This is a German 15 inch model SKL45 railcar mounted gun circa World War Two
with the barrel elevated for firing.
To assemble this car in Surveyor:
1. Place this item on the tracks.
2. Place 15_in_German_SKL45_F_Bolster on the tracks a little way opast the end of the barrel.
3. Place 15_in_German_SKL45_R_Bolster on the tracks a little way past the rear of the body.
4. Move both bolsters under the car body.
5. Whe properly positioned there will only be 1 red and 1 green arrow and the car will move as a unit.