Description
Coal soon represented a considerable part of the traffic on many lines. As a
cost-cutting measure, some large power companies adopted the just in time
approach to buying coal. This means trains had to deliver on time, as only a
small stockpile was maintained, and in essence, the unit trains became a rolling
conveyor belt.
In order to meet these tough schedules, a new generation of cars and motive
power were introduced, and the methods of loading coal on the trains also
changed.
One of the new structures, still in use today, was the flood loader. Served by a
network of conveyors, these large buildings are essentially storage bins, which
load entire trains on the move. After coal has been washed, crushed to size and
graded, it's delivered from these facilities to the flood loader, which can be
quite some distance away.
In operation, a unit train enters the loader at walking speed, about 4 mph.
Loading begins when the first car rolls under the chute, a job handled by
detectors and computers. In a matter of minutes the car is filled to capacity
and loading begins on the next. Some loaders also use their computers to briefly
stop the flow between cars, producing a down hill slope to the load. Others run
continuously, and a wheel loader is used to reclaim the spilled coal. As the
last car clears, the loader stops automatically and begins refilling for the
next train. Now fully loaded, the unit train passes over a weigh-in-motion
scale, to verify the actual amount of coal being shipped to the customer.
Seen in both eastern and western coalfields, this modern structure is a great
way to add variety to coal operations on your line. Since the actual mine and
processing operations are often miles away, this small building and conveyor can
be placed trackside, to imply the presence of a bigger mine operation located
off your layout.
