New tunnels cutting through London are now under construction for the “London Crossrail” urban transportation system. Removing the clay soil from the tunnel is a tricky task for a customized conveyor system and its drive solution.

ISM - Intralogistics

Focus on the Customer

H+E Logistik GmbH is a manufacturer of tunnel conveyorbelt systems, back-up conveyors for tunnel boring machines, and conveying systems for the mining and construction industry and the ports and harbor sector. The company develops custom solutions that are thoroughly adapted to unique conditions on location and particular requirements of the application at hand. H+E is a subsidiary of the world‘s leading developer and manufacturer of tunnel boring machines, Herrenknecht AG.

Focus on the Project
In the “London Crossrail” tunnel excavations passing under central London, reliable NORD gearmotors based on a sturdy, single-piece cast housing drive conveyor systems that are specifically adapted to the London clay soil. The rapid transit line construction is currently the largest infrastructure project anywhere in Europe, with

  • an emerging new route bridging 73 miles from East to West and
  • a designated total budget in excess of 17 billion EUR (approx. 18 billion USD)

Project Challenge

Spanning more than 70 miles from East to West, a new rapid transit connection called “London Crossrail” will soon be added to London‘s public transport network. A number of new tunnels are thus being bored through the heart of the metropolis. H+E Logistik was commissioned to devise a special conveyor solution for taking excavated soil out of the tunnels. The customized system was fitted with geared motors from NORD DRIVESYSTEMS.

Demanding transportation task – Though “London clay” is easy enough to drill through, the sticky texture of the soil, with dispersing agents added by the boring machines, makes removing this material from the tunnel all the more challenging. If standard belts were used, the clay mixture would stick persistently to parts of the conveyor system. H+E Logistik solved the problem by applying special plastic coatings to the belts and developing a dedicated wiper system that mechanically prevents material from clinging to exposed components.

Reliable and reusable – In order to ensure minimal interruptions in the operation, the system also had to be equipped with a reliable drive solution. Besides dependable performance, high flexibility was another key requirement, since potential re-deployment of the systems elsewhere after the completion of the London project had to be taken into consideration from the start. H+E turned to NORD DRIVESYSTEMS for a solution, since various NORD gearmotors had proven to be very suitable before in numerous previous cooperation projects.

Application Solution

For the London tunnel conveyors, NORD supplies helical bevel gearmotors with a double-sided, smooth output shaft. An expansion coupling transfers the torque to the belt conveyor. One benefit of this versatile drive design is that it limits the scope of different gearmotor models that must be managed. In addition, the double-sided shafts allow for particularly flexible and comfortable adaptations of the conveyor systems to a new site of operation, should H+E wish to reuse them in another project.

Seamlessly constructed – All gears suitable for horizontal and vertical conveyor systems are generally based on a singlepiece cast housing with no joints or seams, which ensures particularly high resilience against torque and radial forces. This applies even to very powerful industrial gear units providing up to 178,490 lb-ft, which is required for extreme conveyor inclines and for moving very large amounts of conveyed material. With its offset bearing shaft arrangement, NORD‘s UNICASE design also ensures very compact dimensions, but allows for the use of larger bearings, which achieves enhanced durability.

Readily available – NORD is able to deliver most gearboxes and gearmotors for conveying applications with minimal lead times throughout the world. Even in a long-term project such as the “London Crossrail,” this has been a bonus to the customer. When H+E was commissioned to supply additional short conveyor belts for unforeseeable manual excavation work in a matter of weeks, NORD delivered all required drive technology within five days of the order.

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