ELS-HWL is an upgrade to the ELS system and comprises additionally the HWL system. The system is suitable for long, straight drives up to 400m. The Hydrostatic Water Leveling system supplies altitude data permanently via a reference module, which is mounted in the jacking shaft and via an altitude sensor, which is mounted inside the TBM.

Picture of a straight pipe jacking tunnel and image of the main window of the U.N.S. - Universal Navigation System.