Started thinking about submarines and got some ideas for BattleTech submarines.
Since hull breaches are a pretty big deal in underwater combat, i figured BattleMech HarJel is pretty much necessary to mitigate the problem. But it is also rare, and available pretty late (ca. 3115 per IO) in commonly, which prompts a question who would make a submarine that actually utilizes the stuff?
Naval units, especially submarines, tend to be defensive units by necessity in BTU. In a way, anyone who controls Terra is more or less the most defensive faction by necessity. Between that and the fact this submarine i came up with is pretty high tech, the Republic of the Sphere feels like a natural answer.
However, i really don't want to touch support vehicle rules that are used to make big naval vessels. Such things tend to be exclusive to few worlds. The RotS controls quite many planets, they need something smaller and more affordable than previous big subs, like the Draconis Combine Triton.
Also, guarding only seas and lakes seems limited, and availability of shipbuilding facilities varies by worlds, so i ended up making this an OmniSubmarine. The sub can be configured as needed, and repairs are easier due to modular construction, while extra expense of Omni technology is not much given that specialists like submarines are pretty expensive already. Indeed, the whole submarine might be manufactured elsewhere and then transported to worlds that can use and maintain them but cannot build them.
Thus "Tactical Support Submarine". (Salacia, Neptune's consort in Roman mythology, felt appropriate name.)
It should be noted that as a tactical submarine, the Salacia is not intended for long missions, way too cramped and small for that.
As conventional units go, the Salacia is pretty big at 150 tons. BattleTech's probably most well known small sub, Neptune, is only 100 tons. But features i wanted for the Salacia demanded more mass.
The Salacia isn't most maneuverable unit, with only 2/3 movement courtesy of 270-rated XL fusion engine. But most units cannot maneuver fast at seas, and the Salacia relies on stealth of underwater existence to avoid enemies... and in tactical situations, its vehicular stealth armor. Yes, the Salacia is a stealth vessel. 20 tons of armor gives it a tough shell, and the sub is pretty much completely immune to hull breaches while armor lasts thanks to all locations carrying fixed BattleMech HarJel system, including its twin turrets. Finally the the Salacia has fixed Guardian ECM to power the armor and CASE, though i'm not entirely sure if that is useful in a naval unit.
(A note on the armor: I considered conventional armor because magscan sensors detect subs right away under double-blind rules and other sensors seem kinda irrelevant against them (i must emphasize i haven't actually played DB games ever), but ultimately i decided that as a tactical unit, the Salacia can make use of stealth armor.)
The Salacia has 68 tons of pod space (if i counted correctly), less than half of the unit's mass but far more than most units ever carry equipment.
Each turret can carry up to 24 tons of armament, this weird number is because the fixed HarJel systems eat 1 ton of each turret's 25-ton capacity.
I've made four different configurations, though i'm uncertain about their quality. Also i named the configs after their function rather than the typical "Prime, A, B..."-pattern. I'll post the configs in individual posts, general descriptions here.
The Arrow IV configuration is more or less the "primary" configuration, it dictated the unit more or less completely.
Each turret has an Arrow IV launcher, supplied by total of 50 rounds.
Sub's front has twin LRT-10s and SRT-4s for close combat, while rear has one of each. LRTs and SRTs share five and two tons ammo, respectively.
The Sniper artillery configuration dictated the turret sizes, since each turret carries a Sniper Artillery Piece.
The guns are supplied with total of 100 rounds... because i forgot the guns have 10 rounds per ton.
Close range defenses are provided by two front-mounted and one rear-mounted LRT-10, fed by three tons of ammo. Not much but given the Sniper's range, this should never meet anyone at map-sheet range.
While naval combat is not probable even in a defensive scenario, it cannot be completely discounted, and for that there's a Hunter-Killer configuration.
Each turret mounts a pair of LRT-20s, with an additional LRT-20 in the front. Front and rear have two and one SRT-4, respectively. Rest of tonnage goes for ammo.
For tactical shore assault operations: The Assault Transport configuration.
This one has 16-ton troop compartment (and since it is an Omni, UMU-equipped Battle Armor can ride the hull too), and for close shore bombardment, each turret mounts a Long Tom Cannon. Each turret also has an AMS for additional defense when surfaced.
The Anti-Air configuration is for surface-warfare.
Each turret has a LRM-15 and twin LB-5X ACs, and an AMS. Front and rear sport some LRT-5s for token torpedo defenses. Operated usually in conjunction with the Hunter-Killer configuration for defense against other naval combatants.
Quirks:
Since the submarine is meant for defense, it has Anti-Aircraft Targeting, enabling it to be sea-based air defence unit (i'll add a config for this, though artillery configs are capable).
Unfortunately, as an OmniSub, it has Non-Standard Parts. Yeah, pod-equipment is easy enough, but other stuff isn't necessarily that common.