Gammell Class Raider:
Hull:
11 metre length, three and a half metre width, three metre height.
Copper cladding.Additional: Two single-piece pressed copper hulls approximately two millimetres thick sandwiching a half-centimetre Iron hull. Glyued together with liberal applications of tar and copper rivets.
2 decks.
Propulsion:
A single triangular sail set just behind the centre.
A ballast-bell set just in front of the centre with a lever so that two men can reliably shift the centre of mass into a turn.
A pair of internal pressure-tubes(with systems to maintain pressure, such as a spring-mounted plate to reduce the internal volume of the pressure-storage and a pressure indicator.) at the rear of the ship with exhaust tubes directed out of the rear of the ship. One-way valves shall be set at the base of the exhaust tubes and be serviceable from inside the vessel.
There should be a rowing-mechanism on the rear of the top deck, allowing the crew to use a rowing motion to operate some bellows to force air into these pressure-tubes.
There should be space to wriggle underneath these systems in order to service them.
Both tubes should feed to both exhausts...
Four smaller pressure-tubes externally-mounted in boxes under the vessel. These pressure-tubes will be single-use and sealed. Three pins in each of these tubes that may be removed from inside the vessel through holes or possibly a lever-mechanism. There should be purpose-designed pins and hammers on hand to seal the service-holes if need be.
There should be gently-angled fins running the length of these tubes to keep them oriented and provide gentle pressure to remain at the surface of the water.(they are heavy at the front, this is an obvious measure)
There should be a front panel set a short-distance and attached by a spike to the main body, the spike should extend into an internal chamber containing water, with the spike resting against a container of quicklime or similar agents(saltpetre and something?). If great force is applied to the panel, the spike should break the internal container, releasing water into the quicklime, producing heat, thus denaturing the containment of the quicklime and the sealed containment of the gunpowder behind it, releasing large amounts of heat into the gunpowder...
The middle pin will be centrally-mounted and used to secure the tube within its box. The second pin should be forward-mounted and flexible, with a padded strip extending under the tubes front-panel, solely preventing the front-panel of the tube from being pressed into the body. The third pin should be rear-mounted and partially secure the tube in addition to piercing the rear of the tube(or removing a blockage).
Armaments:
The forward pressure-tube propulsion systems have alternative uses...
A large ramming-spike anchored throughout the forward half of the vessel to both decks and the hull in two places.
Six pressure-powered grapple-mortars at the front of the vessel attached to adjacent rope-ladder spools for boarding.
A pair of adjacent, parallel 8 pound cannons mounted on a rotatable platform(Some bearings in ring-furrows under a circular platform. a sloped sheath around the platform to allow the cannons to be pushed back onto the platform when they need to be rotated. Ropes attached to the platform that can be pulled to rotate the platform.) just forward of the sail's radius.
A rear-mounted 8-pound cannon on a rotatable platform.
A Protected firing platform mounted above the rear cannon with room for three gunners to shoot through narrow slits in a barrier that will stop heavy small-arms fire. Supported on six struts and capable of operating on five and holding its own weight(and a crew for long enough to evacuate) on any four...
Quarters:
Additional: 6 'sailors' and 12 'soldiers' with significant shared duties.
Three rows of three hammocks under the front deck.
Supplies and ammunition for fifteen shots(a dozen balls and three carcass rounds) for each cannon in boxes behind the cannons.
Crew provisions side-mounted above the water-line in water-tight boxes.
Ship supplies in boxes in front of the ballast-bell.
Forward pressure-tubes: The rear pin alone can be removed from a pair or all four to provide a single-use burst of propulsion. Once exhausted, the remaining pins can be removed to allow the tubes to leave the vessel to prevent potential fire-hazards.
Alternatively, the front-two pins may be removed, then the rear pin may be removed, to have the pressure-tube swiftly depart from the front of the vessel thus transferring its potential fire-risk to a less problematic location.
The vessel is intended to use up a revision on removing whatever features are deemed less effective or necessary.
Achievement unlocked: To the Stars Above!
"Dream too big"
P.S.
The R'lyeh class warship needs a spinal cannon, at least 36lb, with 8lb carcass rounds...
P.P.S.
Added a couple of things