07.09.2011

Crane overturns at DC Cathedral

A 500 ton All Terrain crane has overturned at the National Cathedral in Washington DC.

The crane a 500 ton Liebherr, the flagship of Maryland based Crane Service Company, had been assisting with repair work on the cathedral from damage caused during the recent earthquake. It was rigged with almost full luffing jib and Y-Guy boom support system and had just placed a load of steelwork onto the cathedral roof.
The crane was operating with a long luffing jib

The weather was reportedly stormy at the time with heavy rain and, according to some reports, winds gusting as high as 40 to 50 mph.

Something caused the crane, which was slewed over the side at the time to overturn backwards dropping the boom and jib down onto four parked cars, while clipping two smaller buildings int he grounds. Thankfully no one was seriously injured, although the crane operator was taken to hospital with what we understand to be minor injuries.
The first picture to show the fallen crane clearly

The challenge now is to remove the crane just four days before president Obama is due to speak at the cathedral on the 10th anniversary of the World Trade Centre attacks in New York.
The crane flipped over backwards

Occupational Safety and Health Administration (OSHA) inspectors arrived at the scene shortly after the accident and are investigating.
As it tipped the counterweight segments were scattered

A photo reportedly taken just before the crane overturned

The cause does not appear to be ground related

Comments

strretch67
The conversion has more than just the metric to imperial, European Cranes use 75% charts North American charts use 85% charts.
The math works out to roughly 25% increase. [400t X 1.1 = 440T] [440T / .75 = 586.66T X .85 = 498.66T]
Thus a LTM1400 should be a 500 ton crane.
This is more for the Crane service to get more money as the actual capcity at 3 meters doesn't change being based soley on structural limitations, but you can prove anything with the right math. XD

Oct 18, 2011

Mark Krajci
When looking at the pictures of the accident one has to notice the steel beams close to the crane. Was this steel inside of the radius listed in the load chart?
One thing I checked for in a picture of the jib tip and it showed that the wind speed meter was on the jib tip. Now wether it worked or not I cannot say, but if it was; then the wind speed is recored in the Liccon data logger and this will answer all the questions.
The reason for the accident may not only lie with the operator or the crane but also with the fact that the President of the U.S. was coming to the cathedral to give his 9/11 speech and I am sure they had planned to have the job done and the steel out of there by the time the event came around 3 days later.
So you know what that probably meant - get that job done no matter what it takes!!! Seen this many times and I am sure we all have - this is the result and it is NOT the first time safety went out the window when the job HAD to get done.
Fortunately no one was hurt - and I hope I am wrong about this but it stinks of bad decisions - FROM ALL INVOLVED WITH THE JOB!!!!

Sep 15, 2011

Good Evening Gentlemen,

The Influence of Wind on Cranes and Lifting Operations is well known and extremely well documented in the current publication by Messers Liebherr Werk AG of the same title.
( See version 2 of 2011)

So before setting up the cranes outriggers on Timber Mats and Raising the Boom, someone Snr should always undertake a suitable and sufficient Risk Assessment of Wind speed, Location, Gusts, Terrain, Tall Buildings nearby, Load Shape, Size, Square Area, Wind Loading and Wind Drag, especially on irregular shaped loads like wind turbine blades and hub assemblies.

All of which will then produce a Method Statement to determine How, When and more importantly If the lift should proceed. For without taking account of all these variable factors 24/7 then we are working in the dark and putting ourselves and all others others on the ground at Risk of being Killed by a falling crane. Finally all Crane Drivers should monitor very closely the Upper and Lower Wind Indicators on the in-cab computer display, then compare them with the Mfrs recommended wind speed for that particular jib length, Radius and SWL. If the former exceeds the latter, then the jib should be put down and the Lift suspended till the unsafe wind conditions improve.

Fortunately on this occasion, no-one was killed but on Friday 15th Jan 1988, It was my Father in Law David Stanford (d) of Dublin who was killed by an NCK Crawler Crane, in a lifting operation.

So in the words of Mr J. J. Curran of Detroit ” its not luck, its know how” that is required for safe systems of work in Cranes and Lifting Operations Worldwide.

Kind Regards
Mike Ponsonby BA

Sep 10, 2011

Warwick n/a
Yes that is correct, it is an LTM 1400-7.1, Large US cranes are usual listed as having capacities around 100ton greater than outside USA mainly due to the conversion from Metric Tonne to Imperial Ton just as Groves GMK7450 is advertised as a 450Tonne crane outside US and 550 Ton in the US even though technically 450Tonne = 496 US ton?

Sep 9, 2011

Frank
Hi all, I think this is a LTM 1400-7.1 Liebherr Crane. 400 tonne Liebherr and not a 500 tonne.

Sep 9, 2011