A possible explanation for the gap in firepower between ISDs

[MKSheppard]

The ISD-I subtype, as seen in ANH, is described in all kinds
of literature as being much less heavily armed and armored than the
later ISD-II subtype, which apparently appeared around the time of
ESB.

Yet the both of them are the same length. Unless the Empire managed
to make a quantum leap in power generation and weapons technology
in the time between the Flight I and Flight II ships, the only possible explanation
is that the Flight I ships were designed under the Galactic Republic era
to be deliberately undergunned and underarmored, to allow them to pass
budgetary scrutiny to get built in the first place. In essence, there was
a lot of growth room on the ISD from the start.

And once the senate was no longer a problem after ANH, the Empire simply built
the Flight IIs, which were much more heavily armed (and also much
more expensive).

Even with this massive increase, there was enough remaining "future
growth" in the ISD hull to allow for a third speculative Flight III class,
which was only slightly more heavily armed than the previous Flight
IIs were...

This does have basis in real life. The Spruance Class DDGs of the US
navy were built in the 70s, and they were criticized at the time for being
severely underarmed and underequipped for their tonnage size, but
the same hull was used to build the much more capable Ticonderoga
class CGs....

[MKSheppard]

Found This on Saxton's site:

http://www.theforce.net/swtc/isd.html#features

ISD-I
main turrets: six double heavy turbolaser batteries; two double ion cannons

ISD-II
main turrets: eight octal turbolaser batteries

ISD-I then has 12 HTLs,

ISD-II ends up with 64 TLs...

One explanation for this, is that the ISD may have originally been sold
to the Galactic Senate as a "Corps Level" or "Army Level" transport
capable of transporting massive quantities of troops far exceeding those
of the older Acclaimators, with attendant increases in firepower as a
replacement for the old ships...

And once Palpie was in power, the pretense of a "Acclaimator
replacement" was dropped, and sheer ship-to-ship firepower and
planet slagging firepower was emphasized instead of troop carriage,
explaining the ISD's 9,700 troop capacity, compared to the 16,000 of
the much smaller Acclaimator...

[JodoForce]

I bet this happens more often in Star Trek

Reminds me of ship selection in Starfleet Command, where the Space Control Ship has a Dreadnought hull but I think is outgunned by most CAs... god help the fool who bought one--it's 90% the cost of a proper dreadnought

[SPOOFE]

I'm actually of the opinion that the individual HTL barrels on the ISD-I are more powerful than the individual barrels on the ISD-II... it's just that the II has so many barrels that it makes it more powerful overall.

Or it could be that the ISD-II just has superior internal design and less of a need for redundancy, giving it more space for an even larger reactor.

[Ender]

Shep, for an ISD mk1 to be capable of a BDZ in the same time frame as a mk2 it's HTLs must be atleast 1 order of magnitude larger.

The power was there.


Personally I put it down to the presence of the rebellion, the mk1s are armed with an assload of LTLs, which hints that they were designed to go against small groups and smugglers, like a ship patroling space would. THe increas in numbeer of HTLs and MTLs on the MK2 indicate that it was designed to go head to head against other capital ships of the same scale, IE the Mon cal cruisers

[MrAnderson]

The reason is rather obvious. Simple experience gained while designing the IDS Mark 1.

Odds are none of the ISD Mark 1's are very similar to each other. They are probably like USN Nimitz class carriers where each one contains small improvements learned from experience in the last one built.

Finally there were enough changes in the ISD Mark 1 as they were produced to overhall the design to better implement those changes thus granting us the ISD Mark 2.