The 33km subway – the first underground railway system in the Philippines – will connect 17 stations along the route from Valenzuela City to the Ninoy Aquino International Airport Terminal 3.

The two tunnel conveyors for package CP101 will work on the section between the Metro Manila Subway Depot and Quirino Highway.

They are 1509m long and operate at a rate of 225m3/hour. With a single pulley head drive power of 150kW, the conveyors can handle the various materials, including sandy gravel and boulders up to 400mm in size, extracted by the TBM along the entire length of the belt.

The electric conveyor drives incorporate electronic variable voltage variable frequency (VVVF) controllers for each motor to ensure smooth starting, load sharing, and precise control.

Hydraulic tensioning is employed for horizontal cassettes, to provide accurate take-up tensions and reliable control. The carry and return roller sets are wider than standard to allow for enhanced belt wander tolerance and improved control in horizontal curves. Two-roll vee-return idlers are used throughout the conveyors to maintain proper return belt tracking.

Terratec says its patented advancing tail piece levels the conveyor using an active hydraulic system to match the steering/rolling position of the TBM. This enables the smooth negotiation of horizontal and vertical curves.

The conveyors are designed to handle both steady state and unsteady conditions, including acceleration, controlled deceleration, and unpowered stopping for loaded and empty conditions.

The excavation is projected to yield approximately 1.2 million m3 of soil, and overall, the alignment is expected to generate around 7.4 million m3 of soil.

In addition to the conveyors, Terratec’s group company JIM Technology will supply six TBMs. A total of 25 TBMs will be used on the subway project.

The Metro Manila Subway is due to be completed in 2028 and to carry up to 370,000 passengers a day.