Site Records

Glenmoriston: Access Tunnel

The portal of the access tunnel to Glenmoriston power station is located on the right (as you head West) side of the A887, around 1/2 mile before Dundreggan dam. The portal itself is almost invisible from the road:

Gates open, lights on - the access tunnel stretches away. It's 2,200ft long (more than twice the length of most Scottish hydro access tunnels), and slopes down at 1 in 12. 15ft 8in high, 17ft 4in wide. It's unlined except at the portal (although some sections have a sprayed concrete coating on the rock), with a bend in the middle - unlike many underground power stations, it's not possible to see the 'end' of the tunnel from the portal:

Most of the way down, past the bend, we near the power station - and a shallow alcove on the right wall contains the portal to the surge gallery adit (protected by the door on the right of the photo - the warnings on the door concern radioactivity; Glenmoriston is the only Scottish station with a significant radon problem):

There's a further short lined section immediately before the tunnel finally enters the power station. The plastic curtain across the entrance is there to control airflow for ventilation purposes:

Looking back up the access tunnel from the power station - you can see where the short lined section ends. The arch on the left contains the door giving access to the draft tube stoplog gallery:

The watertight stoplog gallery door. Watertight since a backsurge in the tailrace could flood the gallery - and the power station, if the door wasn't watertight:

Another from the Duncan Logan archives - the access tunnel, under construction (floor yet to be laid).

Words and images © 2005 Michael J. Ross