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Outriggers suspected in crane overturn

A crane overturned at a job site on the University of Maryland Baltimore County campus yesterday, after the outriggers appeared to have shifted on soft ground.

No one was hurt in the incident and little damage was done apart to the crane itself. The unit was a four axle Grove truck crane owned by local company Chesapeake Crane Service.
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The outriggers shifted on the soft ground

The crane was working with most of its main boom extended and swingaway extension stowed. The boom narrowly missed the corner of the new building and landed on some façade scaffold.
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The crane's boom came down on some scaffolding


Good Evening Mr Editor,

My Learned Friend Ken Martinek is correct when he says that the Grove TMS 700/E crane can indeed be operated at upto Maximum Boom Length with only One (1) Ballast Block of 5500 Lbs ( Or 2495 Kgs) in place. But close scrutiny of page 13 of the Grove Duty Chart reveals that this is subject to Three (3) Major Qualifications.

1. Maximum Outrigger Spread of 20 Foot Wide is Required.
2. Max Boom Angle is then Restricted to circa 46 degrees.
3. No Crane Stability Data is available. ( This is clearly Printed on the Duty Chart)

Therefore given that this Crane did indeed Tip over, the Root Cause of this Incident may I suggest was an imbalance in the manner in which this Crane was Rigged for this lift. The Outriggers sinking into Soft Ground was simply the Effect, not the Cause. For whenever 33% of the available Ballast is chosen as an option, it leaves a Crane Vulnerable to High Ground Bearing Pressure through the Outriggers on the jib side. Then if they are actually set on Soft Ground with None or Inadequate mats, the Crane is set up for a fall. Which did indeed occur on this occasion, as per the the scene depicted above.

Miraculously No-one was Killed or injured by the Dangerous Occurrence, not an 'Accident' as it was not Accidental but was entirely Foreseeable. ( See London's Court of Appeal Judgment in R.v. Tangerine Confectionery [2012] CA. EWCA 2015 re Forseeability). Unlike 18 previous occasions in 2011 in the UK where a Fatality occured and on 15th January 1988 when my Father in Law David Stanford (d) was Killed by a Crane.

To summarise PPPPPP is my favorite motto, so please consider it at all times where Crane Safety is concerned. Perhaps the CEO of Chesapeake Crane Service would care to Investigate this matter and then share his knowledge with us, so we can all Learn from it ?

Kind Regards
Mike Ponsonby BA

Apr 20, 2013

Ken Martinek
I just want to clear up a misconception. The crane appears to be a TMS700E and there is a load chart for a single counterweight slab (2495 kg)with fully extended 110'(33,5m) boom.

Apr 10, 2013

This incident reminded me of the overturned Costa Concordia cruise ship off the coast of Italy.

Apr 6, 2013

It is possible that the Operator did not program the LMI System to the right configuration of counter weight and boom length.

Apr 5, 2013

Good Evening Mr Editor

The Crane depicted above appears to be a Grove TM70 model. For which the Mfrs Duty Chart clearly shows that Three Counterweight Slabs are recommended for such an extended Boom Length, working at such a Radius.

This then raises a number of questions...

1. Why is this Crane depicted with only One Counterweight Slab in Place on the rear of this overturned Cranes Superstructure ?
2. Where were the Other Two Slabs ?
3. Why was Crane Mfrs Instructions re Ballast Ignored ?

Moreover was the Lack of the Mfrs Recommended Number of Counterweight Slabs, actually the Root Cause of this Crane Overturn Incident in Maryland ?

This Incident could never be described as an Accident, for to operate any Crane with Insufficient Ballast in place on the rear of the Superstructure, makes it entirely Foreseeable that it will Overturn given enough Boom Length and extended working Radius.

Perhaps the CEO of Chesapeake Crane Services Inc would care to enquire into these dangerous matters and advise us when Time Permits ?

Kind Regards
Mike Ponsonby BA

Apr 4, 2013

This happens when the pressure is bigger than the resistance of the ground.
I can't understand why cranemen continue keep setting cranes up on too soft ground or too short near an excavation. Doubts about te resistance of the ground???:use bigger mats! Keep it safe guys!

Apr 4, 2013

Craniac 1
To add a little texture to the story, with information from The Baltimore Sun-
Elyse Ashburn, director of communications at UMBC had this to say- ... "the 70-ton crane with a 100-foot boom was not big enough to cause any severe damage."

That someone could claim a 70 ton crane is not big enough to cause severe damage is ludicrous, at best. Using such a person as an authority for a news story is equally embarassing. I am glad everyone went home to their families!

Apr 4, 2013
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