Most, if not all of the bombers attacking McAuliffe at the opening of the war in 2634 were Gomora class.
Action Stations, page 253:
[Valeri Olson speaking to Winston Turner:] “We have, at this moment over three hundred inbound strike craft, Commander, a mix of Kala class fighters and Gomora class heavy strike bombers.”
Action Stations
by William R. Forstchen
Baen Books
Copyright (C) 1998 by Origin Systems Inc.
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They were carrying over-sized torpedoes, and had booster rockets attached to help them reach the planet faster from the jump point. Gomora's apparently don't have much in the way of retro rockets, as they must do a turnaround maneuver and exercise full thrust to slow themselves down prior to atmospheric entry.
Within the McAuliffe atmosphere they seem to fly comfortably –and even maneuver– at Mach 10…
