The ramp and door system consists of the bow ramp, bow doors, tracks, winches with their wire rope rigging, fixed and positive guidance rollers, vangs, seating device, pivot post, control consoles, various interlock and limit switches, and the interlock control panels. In time, repairs will become necessary to correct the results of wear or to repair damage caused by various casualty conditions. You must know and use the correct sources of information necessary to efficiently disassemble and reassemble the machinery. You must

Figure 8-1.Trackway gravity davit.

Figure 8-2.Double-link pivoted gravity davit.

Figure 8-3.Single-arm trackway gravity davit.

Figure 8-4.Aircraft carrier weapons elevator.

read and heed any of the safety precautions and warnings like the following:

WARNING

Before starting disassembly of any piece of equipment, be certain the power is off and the switch is tagged. Do not re-energize any tagged circuit until safety of doing so is definitely established.

When you determine that a repair or replacement of part(s) will require disassembly, tag the system out. Remove any interfering guards or obstructions. To reduce the chance of dirt and other contaminants from getting into the works as the parts are disassembled, you must take the time to properly clean the machinery. Keep the dirt out of open gear cases and be sure parts are cleaned before reassembly. If the oil becomes contaminated, drain and flush the system with light oil and refill it with proper lubricant. Water in the oil will cause rust, and dirt can act as an abrasive to wear out the machinery. You must match marked parts that could be installed in more than one way so that you can return the machinery parts to their original position.

Components like winches and other actuating machinery are covered in considerable detail by their manufacturers technical manuals. Any repairs to be done must be done according to the applicable technical manual as specified by PMS. You must complete the required PQS for this equipment. For more detailed information, refer to NSTM, Chapter 584, Stern Gates, Ramps, Bow Doors, Turntables, and Water Barriers. Also, a copy of NAVSEA 0916-LP-018-5010, Operation Manual for Bow Ramp System (U) LST 1182-1198, may be very useful.