TM 5-850-1
loaded draft of the largest vessel to be accommodated,
4 times the largest accommodated vessel beam for
plus 4 feet.
On a mud or silt bottom, consider
single berthing, or 5 to 6 times the beam of the largest
increasing the water depth requirements if an
accommodated vessel for berthing two abreast. These
investigation indicates probable fouling of condensers
requirements apply where vessels are berthed on both
on the vessel due to proximity of the mudline to the
sides of the slip. Where vessels are berthed on one
bottom of the vessel.
Where the vessels to be
side only, the slip width may be reduced.
f. Aprons. The width of an apron will depend upon
accommodated are specifically known, the following
values may be used:
the use of portal or semiportal cranes and the number of
Depth, ft1
Vessels
railroad tracks and truck lanes, if any. The minimum
Small boats and seaplanes
6 to 12
width should be 20 feet. Where railroad tracks are
Submarines and destroyers
30 to 35
carried on aprons, the apron width should allow for
Cruisers and general cargo ships
35
passing of train and trucks (or other material handling
Container ships
40
devices on the piers), plus allowances for the piled
1
These depths are based on mean low water
cargo on the aprons. Railroad tracks should be located
(MLW) or mean lower low water (MLLW) statistics for
along the outboard face of marginal wharves. Various
the area under study.
apron widths for different operating conditions are
shown in figure 6-2.
6-3.
Transit shed.
g. Deck elevation. Deck elevations for various
a. Introduction. A transit shed is required for
types of construction and for particular situations are
listed below.
Except for the minimum elevations
handling goods that must be protected from the weather.
specified, pier deck levels should conform to the
Where nonperishable goods (not subject to weather
generally established levels of adjacent station property.
damage) are handled, open storage areas may be used
(1) Flood protection.
To avoid flooding,
in lieu of sheds. Covered sheds are not required for
provide deck elevations at or above maximum high
container slip wharves.
b. Storage area requirements. The total storage
water plus the half-height of an incident wave.
(2) Two-deck piers. Where a tidal range is
area in pier sheds should conform to project
large, deck height may interfere with cargo handling at
requirements. An area of 90,000 square feet has been
low tide. In this case, the pier may be constructed with
found to be about the minimum space needed for one
two levels, one for use at high tide and the other at low
berth. For general cargo, allow 40 cubic feet of volume
tide.
per ton and 50 percent of shed area for aisles. Upland
(3) Concrete deck.
Where economically
storage for each berth can be provided equal to 2.5 to 5
percent of the annual general cargo volume handled.
feasible, pile cap soffits should be 3 to 4 feet above
c. Shed Width. Shed width shall conform to the
mean high water.
(4) Timber construction.
Where timber
following criteria:
(1) Single-story sheds. Transit sheds should
construction is used, the lowest tier of braces should be
at or above the mean tide level, with the deck level
be one story high. The width of a single-story shed (less
adjusted for the required bracing depth.
width of the outboard apron) is obtained by dividing the
(5) Steel construction. Except for piling, steel
pier storage area requirement (including allowances for
office, toilet, passenger, and miscellaneous areas) by
framing should be kept above mean high water. Adjust
the length of the pier.
the deck level for the required construction depth.
(2) Multi-story sheds. These sheds are not
(6) Loading platforms. Loading platforms are
normally economical because of heavy line load
desirable on piers where materials are transferred by
requirements and operational difficulties. Where pier
trucks or freight cars. The loading platform height
widths are limited because of adjacent piers, high costs,
should be 3 feet 9 inches, and the width should be 16
or limited availability of waterfront property, multi-story
feet. On straight railroad tracks, a clearance of 6 feet
sheds may be required. The width of a multi-story shed
should be provided between the edge of a loading
equals the width required for a single-story shed divided
platform and the center line of the adjacent railroad
by the number of floors (plus allowances for ramps and
track. On curved tracks, this clearance should be
elevators between floors).
increased by the amount of the center or end excess
d. Vertical clearance. Provide 20-foot height or
and provide access to platform ends by ramps.
(7) Crane and railroad tracks. These tracks
more to the undersides of beams or trusses.
Clearances of 22 feet are required where railroad tracks
should be flush with the pier decks or pavements.
h. Water depths in slips. Except where heavy
are run into a shed and 24 feet where cargo is to be
handled in the shed by mobile cranes. Clearances
silting conditions require greater depth, at individual
should comply with the loading capacities of forklift
berths at low tide, the depth should equal the maximum
trucks or other cargo handling devices used on the
piers.
6-2
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