Three TERRATEC EPBMS delivered for Ninth Bangkok Water Supply Tunnel


A total of three new TERRATEC TBMs will take part in the Metropolitan Waterworks Authority’s Ninth Bangkok Water Supply Improvement project in Thailand.

TERRATEC celebrated the successful Factory Acceptance Tests of two new 4.39m diameter Earth Pressure Balance Tunnel Boring Machines (EPBMs) and one 4.8m diameter EPBM destined for the Metropolitan Waterworks Authority’s Ninth Bangkok Water Supply Improvement project in Thailand. The events were attended online by representatives of Bangkok’s Metropolitan Waterworks Authority (MWA) and contractor Italian Thai-Nawarat Joint Venture.

The new TBMs will be used to build a water tunnel at the west of Bangkok with a total length of 9.1 km with tight alignments. This project is a joint venture between Italian-Thai (ITD) and Nawarat (NWR). ITD will operate two TBMs (S105 & S106) and NWR will operate one TBM (S102).

To accommodate the alignment requirements of the project, the TERRATEC machines are designed with active-type articulation that can accommodate the minimum radius curve of 90m and 80m. This will mark the 6th, 7th and 8th “tight radius” machines by TERRATEC operating in Thailand.

The geological conditions along the tunnel alignments will consist of silty clayey sand, very stiff clay to hard clay and therefore the TBM’s soft ground cutterhead features a spoke design with a 70% opening ratio and copy cutters.

Traditionally reinforced, 250mm thick by 1200m wide, Universal reinforced concrete segments (4 + 1) will be installed as the machine progresses and a secondary steel lining will be inserted after the completion of the tunnel.

Muck removal, segment transport and supply of consumables will be via rail-bound equipment using battery locomotives.

Designed to increase the water supply capacity, the Ninth Bangkok Water supply improvement project is one of a series of tunnelling projects being undertaken by the MEA, which are being built to meet increased water demands, reduce water leakage and improve water quality in the Thai capital.


Machine operation will be assisted at all times by TERRATEC’s highly-experienced Field Service staff, providing quality after-sales support to ensure optimum performance and successful project completion.

Following the successful factory acceptance tests, the machines will be now shipped to Thailand and are expected to arrive at the end of 2022. The TBMs will then be transported to the project site with excavation due to commence early next year.


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