DSK wrote:
I'm trying to picture how a train is going to tack upwind.

I was thinking if the wind is exactly 0 degrees you get the day off
from work or a hotel coupon. hehe

Walt wrote:
Easy. You just lay track 45 degrees to the direction of the next
station, and then put in a 90 degree turn halfway there. The train will
have to tack. Add in a direct line without a turn, plus another right
angle track on the other side, and the train should be able to sail to
the next station regardless of the wind direction. That is, as long as
your switchman can read the wind.

And the best part about it is: NO LEEWAY.

A solid sail as wind turbine could also work but probably much slower
as z shaped rails. The extra distance is nice as it generates more
energy.

The spring-flywheel should be able to store enough of the collected
energy. The train should have many of them. The build-up momentum
should be stored at the train-station (some how).

http://gabydewilde.googlepages.com/spring-flywheel

I expect the wind to be either much to strong or to weak.

Should it try to keep the schedule or aim for peak performance?

What kind of sails would give the best overall performance in an open
area?