Two years ago, the Australia Pacific LNG project broke ground on Curtis Island, marking the first step in the four year construction of the LNG facility. Last Friday 14 June the Project successfully raised the roof of one of two LNG storage tanks – an event marking the halfway mark on the journey to first LNG export in mid-2015.
The LNG facility, which is progressing on schedule with 2,300 people now working on site, has seen a number of key developments over the past six months, including the completion of the material offloading facility, the arrival of the first modules, and commencement of work on both processing trains.
Kent Anderson, ConocoPhillips’ Downstream Project Manager, said that adding to those milestones, is the raising of the roof on the first LNG tank, which took less than 8 hours to lift and secure the 1050 tonne, 88 metre domed structure almost 32 metres vertically.
“The complexity of the roof raise is in itself a construction feat, with 1050 tonnes of carbon steel, stainless steel and aluminium materials lifted into place by low air volume created by fans – in principle, not dissimilar to blowing up a camping air bed.
“The five fans, which are almost 80 cm in diameter and with 75 horsepower motors, gradually build the volume and create enough pressure to lift the roof from the ground to the top of the tank. The fans are so effective that no cranes are required at all,” Mr Anderson said.
Once the roof reaches the top of the tank, it is simultaneously secured into place by a crew of specialised welders and boilermakers, a portion of the 350 CB&I work forcerequired to safely manage and oversee the lift.
The external domed roof is made of carbon steel, which will act as the support for a reinforced concrete roof, and the inner tank roof is made of aluminum, chosen for its properties at cryogenic conditions, allowing for the LNG to maintain its -161o C temperature prior to being loaded on to the LNG tankers.
“With the roof of the first tank now in place, we will look to raising the roof on the second tank in coming months, and progress the remaining works on both LNG storage tanks,” Mr Anderson said.