This shed is based off set 60103 (Airport Air Show) but it has been turned into a 74 long x 32 wide locomotive shed. (that's the actual shed coverage, not the track itself: the track is 80 studs long alone) LDD file included!
About this creation
The center platform was a last minute addition, and is not attached to the shed or tracks. It is just short enough to let steam engine driving rods pass by without bumping into them.
The side view of the model. The shed can accommodate 8 wide trains with ease and is extendable to be as long or as short as you need it.
The shed is 11 bricks tall at it's lowest point, and 15 bricks tall in the center.
By the way: baseplates were not added for two reasons:
1) the model is slightly off at some point and does fit in real life, but not digitally. (you will either need a 32 x 80 stud baseplate, or a combination of smaller baseplates.)
2) Baseplates keep crashing the model file for some reason.