WHSQ issues vehicle loading crane safety alert

Particular Palfinger model alert spurred by operator incident last year

WHSQ issues vehicle loading crane safety alert
Main pin, secondary steel latch and plastic latch in locked position with stabiliser stowed


Work Health and Safety Queensland (WHSQ) has highlighted the risk of unintentional extension of stabilisers on vehicle loading cranes (VLCs).

In particular, operation of the stabiliser locking system on some models of Palfinger VLCs is of concern to the state’s safety authority.

The alert was prompted by a 2020 incident where a left-hand stabiliser on a Palfinger PK 10000 VLC extended while the truck was being driven and struck another vehicle.

No injuries occurred but the incident had the potential to cause a fatality, WHSQ noted.

The cause of the failure has not been determined but "an initial investigation indicates the truck driver made an attempt to check the stabiliser was locked before driving.

"The VLC involved in the incident was manufactured in 2004 and was not fitted with a warning device in the truck cabin to warn the operator that the stabilisers were extended.

"It is likely that if the crane had been fitted with a visual and audible warning device on the stabiliser, in compliance with Australian Standard AS 1418.11:2014 Cranes, hoists and winches Part 11 Vehicle-loading cranes, the incident could have been avoided."

A WHSQ incident alert on falling load incidents, here

WHSQ noted the VLC was fitted with the Palfinger double locking system that includes a main locking pin and a second lock, which is similar to that provided on some contemporary Palfinger cranes.

"To pack the stabiliser away, the handle needs to be rotated to lift the locking pin out of the locked position before the stabiliser can be pushed in," it said.

"Once the stabiliser is manually retracted, the main pin drops back into the locked position and the second lock engages.

"A plastic ’safety’ latch then needs to be manually moved to the locked position

"A spring incorporated into the design of this latch helps prevent the latch from being closed unless the stabiliser is in the transport position.

"However, it appears that it is possible to inadvertently overcome the spring force and close the safety latch while the stabiliser is locked in the extended position."

Some later model Palfinger cranes have a similar stabiliser locking system design to the VLC involved in the incident while later models include a warning system that uses a proximity switch to monitor the safety latch’s position, WHSQ added.

If the safety latch is open, the system alerts the operator.

The warning system does not, however, monitor whether the stabiliser is also in the transport position.

As result, the system will not alert the operator if the safety latch is inadvertently closed with the stabiliser in the extended position.

"It is possible that an operator can inadvertently close the safety latch so that the warning device will not activate.

"Further, on older models where a spring is not provided on the safety latch, the latch can be easily closed when the stabiliser is fully extended as there is no spring tension to resist this action.

"Although the proximity switch can be retrofitted to some older Palfinger models, the spring cannot always be retrofitted."

WHSQ offered the following points of advice:

  1. All vehicle loading cranes: All vehicle loading cranes should be fitted with both a primary and secondary locking system fitted to each stabiliser and a visual and audible warning device in the truck cabin that warns the truck driver when stabilisers are not locked in the transport position. Cranes receiving a major inspection in accordance to AS 2550.11 Cranes, hoist and winches – Safe use Part 11 vehicle loading cranes should have these features fitted if they are not already provided on the crane.
  2. Palfinger cranes - Older model cranes with no springs on plastic safety latch: On cranes where the spring is unable to be fitted due to the crane design, Palfinger Australia should be approached for advice1.
  3. Palfinger cranes – Inadvertent by-passing of the plastic safety latch: Provide workers with additional training to re-enforce the need to follow the Palfinger operating instructions so that the safety latch1 is not engaged when the stabiliser is in the extended position.
  4. Palfinger cranes - Cranes with broken springs on plastic safety latches: Have the broken parts replaced and provide workers with additional training

The full safety alert is available here.

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