Pigott Shaft Drilling Limited (PSD), the solids separation and mud cleaning specialists have secured another large project in Asia. Following on from their success on the Kai Tak project in Hong Kong, PSD has been awarded the contract for the supply of the Slurry Treatment Plant (STP) on the latest stage of the Circle Line Project in Singapore, Contract C855. The project involves constructing nearly 6 km of tunnels at 6.6m diameter using slurry shield TBMs supplied by Herrenknecht of Germany. The ground conditions through which the tunnels will be constructed are likely to be highly variable, ranging from moderately strong to completely weathered / decomposed Granite (CDG) of the Bukit and Jurong Formations.
When designing the STP particular attention was given by PSD to the fine cleaning capacity of the system with the potential for both TBMs to be tunnelling in the CDG at the same time. With combined flowrates of up to 1800m3/hour and operating up to 24 hrs per day the STP could be expected to remove nearly 3000 tonnes of cuttings per day!
The STP is to be installed and tested during August 2005, with tunnelling due to start in September 2005.