Rigorous tests have been carried out on the life-belts issued by the Institution to members of life-boat crews following some rather disturbing reports issued by the Danish Ministry of Commerce and Shipping on the effects of oil on kapok life-belts. The Danish report stated that a kapok life-belt carrying a load of 16£ Ibs. of iron and placed in a vessel of salt water with a layer of oil l/5th inch thick on the surface, sank with disturbing speed. With a layer of paraffin the life-belt sank in 2 minutes 40 seconds, and with a layer of diesel oil in 4 minutes 30 seconds.

With a layer of petrol it sank even more quickly.

Test in Paraffin The normal tests of the Institution's life-belts are carried out with a weight of 20 Ibs. If a life-belt can support a 20 Ibs. deadweight it can be relied upon to support considerably more than the weight of one man in the water. All life-belts are tested with this weight for twenty-four hours. If at the end of twenty-four hours they are still floating freely, the life-belts are passed as satisfactory.

To test the Institution's standard lifebelt in oil-polluted water a tank was filled with fresh water and a J inch layer of paraffin was placed on the surface. Two life-belts were then tested with weights attached. One was the standard life-belt and the other was a belt lined with polythene, which was expected to act as a protective layer between the kapok and the oil. The standard belt was able to support a load of 34 Ibs. and the polythene-lined belt a load of 33 Ibs. At the end of an hour the standard belt was still able to support a load of 28.8 Ibs. and the polythene belt a load of 32.25 Ibs. At the end of twenty-four hours both belts were supporting a load of 22 Ibs., that is to say 2 Ibs. above the normal testing load. It was not until the life-belts had been in the oil-polluted water for 33£ hours that the load they were capable of supporting was reduced to 20 Ibs.

A similar test was later carried out on a standard life-belt with a J-inch layer of diesel oil on the surface of the tank.

The buoyancy of the life-belt was even greater in this case, and at the end of thirty-four hours the belt could still support a load of 23.6 Ibs. No tests were carried out with petrol because of the risk of fire.

Salt Water Tests The Danish tests had been carried out in salt water, and after the completion of the tests in fresh water the Institution's belts were also tested in salt water. As was expected, buoyancy was even greater in salt water than in fresh water, and at the end of twentyfour hours the standard life-belt could support a load of 27 Ibs.

The tests, in fact, completely vindicated the Institution's standard belt, for they were carried out in conditions much worse than any likely to be encountered on service. At sea the quick spread of oil on the surface would, in any normal circumstances, thin down the concentration of oil to a fraction of the layer used in the tests..