WATER Weights Inc. and Simmers Crane Design & Service Company claim to have completed the heaviest load test ever performed with water bags on an overhead bridge crane.
The test lift of 694 ton (629.6t) was performed at New York Power Authority’s Robert Moses Niagara Power Project in Lewiston, New York USA. Using 20 water bags, each weighing 35 ton, the test took three days from set up to demobilisation, a record time for a test of this magnitude, according to Water Weights. Headroom restrictions in the powerhouse meant that a special lifting beam had to be built for the test. This beam, measuring 52ft (15.8m) in length and standing 8ft (2.4m) high, weighed in at 60 ton (54.4t).
The bags were rigged onto the beam and filled while suspended – minimising floor loading. Gradual application of the load allowed for controlled loading, with the added benefit of allowing identification of any problems before the maximum load was applied.
Water Weights said that using solid test weights for this operation would have meant mobilising 39 semi-truck loads of weights, but as the water bags weighed only 1.5% of the rated load when empty and rolled, all the equipment was moved in three pick up trucks and trailers by four people.
