In order to view all images, please register and log in. This will also allow you to comment on our stories and have the option to receive our email alerts. Click here to register

JLG to announce SkyGuard

We understand that JLG will shortly announce the details of its new control box protection system, which is expected to be unveiled at Intermat next week.

The system has been on test and is, we understand, soon to be ready for launch. We can bring you most of details now as we have managed to obtain the basic details of the device along with a photograph.

The heart of the SkyGuard concept is a pressure switch mounted to a short bar above the control panel, the rubberised moulding of the switch is U-shaped and sensitive to activation from multiple directions.

It can be set off by any substantial contact no matter the direction, with a pressure of around 23kg required to activate it.

Once activated all machine functions are stopped immediately and a loud horn is sounded. In the case of inadvertent activation the machine can be reset by the operator simply removing his foot from the ‘dead-man’ foot switch. A flashing blue warning light is also available.
Please register to see all images

JLG's SkyGuard crush protection system

The system is unique in that as soon as the switch is activated, not only does everything stop, but the functions that created the trapping situation - whether that be drive, lift or telescope - will automatically reverse in order to help reduce the pressure. This is thanks to the memory function in the control system.

A manual override of this and the control lock-out is also fitted to allow the operator to rescue himself, while the lower controls will still override all upper control functions, allowing a ground crew to effect a rescue.

In the case of a shock load, such as when the platform is moved rapidly upwards due to the wheels at one end of the chassis dropping into a depression, the switch bar is designed to shear, working along the same lines as a crumple zone of a car. Thus the switch will have activated and then additional space is created by the collapse of the bar.

We understand that SkyGuard will initially be available on all JLG diesel/gas powered booms and can be offerered for retrofiting to units that date back at least to 2009 - possibly earlier.

Vertikal Comment

The information that we have been able to obtain is of course not fully comprehensive, we expect that JLG will announce the details of the new system on Monday at Intermat. However based on what we have learnt the system seems very comprehensive and builds on the basic principles introduced on Lavendon’s Sky Siren and Niftylift’s SiOPs.

However the automatic reverse function and collapsible bar are innovative additions.

As you might ascertain from our current online editorial, we are not fully convinced of the need for such devices and have some concern over how they might be adopted. However this system appears to ‘tick all of the boxes’ and, as far as any system can, will help avoid most crushing incidents – as few as there are.

The success of this device will depend of course on cost and reliability. We look forward to learning more next week.


Neil Birchall
Another addition to the list. Seems less intrusive than the Genie and AFI anti crush systems and very similar to sky siren. Am A little surprised that JLG have done this as their machines already have numerous systems to prevent so called involuntary operation ie cut off on foot pedal, lifted collars on drive and lift controls. Nevertheless the industry is driving the need for these devices therefore we must address the issue but as per the editorial am still not convinced that these methods are the way forward.
Neil Birchall

Apr 13, 2012