TM 5-850-1
picks up a container and chassis or returns to its
operations base empty. Yard tractors haul both
ports may be provided with double-track sidings from a
exported and imported containers between the
train makeup yard, which preferably should be outside
marshaling yard and the wharf. At the wharf, gantry
the container yard. This railroad configuration should
cranes, either on the ship or on the wharf, lift export
run the length of the wharf apron, with sufficient
containers off the chassis and on board the ship,
crossovers, so that empty or reloaded cars can be
remove import containers from the hold, and place them
switched onto the outgoing track. Instead of the tracks
on the tractor-driven chassis, which then returns to the
running on the wharf, they may be located in back of the
marshaling yard.
wharf, within reach of the inboard extension of the
(2) This system has the containers stored on
gantry crane bridge. A railway spur shall also run down
the ground in the marshaling yard and serviced by
one of the longitudinal aisles in the marshaling and
straddle or forklift trucks. As an export container
storage yard so that a yard gantry crane, straddle truck,
arrives, it is received in the marshaling yard, and a
or forklift truck can transfer containers to and from the
straddle truck removes the container from its chassis
flatbed railway cars.
(2) Provision for truck operations. Container
and moves it to its storage place on the ground or on top
of another container, if stacked two high. The straddle
terminals should have provision for truck traffic. It is
truck loads the container on a yard tractor trailer for
important in the location of a container facility that it be
delivery to the dock, where it is loaded on board the
near main highway arteries. Traffic congestion may
ship. Import containers unloaded from the ship are
occur where the trailer trucks pass the control office. To
carried to the marshaling yard by the tractor trailer, and
prevent trailer truck traffic from blocking public highways
the straddle truck moves them to their place in storage.
leading to or passing by the container yard, adequate
When the containers are ready for delivery, the straddle
length of roadway or parking area should be provided
truck places them on and over-the-road tractor and
inside the main entrance to the marshaling yard ahead
chassis.
of the control office. A Circumferential road may lead to
b. Roll-on/roll-off operation. As the name implies,
the wharf to maintain through traffic along the wharf and
this operation differs from the lift-on container operation
not require turning on the apron. Longitudinal aisles
in that tractors deliver their trailers on wheels on board
may be provided between double rows of parked
the ship, where they are detached from the tractor and
containers, stored on trailers, leading to transverse
secured to the deck. Then the tractor returns to shore to
collecting aisles to the wharf. Aisles will normally be
pick up another trailer. The operation of loading and
about 60 feet wide. AU areas within a container yard
unloading goes on simultaneously.
More detailed
need to be paved and drained so that ponding will not
discussion of roll-on roll-off operation is given in chapter
take place. Subgrade conditions need to be carefully
investigated, and pavements designed for the
concentrated wheel loads; or when containers are
13-3.
Container handling equipment.
placed on the ground, the loads will be concentrated at
the corners.
Excessive loads may result from
a. Efficient handling of large containers requires
containers being stacked too high.
special equipment on the ship or on the wharf, the latter
13-2.
Types of container operations.
being the preferred method since it permits the gantry
crane to reach a considerable distance inland as well as
over the ship. A typical wharf-side traveling gantry
Two completely different types of container operations
crane is shown in figure 12-3.
have been developed. The two methods are identified
b. When rehandling is necessary on land, this is
by the way the ship is loaded and unloaded and are
accomplished by means of giant straddle carriers (fig B-
commonly referred to as lift-on container operation and
roll-on-roll-off (ro-ro) operation.
a. Lift-on container operation. This operation is by
used and can stack the container three high. A heavy-
duty side-loading container handler (fig B-7) can handle
far the most common type. In general, the two
40-foot containers two high.
Likewise, the gantry
principal systems of lift-on operation are as
cranes, on either rails or rubber tires (fig B-8), can stack
follows:
containers four high on the ground, then pick them up
(1) Inbound and outbound containers are stored in
and place them on a railroad flatcar or truck chassis.
the marshaling yard on standard over-the-road chassis.
Incoming containers are weighed, checked in, and
dispatched to a predetermined parking location in the
marshaling yard.
The over-the-road tractor either
13-2
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