Length Overall] 
Types (ft) 
Container ships 600 - 1000 
Lash/Seabee ships 800 
LHA 820 
RO/RO 950 
Breakbulk <600 
2.2.2 Water Depth. The water depth for installation and operation 
shall range from 50 to 150 feet at the pierhead. 
2.2.3 Wind. Prevailing wind speed and directions affect the gen- 
eration of local waves and at times can be a determining factor in berth 
orientation (especially in areas of low current). Two cases need to be 
considered in establishing wind design criteria. First is the facility 
alone. This should be designed for a 100-mph wind for all components 
which must remain in place above sea state 8. The second design case is 
operation. Wind speed with ships in the berth and offloading in progress 
should be taken as steady 30-mph wind speed in a direction broadside to 
the moored vessels. 
2.2.4 Current. Currents are of two basic types: unidirectional, 
resulting from a river or marine stream; and reversing, such as a tidal 
current. In general the most important would be the tidal current. It 
is recommended that installation not be attempted in areas with tidal 
currents exceeding 4 knots maximum. 
2.2.5 Tides. Tides affect the length of the approachway which 
must extend from the pier to shore. Tides also affect operations from 
decks at fixed elevations. Tide data indicate that 8-foot tides are 
rarely exceeded, and this value is recommended for establishing the 
length of the approachway. 
2.2.6 Waves. The wave regime in the vicinity of the pier is the 
most import determinant of the usefulness of the pier as an offloading 
facility. Ship motions and mooring stresses are affected by the 
following: 
D-4 
