Hydraulic tunnel aggregate for DN800 slurry machine (OD 975mm)


When approached by a Canadian contractor in late 2014, Tunnel Service Group GmbH developed and designed a hydraulic power pack for a Herrenknecht AVN800B microtunneling machine. Development and design, part order and building was completed by the beginning of February 2015 so that the machine was on site in Canada and set up for drilling by Mid-March 2015. 


Main specifications:

  • Small outer diameter (975 mm)
  • 45kW electric motor with Bosch-Rexroth A4VG90 and HAWE steering and bypass pumps
  • Highly-efficient pipe-bundle cooling system (exchangeable) with indirect cooling circuit and tank
  • Extra-low build enables also pipe jacking mode with laser/target steering
  • Water-proof electrical cabinet with PLC S7 in case of tunnel floodings
  • Compatible with existing Herrenknecht direct pipe system
inside view of hydraulic pipe in DN800 power pack



The performance of the hydraulic unit built by Tunnel Service Group GmbH exceeded all expectations in combination with a Herrenknecht AVN800A slurry machine (fully rebuilt by Tunnel Service Group GmbH) and a Herreknecht pipe thruster PT750. The crew of IPC, supported by Tunnel Service Group GmbH jobsite expertise, successfully completed a 429 mtrs drive; outreaching the former length record for DN800 direct pipe drives in Canada. Maximum hydraulic oil temperature stayed below 48°C with push speeds of up to 100 mm/min.

Hydraulics pipe of DN800 power pack
Cooling insert of power pack DN800
Electronis and PLC unit of power pack AVN800B
Cooling fluid tank and electronics container of power pack AVN800B
Hydraulic pumps of power pack AVN800B
Maintenance lids for pumps and jacking process


An der Garnbleiche 4 · D-52349 Düren · Germany


+ 49 (0) 24 21. 307 57-0