HC Deb 23 March 1927 vol 204 c371
18. Major OWEN (for Mr. HORE-BELISHA)

asked the First Lord of the Admiralty whether any further experiments are being conducted into the methods whereby a sunken submarine may make its position known; and. whether there is any expectation that these experiments may lead to the discovery of a satisfactory device?

Lieut.-Colonel HEADLAM

A trial apparatus of a new type is being fitted in a submarine and experiments will shortly be carried out.