Pluto,
To Searchlight work they need power, so put one Generator near - Searchlight need stay into generator circle. If Generator is "killed" Searchlight is turn off.
If you look in quick mission "German Attack Bridges" you see a train whit a Bofors (stand alone version) over a open wagon.
If you open this mission in FMB and look in 3D mode you dont see the Bofors over wagon, but when play the mission, they are.
Probable some trick do manually editing files.
In .mis file you see "train name"
/tow stationary...
So you can put Bofors over Tanker Ship - I just don know how
Sokol1