Starfleet and its requirements

[McAvoy]

The warp coils in the nacellea an excellent point and perhaps that is why nacelle designs seem to be reused even if for example the GCS nacelle design may be reused but at reduced scale and different proportions.

However it seems that they have stopped doing that as pretty much every new ship past First Contact has a new nacelle design. Which means new coil shape or design.

Unless of course they layer like fabric or plywood and then cut it.

It could well be that the Dominion war gave them the impetus to build a whole new set of shipyards and production facilities.

That may be. But we have seen basically brand new nacelle designs for every single ship. New warp nacelle design means different warp coil shape. That nacelle probably has different properties and performance requirements than the others.

For them to ramp up the production and make enough of these coils without slowing down shipyard production, they would have to drastically increase production or drastically alter the way they produce the coils.

It would be the equivalent of the USN building new destroyer classes with a different propulsion method (gas turbine, steam turbine, nuclear, etc) for each class and build them at the same time along with a similar proportions of cruiser and carrier classes.

[Coalition]

That may be. But we have seen basically brand new nacelle designs for every single ship. New warp nacelle design means different warp coil shape. That nacelle probably has different properties and performance requirements than the others.

For them to ramp up the production and make enough of these coils without slowing down shipyard production, they would have to drastically increase production or drastically alter the way they produce the coils.

It would be the equivalent of the USN building new destroyer classes with a different propulsion method (gas turbine, steam turbine, nuclear, etc) for each class and build them at the same time along with a similar proportions of cruiser and carrier classes.

It could also mean a large number of nacelle cooking yards, experimenting with different methods. When the Dominion War started (plus the Borg popping in), those yards began to convert to producing the most efficient warp nacelle. The start of the Dominion War was all the existing ships popping over to help out. Later in the war, the new construction has finished, and the better designs are arriving.

After the war, the nacelle cookers can experiment again.


From the DITL Timeline, in the 2300s:
2364 - Borg attack along colonies along Neutral Zone
(no listing of when Enterprise met the Borg, aka Q Who?)
2366 - Picard captured by Borg
2367 - Wolf 359
2369 - DS9 starts
2370 - Odyssey destroyed by Dominion
2372 - Sisko rescues Detapa council, nearly starting Klingon-Federation War
2373 - Dukat takes over Cardassian government after inviting the Dominion in, Dominion War begins same year
2373 - First Contact, aka the Second Borg invasion
2374 - DS9 recaptured, Ziyal killed, Romulans enter war, wormhole closed
2375 - Breen join the Dominion, Dominion War ends

So:
T+0 years: Q Who? (assuming 2365)
T+2: Wolf 359
T+5: Odyssey destroyed
T+8: Dominion War starts
T+10: Dominion war ends

I'd see 2 years for ship design, and 3-4 years for ship construction (which is why nothing was really available for Wolf 359). 2-3 years for shakedown, and the combat designs are popping up in Federation fleets. The key delay would have been the Breen attack on Earth, destroying the yards. Unfortunately, it was too little, too late (and they mainly went after emotional targets, rather than strategic).