VOL. I BOOK 4 CHAPTER I SECTION 4 than the rush job formerly required when a Navy dock with a limited available time at the Jobsite was used. It also provided ready equipment for emergency repairs, With the Gilhoist, Figure 4-1, the lighter craft was picked up and lifted out of the water thus eliminating the need for dragging the craft over the concrete ramps. A complete maintenance history of each craft was kept in which all items of routine maintenance and repairs were recorded. A dry dock record was also maintained, in which were recorded dates of docking and undocking and each item of work performed on the craft while in dock. Maintenance of the marine craft is summarized in general by craft type in the succeeding paragraphs. WATER TAXIS. Three taxis were used in this operation and it was necessary to beach these craft approximately every three months for scraping and painting the hull to offset the action of marine borers. In March 1952, Taxi M-122 was given a complete overhaul including replacement of the engines, fue] tanks and exhaust lines. In May 1952, Taxi M-35 underwent a similar overhaul. In March 1952, the port engine of Taxi M-142 was replaced and the starboard engine was replaced in September 1952. LOM CRAFT. These boats were required to be beached approximately every three months for cleaning, scraping and/or sandblasting and repainting of the hulls. Conditions under which these craft operated were hazardous with respect to propellers, shafting, underwater cutlass bearings and bottoms. In addition to these conditions, the continual movement of heavy equipment over the ramps and well decks subjected them to heavy wear and tear. Continued trouble shoot- ing was necessary in maintenance of these craft over and above routine overhaul. There were 19 of these craft at the Jobsite for this operation. Twelve of these were received from the NAVY after completion of OPERATION GREENHOUSE. After the receipt of these boats they were beached, minor repairs were effected. and they were mothballed. In connection with the mothballing the electric equipment was removed and placed in dehumidified storage. The first of these 12 boats was reactivated for this operation on 17 December 1951, and the remainder at various intervals depending upon requirements. Of these reactivated boats, six required engine changes within one and one-half months' service, and others required cylinder head changes. These craft as received were equipped with 90 mm. injectors which were replaced with 60 mm. injectors as the use of the smaller size injectors materially reduced maintenance costs. DUKWS. These amphibious trucks were used extensively during this operation, especially in the outer islands. Maintenance was very high due to the terrain and shore conditions on which they had to operate. Work on sharp, rough reefs was rather extensive in this operation. Tire and spring replacements were the most frequent maintenance work items. The corrosive action of salt water on the moving parts located outside the hull, such as wheel bearings, universal 4-6