Site Records

Deanie Power Station - Tailrace

The tailrace from Deanie is a pressure tunnel, i.e. not free-flowing, it is permanently filled to the roof with water. Thus, there is a downstream surge chamber to relieve water hammer when the turbines are started and stopped. It is 1415ft long, and discharges into Loch Beannachran.

A short track leaves the main Strathfarrar road almost opposite the access tunnel portal, and runs down to the tailrace:

The bridge structure in the above picture has the stoplog grooves, where stoplogs can be inserted (to cut the tailrace off from the loch, and allow the tunnel to be dewatered for maintenance), and an electric fish screen. Looking towards the tailrace itself, all that is visible is a pool of swirling water; the tailrace tunnel outlet is underwater:

Contrast the above pictures with these archive shots of the tailrace under construction. The tunnel outlet is clearly visible, as is the underwater flow-spreader structure:

A more general view of the tailrace and screen bridge:

Words and images © 2003 Michael J. Ross