Help figuring out how to use mike10's Water Throughs

I'm working on a route with trains traveling at up to 60 miles per hour on a double-track mainline in Indiana. I've downloaded mike10's 300, 400, and 500 meter long water troughs. What I'm trying to figure out is which water through I should use. Obviously the faster the train goes, the longer the water trough. Does anyone have any suggestions on which one I should use?

Water troughs don't work at high speed. I think about 40 was considered ideal. The length of trough determines how much water can be collected so you want to consider the demand for water. How far away is the previous water supply? How hard did the loco have to work to get to this one?

Don't forget to include a water tower and correct signage adjacent to your trough.

Don't think the length is a reflection of the speed but on the capacity of the water tank. Large tanks need more water so need longer lengths to fill them. Speed would need to be fast for the scoop to force the water up to the top of the tank. See this site for more information https://en.wikipedia.org/wiki/Track_pan .