Hello, im the author of the HeavyTank mod and i noticed a bug when loading/unloading using an specific equipment, "diesel generator" and "secondary reactor", they are electric generator equipments, but they consume fuel to work, when load/unload the heavytank the fuel disappear.
Also, would be very cool if use the sprite of the heavytank when loaded.
HeavyTank link: https://mods.factorio.com/mod/HeavyTank