Only very few names of tunnel projects are this much to the point: SMART as the short form for "Stormwater Management and Road Tunnel". The tunnel project realizes a worldwide unique concept. The tunnel has three levels. The lowest one operates as a sewage tunnel throughout the year. The two upper levels are two-lane roads, each one for one direction of traffic. If during the monsun season heavy rainfalls and an overstrained sewage system cause floods, the tunnel's road levels can be closed for traffic and can be used for storing and diverting flood water.
Two Mixshields "Tuah" (S-253) and "Gemilang" (S-252) started tunnelling in 2004 for this seminal project. By no means was it an easy job they were facing. Hard rock and softground were changing frequently and karstic cavities demanded extreme caution while tunnelling. The Sonic Softground Probing System (SSP) as well as probe and injection drilling systems had been installed on the machines in order to facilitate safe and efficient tunnelling.
"Gemilang" reached its target in April 2006, "Tuah" one year later in April 2007. Both three-kilometer-long road decks were opened for traffic on May 15, 2007. The overall 9.7-kilometer-long stormwater tunnel was opened to traffic one month later.