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TERRATEC EPBM breaks through in Thailand helping Samui Island keep its title as a top Asian tourist destination
31 August 2022
TERRATEC EPBM breaks through in Thailand helping Samui Island keep its title as a top Asian tourist destination

Thai contractor SCG (1995) Co Ltd. uses TERRATEC S48C refurbished Earth Pressure Balance Tunnel Boring Machine (EPBM) to excavate a 1.1km tunnel for the Samui Island flood control system.

TERRATEC is proud to announce the completion of Samui Island Water Tunnel Project in Thailand. The tunnel was completed using a refurbished TERRATEC 3.2m diameter Earth Pressure Balance Tunnel Boring Machine (EPBM) by contractor SCG (1995) Co. Ltd. 

The project owner, Department of Public Work and Town & Country Planning Authority had awarded the contractor SCG (1995) Co. Ltd. The contract is to construct a 1.1km long tunnel for the Samui Island flood control system. The tunnel is designed to alleviate flooding and to drain the flood water on Samui Island from busy areas to the ocean.

Samui Island is an island off the east coast of Thailand and it is Thailand's second largest island after Phuket. Each year, there are more than 2.7 million tourists. The island faces severe flood problems and the tunnel is intended to ease the flood water. Being part of the main Ring Road revitalization and improvement project, the water tunnel will significantly improve the rainwater collection from roadway run-off along Samui's main ring road.

Featuring a classic soft ground open spoke cutterhead design, with knife bits to assist break-in and break-out of the steel fibre reinforced concrete shaft eyes, the EPB machine has coped extremely well with the geological conditions along the alignment, which consist of dense sand, stiff to hard clay and decomposed rocks with a groundwater head of about 2 bars.

The receiving shaft sized in 5 x 9 meter, is located at the bottom of two hills where the flood problem prolongs. The flood water will be drained through the new tunnel and connected with a 500m open canal to the ocean. With TERRATEC’s non-tuck hose system, muck can be easily transferred to muck cars and out to the surface.

Machine operation was 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. Tunnelling operations were closely observed throughout the manoeuvre via a settlement monitoring programme.




Prior to the Samui Island Water Tunnel project, the 3.20m diameter TERRATEC S48 Earth Pressure Balance Tunnel Boring Machine (EPBM) was operated for Bangkok Metropolitan Electricity Authority’s (MEA) Phra Khanong Cable Tunnel Project in Bangkok, Thailand. The machine was operated by Thai contractor Nawarat Patanakarn PCL to excavate a sharp 32m-radius curve as it exited the project’s launch shaft in order to negotiate the piles of an adjacent expressway ramp.

To achieve this challenging curved alignment, the TERRATEC machine was manufactured with an extreme X-type articulation system that provided a maximum articulation angle of 6.6-degrees. Designed to accommodate a new high-voltage cable system, the Phra Khanong Cable Tunnel Project was the first of a series of planned tunnelling projects by the MEA that were being built to meet increased power demands in the Thai capital.


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, readily available stock of TBM spares and specialised TBM support throughout the tunnelling operation, TERRATEC has become the country’s leading TBM supplier.

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