After a 5.1km journey, a Lovat TBM has broken through the first connection between the existing sewer networks and the new works as part of Singapore’s Deep Tunnel Sewerage System (DTSS).

After starting its journey in January 2003, the Lovat model RME129SE Series 14900 machine bored through predominantly marine clay, erecting a 3.2m external diameter reinforced concrete lining consisting of five segments plus a key. All of the alignment was below the water table.

The Public Utilities Board (PUB) of Singapore awarded the US$26.4M Kim Chuan Link Sewer Tunnel to the Tiong Seng-Dong-A Consortium of contractors, who then commissioned Lovat to supply components and carry out engineering work on the 3.28m diameter TBM owned by Dong-A Geological Engineering Co. Ltd.

The works are part of Phase One of the DTSS scheme, which includes a further 12 link sewers totalling 50km in length to connect to the new system. The Kim Chuan works are the first of the link sewers to have broken through into the deep tunnel that is being constructed. Eventually it will transfer flows from three pumping stations into the deep tunnel, serving a catchment area of Paya Lebar to Marina South. In addition, the link has been designed to accommodate future flows from new developments in the area.

A breakthrough ceremony was held on 28 October, attended by the Senior Parliamentary Secretary for Defence and the Environment and Water Resources who said: “The high-technology tunnel boring machine had been used to construct the Kim Chuan Link Sewer, this method was suitable as it obviated the need for numerous jackings along the 5.1km route, which is mainly along built-up areas. Disruption to residents in the vicinity of the construction was greatly minimised as a result.”