30.08.2016
Underbridge overturn
A truck mounted under bridge work platform overturned yesterday while working on the Sakonnet River Bridge in Tiverton, Rhode Island.
The two men who are employed by infrastructure and engineering consultant AECOM, were inspecting the underside of the bridge from the platform, a six axle Aspen A-75 bucket type unit, owned by N.E Bridge Contractors - which trades as Bridgeriggers. The were harnessed in and managed to remain in the basket and avoided being crushed against the underside of the bridge.
They suffered some minor scrapes and bruises, and were stranded for a while, before they were rescued by another under bridge unit, and a transfer from one platform to the other. They were taken to a local hospital for a precautionary check over.
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The underbridge unit overturned during a routine bridge inspection
A spokesman for the Rhode Island Turnpike and Bridge Authority said that the two men were employed by a contractor which was carrying out a routine inspection of the bridge. He added: “There will be a full inspection into why this vehicle tipped when all the protocols and safety procedures were followed. Anything they may learn from this will be incorporated into future safety procedures.”
The Occupational Safety and Health Administration is investigating along with the authority and the contractor. The Aspen units do not require outriggers, and can travel with the platform deployed.
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The two men are rescued
Good Afternoon Mr Editor,
Lifting Operations are inherently Dangerous as we are always attemting to defeat Gravity, confirmed by this incident above : The Dutch Safety Board (DSB) also reached this conclusion in the Official Report published 29th June 2016 into the Crane Disaster at Alphen-en-den-Rijn on 3rd August 2015. Crane Safety Professionals may find this Report of interest, as it shows what can go wrong when Safety is not Pro-Actively Managed from A to Z. The Relevant Facts of this Report are…..
a. Two Large Capacity Hydraulic Telescopic Mobile Cranes of 400t and 700t WLL were Rigged on Two Seperate Pontoons (Barges), both floating on The Queen Juliana Canal in South Nederlands 030815. The Peinemann Lift Plan shows that the objective was an assymetric Tandem Lift of a 187t Bridge Section at Two Different Radii of circa 10.5 metres and 19 metres from each Cranes Centreline (CL) .
b. One Crane Boom was planned to extend 36 metres, the second to 45.5 metres. The LMI download(s) confirms that one Crane was at 98% of Maximum Rated Capacity, the other at 99%. In both Cranes the LMI had been Overridden by means of the Manual Override switch(s) in the Cab, which silenced the Warning Device(s), see page 178 of DSB Report ?
c. The Risk Assessment & Method Statement ( RAMS) clearly states in Top Right Corner of page 10 that “ Stability Calculations Must be Done” (in advance of the Lift), Yet for unstated reasons this was never done. So when both Cranes took the Weight both Booms deflected in the normal way. This caused Barge number One to List, then Heel, which caused Unchained Crane One to slide on the Steel Deck dropping the OSR Outrigger Leg Jack off the side, this caused the Boom to go backwards which promptly Failed. The Root cause of the List was the Inherent In-Stability of Barge Number one. Within seconds the Entire Tandem Lift was out of Control, with Both Cranes and Load Tipping over onto the Homes of Alphen residents wrecking all. Miraculously No-one was Killed DG.
This comprehensive DSB Report was undertaken by ORCA Offshore and confirms that the root cause of this Incident was the use of Land Based Mobile Cranes which have Low Stiffness at Boom Tip being Operated on Water based Pontoons (Barges) where Horizontal In-stability is always a potential problem, due to Displacement of Water under the Hull. The DSB Report concludes that the Std Rules & Recommendations on how to calculate the Metacentric Centre of Ship Stability, is not sufficent to evaluate Barge Stability requirements for the Safe Use of Land Cranes based on Water and that the Two Cranes Overturning was the Inevitable result of Barge Instability, with NO single Company having responsible for Managing Safety in the Run-up to this Crane Disaster.
Crane Safety Professionals can find the Dutch Safety Board Full Report on www.onderzoeksraad.nl/en
ORCA Offshore Summary Report on Alphen Crane Disaster can be found on www.orca-offshore.com
Fortunately on this occasion above, the men were Rescued Unharmed. Worker Safety is Important.
Kind Regards
Mike Ponsonby