I was looking at the TNE NT Warheads, especially the 500kt TL15 which is probable the standard. It is also the biggest warhead listed. The laser generated by this has a maximum penetration (ignoring the 2d6 random factor) of 1975.
I then looked at my design of the BI-15 Titan class dreanought with armour of 2520, obviously the warhead cannot penetrate this level of armour at all. This means that all the missile can do is scrape surface fixtures (how many back-up antennas are fitted anyway?). Against my version of a Ghalalk class cruiser (armour 1680, 295 remains equating to a damage of only 12 reaches the interior. A critical success only doubles this.
The obvious conclusion is that at TL15 at least, the missiles function in battles involving dreadnoughts and cruisers is just to remove sensor arrays, this could be done with smaller warheads allowing higher thrust on the missiles. (This can produce combat kills but the ships themselves can get away and the damage is readily repairable.)
Another conclusion that can be made is that the 500kt warhead is not the largest available or that the ND missile is itself no longer used much by the big ships when they fight each other (the 500kt missiles laser equates to a beam intensity of 998.56 Mj. Many high tech warships carry weapons of higher intensity.
So are missiles growing in size to accomodate larger and larger warheads? or are they gradually becomming an irrelevance in major fleet battles?
Note this only applies to modern battle and cruiser squadrons fighting each other, against smaller targets ND missiles are still effective and will likely remain so until the introduction of TL17 Coherant SD armour.
At lower techs or against targest smaller than cruisers the ND missile is still potents, made more so by the fact that a ND missile on a successful hit rolls 1D6 for the number of beams actually hitting the target, critical hits doubling the final penetration value.
Incidently from memory the ND missiles in the Honor Harrington came in various masses but a mass of 70 tons was mentioned in one novel. (Though ship masses are way off given the dimensions of the ships.
Just a few thoughts. Any comments?