"The Thunderbird heavy gunboat design was originally created and produced by DSE for high-level corporate escorts or personnel transport. The company's outsourcing of "minor" ship construction work to shipyards in Rheinland and Kusari resulted in the spread of this vessel to the burgeoning markets either house. The houses both found that the design became quickly popular - among miners looking for a ship sturdy enough to survive the asteroid fields and pirate attacks, rich civilians looking for a ship more prestigious and safe than the Armoured Transport to fly, and corporations looking for a very imposing pirate deterrent - and soon DSE's engineers cheapened the Thunderbird's design enough to allow for easy mass production. Some high-level clients were lost in this move, but the overall gain of lower-level purchasers far outweighed that loss.
The war between Liberty and Rheinland in 817 did not even stop the production of this vessel, as the need for it - although it was somewhat aged by this time - was still high enough to warrant Rheinland's continued production of the ships without the direct oversight of DSE, perhaps because Bretonia purchased these gunboats from Rheinland, due to the small size of Liberty's own facilities for producing this vessel. Quite effectively, it can be found on the open market in any house, and it is not even uncommon to see unlawful groups fielding these gunboats in their ranks - probably something that would make the DSE engineering roll over in their burial-pods.
It remains a sturdy and popular design, a stocky and powerful workhorse for a man with money."