Pfaffensprung Diversion Tunnel Amsteg HPP - Floor Rehabilitation

Over two winters the exisitng tunnel floor was lined with butt joined granite blocks  after two test areas were already created during the winters of 2011 and 2013.
The granite blocks were manufactured to specification and were fitted according to the block plan.

The tunnel was drained from December to the end of March.

Main Data

  • Length of tunnel: 270 m
  • Width of tunnel: 4 m
  • Size of blocks: 1 x 1 x 0.4 m


KW Amsteg AG (HPP Amsteg)


IUB Engineering AG

Construction period


Construction costs

CHF 1,000,000

Scope of services

Tendering and construction supervision