TERRATEC’s Ø4.39m EPB TBM breaks through on Ninth Bangkok Water Supply Project in Thailand.
TERRATEC is pleased to announce the successful breakthrough of a Ø4.39m EPBM, S105, on the Ninth Bangkok Water Supply Project in Thailand. The milestone was achieved on 23 June 2025, marking the completion of a challenging 3,760-metre tunnel drive under a major highway— delivered with surface settlement maintained within controlled limits despite complex geological conditions.
TERRATEC 4.39m diameter EPBM (S105) was custom-engineered to tackle the specific geotechnical challenges of the project alignment. Featuring a soft ground cutterhead with a spoke-type arrangement, injected tungsten carbide cutting tools, and a maximum cutterhead rotation of 2.4 rpm, the machine was tailored to manage Bangkok’s notoriously variable soil conditions, including fine sand, clay, and high groundwater pressure.
The machine was launched following TBM assembly on 14 February 2023 and completed its full 3,760m drive with consistent performance and face stability throughout.
TERRATEC S105 is one of three EPB TBMs supplied for the Ninth Bangkok Water Supply Project—an initiative led by the Metropolitan Waterworks Authority (MWA) to expand and upgrade the city’s potable water distribution network. The project, managed by contractor Italian-Thai Development PCL, includes more than 9.0km of tunnelling in total.
Designed to work within the constraints of densely populated urban areas, TBM S105 was equipped with active articulation, tail skin grouting, and automated bentonite and foam injection systems to ensure minimal surface impact. TERRATEC field service engineers provided full-time technical support throughout excavation.
This achievement reinforces TERRATEC’s track record in delivering high-precision EPBM solutions across Southeast Asia and underlines the company’s commitment to safe, efficient, and technically sound tunnelling in urban environments.
TERRATEC has a well-established regional base in Thailand, having sold its first machine in the country more than ten years ago for the Metropolitan Rapid Transit (MRT) Blue Line Extension Project. With outstanding tailor-made robust TBM design, prompt onsite assistance, a readily available stock of TBM spares, and specialised support throughout the tunnelling operation, TERRATEC has become the country’s leading TBM supplier.
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