Hi Simon, the curtain is quite a simple process. i generally start with some toilet paper or kitchen tissue folded over a few times. Cut it to the approximate size and then carefully give it a coating in diluted white glue. From experience I found to color the glue mix helps tremendously.
It is best done on a sheet of glass or plastic. When the glue has dried enough to lift the tissue off the base start to wrinkle it a bit and let it dry completely. Even after the drying it is real easy to work on the wrinkles. i then cut the piece to size and glue it in place.At this point it is best to do all the shading etc.
Since mine are generally attached from the inside this is quite a simple process. But I have used the same method to create tarps and a canopy.
One can also make a simple wire frame and fold the ends over it, for tarp doors etc.
Have fun and let us know how it went.
the Grubenlock you mentioned is an above ground standard gauge one.And they where true monsters, it was used generally to transport coke or spoil, there are "Narrow gauge ones" that look quite similar and ran on meter gauge. they where used in the Tagebau/ Above ground mining for BraunKohle( sorry cant think of the English word) They ran in unit trains transporting coal and spoil from the mine (loaded by a flood loader attached to a bucket wheel excavator, that's why they have a second set of pantographs on the side under the loader was no overhead power possible also at the unloading) directly to a power plant or the spoil heap( there it was generally spread by a similar machine as the bucket wheel excavator) refilling the mine.The last real monsters where used in the Eastern part of Germany. don't know if some are still in use.
here is a link to her little sister in meter gauge and how it was built in 1:22.5http://www.buntbahn.de/modellbau/viewto ... ok&start=0
Have fun everyone