18.02.2011

Land Rover chassis failures

We have received several reports of a ‘catastrophic’ structural chassis failure on at least five Land Rovers fitted with aerial work platforms.

The reports began coming in almost two weeks ago and concerned Land Rover-based work platforms being used in the UK by Fountains forestry working on a contract to Central Networks. The Gardner Denver platform installation had had been officially approved and signed off by Land Rover.

The chassis on the units concerned are all said to have broken just behind the cab, splitting the machine in half.
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The first failure was on a 2009 Land Rover Defender 130 - the chassis fracturing in front of the radius arm connecting the rear axle to the chassis.

Initial reports suggested that the problem was caused by the Overland cab extension forcing the platform to be fitted further back from the engine, however there are reports of other platforms with regular cabs having also failed, seeming to rule out this as a possible cause.

The first machine failed on the evening of 24th January and was a 2009 model Land Rover Defender 130 being used by Fountains. The machine’s two chassis rails that support the vehicle’s body, engine and transmission fractured.

Fortunately the incident occurred as the vehicle was being parked and no-one was injured. The driver heard a loud band – a result of the chassis failure and the platform’s boom came down onto the roof of the cab.
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The chassis failure with the rear radius arm fixing to the bottom right.

Fountains had a total of five Land Rover platforms on the contract – three Defender 130s and two Defender 110s.
The remaining four were inspected and revealed hairline fractures on the Defender 130s at the same place as the first failure. All four remaining machines were immediately quarantined. Later reports suggest that five machines are now affected.
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Underneath the vehicle with the front support to the left and rear radius arm in front of the wheel.

We have tried repeatedly and systematically to speak with both Gardner Denver and Land Rover in order to include for their comments but both have declined to return out calls.

We do know that in 2009, Land Rover was informed directly about concerns regarding its installation recommendations by at least one other lift manufacturer. That manufacturer has since refused to follow Land Rover’s installation guidelines which it considers inadequate.

We will update this report as soon as we hear from either Gardner Denver or Land Rover.

Vertikal Comment

This is a hard one, in that structural failures arise from time to time that are not related to design but to exceptional/extreme use, overload or one-off and batch errors in welding or material specification.

However in this case much, although not all, of the evidence suggests that it is likely to be related to the installation design. It is always a challenge fitting a work platform or crane to a commercial chassis. The two have totally different needs.

The commercial chassis is usually designed to flex in order to absorb and cope with high speed road conditions, the platform though needs to be as rigid as possible – flex is not something you appreciate at 12 metres.

The marriage of the platform sub-fame to the chassis is therefore critical, the sub-frame should not supress the vehicles need to flex down its entire length or it will change its road performance. However once the lift is jacked up on outriggers the chassis is semi-suspended and the manner in which the lifts movements are transferred to it is also important.

And finally the way in which the outriggers are retracted can have an impact. If the machine is jacked to the maximum height, and the front jacks are retracted first, the front tyres can be forced into the ground which has the effect of trying to break the back of the chassis. Do this repeatedly and………

The sad thing here is the wall of silence we have faced from the two manufacturers. There are hundreds of these machines at work, often travelling on the highway at speeds of 70mph or more… the possible repercussions do not bear thinking about.