You are right about the original Ondine Klasse. The idea was to get *Any* SSN to sea, and are strictly first gen boats, and I don't see the design being modular in light of that, though they would, I suppose have the ability to fire TLAM through the normal tubes, just as Sturgeon did. The Improved Ondines are an evolved design that while keeping much the same external lines as the originals, are modular and built from the beginning for Tomahawk, are are some 10 years in advance of the originals. They should be longer, perhaps, but I'm restricting their size to reflect the evolutionary aspects of the design, as it is still basically derivative of the original boats, albeit with better tech. They are sorta 1.5 gen boats. I'd say besides being smaller and generally less capable, they are the rough equivalent of early 688s. The next class will hopefully fall somewhere between I-688 and Seawolf in that regard, and be a good deal longer.
In this case I'd put a plug in aft of the sail and stick the VLS tubes there*. You'll interrupt the boat's interior less, and you'll actually have room to stick VLS tubes.
*This is how the built
U.S.S George Washington (SSBN-598). They took the ship programed to be the
U.S.S. Scorpion (SSN-589), cut her in half, and put in the 130 foot plug that housed the SLBMs.
That is a most intriguing idea. It would create something like SM-6 decades before it arrived on the scene. It would be a very nice alternative to Aegis, and allow for smaller navies to cope with saturation attacks. I wonder how such a system afloat in a foreign navy would affect the Aegis programme? I will work on a version of this ship.
Erik_T and I have talked about this before and we think if anyone does this it's going to end up on a US destroyer as well, and might delay the introduction of AEGIS into the US fleet (if deployed early), then again AEGIS was delayed mostly by the time it took to get a hull designed for it in service so it might not delay it's introduction.
While the system I outlined gives you a bump up from the prior system, and comes into it's own in the 1980s, it's still has capabilities far far less than the AEGIS Combat System.
As for the numbers I got for missiles under guidance, the AWG-9 in the F-14 could control up to 6 missiles at a time, but the computer was limited for size and weight by the fact that it had to fit in a Tomcat. Remove those limits and you can upgrade the electronics significantly.