The slurry shield tunnel boring machine consists of four main parts.

The first is the Rotary Cutter Head with tungsten pick bits used for excavation of soil and disc cutters used for the excavation of rock.

The second part of the machine is the Bulkhead located immediately behind the Rotary Cutter Head. This is where the pressured bentonite slurry shield is formed to provide stability during the tunnel excavation.

The third part of this machine consists of hydraulic rams, which are used to propel the machine forward and to keep the tunnel in its right alignment.

The fourth and the last main part of the machine is the tunnel lining erector used to install the pre-cast concrete lining of the tunnel.

Other parts complementing the main Special Features are two boogies on rails that house electrical, slurry pumping, ventilation equipment
and cable and pipes.

Initial TBM boring.

TBM advances ahead.

Installation of segment lining.

The pre-cast concrete linings for the tunnel are transported continuously to the erector by boogies on rails. These linings are then hoisted and placed in the correct position in the tunnel with the help of vacuum pads attached to hydraulics arms. The arms are ex tended to keep the linings in place while the linings are bolted together.

The void between the excavated ground surface and the linings is immediately filled with cement mortar grout under pressurized conditions to ensure all the voids are fully filled.

For SMART, two Slurry Shield machines are used, both starting from the JKR field area in Jalan Chan Sow Lin. The first machine will head North under Jalan Tun Razak and Jalan Desa Pandan before terminating at the pond at Ampang behind
Gleneagles Hospital.

The second machine will head south under the Jalan Chan Sow Lin and the KL-Seremban Highway next to the Sg Besi airfield before terminating at the existing pond in Taman Desa.