(This crane is larger than is used in the average foundry but it has
some safety features that should be universally adopted. At A is the
landing platform leading to the foot-walk on the crane bridge; B is a
stairway which extends from the safety platform, C, just outside the
operator’s cage, to the landing platform. The railing and toe-board on
the crane bridge and on the trolley are also essential for safety.)]
All electrical wiring should be installed in conduits; and it is
particularly important that hoist-limit stops be provided, in all
cases, both for the main and for the auxiliary hoists. In the best
crane practice the hoist-limit stops employ dynamic braking to check
overtravel and to assist in lowering loads. To prevent the crane from
being operated by unauthorized persons, or while repairs are being
made, there should be a safety switch in the main line, mounted above
the cab where it can be conveniently reached from the foot-walk. This
switch should be fitted with a lock so that it can be secured in the
open position, and the key should be only in the possession of the
crane operator or the head repairman.
Woodwork should not be used about a crane, because it is likely to
become oil-soaked, and it is then exceedingly combustible. If it should
take fire and the craneman, in order to make his escape, should run the
crane to a stairway, the time required for this purpose might increase
his danger quite materially, and the motion of the crane would also
tend to increase the fire. If, on the other hand, he tries to leave the
crane in any other way than by the regular stairway, he will be exposed
to hazards of other kinds, and these will be accentuated by his haste.
[Illustration:
_Courtesy of the Shepard Electric Crane & Hoist Company._