The project involved a total of 143 lifts, 31 of which were carried out using the 1,600t capacity Terex CC 8800-1 crane and two lifts installing two advance gas reactor (AGR) absorbers each weighing 1,300t with the crane in its Twin format.
The lifts were planned by Al Jaber site manager Sevi Phillip over a period of 18 months with the two AGR absorber lifts critical in the company being awarded the contract. With the single boom 1,600t capacity CC 8800-1 crane already on site to carry out the smaller capacity lifts, the crane was then adapted to SSL Twin configuration by adding the second boom to lift the two AGR absorbers.
Once fully rigged in Twin format, the self-propelled modular trailers (SPMT’s) used to move the huge columns into position were also assembled. Each absorber was raised from the horizontal to the vertical using the CC 8800-1 Twin crane as the main lift crane and using a tail frame to control the base of the absorber.
Once the CC 8800-1 Twin crane lifted the absorber clear of the SPMT’s, the trailer was moved out of way and the lift continued until the column was vertical. At this point the tail frame was then removed leaving the crane to carry the whole weight of the absorber.
Next the crane slewed through 90 degrees and placed the column into its final position on the specially prepared foundation. The Twin was then partially de-rigged so that it could track a short distance into the correct position to carry out the second lift and then be re-assembled to carry out the identical lift sequence with the second AGR absorber.
"We were all very pleased with the crane and how it performed. Everything went according to the plan – it was a dream come true!" said Phillip.
"We were all surprised how compact the CC 8800-1 Twin was given its huge lift capacity. There were 27,000 people on site so space was at a premium.
