This is a British Armoured Train design for Shadowless, based on real life armoured trains operated by the RNAS (Royal Naval Air Service, the air arm of the Royal Navy) in Belgium during the early part of WW1.
Most of the cars are either copies of real life examples from the 1890s or based upon them and modified as the story requires.
One such example is the "Ordnance BL 20 inch
Railway Howitzer", which is an enlarged mash-up of the real life 1918 "Ordnance BL 18 inch howitzer on truck, railway"
and the 1915 "Ordnance BL 12 inch Gun Mk IX".
Since this drawing is primarily meant as reference for the comic, I only drew the different type of cars and not the way they fit into the completed convoy. In operation, the actual car order would be: 1_2_3_4_8_9_6_6_5_5_5_5_5g_5g_5g_10_7, where "5g" is a "gunpowder van", similar to the general goods van but with the sides made out of steel plate instead of wood (for obvious reasons).