Asia Class Refit

After the performance of warp propulsion systems had been improved up to short-term maximum speeds in excess of Warp 6 in the Constitution class, the following decades didn't see any noticeable progress. It was as late as in the 2250's when Starfleet decided to follow guidelines of their engineers that would allow sustainable speeds of Warp 6 and beyond. This improvement, however, required a fundamental redesign of matter and antimatter injectors, containment fields, the warp core, the power transfer conduits and the nacelles. Especially the refinement of dilithium and the adjustment of the plasma beam, at temperatures in excess of 2 million K, was still a problem. Experimental reactors had been successfully operated, but the implementation of the new principles aboard a starship was still pending. For this purpose, Starfleet agreed to have one starship of the 55-year-old Asia class, USS Africa, completely rebuilt with a new warp core and nacelles in 2258. Only the construction of the secondary hull and the core of the primary hull remained substantially unchanged; 50% of the ship's volume and 70% of all sub-systems were completely new. As it was always supposed to be a model for refits of other vessels of the same and of other classes and not only an experimental testbed, the Africa was fitted with state-of-the-art phasers and photon torpedo tubes too. The ship was completed in 2262.

The maximum short-term speed achieved with the USS Africa was Warp 7.5, and the maximum sustainable speed was laid down to be Warp 5.8 (although Warp 7 was regarded as safe, an extra safety margin was deemed useful because of the age of the spaceframe). Three more ships of the Asia class were reconstructed in the years 2262 to 2265. The experiences with the reconstruction of the Asia class turned out immensely useful when the refitting program for the Constitution class started a few years later. Refitting proved advantageous, since it was still 50% less expensive than building a completely new starship. However, the reconstructed Asia class could not compete with newer designs and, with only four ships left, there were too few of them to allow economic operation and maintenance, so all of the were decommissioned until 2287.