Forward Operating Lever
If the forward operating lever moves freely but does not operate the mechanism the
machine has been overloaded and the shear pins have sheared. (See Chapter 10
Procedure 10.30 for replacing the shear pins).
A lack of lubricant in a TIRFOR machine sometimes brings about a condition known
as pumping which is not at all dangerous, but which is inconvenient. This situation
occurs when the jaw, which is gripping the rope, becomes locked onto it preventing
the other jaw from taking over the load. As the operating lever is moved in one
direction the machine travels a few centimeters, but when the operating lever travels
in the other direction the machine moves back the same distance in conjunction with
the jaw which is locked onto the rope.
The TIRFOR machine should be thoroughly lubricated and it will recommence
working normally. (See Chapter 10 Procedure 10.32).
This is also a symptom of lack of lubrication. The TIRFOR machine should be
thoroughly lubricated. (See Chapter 10 Procedure 10.32).
If the wire rope becomes blocked in the machine, generally because a damaged
section of wire rope is stuck within the jaws, it is imperative to stop operating the
machine. The load should be taken by another machine on a separate wire rope, or
by another means, while ensuring that all safety precautions are taken. When the
blocked machine is no longer under load, the damaged rope may be released and
removed. Should this not be possible, return the machine and wire rope to the