Usually, you'll see them on Excelsiors (turn rate and Tac powers to make good use of them), Negh'vars (because they do better damage than beams, though the Negh'Var loses out a little bit in the turn rate department), and occaisionally Vor'chas (though they often op for DHC's given their maneuvrability).
Rarely do you see them on Gal-X's (who are looking to optimize their forward firepower without completely giving up a broadside), and Assault Cruisers (who, like the Gal-X, have to work that turnrate pretty hard to get good mileage out of them).
Oh, they're also common on a lot of sci Ships, particularly the RSV, and when its available, the Fleet Science Ship (Fleet Nova).
I see them more often on Klingon ships, but I did see an Intrepid class that was using phaser cannons and (I think) turrets in the back. I had to double check and look because that's typically an escort loadout.
i use regular cannons a lot. on cruisers, science ships and escorts. with 180 degree firing radius and rapid cannon fire or cannon volley i do very well with them.
typical cruiser build for me: 4 beams, 2 front and 2 aft, 2 cannons up front and 2 turrerts on aft.
on a escort i will sometimes mix cannons with DHCs up front and typically turrets in back or sometimes a photon torpedo on aft; the only projectile i ever use. and i like the torp rapid fire and/or spread.
Escorts with single cannons can be very powerful if you know how to use them.
If you find you're limited by the 45 degree DHC arc, swap them all out for 4x single cannons and you can now do S-turns while peppering the enemy with MG fire. Very effective with Omega x2 set as the shield drain Tetryon Rider seems to activate each weapon pulse.
My favourite fleet escort build is 4x cannons 2x turrets and 1 quantum launcher, backed up with APB1, CSV1, CRF3, TS1 and 2x APO1 IIRC.
DHC builds rely on "sit and point" or "strafe" tactics for maximum forward DPS. On targets that do shoot back sometimes you find yourself valiantly keeping that front shield up using Tactical Team and other defensive powers.
With a single cannon / turret build you can fly rapid S-turns for maximum defence bonus while shredding the enemy (or 3 enemies with CSV) like toilet paper, occasionally doing a full 360 to unleash the rear torpedo spread.
With Attack Pattern Alpha and other Tactical Captain buffs, a APB + CSV + TT salvo spam can eat through targets like well, toilet paper.
Thus if you get sick of pointing your nose at the enemy to use DHCs (or if others are neutering your maneuverability), use single cannons and fly a mad evasive pattern to confuse, stay out of the opponent's DHC arcs and do superior damage over time.
My current Regent build (posted on the Regent thread on this forums) uses single cannons (CRF1) plus Auxiliary to Battery 1 (with 3 pink technicians) to cut down the CRF recharge time from 20 seconds to 11 seconds. This is doable on any cruiser type even the Galaxy R for potent short range 'shredding' damage as again.
Same for the escort example above, it's best to use Tactical captain skills to buff your weapons damage so you can indeed, do wanton destruction at short range.
For cruisers with 3 or more tactical slots I tend to run 3 cannons 5 beams and no or one torpedo. Firing 8 weapons at once requires EPTW boosting so be warned to master your EPTS/W chains otherwise you lose damage potential.
The downside of this loadout is although close assault power is increased, the optimal 8-weapon firing arc is a narrow 30 degree field on each broadside and cannons DO lose a part of their damage potential outside of 6km range.
Do they work?
Yes they do. Sure it might not be "optimal" to most but results speak for themselves. I love my lolaron patrol escort of doom :3
STF Flight Instructor since Early 2012. Newbies are the reason why STO lives and breathes today. Do not discriminate.
i love that build, makes me think i should do something like that. i fly like a mad man, making me and others dizzy most of the time, and i run beams to allow me to continue firing. but i do a few strafes too. glad to see im not the only one my build is currently in flux, and ill prolly switch to the fleet sci vessel. but ill prolly be running beams because beam overload is REALLY satisfying...with cluster torps, because i have to have some yellow somewhere. i just hope i can keep the level of maneuverability that im used to with my MVAE
For the most part if that was at my load out I love it. I can do some good DPS. I've been using it on my Oddy but even on a lot of my other birds including Klingon Cruisers, a Majestic and moving to it down to lower levels even to the point that as soon as I can with new chars I do that load out on almost every ship.