CoJackHydra - The new force transmission in pipe jacking

Jul 20, 2015

S & P Consult expands its range of microtunnelling and pipe jacking services by a new pressure transmission system (hydraulic joint) under the product designation CoJackHydra. It represents a smart combination between the optimized hydraulic joint the online monitoring and quality assuring system CoJack which is adjusted accordingly. Consequently, even three-dimensional curves and S-curves with narrow curve radii can now be driven smoothly with high permissible jacking forces.

Modern alignment of jacking spans poses constantly increasing requirements for jacking pipes. Looking back to recent years, it is apparent that jacking lengths are getting longer and longer while narrow curves are becoming more and more frequent. Even complicated curve combinations, partly with multiple S- or three-dimensional curves, are no longer a rare sight in calls for tenders.

Conventional pipe joints with pressure transfer rings made of wood or chipboard often reach their limits in such cases. Sometimes, the problem remains unnoticed until the obligatory structural calculation for pipes according to the DWA worksheet A 161 shows such small permissible jacking forces that the number of required intermediate jacking stations increases unexpectedly. Even the tried and tested OSB (oriented structural board) is overstrained.

The use of CoJackHydra represents a new elegant method allowing for high jacking forces even for difficult line alignments.

CoJackHydra is a combination of a new pipe joint which is optimized for difficult jacking lines and a specifically adjusted electronic monitoring system. The essential feature of CoJackHydra is the hydraulic force transmission combined with sensors installed in situ which provide measured data for a comfortable and reliable online monitoring by means of CoJack.

The most important pros of CoJackHydra are:

  • Reduction of construction costs
  • Flexible alignment in the planning stage
  • Increased jacking lengths
  • Increased pipe lengths
  • Waiving of intermediate building shafts
  • Decreased number of intermediate jacking stations
  • Increased power reserves
  • Increased jacking velocity
  • Continuous monitoring of pipe stress

CoJackHydra, i.e. the provision of the hydraulic joint and online monitoring as a service by S & P in cooperation with TuSo GmbH, Pullheim.

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S & P Consult GmbH

Dr.-Ing. Robert Stein

Konrad-Zuse-Str. 6

44801 Bochum



+49 (0) 234 / 5167-113


+49 (0) 234 / 5167-109



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