A British salvage vessel, the Help, was reported today using heavy explosives in the north Atlantic roughly over the spot where the Titanic sank in 1912. Nothing could be learned of the nature of the ship's activities, first reported from Halifax, Nova Scotia.

The Help is operated by Risdon Beazley Ltd., a Southampton salvage firm on long term charter from the admiralty. Admiralty spokesmen admitted knowing the whereabouts of the Help but would not say what he was doing there. Neither would the company.

The 46,000 ton White Star liner Titanic sank on its maiden voyage 360 miles south-south-eat of Newfoundland, on the night of April 15, 1912, after hitting a huge iceberg. Fifteen hundred persons were lost and 700 were picked up by ther liner Carpathia.

London, July 31 [Reuters]