Weighing, skidding and load-out of a hull, South Korea
ALE has performed the weighing, back skidding and load-out of an Appomattox hull, weighing over 40,440t, in South Korea. This is the heaviest module ALE has ever loaded-out by hydraulic skidding.
ALE performed the skidding of the half hull from water side further on the quay using 48 skid shoes. This was undertaken so space could be created for the client to complete the hull using sheerlegs.
A few days prior for the load-out, ALE performed the weighing using a 112 point weighing system comprising of hydraulic jacks and load cells. The weighing was done with an accuracy of ±0.5%
To perform the load-out, ALE installed 96 skid shoes under the hull, including 48 of ALE’s new 800t skids shoes. The skid shoes were divided over eight tracks and moved forward using 32 push pull units. The skidding was controlled using the new ALE computerised skidding system.
The ballasting and real-time barge monitoring was undertaken by ALE-Offshore Services, a specialist offshore division. The ballasting was undertaken using ten 24PS pumps, each pump capable of pumping 2,400t/hr capacity, and 47 10PS de-ballast pumps, each with a capacity of 47,000t/hr, to achieve a combined capacity of 71,000t/ hr.
The maximum deflections of the barge were set within a very tight window. Therefore, the maximum skidding speed was set at 8m per hour
The load-out took 19 hours and the entire operation was completed in five weeks.