Endeavour sub-class

The Endeavour sub-class of the Constitution class heavy cruiser lineage was a class of vessels converted from prior sub-classes and entering service from 2277. Created as a "third tier" uprating redesign of the Constitution line to enable relatively new vessels commissioned from around 2260 and onwards at least some of the benefits of the New Technology revolution in starship equipment and design. Due to their relatively minimal increase in capability over the pre-New Technology vessels, they are classified as Heavy Cruisers of the Third Rate.

These ships are alternately known by the following designations:

• Endeavour sub-class
• Constitution-class Mk VII

Class History

With the Class One starship linear warp drive redesign and refit program fully under way and "First Rate" ships of all Class One types and "Second Rate" heavy cruisers already in service, pulling in ships that were less than ten years old  for a twelve-to-eighteen month uprating was looked at and very decidedly placed on the back burner. These newer ships were the ones holding the line and working overtime to cover the older ships being pulled off the line for their uprating. As more and more of them were uprated, however, and with losses from the three-year long Klingon Privateering phase and Mirak Federation-War of 2275, additional uprated units were still needed in larger numbers than could be supplied.

A solution was drawn up much like that done for the Constitution-II sub-class, though on an even further-reduced scope. This "third tier" uprating would equip ships with the bare minimum of New Technology aspects and could be completed in four-to-six months by shipyards with minimal capabilities themselves. This further allowed the Federation's vast shipbuilding capabilities at all levels to be fully utilised to introduce modern heavy cruisers at an accelerated rate.

Class Design

The Endeavour sub-class was visually very similar to its predecessor the Achernar sub-class, but with several very noticeable and distinctive differences. Primary among these was the new linear warp nacelles that had been designed prior to the famous LN-64 series nacelles produced by Cochrane Warp Dynamics of Alpha Centauri, and the less well known but broadly comparable LN-60 series from Vickers Shipbuilding & Engineering Ltd. (VSEL) of Terra. The LN-52 SCNN "Fleetwing" nacelles had been developed in the late 2260s to field-test the linear warp drive theory and engineering whole still being used on vessels that had not been designed with what would become the linear warp configuration in mind. 

The LN-52s were hybrid designs, generating ship's power within the nacelles as did their circumferential warp drive predecessors, but also housing reduced-scale linear warp coils. As such they could be quickly and simply mounted on a vessel's existing warp nacelle pylons, with their new control routines and operating software integrated into the ship's computers.

So powerful were even these proof-of-concept engines that they could push the ship faster than its structure could withstand. For their use in the third tier uprating a decade later, additional hull bracing and stress-point buttressing was required, with additional shielding and Structural Integrity Field (S.I.F.) reinforcement to prevent the ships from collapsing in on themselves under the stress of their new engines' top speed. The systems integration time of these and selected compatible New Technology systems is what would take up the bulk of the predicted six-month refitting time.

Class Comparison

The Endeavour sub-class rates a very distinct third place in capability behind the Enterprise and Constitution-II sub-classes. They are more properly regarded as Generation 3.5 rather than 4th Generation heavy cruisers. Their retrofitted New Technology systems increase their speed, durability, and passive defences considerably over their 3rd Generation Achernar sub-class predecessors, but most other systems received only marginal increases in capability. 

Most internal systems such as crew quarters and hull fittings renamed in their pre-linear "Classic" configuration and styling, though standard system maintenance and upgrade cycles and parts replacement was also performed.

Speed and power levels were significantly increased, with the LN-52s pushing the ships' emergency speed up to the maximum safe cruise speed of their First and Second rate siblings.

Defensive systems were moderately increased in capability over the Achernar sub-class, mainly due to increased shield grid coverage.

Durability was increased with boosted power to the S.I.F. and internal hull bracing improving hull strength and integrity.

Most other systems such as navigation, weapons, impulse engineering, crew facilities, and sensor systems remained as they were, with any improvement in performance down to newer components increasing their efficiency as per standard upgrading practice.

Members of the Class

• U.S.S. Endeavour NCC-1895
• U.S.S. Indefatigable NCC-1760