Site Records

St. Fillans Power Station - Construction Adit

OS Grid Ref: NN 69045 2460
Date opened: 1957
Date closed : Operational

On the turbine floor in St. Fillans power station, beyond the MIV, there's a low archway with a green 'EXIT' sign above it. This leads to the construction adit, which still serves for ventilation, maintenance access to the high-pressure system - and as an emergency exit.

Looking through the archway reveals a short flight of steps in an unlined passage, ending up in a tunnel which runs from left to right:

Looking back up the steps from the tunnel - MIV clearly visible:

Descending the steps and turning right down the tunnel, it ends after only a few yards - plugged with concrete. This was the original construction access to the high-pressure shaft & tunnel which brings water to the turbine:

It's not a complete dead end: a small tunnel continues into the concrete plug, ending with a heavily-bolted circular cover over an access tube. It's heavily bolted because it's holding back a head of 800ft of water on the other side; this can be unbolted and removed to provide maintenance access to the high-pressure system when it's dewatered:

Going back to the bottom of the stairs, if we turn left instead of right, the tunnel continues round a bend to the left...

...then runs out straight to where daylight can be seen:

Following the tunnel to daylight, it ends in a concrete wall - this would origninally have opened up to the shoreline of Loch Earn, into which spoil would have been tipped. Nowadays there's a short shaft...

...with a grille letting daylight in, and a ladder up to a manhole. This is the emergency escape route:

On the surface, an unremarkable grille and manhole right next to the A85 - there's a layby opposite.

Words and images © 2005 Michael J. Ross