Snowy 2.0 Headrace Surge Shaft & Tank Design

This is my design for the Snowy 2.0 Headrace Surge Shaft & Tank.
See – Snowy 2.0 design botch – water hammer.

Snowy 2.0 Headrace Surge Shaft & Tank design by Scottish Scientist. Diagram original from Longitudinal profile of the Inclined Pressure Shaft (IPS) of Snowy2.0 and range of rockmass moduli.

Headrace Surge Shaft & Tank

Shaft & Tank Chainage 19+200m or thereabouts
Shaft diameter 10m as per headrace tunnel
Tank cylinder base diameter at least 54m
Tank base elevation no higher than 1,175m
Tank crest elevation no lower than 1,260m
Tank height at least 85m

Note: the above typed design values may differ from those in the diagram after this blog post is updated when values are re-calculated as and when better approximations to the following assumed values can be made:
Length of headrace tunnel: reservoir inlet to the shaft – 19,405m
Maximum flow rate through the tunnel – 418m3/s
Maximum frictional head loss – 31m

My design is better

To reiterate – Snowy Hydro / WeBuild’s Snowy 2.0 design of the headrace surge shaft is botched. Their positioning of the headrace surge shaft at the top of the inclined pressure shaft is in the wrong place!

A surge shaft in that place cannot receive water surging down from the inclined pressure shaft as generation reduces.

If this design error is not fixed then a damaging water hammer problem ensues.

FIX IT! 😡

See also –
Snowy 2.0 Headrace Tunnel Rescue Plan
Snowy 2.1 – pumping up from Blowering Reservoir
Active feral horse shooters blackmail Snowy 2.0