Comment on Switzerland’s solar railway has been a success. What happens next?
iocase@lemmy.zip 1 week agoInstead they just put it in a place where they have to be disconnected and removed to reballast or tamp the permanent way, or for railhead grinding, or for sleeper replacement, or for any maintenance task that needs access between the tracks…
Transform2942@lemmy.ml 1 week ago
I certainly have never done maintenance on railroad tracks. Do you think that’s more frequent than maintenance that needs to be done on rooftops?
iocase@lemmy.zip 1 week ago
Yeah by a long shot. Railroads spend 1-3% of the capital cost on maintenance. So if it cost $3 million to build a km of track they spend roughly $30-90k/year. It might not look like it since tracks are just kind of always “there” but there is a decent amount of work you need to do pretty much constantly.
The stones underneath the tracks and sleepers is called ballast and it needs to be rough, angular rock of a certain size. It’s an engineered fill material that’s designed to lock together and hold the rails in place. Every train that passes by does a couple of things at once. It cyclically loads the ballast and breaks down those sharp edges that lock it together. At the same time the force of the wheels on the rails contributes to fatigue causing microcracks to form on the rail surface.
If you leave rails unmaintained long enough (by gross tonnage BTW. Rail can last a long time if it’s hardly used at all) the track will start pumping, where it compresses and expands as each axle passes over it. You’ll start lifting the subsoil up into the ballast ruining its ability to hold the track in alignment even more. Also, microcracks can combine enough that the railhead begins spalling and eventually the cracks can combine enough that the rail itself can fracture well before it’s service life tonnage.
To fix this you have to tamp ballast every X number of tons, grind the railhead every Y tons, and replace the ballast every Z tons .etc
Basically every part of the permanent way is some kind of wear item that needs maintenance. Mind you, only mainline track needs to be perfect. As long as speed limits are low enough along with an inspection, you can run on degraded secondary rails or spurs safely. It just wears it out even faster.
Transform2942@lemmy.ml 1 week ago
Fascinating!
I have seen these hulking machines sitting on the tracks sometimes, I think the manufacturer might be “comaco” - is that what does the tamping/grinding/replacing?
iocase@lemmy.zip 1 week ago
There’s a huge variety. Grinding trains usually travel at around 30km/h and it looks like what Hollywood thinks an emergency brake application looks like
Track POV of a grinding train
They usually have a water tender at the end with a water cannon to spray down fires started by the grinding train itself.
Railway ballast cleaning to remove fines and tamp
Sleeper replacement