The DDG-62 is a model of sublight engine, outdated by the time the Fall of the Twelve Colonies had occured. The engines were apparently meant for small, one-manned craft, and provided ample acceleration that seems to match that of a Viper Mark II.
During the construction of the Blackbird, a prototype craft devised by Galen Tyrol and constructed by crew of battlestar Galactica, Colonel Saul Tigh offered Tyrol a pair of these engines that were taking up space in the Boppa Kala's cargo hold. (Flight of the Phoenix)
The engines were designed by areonautics enginneer Laird. (Pegasus)