I need some steam ships of various sizes. Frigates and ships of the line as well as some Ironclads like these.
By fitting a steam engine and all its machinery into an existing hull, naval architects created a small ship-of-the-line not entirely tied to the wind and tide. The results are moderately successful, as a steamship can sail independently of the wind, but still spend a good deal of time under sail to save fuel. Tactically, however, the steamship has another advantage: manoeuvrability. The 38 guns aboard can be brought to bear with ease.
Historically, steam shipbuilding owes a great debt to the British engineer Isambard Kingdom Brunel, a man who built ships, bridges and railways. His first ship, the SS Great Western, made 74 Atlantic crossings during its life. Not content with this, Brunel designed and built an iron, screw-driven liner, the SS Great Britain. The first screw-driven ship to cross the Atlantic, she is now splendidly restored and preserved at Bristol Docks in England.
Carrying powerful 32-pounder cannon, this frigate is a valuable asset to any admiral. At close range, her guns fire a powerful broadside, but this does not make her invulnerable. No frigate has a hull that can withstand a broadside from a ship-of-the-line, and in this case the paddle wheels are vulnerable too. While a paddle-wheel powered frigate is not entirely at the mercy of the wind, it is not possible to carry enough fuel to cruise over long distances; steam is a tactical advantage, not a strategic one.
This vessel would obviously be a good candidate for future tech.
By having a good weight of broadside that can be brought to bear regardless of wind conditions, this 80-gun ship is a significant force in any fleet. The ability to sail directly into the wind is something that no sail-powered vessel can ever match.
The idea of going into battle with a fire raging in his ships belly was not one that appeals to every captain. Fire was always a risk aboard a wooden vessel, and boiler explosions were not unknown. There was also the problem of coaling stations: while these ships carried sails, they did need regular supplies of coal. Steam was a tactical advantage, not a strategic one.
Historically, the first British ship to be designed and built from scratch to use steam was HMS Agamemnon, laid down in 1852; previous steam warships were conversions from sailing ships-of-the-line. Agamemnon was fitted with sails and carried 91 guns. She also had a short career as the Navys pride and joy, as she was paid off in 1862. She did, however, help lay the first Transatlantic telegraph cable in 1857-8.
And Finally The Ironclad
An ironclad is an incredibly tough ship, able to withstand pounding by almost any comparable vessel. A thick outer skin of iron is riveted to a conventional wooden hull, and the two layers can defeat most solid shot except at very close range. Combined with a steamships ability to ignore the wind and go where the captain wills, this makes an ironclad a formidable opponent. This power is not without risk, though, as a boiler explosion will rip out the heart of any steamship.
Historically, ironclads first saw action during the American Civil War (1861-65). During the Battle of Hampton Road CSS Virginia made short work of the wooden ships in the river, but an encounter next day with USS Monitor ended inconclusively, as neither ship could knock out the other. These vessels were not, however, the first ironclad warships; they were heavy river gunboats or monitors, and almost incapable of going to sea. The first ocean-going ironclad warships were HMS Warrior and the French Navys La Gloire, launched during yet another arms race between Britain and France. Warrior was launched specifically to steal French thunder and make their ship obsolete, being commissioned and built while the French vessel was still on the slipway.
Before anyone mentions it, I have already DLed Wyrms steamfrigate and warrior. I need more. 
Good to see that requesting units here can be crowned with success. 
