28 July 2005
The requirements discussed above apply where ships are berthed on both
sides of a slip. Where ships are berthed on only one side of a slip, the
width may be reduced. See Figure 2-3. When more than two abreast
berthing is employed, the width of slip should be increased by one ship
beam for each additional ship added in order to maintain adequate
clearances between moored ships during berthing and unberthing
maneuvers. Thus, for three-abreast berthing on both sides of a slip, the
slip width for single-berth piers would be equal to 10 times ship beam and
the slip width for multiple-berth piers would be equal to 11 times ship
Minimum Width of Slip for Inactive Berthing.
At slips containing inactive berths where ships are stored for long periods of time
on inactive status in nests of two, three, or more, clear distances between
moored ships and slip width may be reduced by one or two ship beams to reflect
the reduction in the frequency of berthing maneuvers and the decrease in
activities of small boats and floating equipment.
Water Depth in Slips.
Information on required water depth in slips and at berths is contained in UFC 4-
Pier and Wharf Deck Elevation.
Set deck elevation as high as possible for surface ship berthing and as low as
possible for submarine berthing, based on the following considerations:
To avoid overflow, deck elevations should be set at a distance above mean
higher high water (MHHW) level equal to two thirds of the maximum wave height,
if any, plus a freeboard of at least 3 ft (0.9 m.) Bottom elevation of deck slab
should be kept at least 1 ft (0.3 m) above extreme high water (EHW) level.
Where deck elevation selected would result in pile caps or beams being
submerged partially or fully, consideration should be given to protecting the
reinforcing from corroding.
Consideration should be given to the varying conditions of ship freeboard in
relation to the use of brows and the operation of loading equipment such as
conveyors, cranes, loading arms, and other material handling-equipment. Fully
loaded ships at mean lower low water (MLLW) level and lightly loaded ships at
MHHW level should be considered for evaluating the operation of such