Effect Of Under-water Explosions On Warships' Hulls Being Studied

Bay of Plenty Times, Volume LXXVII, Issue 14860, 23 December 1948, Page 4

Effect Of Under-water Explosions On Warships' Hulls Being Studied

ADMIRALTY INSTITUTES SHIP TARGET TRIALS AS GUIDE TO CONSTRUCTION

(N.Z. Press Association)

The Admiralty is conducting trials at Loch Striven on the effect of non-contact underwater explosions on the cruiser Orion, the destroyer Ashanti and the submarine Ace. The Ace is an A Class submarine, the building of which was stopped, at the end of the war, and she therefore represents modern submarine design practice and is of particular importance. These underwater explosion trials are carried out by placing a known quantity of explosive in the water at a chosen position near the target ship. The charge is detonated electrically, the immediate effects upon the target beingrecorded by instruments fitted within the ship, the structure and equipment of Avhich is afterwards examined in detail so that the damage sustained can be assessed. In the case of the submarine, trials will be done both when on the surface and

submerged

At Rosyth trials are _ being conducted with the Albuera, a Battle Class destroyer, the completion of which was stopped at the end of the war. This ship is being subjected to various conditions of loading by flooding compartments - while the vessel is afloat. Trials in dock with the same vessel will be done later at Rosyth, and these trials will continue up to the point at which the hull structure fads. Future Trials Planned

destroyer Pathfinder and sloops and corvettes. By doing the bombing trials first wi'th inert bombs, then with bombs containing small charges and finally by exploding filled bombs at the required positions within the ship it is possible to examine on full scale all the characteristics of a bombing attack from the time that a bomb is released to when it explodes, under what amount to laboratory conditions. Gunnery trials against Flower class corvettes, minesweepers, landing craft and coastal force craft have been done off Portsmouth and Plymouth. The safety of stowage of aircraft rockets, effectiveness of flash seals of magazines and ammunition stowages and an investigation into the methods of spraying and flooding magazines has been done in the aircraft carrier Furious at Loch Striven. Valuable Data

Future trials, including further research into underwater explosion effects, bombing trials, trials of security against flash, the effect of ship’s gunfire on its own structure, the effect of damage and flooding on the running of machinery in a destroyer and further structural strength trials, are now in the planning stages. These trials form part of the Admiralty Ship Target Trials, which were started in 1945 with the object of using surplus warships to amplify experience on ship and weapons. The trials are sponsored by the Ship Target Trials Committee, under the Chairmanship of the Assistant Chief of Naval Staff, Rear-Admiral R. A. B. Edwards, C.8.E., the Air Ministry, Ministry of Supply, Combined Operations Staff and the Ordnance Board are represented on this Committee.

Trials completed to date have included shock and damage by underwater explosions against the cruiser Emerald, the destroyers Ambuscade, Active, Anthony, Brilliant, Z. 30 (exGerman ship) Jervis and Amazon, various M.T.B’s and submarines. Bombing Vessels

Bombing trials have included an extensive series against the cruiser Hawkins off Portsmouth in 1947, during which 29 hits were obtained by bombs dropped by R.A.F. bombers. This bombing was done partly with inert bombs and partly with bombs fitted with small charges, in iy*iß similar trials have been u.me against the Nelson, which was moored off Inchkeith Island in the Firth of Forth.

The damage done by the explosion of bombs within ships is investigated by placing live bombs at selected positions in the targets and detonating them electrically. Such trials have been done at Angle Bay and Hilford Haven using the

The trials mainly owed their inception to the Director of Naval Construction, Sir Charles Lillicrap, head of the Royal Corps of Naval Constructors. The data obtained from these trials is immediately available to the technical departments of the Admiralty who are mainly concerned with the conduct of the trials. Improvements in ships and weapons resulting from this work are being incorporated in new design as well as in ships already built as far as possible. In addition, the trials themselves have provided considerable and valuable experience for the Naval personnel employed in the organisation. The difficulties of carrying out this programme of research have been critical as far as manpower is concerned and it has been necessary for those engaged in the trials to work very hard and for long hours.

The cost of the trials is small in comparison to their value to the Admiralty, since to obtain the information required by any other means would involve the building of full scale targets. The ships used are already on the list for scrapping and ship target trials provide a means of employing them usefully in their last days. When they have completed trials the ships are turned over to the shipbreakers so that the materials used in their construction may be salvaged fcr the country’s other needs.