Based on the standard Starfleet design tree and hull components of the time, the Ptolemy-class replaced the engineering hull of the Constitution-class with a connector at the base of the connecting neck, which could accept a variety of transport containers.
In 2291 a warp core breach occurred on the Rittenhouse. The chief engineer was able to save the ship from destruction, but only after disobeying a direct order from a visiting commodore. Even though the ship was not destroyed, seven crew members were killed in the incident, including the Rittenhouse's captain. (Tales of the Seventh Fleet)
|Al-Rashid - Aristarchus - Copernicus - Deirdre - Ptolemy - Thales|
|Kepler subclass: Brahe|
|Doppler subclass: Rittenhouse|
|Dollond subclass: Chandrasekhar - Lagrange - Wolf|