15 August 2002
Table 3-1 Basic Drydock Dimensions
Clear Inside Body
Length, Coping at
Depth, MHW to
Head to Outer
Floor of Dock
Destroyer or Frigate
Allowance for sonar domes included.
Except Ohio class.
Caisson Seats. Provide an inner and an outer caisson seat at the
entrance to graving docks. The outer seat is required to permit repairs to be made on
the inner seat. For seat dimensions, refer to Chapter 9. Double-faced seats are
required if a superflooding feature is installed.
DRYDOCKS FOR SHIPBUILDING ONLY. These drydocks, although
sometimes built under the auspices of the Navy, are generally built in private shipyards
and usually for a particular class or classes of ships.
Height of Floor. The draft at the time of undocking is predicated on the
degree of vessel completion to be attained in the drydock before removal to fitting-out
pier, and the height of the floor below mean high water must be established accordingly.
Width. This type of drydock is usually semi-permanent for economical
reasons, and may be made narrower than repair drydocks for the same class of ships.
Provide sufficient clearance to accommodate the required construction equipment
between the hull and walls.
. Provide only electricity, steam, air, water, and other services
necessary for ship construction.
Head End Shape. The head end of the drydock may be trapezoidal,
semicircular (see Figure 3-1), square, or ship shape. Although there are advantages
and disadvantages for each shape, sometimes one best fits the pattern of adjacent