The ASC VGN-03 Catfish fighter-sub (Logan variant)

Note: The designations used in the following are my own personal reworking of the RPG & Robotech OSM designations, and have no relation to the raping of Robotech currently being propagated by robotech.com and its staff.

The RDF/ASC Catfish Aquatic Veritech

Early on in the Post-Dolza era, the need was seen for an aquatic mecha, to be able to search, salvage, and sometimes even assault, underwater Zentraedi vessels. Untold thousands went down in the seas of Earth, and the multiple redundancies in ships outer locks, passageways, etc. meant that many of them (if not most) had areas where there was still air. And, if there was enough power remaining in ships' systems, those "derelict" ships could be used as a base of operations for Malcontents - and often were.

The first attempt at making an aquatic mecha was the MBR-07 Mk VI Aquatic Crusader, an adaptation of the MBR-07 Mk V Crusader. The three Crusader mecha (standard Mk V, aquatic Mk VI & space Mk VII) were an attempt to combine the best features of the Excalibur & Gladiator mecha into a single body design (derived from the hull of the MBR-07 Mk II Gladiator). However, this idea proved flawed in several ways, not the least of which was the mass and lack of buoyancy of the basic MBR-07 chassis.

As long as the Crusader VI was set down on the outer hull of a vessel, or on a thick stone outcropping, it was fine. But, away from such optimum conditions, it had to rely on thrusters to do more than sink to the bottom, unless one went to the trouble of attaching floatation tanks (which of course, hampered performance). If those thrusters went out, while operating in deep ocean areas, the crew had the choice of either disengaging the pilots compartment/lifeboat, and floating to the surface, or riding the mecha down to the bottom, which could be well below crush depth. Even if the depth was tolerable, the resulting impact could severely damage the mecha, or bury it under meters of sediment, and that could lead to hours, if not days, of waiting for rescuers to arrive, find them, then dig them out.

By 2016, it was apparent that a replacement was needed that was truly water-mobile. The Robotech Research team that had the project given to them started with the concept that since water was a fluid medium, much like air, a successful aquatic mecha should be more related to the Veritechs, not the ground-pounding Destroids. They noted that people had been experimenting with subs that functioned more like aircraft than traditional submarines for a half-century, and as such, it would not be such a stretch to take that to the next logical step, that of a Veritech fighter/sub.

The basic chassis chosen for the redesign was the new VGF-3 Logan Veritech, which was designed for combat in confined spaces. Its wider nose and multiple thruster housings both lent to their plans better than any of the more conventional VF designs. And, like the Logan, it would not need the complexity of a full Battloid mode. However, other than the basic transformation process, the design underwent massive changes from the Logan.

The first major change was the elimination of all hydraulic systems from the design. Instead, all joint systems were entirely mechanical, and all control systems were fiber-optic. Care was made to insure that once in the water, all trapped air in the fuselage would be evacuated in favor of water, to prevent pressure damage. Everything would be powered by the mecha's onboard fusion reactor, as tests showed that the benefits of using Protoculture power were minimized to negligible amounts by the hydrodynamics involved with underwater operation. Only the control systems would be Protoculture powered.

The thrust systems were replaced by water-driving turbines powered by the mecha's reactor, and additional positioning thrusters replaced the space-use verniers. The lift & control surfaces, now all-mechanical, were modified to produce optimum efficiency in the aquatic environment. Instead of landing gear, rails like those of mini-subs were mounted on the hull underside, with breaks at the points needed to allow leg positioning for its guardian mode. Additional hard points for mounting of torpedoes were installed between the rails.

The cockpit underwent the biggest change. It was replaced by a 2.5-meter diameter (1.8 meters usable interior diameter) diving ball similar to those used on pre-Global-War scientific subs, but made with the superior materials resulting from the SDF-1 reconstruction research. While a surface-pressure environment, the pilot would still wear an environmental suit, for comfort (the deep ocean environment is very cold), and the helmet worn by the pilots has a full HUD, that has the option for computer correction of sight through the cockpit, to offset the distortions caused by the ball's thickness & curvature. The cockpit itself is rated for depths up to 8000 meters, but that's with safety margins typical for such designs. In actual tests, the tested balls survived simulated depths ranging from 9000 to 16,000 meters (the latter, 3000 meters more that the deepest known ocean depths) before failing. In the event of body shutdown, the cockpit can be separated from the body, and has a slight positive buoyancy, even without emergency floats. The ball is mounted in a ring that provides the structure to which a streamlining nose unit (with sensors & weapons) is mounted, giving it a profile more like the Logan, as well as a crumple zone, in case of a collision.

Weaponry includes blue-green lasers mounted on the body, multiple torpedo mounts on the ventral surfaces, two small weapons bays where the Logan's rear landing gear would be, and a choice of gun pods, ranging from normal gun pods, to harpoon or magnetic grapple guns, to the RL-24 mini-missile rifle of the RDF light battloid (the "RL-2" from Strike Force - designation changed as there is an RL-2 man-portable launcher in the Sentinels RPG). The pod used will depend on mission assignment, and many are useless either in, or out of, water.

The Catfish is a mainstay of the RDF/ASC navy, used to supplement the navy's SEALS/Sea Squad in assaulting underwater targets, as well as providing an underwater defense screen for the CVS & SLV class submersibles. A role it is well suited for, but rarely called on as, is as a sub hunter, as most threats tend to be thick-hulled spacecraft & mecha (especially the large Zentraedi mecha code named Cyclops & Tarantula, and the Fighter Pod) pressed into service as submarines by malcontents, pirates, and (should it ever come to blows) the EBSIS. Of course, the EBSIS is also the owner of the largest conventional sub fleet on the planet, which is why this use of the mecha is downplayed, for the sake of diplomacy.


VGN-03 CATFISH

Vehicle Type: Veritech Undersea Fighter (transformable)
Crew: One. A passenger can also fit in the cockpit, but without any amenities. A few Catfish are modified for research purposes, and seat two, but those models lack weaponry (other than one of the "tool" pods described below).

M.D.C. by Location:
Forward Lasers (shoulders): 30 each
Nose Tn-Cannon: 50
Upper Arms: 75 each
Forearms/Shields (wings): 360 each
Hands: 50 each
Legs/Thrusters: 150 each
Underside Rails (4): 30 each
Main (Dorsal) Thrusters (2): 250 each
Tail Fins (2): 75 each
Retractable Utility Arms(4): 10 each
Gun Pod: Varies by type used.
Reinforced Pilot's Compartment:400
*Main Body: 300
*Depleting M.D.C. of main body shuts the unit completely down.

Speed - Vessel Mode:
Flight: Impossible, despite being a variant of the Logan. Can pop out of the water like a flying fish, at underwater speeds over MPH, but won't get more than 30 ft from the water surface, and pilot will take 1D6 S.D.C. from the impact on hitting the water, despite body armor.
Underwater Movement: Hover (station-keeping against currents, if need be) to approximately 150 MPH/250 kmph. Rated for a depth floor of 8000 meters (~27,000 feet), but can in extremis take much deeper depths (8000+10D8x100 meters - Game master rolls for each mecha, each dive, and keeps secret - the variance between missions indicates preventive maintenance, or lack thereof).
Surface Movement: Floating on surface, to 40 MPH. While too inefficient for flight, the thrusters can provide some motive power with air. The underside rails can be mounted with hydrofoil equipment, allowing speeds up to 100 mph on the surface, but doing so takes up all the between-rail torpedo mounts.
Speed - Guardian mode:
Underwater movement is halved (75 MPH); surface movement is limited to 25 mph/40 kmph (looks like it is treading water).
Walking Speed underwater is as fast as 15 mph, if not using thrusters to make moves similar to the moon-hopping used by astronauts in low-g environments (doubles speed, but halves combat bonuses to strike). In an atmospheric environment, running speed is 40 MPH.

Height: 10.5 feet in sub mode; 14 ft in Guardian mode.
Width: 22.5 feet from wing tip to wing tip. Is about 12 feet wide in guardian mode, with the arms more under the shoulders than on the Logan, due to placement of the cockpit sphere.
(The Logan was about 8 feet wide in guardian, mostly from the slant of the tail fins)
Length: 24.25 feet
Weight: 6 tons, as the changes made to change to water propulsion balanced out the size increases for other parts. Most of the areas once used for space reaction mass, are now ballast tanks.
Main Engine: FH-300l Fusion Turbine
Range: Effectively unlimited. The reactor-style power source provides enough energy to operate for about two years of constant use. The control system initially runs off two Tornado Protoculture cells, with an average life span of 3 months. However, by 2020, the system is modified to use a single REF-style cell, with a life-span of a year.

Weapon Systems

1. Forward High-Powered Lasers: A pair of blue-green lasers are built into what might be viewed as the shoulders of the guardian mode for dog fights and assault. They can be fired in both jet and guardian modes, Angle of fire is fixed to fire forward only.
Primary Purpose: Anti-submarine warfare
Secondary Purpose: Assault
Range: 4000 feet in water, 3000 feet in air
Mega-Damage: 6D6 M.D. per twin blast. If one laser is destroyed, reduce damage by half.
Rate of Fire: Equal to the pilot's combined number of hand to hand attacks per melee.
Payload: Unlimited

2. Rapid-Fire Tri-Cannon: This is the main weapon of the Catfish, inflicting massive damage. It is limited to a fixed forward mounting in the nose of the mecha, which restricts firing to straight ahead. To fire up, side to side, or other angles, the entire torso must be moved. It is the same weapon as on the Logan, and is meant more for use in ship entry situations and surface attacks (using the optional hydrofoil system) than attacking underwater targets.
Primary Purpose: Assault
Secondary Purpose: Anti-Vehicle
Range: 8000 feet in air, 4000 feet in water (targeting system calibrated for atmospheric use; is -1 to hit for every 100 feet beyond 2000 feet, when used underwater)
Mega-Damage: 1D6 X 10 per each blast.
Rate of Fire: The number of blasts is equal to the pilot's combined number of hand to hand attacks.
Payload: Unlimited

3. Gun Pods. The Catfish can use the EU-20 (original designation E-20) Energy Gun Pod of the Logan, the RL-24 of the RDF light Battloid, the GU-XX issued to the Alpha, or any of the following weapons.

A. Salvage Pod: Contains a cutting laser (settings from 1D6 S.D.C. to 1D4 M.D., range 10 feet), magnetic grapple (4 shot payload, with 100 meters line each), and 10 underwater flares (1 hour duration each, can be fired up to 200 feet away - damage to a soft target in path is 20D6, remove 1D6 for every 10 feet traveled, so that a target at 150 feet would take 5D6 S.D.C.) Alternatively, a harpoon can be mounted to the magnetic grapple (by sticking the harpoon into the grapple-launcher barrel - harpoons mounted on outside of pod), for 1D4 M.D., but aren't always issued.

B. Breaching Pod: Contains a short-range high-power laser (range 40 feet, damage 2D6x10 M.D.) Designed to quickly cut through ship hulls. Also contains 6 magnetic-grapple-mounted cobalt limpet mines (see RPG description), with a firing range of 500 feet (no rope attached).

Gun Pods Not Allowed: The GU-1X/GU-20 of the VXF-2 Veritas (the VF-1X/VF-2X of Strike Force) is not an option, as it cannot be made suitable for underwater use. Similarly, the EU-XX plasma gun pod for the Alpha (effectively, the Mospeada version of the GU-XX) is also not suited for use underwater due to its very nature.

4. Torpedoes: Instead of using wing mounts, the Catfish uses the area behind the cockpit on its ventral (underside) surface to mount torpedoes (similar to the body hard points used by the F-14 Tomcat to carry Phoenix Missiles). Torpedoes are equivalent to medium range missiles, but with a much shorter range. Only Explosive, armor piercing & multi-warhead types are available (the multi-warhead splitting into 4 HE mini-missile warheads when in proximity of target).
Primary Purpose: Anti-Submarine Warfare
Secondary Purpose: Anti-mecha
Range: 20 miles (32,000 meters)
Mega-Damage: Varies by type. Usually 2D4x10 for HE & AP, 4 x 5D6 for Multi-warhead.
Rate of Fire: One or Two. They use smart missile-equivalent technology, speed 250 MPH, +5 to strike, +4 to dodge, will continue to attack (2 attacks per round) until end of range reached.
Payload: Twelve. The torpedoes drop clear of the hull, then engage their thrusters when more than 5 meters away from the sub, to prevent accidental striking of the launching vehicle. The rear rank of 3 missiles can be mounted to fire toward the rear, but is rarely done so, unless encounters with sea-going Zentraedi fighter pods are expected (the only real rival to this design, underwater).
Note: Torpedoes cannot be used with the surface hydrofoil package, as the package mounts in the same space as the torpedo hard points.

5. Optional Missiles. The Catfish can carry and fire a limited number of short or medium range missiles on its wing. But only when operating as a hydrofoil. However, this is only done when a first strike, long- range assault is anticipated. Otherwise, the addition of missiles prohibits the transformable nature of the vehicle, and therefore its versatility and success as a combat mecha. The base commander must authorize all use of missiles.
Primary Purpose: Assault
Range: Short or medium range missiles only.
Mega-Damage: Varies with specific missile types.
Rate of Fire: 2, 3 or entire payload.
Payload A total of four short range or a total of two medium range missiles.

6. Optional Hand to Hand: Punch does 1D4 M.D., body block does 1D6 M.D., and kick does lD4 M.D.

7. Optional Equipment:
Hydrofoil package: Adds 1 ton to weight, and cannot transform until jettisoned. Package has 40 M.D.C.

8. Standard Sensor Suite:
ULF command radio, for receiving orders and transmitting questions back. Onboard computer takes text messages, converts them to speech for pilot, and does the reverse for messages sent back to command.
Radio (50 mile range, due to interference from water)
The external speaker and microphone can be used as a hydrophone system., but not too well.
Passive sonar
Active sonar systems:
A. surface scan (for ships, ice, etc.)
B. side-scan (for ocean floor research)
C. Bottom-penetrating deep scan sonar & radar (gives a composite computer-generated image).
The use of these systems gives the vessel almost as many scientific uses as military ones, and it is common for even the combat versions to be found doing scientific or archeological research.

Due to its nature as being a ship-launched combat craft (a submarine equivalent of a fighter interceptor), it usually relies on active sonar (As the enemy usually already knows you're there). Passive sonar is usually reserved for stealth missions (such as tracking enemies), lying in ambush, and surprise assaults. Both the side-scan and bottom-penetrating sensors are used to look for hidden enemies & traps, and salvage buried from impact.

Note that due to the attenuating effect of water on radar signals, use of that bottom sensor requires proximity to the bottom, while the less-detailed sonar complementary system can be used from considerably higher. Both systems, used together, can produce a composite scan with much greater detail than either alone, as they pick up vastly different details.

In addition, has a total of 4 remote utility arms (one per regular arm, plus two mounted in nose) for fine manipulation of bottom artifacts