A character generation session for Star trek the Magalanic voyage.....
at the same time as the Warp5 project which resulted in the first USS Enterprise Starfleet was involved in a number of other projects of which the tunnelling warp drive was one of the few which reached prototype effectively a transwarp drive a century before they became practicable it was filled abound the test ship USS XB263 and fired up with a small skeleton crew of engineers and scientists. it apparently exploded when engaged and the Tunnelling warp drive project was scraped as too dangerous and it was a century and more before any one successfully revisited the transwarp concept.
however the drive worked & left the crew stranded on the fringes of the lesser megalenic cloud with like the later USS Voyager a long way home on a main engine capable of warp 3.7 flat out.
Ginger