Figure 10-28. - A 1500 barrel , 6x18 fuel storage barge.

used as a pier or wharf or, by installing heavy hinges, could be connected to any existing pontoon wharf to enlarge or extend that structure.

Essentially, tugs are barges equipped with outboard propulsion units and the accessories required for the operations to be performed. The P-series equipment tugs are widely adaptable and can be used for towing, causeway tending, placing and retrieving

Figure 10-29. - 100-ton derrick mounted on a 10 x 30 barge.

anchors, salvage operations, assisting in the installation and recovery of fuel systems, and other services.

The 3x14 warping tug shown in figure 10-30 is equipped with two outboard propulsion units. The after end of the center string incorporates an anchor housing to accommodate the 2,500-pound mooring anchor and also holds the anchor wire away from the propulsion screws. An A-frame, mounted on the bow of the tug, stands approximately 13' above the deck of the barge. A double-drum winch is mounted near the center of the barge. A line from the after drum is fairlead to the deck and back to the anchor astern, while the line from the forward drum is run over a sheave in the top of the A-frame and is used for lifting over the bow or pulling from the bow of the warping tug. The winch is mounted on a welded steel cross-braced frame. Standard equipment for the tug also includes M147 double bitts and navigation lights. The warping tug is approximately 90' long and 21' wide, has a stem draft of 48", a bow draft of 18", and a speed of 6 1/2 knots. The 3x14 warping tug replaces the 3x12 tug throughout the pontoon system. The only difference in these two is that the 3x14 tug is longer by two P1 pontoons and incorporates new style winches with lines feeding off horizontally laid drums.