Hi everyone. I am thinking of building a USS Portland for my next scratch project. I just have one question, though. I noticed that the stern of the ship is very shallow and I don't know how I am going to fit the cannons back there. Does anyone have pictures of a US treaty CA they can show me? Do you use straight mags or coils? How did you get the cannons to fit? Thanks!
I did straight and shallow. consider possibly using an Avenger-style gun though. that's what I'd do if I built another. the room's not much, but if you're handy in any way, you can do it. I have heard people using coils, but that is usually for a fore and aft armed boat.
there's a configuration used by the guys making the Vac-U-Boat Fletchers and Gearings. the 3 way used to hold the interrupter mechanism is laid out such that the barrel and the magazine are in line. I think they did some special stuff to the interrupter pin, but otherwise it's just a weird foster breech cannon. since it's in-line, the gun would be entirely above the main deck with the magazines inside the superstructure behind the turret. it's a clean way to deal with the problem, and you won't have to drill a hole in the deck for the turret barbette, which would prevent water infil during high speed maneuvers to stern.
Normal straight magazine cannons should fit no problem, just will have a short up-tube. BC cannons come without up-tube attached to the T, so you can trim it to size and use compression fittings to attach to top port of T. I fit triple sterns in the aft turret of a Fiji, I had to be conscious of the height but it worked out fine. You’ll have to pay attention to motor placement to make sure they won’t interfere (it dog bones if used). Motors would probably end up forward of the aft-most turret. Portland is on my list for making hulls in the future, should be good boat with the low aft deck
The design sounds similar to the cannon I built to fit in my I400's hangar. Because the magazine and barrel were in-line I had to make an interrupter pin that tapered to a point to push up through the BBs in the T-fitting, and adjust the space ahead of the pin for the number of BBs between it and the O-ring. The I400's cannon was a 1.5 unit spurt gun designed to 3 BBs at once (an alternative gun fired 5 BBs at once). For a regular BB cannon there would have to be space between the interrupter pin and the O-ring for only 1 BB, so one arm of the T-fitting would have to be shortened. I'll probably use this design for Profintern's casemate-mounted cannons.
This is the cannon you want. I used to sell these on this forum but I'm out of the hobby now. These shoot faster and harder at a third of the weight of any BC gun. I have bits left to build a few that I wouldn't mind clearing out of the shop. If interested, PM me.