According to a computer readout in TOS' "Space Seed", the USS Constitution was registered NCC-1700. However, the USS Constellation and USS Republic were seen on screen as Constitution-class ships w/ registries of NCC-1017 and NCC-1371, respectively. Also, in ST6's Operation: Retrieve scene, there is listed the USS Eagle, NCC-956. I am not certain if this was shown to be Constitution-class or not, but the ST encyclopedia says it was. In addition, the encyclopedia lists six additional Constitution-class ships w/ registry numbers lower than 1700. Obviously, something is amiss...
Theories abound that these early ships started out as one class and later were converted into Constitutions. Some of these involove the idea that the class name changes every time a significant upgrade is made (some people still think of the Constitution upgrade as Enterprise-class). Also, there is still nothing to say for absolute certain that registries are assigned chronologically (though I can't imagine why they would be assigned so unchronologically...). While there is really no evidence to conclusively refute these theories, I'd like the present an alternative:

USS Constitution NCC-1700 was not the class ship of the Constitution class.

Now, you may be thinking "If the Constitution wasn't the class ship, why would it be called Constitution class?". Well, let me point out that I never said the class ship wasn't the Constitution. I said that the class ship wasn't the Constitution-1700. In my mind, the easiest explanation of this phenomenon is simply that there was a USS Constitution before the 1700. It would have had a registry probably in the 900s, or, if you don't buy the Eagle bit, at most in the very early 1000s. It was destroyed sometime before 2245, when the second batch of Constitutions was launched (assuming there even was an entire batch all launched at once), so one of those ships was named in it's honor. This ship happened to be the one w/ the registry NCC-1700, which happened to be presented in one of Scotty's tech manuals in "Space Seed".

Of course the real reason being it was easier to mix up the numbers on the model, NCC-1701 NCC-1017, than build a new model or anything else. And at the time of TOS's production I think the staff hadn't considered any type of registry order and just made up whatever they wanted.

I also noticed that alot of Constitution-class ships had registries in the 1600 range. I have an USS Endeavor NCC-1895 marked on my Constitution-class ship list. I think I got it from Matt359. This would make it the latest Constitution-class ship to date.

Hobbes
9906.14

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For everything else there's...Austin Powers.

As fas as I'm concerned there's only two Constitutions with lower than 1700 registries (the Constellation and the Republic) and they are both upgraded from an earlier class (the Horizon class).

The Republic was a testbed, soon removed from active service and used as a training ship.

(Actually there's no on screen evidence that the Republic was a Constitution, so you don't even have to include that if you don't want to.)

The Constellation was the last of the originial Constitutions, converted only after the USS Kresta had been cancelled. In 'The Doomsday Machine' you can see that the USS Constellation is less sophisticated than the Enterprise.

If you really want to belive in that 9xx registry those 16xx registries then you can but as far as I'm concerned all the other Constitutions had registries higher than 1700.

Those registries could be explained by more refits (yawn) or by saying that the registries had been assigned to earlier ships that in the end hadn't been built. The 'spare' regstries were later recycyled.

But personally I can't be bothered with all that.

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-->Identity Crisis<--

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Brandon "Enterprise" Grasmick
Commanding Officer, USS Sovereign (NX-74222)

"Captain, the Sona crew are willing to negotiate a cease fire. It may have something to do with the fact that we have 3 minutes of air left."
-- Worf

This could easily explain the Constitution inconsistency: The Constitution NCC-1700 was the first ship of her class, the Enterprise NCC-1701 was probably the second. Some of the subsequent ships were given lower registries of ships that had just been decommissioned. Maybe the Constellation NCC-1017 was named and numbered in honor of a previous Constitution NCC-1017 of another class.

It could also explain the Oberth registries being very low, although they need to be relatively new ships as of 2284.

Finally, it could mean Starfleet has had many more ships already in the 23rd century. I think this assumption is necessary to maintain credibility of Federation history. I can't imagine that a few ships were sufficient in the 23rd century (consider that Federation space was already large and there was a continuous threat by Romulans, Klingons, Tholians,...), while a fleet of thousands of ships is not able to defend the Federation in the 24th century.

Are you saying that my theory contradicts anything?

Here is how my theory works (using the Constellation and a generic XYZ-class):

1. It was decieded to name a new XYZ-class ship Constellation and give it the reg. num NCC-1017.

2. Production of the Constellation was stopped before it began or before it could be finished.

3. Production 'resumes' or begins on the Constellation. It was decieded to make it a new Constitution-class ship Constellation. For some stupid reason, Starfleet forgets to change the registry number from NCC-1017 on the ship.

Is my theory understandable to everyone?

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Brandon "Enterprise" Grasmick
Commanding Officer, USS Sovereign (NX-74222)

"Captain, the Sona crew are willing to negotiate a cease fire. It may have something to do with the fact that we have 3 minutes of air left."
-- Worf

The class ship of the Constitution class is NCC-1700, no question about that. Now as for the other ships with registries not falling in the 1700-range, is as follows:

These were ships that were either:
1. Old starships from old classes, refitted as Constitutions
2. Empty registries that were never built, so the numbers were given to the Constitution class
3. The people at Starfleet Construction Yards were on high doses of crack, and for fun, decided to mix up all the registry number

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