Reliable solutions for efficient tunnelling on the HS2 project

• Name

  MC tunnelling expertise in demand for europe's largest infrastructure project

• Country

  United Kingdom, 2025

• Fields of Expertise

  Tunnelling

• Categories

  Tunnelling Systems

• Products

  MC-Montan Drive FL 04
  MC-Montan Drive CA 02
  MC-Montan Drive LB 02

The HS2 project is the second high-speed line in the UK following the successful completion of the HS1 high-speed line which connects London with the Eurotunnel under the English Channel and was built between 2003 and 2007. With a route length of 225 km and a planned completion date of 2031, HS2 will reduce the journey time between London and Birmingham from 80 to 42 minutes and offer a capacity of 14 trains per hour at a speed of up to 400 km/h. The costs for this mammoth project amount to the equivalent of more than €120 billion. A particular challenge is the approx. 11% tunnel section – 21 km in twin-tube tunnels, totalling approx. 42 km of tunnels running through the hilly landscape of the Chilterns and under the metropolis of London. Six tunnel boring machines (TBMs) with a diameter of 8.48 to 9.5 m are being used in the construction of the HS2 tunnels, which began in 2022.

Accelerated construction progress thanks to MC's innovative solutions

MC’s tunnelling team helps tackle these enormous challenges with high-quality products and comprehensive service. With MC-Montan Drive FL 04, a special soil-conditioning foam, the London clay can be driven up quickly without sticking to the TBM. MC-Montan Drive CA 02, an eco-friendly, biodegradable anti-clay polymer for TBMs, reduces clay adhesion, clogging, tool wear, torque, and energy use while improving soil removal. Both products ensure faster and safer tunnelling. In addition, the innovative ArtSoil™ technology recently launched by MC is also being used in the HS2 tunnels. This technology consists of the liquid long-chain polymer MC-Montan Drive LB 02 which is used in com- bination with a high-density slurry (HDSL) for demanding TBM launch and heading situations.

 

The tunnel tube also has to be stabilised by filling the space between the tunnel segments and the surrounding soil. This is performed using MC-Montan Grout, a backfill mortar previously tested in the laboratory to confirm its mixing stability and fully qualified in subsequent site trials. Thanks to its special composition, MC-Montan Grout ensures even distribution of the backfill material and speedy curing, which in turn provides the basis for rapid construction progress. Damaged concrete elements are repaired with the fire resistant, fibre-reinforced PCC/SPCC concrete replacement Nafufill KM 250 , which is ideal for tunnel construction thanks to its outstanding properties. Cracks in the concrete are filled using MC-Montan TR-X, a swelling, elastic hydrogel sealant that increases the stability of the tunnel construction and ensures water impermeability.

Stable tunnels thanks to MC-Bauchemie

MC's solutions are helping ensure the safe yet rapid construction of the HS2 tunnels. This major project impressively demonstrates how specialised products and tailor-made solutions from MC-Bauchemie can accelerate progress in tunnel construction. With innovative soil-conditioning products as well as high-performance backfill mortars and concrete repair products, MC is making a decisive contribution to overcoming the demanding challenges of the project and achieving the planned completion date of 2031.