It's a torpedo launcher you daft bugger 
Luckily I figured it out, just before getting tarred with the same brush. My secret is safe...

Do need something on the end to suggest 'not cannon'. Maybe S-cutout like naval torpedo launchers.
Incidentally....have you ever thought of making some Neff 'wrecks'...?

Black smudge on the sands?
actually I would be very curious to learn about this concept of air-torpedoes, as I was contemplating about it myself. But I imagine they would be simply rockets?
Space 1889's Ironclads and Ether Flyers had drogue torpedoes (on a wire, used like ACW torpedoes, but dragged into targets), aerial torpedoes fired straight ahead, and the Smuts Discharger, which steam-launched what was basically an aerial torpedo with liftwood vanes to let it 'fly' other than level or down. Any applicable ideas?
Doug
Edit: Of course, my Google Fu is failing me; I can only find flat-ended torpedo tubes, whether perpendicular or cut at an angle...
