be provided with means to counter buoyancy.

To enhance righting of a body, it has been found that it is easier to turn a body by moving it in a pendulum fashion rather than trying to create rotation about the longitudinal axis of the body. It is thus necessary to bring an unconscious person's legs together and down.

According to the present invention, there is provided a survival suit having a weighted lower portion or means thereon for attachment of weights thereto.

The weights may be permanently incorporated into the suit, or the suit may be provided with pockets into which appropriate weights might be added Preferably, the weights are in the form of a dense material, such as lead.

The amount of weight to be incorporated into the lower portion of the suit will depend directly upon various factors, the object being to achieve a slight negative buoyancy in the lower portion of the suit.

The factors which effect the amount of weight that is added will include, amongst other things:

1. The inherent buoyancy of the suit material.

This will in turn be effected by the materials type and its thickness.

2. The wearers weight, and 3. The waters condition (in cold conditions the water is denser and will provide more support) It will thus be appreciated that specific details in the way of examples will be just that, but the general principle behind weighting the lower portion of a survival suit are outlined below.

In order to achieve self righting of a body it is necessary to weight the lower body portion enough to provide a slight negative buoyancy in the lower portion of the suit so that when worn; the wearers legs are brought together and downwards in the water.

The amount of weight which has to be added to achieve this will depend on various factors.

However, if a minimum amount of weight is to be added and this is preferred since the wearer will have to move in the suit, that weight should be distributed at a distance furthest from the wearers centre of gravity in the lower region viz the feet.

However, in some situations it may be preferred to distribute the weight more generally about the lower body region, preferably below the knees.

-5a- A survival suit should therefore have the weights specifically selected so that when the suit is worn in combination with a life jacket the weights will bring the wearers legs down in the water so that the wearers body is inclined at an angle of from 200 to 500 from the verticle. The lower part of the suit Phould in other words have a negative buoyancy. However the weighting should not be so great that the wearer is pulled down beyond that which is necessary to achieve the required result, namely to keep the wearers air passages free.

In one embodiment a suit made from super stretch neoprene, of 7 mm thickness about the torso and the hood, and 3 mm thickness about the limbs, was found to require between 1 andl.5 k i 1 ograms weight in each foot. Preferably, the weight is distributed in the soles, although this is not essential.

In another embodiment a suit made from super-stretch neoprene, of 7mm thickness about the torso and hood and 3mm thickness about the limbs, was found to require 4.7 kilograms of weight in its lower portion to achieve a slight negative buoyancy. This weight was found to be best distributed along the length of the legs.

In for example an embodiment where the suit is thicker, for example in artic conditions, greater weighting would be required.

Thus the greater the buoyancy of the suit (about the lower portion) the greater the weighting required to achieve a negative buoyancy effect.

The present invention will now be described, by way of example only, with reference to the following drawing, which shows a survival suit illustrating the features of the invention.

A survival suit 10 is an all-body suit adapted to be worn over the body of a normally fully clothed individual. Its function is to orientate its wearer into a face-up position and keep its wearer afloat, in a face-up position, and warm until the individual is picked up by a rescue team. The suit has a zip 12 positioned on its front 14 which runs from the bottom of the hood piece 16 to a position at the upper part of leg 18 of a pair of legs 18 and 20. The suit is made from an elastic material having heat retaining properties, for example Superstretch, a proprietary product of Yamamoto Corporation. The legs 18 and 20 are made from a superstretch neoprene of minimal thickness to ensure recognised thermal requirements are met, preferably 3mm to 5mm thick. The neoprene has the added advantage of being more flame resistant than rubber, and can be iso cyanate modified to provide a biqh flame resistance. The arms 22 and 24 are made from a superstretch neoprene of minimal thickness, to allow quick donning and dexterity of movement whilst still ensuring minimal thermal requirements are met, preferably 4mm to 6mm thick. The torso 26 and hood 16 are formed from at least a 7mm thick material. since they are responsible for the greater loss of body heat and have the best effect on legflotation.

The legs 18 and 20 are provided with two polythene liners 28 and 30 which are releasably held in place. When the wearer steps into the suit, these liners facilitate easy sliding of the feet and legs into the suit, the feet extending down into the shoe por tions 31. and 34 of the suit.

The lower part of the suit is weighted and has weights 36 sewn into the thigh portion 38, sole portion 39 and calf portion 40 of the suit. The weights are in the form of shaped lead plates although other dense materials of alternate shapes could be used. The weights used in the suit shown are based on the weights required to right a man of average weight wearing a superstretch neoprene suit having the following neoprene specifications, namely a 7mm thick torso and head, and 4mm thick arms and legs, and totalled 4.7 killograms. It has been found that the most effective distribution of this weight is as follows: 30% weight distribution below the knee of the legs and 70% weight distribution above the knee of the legs.

However, the weight used will depend upon its distribution and between 1 and 1 lli kg distributed at the sale 39 has been found to be equally effective.

The use of weigh t proves more beneficial when the suit is inherently elastic, since less weight is required to achieve the object of the invention, namely the self righting of an exhusted or unconscious person.

The suit has two other major features.

It has a life jacket 42 integrally fitted thereto about the back of the neck and the torso. The jacket is of a type which inflates on wetting and has a bladder compensator arrangement.

The suit also has a double glove/mitt arrangement 44. The inner glove 46 is waterproof and has five fingers allowing the wearer dexterity, and the outer mitt 48 provides the insulation. The outer mitt 48 is hingedly attached to the suit and is retained on the arm of the suit when not in use by, for example, hook and loop fasteners or a flexible neoprene tube or pocket. Once again, due to the elasticity of the suit material, the outer mitt could easily be put on over the inner glove. By hinging the outer mitt to the suit there is no danger of wave action removing it from the wearer.

The suit may also be provided with strategically placed pockets or tabs for the retention of, for. example, a whistle, a light, a personal attachment cord and quick-clip, a lifting harness and hook and a face anti-spray clear visor hood cover system, none of which are shown. Furthermore, the suit may be provided with reflective tape thereon.

Claims (11)

1. A survival suit having a weighted lower portion or means thereon for attachment of weight thereto.

2. A survival suit as claimed in Claim 1 in which the lower portion is weighted to achieve a slight negative buoyancy in the lower portion of the suit.

3. A survival suit as claimed in any of the preceeding claims in which the weight is distributed about the calf, thigh or feet of the suit.

4. A survival suit as claimed in Claim 3 whereas the weight is distributed about the sole regions of the feet.

5. A survival suit as claimed in any of the preceeding claims in which the weights are in the form of a dense material.

6. A survival suit as claimed in Claim 5 wherein the dense material is lead.

7. A survival suit as claimed in any of the preceeding claims in which the weights total from 2 to 5 Kg.

8. A survival suit as claimed in Claim 7 in which 1 to 1. 5 kg,is provided in each foot.

9. A survival suit as claimed in any of the proceeding claims which further comprises a life jacket.

10. A survival suit as claimed in any of the proceeding claims in which the suit is a super stretch neoprene.

11. A survival suit having a weighted lower portion as described with reference to the drawings.

Published 1991 at Ilie Patent Office, State House. 66171 High Holborn. London WC1 R 4TP. Further copies rmy be obtained from Sales B. UnIL 6, Nine Mile Point, Cwmfelinfach, Cross Keys. Nmport. NP1 7HZ. Printed by Multiplex techniques ltd. St Mary Cray. Kent.