Concept art: Iron Thunder (Patreon)

A piece of technology that captures the spirit of the diesel-punk/ pulp universe of Roan https://www.kickstarter.com/projects/349890202/roan is the mighty airship! These great metallic leviathans soar majestically through skies of Roan. If one has seen the anime Last Exile or Hayao Miyazaki's film Laputa then one has gotten a taste of the adventure awaiting in the skies of the pony rpg Roan! The ship posted here is not necessarily one you'll encounter in the game, but I developed it as an intellectual exercise to explore the challenges and problems associated with building a sky dreadnought. Also I often do concept designs that have inherent problems since real world devices often have minuses along with their pluses. Nothing is perfect.

Now Roan will be evoking more of the interwar and early 1940's feel in its technology, but everything has to start somewhere, and when it comes to designing large, complicated, and expensive devices like airships there can be a lot of trial and error before one gets the knack of building one. Especially if the technology is constantly changing and evolving. Such was the case of the Iron Thunder.

The Iron Thunder was developed as a proof of concept vessel. It was hoped it would be the first in a large class of warships that were slated for service in the Roan navy. The Iron Thunder was the developed by team of naval officers, engineers, scientist, and industrialist from across the nation. Using the latest scientific concepts in airship construction and testing it would be the ship that would set the standard for airships to follow. It was one of the first airships to have scale models of it tested in first generations of wind tunnels, and from these initial tests the design was carefully refined and developed. The design team also interviewed numerous airship crews and their officers to try and determine what were the most common problems encountered in operating an airship in combat. After more than year of development and review the team was confident they had a winner. The reality had its say.

First the finance minister and certain members of government dictated that the ship could not exceed a certain tonnage or length. This was supposedly to done to keep cost in check and to allow the maximum number of yards to submit bids to build the ship. However this decision was made after certain key facets of the design had been settled on which meant the design team had to hastily modify the original design. Systems had to shuffled and moved closer together, but another round of wind tunnel testing showed no serious detriment to the fundamental design. However this was to prove otherwise in real word testing.

Second, although the team had consulted with numerous airship crews and their officers the design team had come to several faulty conclusions. One thing that had been mentioned by crews was problem associated with dead astern fire; in fact there had been several critical engagements where ships had been damaged or lost due to their inability to provide adequate stern fire. The problem was due to the plethora of control surfaces and thrusters mounted at the back of the ship that could be damaged by the muzzle blast of 10" and larger guns. To solve this problem the team mounted stern the stern 12" gun turret underneath the top rear control fin. This gave it direct stern fire and could be rotated to 90 degrees in either direction to provide much coveted broadside fire. The Iron Thunder also had a 12" gun mounted in Sponson turrets on either side of the hull that in theory could fire almost to a full bow or stern positions.

Unfortunately the engineers and managers of the project did not truly appreciate the devastating effects these guns would have on their own hull. Especially if the stern turret was rotated to 90 degrees since then its muzzle was almost directly over the main elevator. In fact in the first full broadside firing the starboard elevator was torn clear off the Iron Thunder which caused the ship to almost roll completely over. In the original design the turret had had much more distance between it and the control surfaces, but when the tonnage had been changed the hull had been shorten. With unfortunate consequences. Also the engineers had not adequately accounted for how their heavy, armored turrets would handle rotating when the ship was banking in a turn. Bow 12" turret stripped its main bearings twice during its acceptance trials.

even the 8" secondary turrets created problems. In theory the two bow 8" guns could very forward to either side of the bow 12" turret. Unfortunately the effects of reducing the tonnage again reared their head. The turrets had been moved inward several feet from their original locations when the beam of the ship had been reduced. Firing of the 8" guns routinely broke the rangefinders found on either side of the 12" turret rendering the gun effectively useless except for point blank fire.

Their was even problems with the observation/anti-fighter gun mast. Scale model tests had shown no problem with their location. However in real life they created turbulence severe enough to make the top rudder flutter violently enough that the commander of the ship had to lock it back in straight position to keep it from being damaged. Even with that problem had been addressed it was found that turbulence rendered the top fin effectively useless which meant the ship yawed excessively at full speed. Eventually secondary fin was attached to the front of the rear mast to regain some stability.

Numerous other faults were found in the design. What had been hoped would the way to the future turned out to be a cautionary tale about the perils of development and the insidious effects of what seemingly insignificant changes could have on a design. What had been hoped would be the first of a large class ended up being a dead end. The final irony was that one year after its commissioning new regulations went into effect requiring all yards to increase their assembly docks so they could handle larger hull sizes.