20.09.2012

Crane boom swipes school bus

The boom of a crane being transported slewed in to the road and caught a school bus in Hillsboro, Oregon yesterday.
The boom caught the bus on the drivers side, but he escaped with rib and shoulder injuries

The boom struck the bus with such force that it lifted it off the ground, but narrowly missed hitting the driver full on. He was though taken to hospital with rib and shoulder injuries. Thankfully the children had already been dropped off and only the drive was on board.
The bus was lited off its wheels, such was the impact

The crane, an old truck mounted Link Belt was being transported on a low boy trailer when the superstructure lock gave way, or was never secured in the first place, allowing the boom to swing out in the oncoming bus.
The crane on the low-boy


Vertikal Comment

Everyone involved was very lucky here, with different timing this could so easily have been a major tragedy. The boom does not appear to have been tied down or blocked at all, either that or any tie downs were not sufficient to hold the boom as it slewed free.

Whether a boom lift, 360 degree telehandler or a crane Superstructure slew should be pin locked where possible and the boom and or superstructure strapped down securely. The damage that can result from a free swinging boom on the road is devastating and usually proves fatal to innocents who just happened to be in the wrong place at the wrong time.

Comments

Good Afternoon Mr Editor,

Thank you for publishing this appalling series of photographs, as this is a perfect example of the Driver not asking himself " What If " (The slewing brake fails while that Crane is on my Trailer ?) and then not Chaining down each side of the Jib to that side of the Trailer, to stop any unwanted Side-to-Side movement while in-transit.

This Dangerous Incident could never be described as an 'Accident' as it was not Accidental, because it was entirely 'Foreseeable' for anyone who cared to look.

"Never trust a slewing Brake' was and still is my personal motto ( From the excellent philosophy of those brave Men and Women in the FDNY who say 'Never trust a Truss). With all Machines requiring Chains to be applied as Load Security to stop movement to the front, side and rear of the trailer in ratios of 100, 80 and 50% of the Cranes Unladen Weight.

From this camera angle, the Crane looks like a Link Belt HC-108b (?) and if it is, then this machine with Tubular Steel Jib has an unladen weight of circa 96480 Lbs, from Mfrs Spec sheet. ( or 48 short US tons or 43 metric tonnes in EC states). This means that Ten (10) or more 5 ton SWL chains and tensioners should be used to secure it on that trailer, with one chain expressly applied to each side of the Jib to stop any and all unwanted sideways movement.

Ideally two chains should also be applied to the rear of the Superstructure and anchored on each side of the Ballast Block, arranged in a large X and terminating on the opposite side of the trailer. Then and only then can the Crane Upper works be correctly restrained from slewing to one side or the other and Hitting a School Bus going in the Opposite Direction, the very subject highlighted on this excellent Blog on Thursday 30th August 2012.
( See Truck Mounted MEWP parked on Concrete Overbridge in Germany with Hydraulic boom dangerously close to traffic passing underneath that same Bridge, with no Warning Signs or other Traffic Control measures in place. )

Please, please dont ever rely on weight to hold a Crane in place, as its only a matter of Time, Speed and Centrifugal Force before it will move on the trailer.... and the next time it could be your Children riding on that School Bus ?


Kind Regards
Mike Ponsonby BA.



Sep 23, 2012
This website is using cookies to provide an optimised user experience. By continuing you are agreeing to the use of cookies. More Info
OK