05.03.2013

Boom levelling cylinder alert

UK contractor Bam Nuttall has issued a safety alert following an incident with a JLG boom lift last week.

The incident involved the platform levelling cylinder rod bending, allowing the jib and platform to drop through 90 degrees. The two occupants in the basket were not hurt in the incident and were travelling with the boom lowered at the time, but the jib fully raised.

The aerial lift concerned is a 2012 build JLG 450AJ series 2, owned by rental company A-Plant with just 266 hours on the clock.

The machine had an in date inspection certificate, was being used by an IPAF trained operator who was wearing a harness and short lanyard. The rod apparently failed without warning and there was no oil leak.

The contractor has suspended the use of the 450AJ while an investigation is carried out and the cause of the failure determined. The original bulletin can be seen below.
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UPDATE:
A subsequent investigation has suggested that the cylinder rod was damaged prior to the incident through some type of overload. As a result the suspension has been lifted. See Bam issues update to lift cylinder bulletin

Vertikal Comment

This is a highly unusual incident, this jib design has been in use for many years, is very well proven and there are thousands of machines in operation. It is possible that a bad batch of cylinders was supplied with ‘soft’ levelling cylinder rods?

It is pointless to speculate on whether this is a one off or more widespread, we have asked JLG for a comment, although the company has not yet had sufficient time to respond, We will of course update this with any response when we receive it. At this stage it is likely to state that it is investigating the incident and not wish to comment.

Most importantly, all boom users should wear a harness and short lanyard at all times, this type of failure is controlled, and is likely to be most pronounced with the jib fully raised and the boom horizontal, as in this case. As such it is unlikely to cause serious injury should it occur.

Regardless of that attention should always be paid to this area during routine inspections and a harness and lanyard always worn.