And you thought the Aliens, evil AIs, secret empires, and Immortal Conquerors were the only points of divergence with the canon universe. "...And I Feel Fine" is and will continue to be a fairly naval heavy setting. These ships and their backstory are just a part of that. :P
The Type 51 is a positively ancient design, dating back to the last years of the Terran Alliance, where it served as a light escort and patrol ship for the new navy of Admiral McKenna. Originally designed as a stopgap measure, meant to serve only until there were enough true WarShips to take over its role, the Type 51 nonetheless managed to persist for centuries, with the last vessels operating among Periphery forces up to the end of the Reunification War.
At first glance, such a primitive design would seem to be an unlikely candidate to be resurrected. In truth, the first new Type 51s to be built, constructed for private use by the fiercly independent Lyran world of Kowloon, were likely chosen because their archaic basic design would ruffle few feathers. The performance of these ships during the Jihad, however, caught the attention of both national and local authorities alike. With the Word of Blake rampaging across the Inner Sphere and the Warship fleets of the houses already devastated, these new ships quickly became an attractive proposition as a vessel that didn't demand the vast resources of a true Capital WarShip, but also possessed independence lacked by assault dropships or so called "pocket warships".
By the end of the Jihad, every Great House (as well as the Magistracy of Canopus and Raven Alliance) were building and operating small, jump capable, heavily armed "retrotech" vessels under a variety of designations (Gunboat, Cutter, or Sloop being the most common). While some experimentation was seen with different designs (Kowloon in particular, having started the craze, has produced several generations of larger and more capable versions of their original Sampan), the Type 51 hull is by far the most common design for two reasons. First, it's a battle tested, proven design, and second as an ancient ship that spread across the Inner Sphere and near Periphery over two centuries of service, it was effectively an "open source" design, allowing manufacturers to quickly tool up for construction without having to haggle over licensing concerns.
Though all of these Type 51 clones share the same basic hull, jump drive, and support systems, armor and armament can vary wildly depending on the Manufacturer. Several common loadouts are presented below, as are varying armor configurations. In general, a Type 51 is more than adequate to fend off or destroy a typical pirate vessel or assault dropship, and even some of the largest pocket warships should fear to encounter one of these ships. There are Jihad era accounts of such ships even successfully engaging small, Star League era warships in one on one combat, though this was the exception rather than the rule. And of course, all such ships suffer the limitations in jump range inherent in their type.
Though generally considered Retrotech due to the primitive nature of the design, the Type 51 and its derivatives did not follow other examples of retrotech back into extinction in the post Jihad years, as the forces it was replacing were never really rebuilt. The post Jihad reconstruction and general disarmament hit the WarShip fleets hardest, not only killing any thoughts of rebuilding lost assets, but in some cases actually resulting in surviving ships going into mothballs or the breakers in pursuit of some nebulous concept of peace. As such, naval defense fell primarily to a combination of pocket warships, assault and carrier dropships, and small jump capable vessels like the Type 51. In some cases, such as with the Lyran Commonwealth, this has created a disastrous power imbalance, especially when their neighbors continue to possess powerful naval assets. In the ongoing war with the Jade Falcon and Wolf clans, the Lyrans' sizable fleet of Type 51 and Sampan derived vessels have proved wholly incapable of stopping the small but powerful WarShip fleets of their adversaries (the "Bristlecone" configuration, described below is a recent stopgap measure to produce cutter class vessels with additional ship to ship capabilities).
Type 51 (Modernized) Gunboat/Cutter/Sloop
Mass: 50,000 tons
Transit Drive: 9,000 tons
Thrust Capacity: 3/5
Fuel: 500 tons (5000 points, 9.77 tons per burn day)
Pumps: 10 tons
Structure: 5000 tons
Structural Integrity: 100
Jump Drive (primitive, 15 light years): 25,000 tons
Drive Integrity: 3
Jump Sail: 33 tons
Sail Integrity: 3
Control System: 125 tons
Crew: 12 officers, 60 men, 540 tons
Heatsinks: 339, 200 tons
Armor: 100 tons
*Primitive Armor: f/a:16, fl/fr/al/ar:15
*Standard Armor: f/a:24, fl/fr/al/ar:23
*Ferro Aluminium Armor: f/a:28 fl/fr/al/ar:26
*Ferro Carbide Armor: 30 all locations
Equipment:
6 Aerospace Fighter Bays, 900 tons
2 Small Craft Bays, 400 tons
8 Escape Pods, 56 tons
28 Marines, 140 tons
1000 tons of Cargo
Weapons: (17 gunners available)
6996 tons
five capital weapon blisters (fwd/fl/fr/al/ar)
six standard weapon blisters (fwd/aft/fl/fr/al/ar)
six point defense blisters (fwd/aft/fl/fr/al/ar)
*Heavy SCC Loadout:
Fwd:
2 White Shark Missile tubes, 20 missiles, 1040 tons
FL/FR:
2 Heavy Subcapital Cannons, 25 shots, 2900 tons
4 Large Pulse Lasers, 56 tons
6 AMS, 96 shots, 22 tons
AL/AR:
2 Heavy Subcapital Cannons, 25 shots, 2900 tons
4 Large Pulse Lasers, 56 tons
6 AMS, 96 shots, 22 tons
*Add 22 tons to cargo
*Light SCC Loadout:
Fwd:
2 White Shark Missile tubes, 20 missiles, 1040 tons
FL/FR:
6 Light Subcapital Cannons, 200 shots, 2600 tons
4 Large Pulse Lasers, 56 tons
6 AMS, 96 shots, 22 tons
AL/AR:
6 Light Subcapital Cannons, 200 shots, 2600 tons
4 Large Pulse Lasers, 56 tons
6 AMS, 96 shots, 22 tons
*Add eleven gunners (two officers)
*Add 517 tons to cargo
*Capital Missile Loadout:
Fwd:
2 Maelstrom AR-10s, 20 Barracuda, 10 White Shark, 15 Killer Whale, 2250 tons
FL/FR:
2 Maelstrom AR-10s, 20 Barracuda, 10 White Shark, 15 Killer Whale, 4500 tons
4 Large Pulse Lasers, 56 tons
6 AMS, 96 shots, 22 tons
AL/AR:
4 Large Pulse Lasers, 56 tons
6 AMS, 96 shots, 22 tons
*Add 90 tons to cargo
*Naval Laser Loadout:
Fwd:
2 White Shark Missile tubes, 20 missiles, 1040 tons
FL/FR:
2 Naval Laser 35, 2800 tons
4 Large Pulse Lasers, 56 tons
6 AMS, 96 shots, 22 tons
AL/AR:
2 Naval Laser 35, 2800 tons
4 Large Pulse Lasers, 56 tons
6 AMS, 96 shots, 22 tons
*Add 222 tons to cargo
*"Microdriver" Loadout:
Fwd:
Medium Naval Gauss Rifle, 50 shots, 5520 tons
FL/FR:
1 Subcapital Laser 3, 500 tons
6 Large Pulse Lasers, 84 tons
6 Medium Pulse Lasers, 24 tons
6 AMS, 96 shots, 22 tons
AL/AR:
1 Subcapital Laser 3, 500 tons
6 Large Pulse Lasers, 84 tons
6 Medium Pulse Lasers, 24 tons
6 AMS, 96 shots, 22 tons
*Add 216 tons to cargo
*Bristlecone" Loadout:
Fwd:
6 Medium Subcapital Cannons, 100 shots, 3100 tons
12 Improved Heavy Gauss Rifles, 160 shots, 280 tons
FL/FR:
2 Stingray Missile Launchers, 30 missiles, 1200 tons
6 Large Pulse Lasers, 84 tons
6 Medium Pulse Lasers, 24 tons
6 AMS, 96 shots, 22 tons
AL/AR:
2 Stingray Missile Launchers, 30 missiles, 1200 tons
6 Large Pulse Lasers, 84 tons
6 Medium Pulse Lasers, 24 tons
6 AMS, 96 shots, 22 tons
* Add seven gunners (two officers), 55 tons
* Add Lithium Fusion Battery, 500 tons
* Add 401 tons to cargo
