Ice and wood pulp boat goes down with all hands
by Sail-World Cruising on 3 Oct 2010
Hardly an hour out of the marina SW
There's no chance that your newest dinghy will be made of ice and wood pulp any time soon.
An attempt this week to test one of the most bizarre proposals of the Second World War - a boat made from ice and wood pulp - hardly left the marina before the BBC crew, trying to cross Solent to test the boat, sank with all on board and were rescued by the nearest boat, all of a metre away.
In the event of steel stocks running out in the 1940s inventor Geoffrey Pyke
suggested it was possible to make an unsinkable aircraft carrier using a material called Pykrete, made of both ice and wood pulp. He claimed his five and a half ton craft would both save on steel and be impossible to sink.
Yet a mock-up of his brainchild took on water and melted within minutes of its launch in Portsmouth harbour this week. Experts said that the experiment for science show Bang Goes The Theory probably failed because the boat was too small, and so less resistant to melting, and because the water they tested in was far warmer than the Atlantic - where the invention
was designed to be used.
The bizarre mixture could be moulded into any shape and, with a slow melting rate, it was thought perfect for seafaring vessels.
The BBC decided to put Pyke's theory to the test by mixing 5,000 litres of water with the hefty material hemp and freezing it in a 20 feet-long boat-shaped mould.
It took three weeks to freeze it in one of the UK's largest ice warehouses, in Tilbury, Essex, before it was ready for launch in Gosport, Hants.
The team made it in to Portsmouth Harbour where they were
saluted by members of the navy stationed on destroyer HMS Diamond.
But shortly after that, after just over an hour in the water, it began to take on water and capsized.
Four BBC presenters, who had hoped to make it all the way to Cowes on the Isle of Wight, had to abandon ship and swim to rescue craft.
Lynette Slight, of the BBC science show, said: ‘They had just got out of the marina when it began to sink.‘It was all a little bit strange. I don’t think they realised what would happen. In the end it just tipped upside down. It was taking on too much water at the back and the engine became too low.’
Jon Edwards at the Royal Society of Chemistry said 'It’s hardly a surprise that the boat sank – the temperature in the Solent is probably a fair bit higher than the middle of the Atlantic, where Pyke designed his material to be used.
'He also used enormous cooling units to keep the pykrete in his tests below zero degrees centigrade. If they didn’t use those refrigerators, the intrepid ice-sailors from Bang never stood a chance.'
He added: 'The size of the boat may have added to their problems, too. A huge aircraft carrier, as Pyke envisioned, would have been more resistant to melting – a larger surface area of ice requires a lot more energy to start melting, so the non-surface ice stays cooler for longer.
'A 1000-ton test boat, built out of normal ice on a lake in the Rockies, lasted a whole summer.'
Whatever went wrong, the resulting publicity accorded the the program, to be screened on BBC1 October 13 in the UK, will no doubt make it a smash hit.
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