CO2 fire extinguishers for 'firing' the confetti, gives a good cloud of 'smoke' when fired...compressed air will do the job also.
PVC for the cannon tubes, and I like the idea of the blue/pink foam glued and carved around the tubes for the cannon shapes. Paint black or bronze....
IF using hairspray propellant (like a spud gun), use cut off chunks of Zoobers pool toys (foam lengths) as 'round shot' (actually cylindrical).
JUST DON"T POINT THEM AT ANYBODY!!!!!!
Hinge 'em at the bottom so they fold down atop the roof lengthwise. Use large/heavy hinges, as a loaded mast with sails will exert a HUGE amount of pressure on the bus. Uhhhhh, hmmmm....maybe wind'll tip over the bus?
Fill the bottoms of the hollow masts with wood plugs solidly glued/bolted in place, as bending/hoisting stresses will be high at that point(s).
Hmmm....two angle irons bolted to the bus roof.......drilled mast between them....bolt passing through them all to form the pivot. Yeah, THAT's the ticket!!!!
To attach the cables to the 'masts', use electrical clamps as the attachment points...they accept bolts well, and make an ideal cable attachment setup.
Use steel cables to secure everything fore-and-aft, NOT ropes as ropes will stretch.
Think of it as a giant "ship in a bottle", that's the way they're put in; the masts are raised AFTER the ship is slid in. Except, no bottle!
The shrouds (ropes on the sides of the ship you climb to get up the masts) can be rope, as they don't need to hold a HUGE amount of wind pressure/side loads. Four ropes up each side of a mast, with foot ropes laced in will look really cool, and if done right COULD be climbed....
BTW, they replaced the tarred hemp ropes on the U.S.S. Constitution with black synthetic rope, stronger and much more weather resistant.
Use wood or metal masts, as PVC may not have the strength/bending resistance you'll need....maybe, maybe not. You'll need to experiment with large (4 inch or larger) PVC. I see the glued joints as a weak spot in their length, as they are only 10 feet long, and I'm sure you'll want taller masts.
IIRC, I've seen large PVC pipe with amaller PVC inserted in it, and the space in between filled with rigid foam to stiffen it. Light and pretty stiff.
White plumbing PVC is stronger than the grey electrical PVC, and has more fittings available. BTW, electrical and plumbing PVC do not fit together.....deliberately!
Maybe get a ruined mast or three from a boat yard, to modify? They usually go for scrap price.
PVC yardarms to be swung alongside the masts when lowered. BTW, many yardarms on the larger sailing ships were hung with chains, that makes for a fast 'n easy attachment for the yards on your bus, and flexible too!
The rigging stays attached permanently, and use trailer/boat winches (several working together, sing a chanty when raising the masts).......consider an electric winch to do it faster (but costs more $$$).
Start the raising by hand, then continue up with the winches until fully raised.
BTW, masts look good if raked back (towards the stern) a couple-three degrees, just like real ships.
The PVC can be lightly sanded, washed w/soap and water and then wiped with paint thinner to remove release agents/greasy handprints, and primed/painted.
Can you tell I've been thinking about this for a while?