12 December 2001
smaller ships and submarines. A floating drydock must be moored or anchored in a
location where the water is considerably deeper than the draft of the ships it serves,
and it must have access to the shore for supplies and utilities. A staging and laydown
area alongside the drydock is required to provide operational support.
A graving drydock is a permanently placed facility dug into the
embankment. Such drydocks are usually equipped with portal cranes that travel around
the perimeter of the dock and are surrounded by service and laydown areas for large
ship parts and equipment. Space along the quay near the drydock or other moorage
and clear of vessels maneuvering into the dock is required for storage of the drydock's
caisson gate. For all types of drydocks, keel blocks for the various vessels served must
be stored nearby.
Ancillary Facilities. Additional facilities and water area should be
allocated for anchorage or moorage of ships awaiting repair service and for tugboats
and fireboats. These facilities and areas may not be required within the shipyard limits
if they are available nearby in the harbor.
Land Needs. Land area should be allocated to shipyard use in sufficient
quantity to provide for rail or highway access, including onsite storage of vehicles and
goods required for shipyard operations. Shop and office buildings, storage areas, and
laydown spaces should be arranged to provide the most efficient flow of work and
personnel within the facility consistent with the available space and mission of the
Figure 5-16 is an example of the space allocation and arrangement of a
Degaussing and Deperming Requirements. NAVORD OP 2706,
Introduction to Degaussing (NAVORD, 1960) and NAVSEASYSCOM SS475-AD-MMD-
010/MAG FAC, Magnetic Silencing Facilities Description and Installation of Permanent
and Portable Equipment (NAVSEASYSCOM, 1980) cover the two methods used in
magnetic silencing: magnetic compensation (degaussing coils) and magnetic treatment
(deperming). Deperming which reduces the permanent magnetization accumulated by
a ship during construction and operation complements the use of opposing magnetic
fields in degaussing.