Profabricated Tugs (a) In this yard, fifty miles island, a splendid job was done during the war in building prefabricated tugs, known as Tids, They were used primarily for towing Mulberry units to Normandy and speed in production and large numbers were essential. The factories prefabricating the eight tug units were all non-shipbuilding firms in many parts of the country. The tugs hare are a slightly altered version for work on the Irrawaddy.Again Japanese ***** made speed and large umbers necessary The tugs are 70 foot Overall length, prefabricated in eight transverse units joined ty circumferential welds in the shipyard. September 19, 1951.