Normally, you will maintain three types of anchor windlasses–the   electric,   electrohydraulic,   and hand-driven  windlasses.  Hand-driven  windlasses  are used only on small ships where the anchor gear can be handled   without   excessive   effort   by   operating personnel. The major work on a hand windlass is to properly adjust the link, friction shoes, locking head, and brake and to keep them in satisfactory operating condition at all times. In an electrohydraulic windlass, your principal concern is the hydraulic system. A windlass is used intermittently and for short periods  of  time.  However,  it  must  handle  the  required load under severe conditions. This means that you must maintain and adjust the machinery when it is not in use. This practice will prevent deterioration and ensure dependable   use. Windlass  brakes  must  be  kept  in  satisfactory condition if they are to function properly. Wear and compression of brake linings increases the clearance between the brake drum and band after a windlass has been in operation. Inspect brake linings and clearances frequently.  Make  adjustments  according  to  the manufacturer’s   instructions. You  should  follow  the  lubrication  instructions furnished by the manufacturer. If a windlass has been idle  for  some  time,  lubricate  it.  This  protects  finished surfaces from corrosion and prevents seizure of moving parts. The hydraulic transmissions of electrohydraulic windlasses  and  other  auxiliaries  are  manufactured  with close tolerances between moving and stationary parts. Keep dirt and other abrasive material out of the system. When the system is replenished or refilled, use only clean oil. Strain it as it is poured into the tank. If a hydraulic   transmission   is   disassembled,   clean   it thoroughly  before  reassembly.  Before  installing  piping or valves, clean their interiors to remove any scale, dirt, preservatives,  or  other  foreign  matter. WINCHES Winches are used to heave in on mooring lines, to hoist  boats,  as  top  lifts  on  jumbo  booms  of  large auxiliary ships, and to handle cargo. Power for operating shipboard winches is usually furnished by electricity and,  on  some  older  ships,  by  steam.  Sometimes  delicate control  and  high  acceleration  without  jerking  are required, such as for handling aircraft. Electrohydraulic winches are usually installed for this purpose. Most auxiliary ships are equipped with either electrohydraulic or  electric  winches. Cargo Winches Some of the most common winches used for general cargo handling are the double-drum, double-gypsy, and the  single-drum,  single-gypsy  units.  Four-drum, two-gypsy   machines   are   generally   used   for minesweeping.. Electrohydraulic  Winches Electrohydraulic winches (fig. 10-39) are always drum type. The drive equipment is like most hydraulic systems. A constant-speed electric motor drives the A-end  (variable-speed  hydraulic  pump),  which  is connected to the B-end (hydraulic motor) by suitable piping. The drum shaft is driven by the hydraulic motor through  reduction  gearing.. Normally,  winches  have  one  horizontally  mounted drum and one or two gypsy heads. If only one gypsy is required, it is easily removed from or assembled on either end of the drum shaft. When a drum is to be used, it is connected to the shaft by a clutch. Electric  Winches An electrically driven winch is shown in figure 10-40. This winch is a single-drum, single-gypsy type. The  electric  motor  drives  the  unit  through  a  set  of reduction gears. A clutch engages or disengages the drum from the drum shaft. Additional features include an electric brake and a speed control switch. CAPSTANS The  terms  capstan  and  winch  should  not  be confused. A winch has a horizontal shaft and a capstan has a vertical shaft. The type of capstan installed aboard ship depends on the load requirements and type of power available. In general, a capstan consists of a single head mounted  on  a  vertical  shaft,  reduction  gearing,  and  a power  source.  The  types,  classified  according  to  power source, are electric and steam. Electric capstans are usually  of  the  reversible  type.  They  develop  the  same speed and power in either direction. Capstans driven by ac motors run at either full, one-half, or one-third speed. Capstans driven by dc motors usually have from three to five speeds in either direction of rotation. 10-44