#oberth class

This is Head canon / Non Canon - These are my thoughts as to why why the Constitution class doesn't continue into TNG, but Miranda and Oberth do.

When the Excelsior broke the then maximum warp-barrier, it created the new Warp speed scale we see in TNG. This "TransWarp" would eventually become the standard default over time, leading it to be shortened to "Warp" For any starship class to remain viable in this new era of speed, it had to be on par with at least the low to medium end of the new scale.

Naturally Starfleet sought to do a fleet wide refit, but not all the ships were suitable. The stresses of the new warp speed were greater than most had been developed for.

The Miranda class was relatively recent, with a more modern and robust hull. Also its compact shape required a smaller warp bubble, allowing the new warp systems to work within the class's power limits.

It takes time to design a new type of starship - especially with such a big warp technology shift. This is why there are so many Miranda variants and off-shoot classes. It is simpler to build up the fleet from a known design as a base.

The Oberth class is a small compact ship, and so like the Miranda class, it had smaller warp bubble power requirements. It survives all the way into TNG because of its ability to be retrofitted for the new warp tech - swapped out the coils, core and control systems.

Obeths are not an ideal starship - as well as its well known lack of modern defences, its systems had a habit of burning out under strain. Almost all Oberth ships at one time or another had to be towed back to Spacedock.

Starfleet should have replaced these ships with something more robust, and maybe they tried. Its possible that the Oberth replacement was ready to go, after the usual extensive and expensive development period. But what if it was developed before the Excelsior? The replacement class may have not been compatible with TransWarp.

Starfleet would have been left with a science ship design that would have far less warp performance than its upgraded predecessor. In the end, upgrading the Oberth class was the only possible option. Also with the sunk costs into the replacement, there would be less of a desire to restart the design process for another Oberth successor. Ultimately keeping the Oberth class ships running as long as possible would be a more economic move.

The Constitution class is a very old ship by this point. It had already had been refitted to the maximum speed the space-frame could handle. It would have torn itself apart at TransWarp, which is why the "Great Experiment" opted for a new ship over the reliable Constitution.

With its duties to be assigned to faster ships, it could have still limped on working within Federation space, but it would have been well over-spec and over staffed for these lesser duties.

With the end of Klingon hostilities, Starfleet took the opportunity to decommission ships that couldn't be upgraded. It would be many years before it was possible to design Constitution style vessels that could withstand the new warp scale - culminating in the Ambassador class.

a few things i remembered from before my time on the Cerritos but after I graduated from the Academy, during about a year from late 2379 to 2380.

One is that Oberth Class starships are pretty neat overall, but they are extremely mission-specific vessels. They only have enough delta-v for their specific mission profile and as such don't have particularly strong or powerful impulse engines. But they do need a lot of servicing when they get back to spacedock to replace laboratory equipment, refuel, recalibrate, etc. The one time I got to do anything interesting with the impulse engines on one, was when we were outfitting one for a stellar survey. It needed a lot more delta-v than usual due to its target having a relatively high velocity, so I 're-geared' the impulse engine to use more of its fusion reactor power for subspace than for the main reactor, which drove up the specific impulse and reduced the thrust. As far as I know that ship ended up completing its mission just fine. That's when I learned that a lot of impulse engines, which are specified for a safety factor of 4, are actually due to an error given a safety factor of 8. (The fact that this error is pervasive in so many starship classes makes me wonder if it was intentional. Engineers DO like to push safety factors to the limit. Including me sometimes.)

The other thing is there was one time I was servicing an Intrepid class. These use bio-neural gel computers, and for some reason my manager brought me into the computer core to take a look at the bio-neural gel. I tried to diagnose the problem but computer science is really not my specialty. Now I realize that they were probably just laughing at me behind my back.

(The Intrepid class isn't the only class of ships that use bio-neural gel packs, but that was the only time I was ever called to look at them. The only other one I can recall off the top of my head is Sovereign class, but we never serviced a Sovereign class at Douglas Station during my time there.)

Klingon Oberth what she gonna study...