Bluesqueak wrote:
Personally, I'd say the Dahak class and the angle-gun bombardment ships are the gunboats. Then the City class become a longer legged version - but still need a sequence of coaling stations to travel the distances required. Actual historical gunboats usually had a support structure providing coal, or still carried sails where they couldn't expect that support structure.
Dilandu seems to be thinking of USS Monitor style gunboats, which are generally called monitors. Merlin and the Inner Circle appear to have paid considerable attention to the faults of that design, because the main problem with using it to attack fortifications was its inability to elevate its guns high enough. They work on that problem even before they build steamships.
In fact, there are many, many historical examples of ships defeating land based defences; mostly WW2 onwards. In WW1 the ships defeated the land based guns in the Dardenelles campaign, but the mines defeated the ships. Does that remind you of anything?
I assumed he was thinking of the Crimean War gunboats built by the RN to operate in the Baltic. These were shallow draft single screw ships around 200-300 tons. The Dapper class carried a 68 pounder, a 32 pounder and a couple 24 pounder howitzers.
The theory was you could build a bunch of these rather than one larger ship and mostly not get hit because they were small. In practice they went in with larger warships because if you didn't have those, enemy frigates or their own gunboats would ruin your day.
Really, the primary example of gunboats as specially designed bombardment vessels was for the Baltic.
Amusingly, even with the Jeune Ecole advocating small warships, IIRC France opted to armor larger ships to survive combat with Russian fortifications and the RN ended up with dozens of these little gunboats.
So it was a relatively short period where gunboats were specifically designed to be bombardment platforms and not just small warships that filled various roles. Originally they were intended for coastal defense or when your real navy got sunk and you had to make do. Monitors eventually took over the bombardment role.