Spinal Lasers
You can now design Spinal Lasers, which are larger weapons than could normally be constructed using available technology. A ship can only mount one spinal weapon and they cannot be mounted in turrets.
A fifth category has been added to laser design, entitled Energy Weapon Mount. The possibilities are Standard Mount, Spinal Mount and Advanced Spinal Mount. The latter two cost 5,000 and 20,000 RP respectively. A spinal mount uses a focal size 25% larger than the maximum possible for a normal laser. The Advanced Spinal Mount uses a focal size 50% larger. Here are three examples using the same technology level but with different mounts. For the moment this is just for lasers but I intend to also add particle beam and railgun versions as well.
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I squealed like a little girl. Literally, I went 'Squeeeeee.'
This is God-Given Gloriousness.
The only addition I could ask for is the ability to mount
multiple spinal weapons on a ship.
I know a lot of you are probably thinking 'wut?' to this but hear me out
Given the size of ships involved a large-calibre spinal weapon is a given, but if you reduced that size you could pack in more of them.
Instead of having a large-calibre laser or particle lance or something (AKA Homeworld-esqe Ion frigates) you could for example have 2 or 4 particle lances on a spinal mount (with a reduced calibre compared to a single) for more continuous fire or rapid-fire ability. Personally I can't see the maximum amount of spinal lasers going above 8 without the reduced calibre becoming more of a hinderance than a help though, it'd be like sticking a few needle guns to the front of your ship.
Also there's mass and balancing to take into account.
Also as already stated, a fixed-facing weapon doesn't necessarily mean it's a spinal mounted one. You could have a fixed-facing broadside or chase armament, think victorian era frigates, cannon broadside, for example.
In contrast, a spinal mounted weapon can only ever be forward facing and more than likely the entire ship would be built around it. Also it should really be drawing power directly from the engines.