As it is a custom-built machine specifically designed for SMART project, the possibility of them being used elsewhere is remote. However, there are parts in the TBM that fetches good price as scrap. There is also the manufacturer buy-back option. We will leave it to the end to decide.

Between 15m - 20m deep from the surface to the top of the tunnel

We were careful about our priorities. The first, being the project is primarily a flood mitigation. The motorway is only incidental and complimentary to the main objective. Putting in a motorway the entire stretch of the tunnel would reduce the flood capacity of the stormwater tunnel. In addition, the critical stretch that needs redress in term of traffic congestion is between KL-Seremban Highway and the city center.

In the event the traffic comes to a standstill in the tunnel due to congestion at both ends of motorway (ie Jalan Tun Razak / Jalan Sultan Ismail and KL-Seremban Highway) when there is an urgent need to activate Mode 3 operation, SMART has identified alternatives. In the North, traffic from the motorway heading towards the city center will be temporarily diverted into service road off Jalan Davis and off Jalan Tun Razak.

Traffic from the motorway heading towards the South will be diverted onto East-West Link which is historically not known to have any congestion.

In term of operations, the upstream monitoring facilities and the retention capacities of the two holding ponds and the tunnel give the system operators at least an hour warning for the need to close the motorway to traffic and avail it for flood water diversion. Clearing the road tunnel will only take about 30 - 45 minutes including closing of the gates and cross passage doors, conducting a walkthrough check and opening the flood tunnel barrier. As added precaution, there is no possibility of opening the flood control gates without first closing the road's on and off ramp gates and likewise no possibility of opening the ramp gates without first closing the flood control gates. The two are deliberately linked as part of the scheme's failsafe / defect-proof operation. This is the only way the dual purpose operations could be combined safely in a dual purpose structure.

Four ventilation shafts divide the road tunnel into three, approximately 1km-long sections. These powerful air ventilators would constantly renew the air and maintain the air quality within the motorway. To protect the ventilation system during floods, the systems consist of a series of shafts, each containing and exhaust and fresh air injector. This design enables the fans to be situated outside the SMART tunnel and also allows for smoke control in the event of fire.

Yes

The motorway is only accessible to Class 1 vehicles (cars, MPV, SUV) at speed limit of 50km/hour

The motorway section of the tunnel is fitted with water-tight flood and traffic gates at either end to separate the motorway from the stormwater tunnel for the safety of the motorway users. The flood gates at both ends of the motorway will remain closed at all times during traffic operation and opened only when the tilting road gates in the ingress and egress are closed. The first line of protection against water entering the road tunnel is an emergency gate at each end. There will be five gates at either end of the motorway: two flood gates, two road gates and an emergency gate. Similar gates have been used successfully in the London underground tunnel to prevent flooding.

The TBM moves at an average distance of 10 meters per day. The furthest achieved was about 24 meters, believed to be a world record for this type machine size.