OS Grid Ref: NH 22393 10846 (access tunnel portal)
Date opened: 1959
Date closed : Operational
A major refurbishment of Ceannacroc took place in 2002-2003. I'm lucky
enough to have a library of shots taken both before and during the refurbishment.
Ceannacroc is a very pretty station - brightly lit, brilliant white ceiling,
and bare rock walls. In addition to the main 22MW generator, there's a
4MW compensation set. Here's how it looked in the late 1990s, prior to
refurbishment:
Photo: Ceannacroc Power Station
Photo by: Mike
Ross
Here's a drawing to give you a better idea of the layout:
Illustration: Ceannacroc Power Station
Illustration by: Scanned by Mike Ross, from Proceedings of the Institution
of Civil Engineers, Sept. 1958
A closer view of the compensation set:
Photo: Ceannacroc Power Station
Photo by: Mike
Ross
Going 'below decks' now - the cable tunnel which runs round the front of
the machines:
Photo: Ceannacroc Power Station
Photo by: Mike Ross
The 4MW compensation machine:
Photo: Ceannacroc Power Station
Photo by: Mike Ross
The MIV for the compensation machine:
Photo: Ceannacroc Power Station
Photo by: Mike Ross
A glimpse of the main 22MW machine - looking through the access passage
under the generator, towards the shaft and guide vanes. A portion of the
spiral casing is exposed in the floor:
Photo: Ceannacroc Power Station
Photo by: Mike Ross
The MIV for the main 22MW machine:
Photo: Ceannacroc Power Station
Photo by: Mike
Ross
All change. The refurbishment is in full swing, the machines have been
torn down and partially rebuilt, all the control equipment has been torn
out. A view from the crane gantry:
Photo: Ceannacroc Power Station
Photo by: Mike Ross
With the major refurbishment under way, and the entire system from dam
to tailrace dewatered, access was possible to areas that are normally inaccessible.
At the bottom of the MIV pit, a short tunnel leads to the watertight access
door to the draft tube. No water, and the draft tube is full of scaffolding:
Photo: Ceannacroc Power Station
Photo by: Mike
Ross
Inside. Looking down the draft tube, past the scaffolding to the 'heel'
at the bottom, where the tube turns 90 degrees:
Photo: Ceannacroc Power Station
Photo by: Mike
Ross
There's still some residual ponded/seepage water at the bottom of the draft
tube. Here's we're looking back down the tube - a temporary wooden bulkhead
has been erected, the 'heel' of the tube, seen from above in the previous
shot, is through the small open door in the bulkhead. There's a splitter
wall in the draft tube, visible to the left of this shot:
Photo: Ceannacroc Power Station
Photo by: Mike
Ross
Looking back down the twin tunnels of the draft tube; splitter wall in
the middle, wooden bulkhead at the end:
Photo: Ceannacroc Power Station
Photo by: Mike
Ross
A slightly better shot of one of the draft tube. Apologies for the poor
quality; I had no idea I was going to be able to get into these spaces,
and only had a handheld 'point & shoot' digicam:
Photo: Ceannacroc Power Station
Photo by: Mike
Ross
Up in the station, the refurbishment was in full swing too. The 22MW alternator
rotor was out...:
Photo: Ceannacroc Power Station
Photo by: Mike
Ross
...as was the 22MW turbine runner:
Photo: Ceannacroc Power Station
Photo by: Mike
Ross
This exposed the spiral casing...:
Photo: Ceannacroc Power Station
Photo by: Mike
Ross
Inside the 22MW spiral casing, prior to refurbishment:
Photo: Ceannacroc Power Station
Photo by: Mike
Ross
Inside the 4MW spiral casing, after refurbishment:
Photo: Ceannacroc Power Station
Photo by: Mike
Ross
Compare with earlier pictures: the 22MW MIV removed, blank flange installed,
and access manhole to high pressure penstock open:
Photo: Ceannacroc Power Station
Photo by: Mike
Ross
The 4MW machine, stripped bare, MIV removed:
Photo: Ceannacroc Power Station
Photo by: Mike
Ross
