Cable laid from Oban to Newfoundland . Oban , Argyll : The link - up of the first Transatlantic cable from Newfoundland to a point south of Oban was completed today when the final splice between the two cables was made on board the HMTS Monarch . For this link - up the Monarch has been laying the longest submarine telephone cable ever to have been laid on one operation . She picked up the end of the two mile long cable and laid from the telephone staton on the mainland of Argyll out into the Atlantic and the final connection was made . Photo shows ; The finish of the job of splicing the cable on board the Monarch . 26 September 1955 *** Local Caption *** 305398