But even as the ships began their service, the technologies which would make them obsolete were beginning to appear.
Most importantly, the sail drive itself was well past the point of diminishing returns. Ever more and larger sails were yielding
smaller and smaller increases in actual performance. Fortunately, an entirely new approach to interstellar travel was already in
the works in the form of the Midspace drive system. Unmanned test rigs had already managed to penetrate Midspace by the time
the Theramel was launched, and development of a full sized rig was already proceeding. The HMS Swiftsure was intended to test
a full scale version of the technology.
Swiftsure was vast by the standards of the time - far larger than the Theramel class. It was also horrendously expensive,
with development costs five times higher than the entire Theramel project.
But the results could hardly be argued with. The Swiftsure's ability to penetrate into Midspace and manipulate the energistic
environment there allowed it to attain speeds vastly higher than any sail ship could hope to.
Whereas the Theramels had a top speed of around 350 c, the Swiftsure was expected to reach speeds of 4,600 c. In
the event, this was never reached; the interaction between field and hull created far greater than expected stresses in
the connecting neck between the hulls in each field lobe, and serious cracking was encountered during early flights.
Although several fixes were attempted non was very effective and the ship was eventually limited to a top speed of 3,800 c
to reduce the problem to manageable levels. This still represented more than a tenfold increase in speed over the Theramel
generation of sail vessels though, and the mass
production of midspace ship would eventually represent the death of the sail ship as an effective interstellar vessel.
Swiftsure's rift generator could be recharged in ten and a half hours using full power. Since her inertial navigation system
could only keep her on track in midspace for twenty four hours, her usual mode of cruising would be to travel on 56.25%
full power (three quarters speed) for one day, then drop out of midspace. She would then spend ten and a half hours
recharging the rift generator and updating her navigational fix before re-entering midspace to resume the cycle.
This gave her an average maximum cruise speed of 2,400 x c.
Swiftsure was designed more as a technology development project than as a practical vessel, but the breathtaking speed
she posessed meant that she was pressed into service on several occasions, usually as a courier. She was not
intended to carry any weaponry, but she did act as a testing platform for some systems.
Swiftsure was launched in 2672, and served until 2684, making 247 flights over this period. The navy collected enormous
amounts of data from these missions, creating a theoretical and practical groundwork which was a vital bedrock for future
development - indeed, some of the data Swiftsure provided is still used in ship design 330 years later!
