Weldable Steel Sleepers for Tunnel TBM

For Tunnel Boring Machine (TBM) projects, steel ties (also known as tunneling ties or sleepers) are specialized rail supports engineered to handle extreme industrial loads on the curved, non-flat surface of a tunnel invert. 

Specialized TBM Tie Designs

• Curved Invert Support: Unlike standard ties, these are custom-designed to match a specific tunnel diameter. This allows them to provide stable engineering support directly on the concrete segments without the need for additional blocking.

• High Load Capacity: These ties are engineered for the punishing haulage of muck trains and gantry equipment. Axle loads of 45,000 lbs on 30-inch spacing have been successfully implemented in major projects.

Weldable vs. Bolted Options:

• Weldable: These provide a permanent, seamless connection with higher structural performance and rigidity, often used for critical gantry rail sections.

• Bolted: Often preferred for temporary logistics tracks because they are easier and faster to install, adjust, or dismantle as the TBM advances.

• Staggered Clip Ties: A specific design featuring stationary clips at alternating ends (inside on one end, outside on the other). This allows for the insertion or removal of a tie without disturbing the track gauge, which is highly efficient for rapid track maintenance behind an active TBM.

Key Benefits for TBM Logistics

• Reduced Profile: Steel ties are significantly thinner than concrete alternatives, saving critical vertical clearance in tight tunnel bores.

• Durability: They are typically treated with hot-dip galvanization to survive the harsh, humid, and corrosive underground conditions of a boring operation.

• Logistical Savings: Because they are lightweight and stackable, they are less expensive to handle and transport into the tunnel compared to bulky concrete sleepers.

Signum Rail Fastening offers a wide range of sleepers for different purposes. We customize the matching steel sleepers and track fixing system according to the size of the tunnel and the type of track used. The excellent technical team and processing experience ensure that the sleepers produced by Signum team are of stable quality and have a good user experience.