d is fixed to the end of the train or set
of tubs. When the load is being drawn out, the engine pulls directly on
the main rope, coiling it on to its own drum, while the tail drum runs
loose paying out its rope, a slight brake pressure being used to prevent
its running out too fast. When the set arrives out bye, the main rope
will be wound up, and the tail rope pass out from the drum to the end
and back, i.e. twice the length of the way; the set is returned in bye,
by reversing the engine, casting loose the main, and coupling up the
tail drum, so that the tail rope is wound up and the main rope paid out.
This method, which is the oldest, is best adapted for ways that are
nearly level, or when many branches are intended to be worked from one
engine, and can be carried round curves of small radius without
deranging the trains; but as it is intermittent in action, considerable
engine-power is required in order to get up the required speed, which is
from 8 to 10 m. per hour. From 8 to 10 tubs are usually drawn in a set,
the ways being often from 2000 to 3000 yds. long. In dip workings the
tail rope is often made to work a pump connected with the bottom pulley,
which forces the water back to the cistern of the main pumping engine in
the pit.

For the endless chain system, which is much used in the Wigan district,
a double line of way is necessary, one line for full and the other for
empty tubs. The chain passes over a pulley driven by the engine, placed
at such a height as to allow it to rest upon the tops of the tubs, and
round a similar pulley at the far end of the plane. The forward edge of
the tub carries a projecting pin or horn, with a notch into which the
chain falls which drags the tub forward. The road at the outer end is
made of a less slope than the chain, so that on arrival the tub is
lowered, clears the pin, and so becomes detached from the chain. The
tubs are placed on at intervals of about 20 yds., the chain moving
continuously at a speed of from 2-1/2 to 4 m. per hour. This system
presents the greatest advantages in point of economy of driving power,
especially where the gradients are variable, but is expensive in first
cost, and is not well suited for curves, and branch roads cannot be
worked continuously, as a fresh set of pulleys worked by bevel gearing
is required for each branch.

The endless rope system may be used with either a single or double line
of way, but the latter is more generally advantageou