When I got my second steam engine and needed a way to transport it to meets safely, I designed a box. I already had boxes for my electric locos. Those boxes required the the locos to be placed in the box and then foam placed on both sides.
Given the box was for a live steam engine, I was concerned about the oil residue and placing a warm loco in a box with foam; that lead me to design a box that held the loco in place with small bungee cords. Eyelets are attached to the bottom for the bungees. The loco is placed on the bottom which has two groove cut at 45mm or track gauge. The rest of the box is the “top” that attaches to the bottom using a tight seal sash lock. A one inch wide safety strap around the box serves as a backup.
The bottom of the box is constructed of a 1X8 cut to whatever length required for the locomotive. The rest of the box is constructed of 15/32″ plywood, glued and screwed together. The screw were countersunk and filled. The entire box was sanded and then painted with satin latex paint. The bottom was stained with maple stain/polyurethane. A border was painted with the latex paint.
The latches were attached to the ends and the handle to the top.
Sides 8.46875″H – Length determined by loco.
Top 6.5″W – Length determined by loco.
Ends 6.5″W 8″H
Bottom – 7.5″W – Length determined by loco.