|usage = penstock|
|Pipeline specific usage dedicated to water channelling for power generation at bottom of mountains, the pipe is located between headrace and turbines|
|Used on these elements|
|Tools for this tag|
Penstocks are intended to direct water down a moutain for power generation with the highest elevation difference between its start and its end.
They are physically tilted pipes taking water from a high elevation to power turbines. Such pipes should be mapped with existing man_made=pipeline + substance=water + usage=penstock.
Those structures are particular and usually shielded to handle large amount of water flowing at a high pressure. The most the elevation difference is high, the most will be the pressure.
waterway=pressurised applies here.
Penstocks can be whether overground or underground (location=*). Underground penstocks can be directly dug in bedrock or located inside a human accessible tunnel. tunnel=yes should only be used for human accessible tunnels hosting pipes. If not, don't use tunnel=* key.
|waterway||pressurised||This is always a pipe flow waterway||mandatory|
|man_made||pipeline||A penstock is here considered as a pipeline||mandatory|
|substance||water||A penstock always carries water||mandatory|
|location||<penstock location>||Depending of environment and ground shape, penstocks can be overground or underground||recommended|
|diameter||<penstock nominal diameter>||The nominal diameter (ISO 6708) of the pipe||optional|
|pressure||<nominal penstock pressure>||The nominal pressure the penstock is designed for||optional|
|material||<penstock material>||The material used to build the pipes.||optional|
|operator||<penstock operator>||Name of the company operating the penstock||recommended|
|direction||both or nothing||Only use both for pumped storage power plants where water can go up & down||optional|
|--||Metallic penstocks feeding a power plant down the mountain. No air can get inside and water goes pipe flow|
|--||Vertical shafts are shielded as pipeline without tubes. Pipes are connected upstream and downstream.
See the two vertical shafts on the power plant digital model and some pics of how it was built with a raise drill machine.