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Unread postPosted: Sun Nov 03, 2019 2:29 pm
  

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Knight

Joined: Thu Mar 30, 2006 10:50 am
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Location: WI
With the cancellation of the Veritech Beta Fighter in 2022, adoption of the Veritech Alpha Fighter suffered a serious setback in terms of adoption. There where now roles the Alpha Fighter would not be able to perform, which would necessitate development of some type of solution to plug the whole in the UEEF's TO&E as there was no Veritech Fighter available (in sufficient numbers) that would be able to preform the missions the Alpha-Beta Combiner Stack was slated to handle. Development of a completely new platform was not possible in the time frame available, and adapting the Beta Technology to another platform was limited by the size differences in available mecha in production or slated to (the VF-1 having ended production with the VF-1R refit, and it was determined to be to costly to reactive the line). Due to cost and available time considerations the UEEF looked toward modular add-on(s) in the same vein as the VF-1's FAST-Pack system(s).

Looking to capitalize on as much existing hardware and manufacturing capability as they could, a UEEF design team proposed a pair of heavy Alpha-centric derived design boosters: a top mounted one slotted between the arms (and connected to the left arm in Guardian or Battloid Mode) and an undercarriage mounted one (looking at a side/front/rear profile it would look mirrored). The two booster types are incompatible with the other's connection ports, but otherwise nearly identical. Unlike some other add-on setups, the Six-Arm Boosters can be used in a single (only one) or double (both) configuration.

As the name suggests the Six-Arm Boosters are derived from the Alpha's own Arm assembly (at maximum configuration would give it "6 arms" in Fighter Mode). The design team removed all the robotic actuators (shoulder joint, transformation, hand, elbow) and other unneeded hardware turning the arm into a mode locked limb (fighter mode position) and installing a large propellant tank in its place. The upper arm MM-60 station was retained, however the MM-60 forearm stations were replaced with pop-up air intakes for the engine (allowing atmospheric operation without serious drain on propellant) using technology borrowed from conventional cruise missiles. Other than the different connectors, the only other piece of unique hardware not shared by the two boosters is that the lower booster includes space for a retractable landing gear. For an engine the team proposed two different engine configurations, the main engines from the Logan or the existing ATF-401 engines on the Alpha.

The ATF-401 Engine variant was designed to operate with Protoculture Cells, though some on the design team felt a modified version of the engine to use another source for reaction mass was called for it was shelved due to time constraints. The large empty cavity was converted to hold 16 protoculture cells and associated hardware only took up 1/10 of the available volume, but utilizing the remaining volume within the confines of the mission directives was difficult. The ATF-401 wasn't designed to use alternate propellant sources, and they couldn't use the space for reloads (no reload equipment of this type was designed into the MM-60) or to restore the forearm stations so it went largely unused and was sold to the UEEF as offering room for potential future growth. It was suggested to increase the number of Protoculture Canisters on the Booster (this would increase operating time and Delta-V), however there was some concern on putting so much of the rare fuel into the booster (in service this meant 32-48 Protoculture Cells per Alpha with the design as presented, equal to a Beta but with far less performance).

The Logan Engine Variant was designed to operate with SLMH as a fuel source. The main draw back is that the UEEF would need to support two fuel sources, however this did come with a few advantages over the ATF-401 engine: ~40% more thrust and greater Delta-V capacity (Palladium-RPG speed in space). The Logan Engine was bigger than the ATF-401, so it used up more of the available volume leaving ~30% for tankage and the other ~70% going to the oversized engine. The extra thrust also made the unit more agile (bonus to dodge and roll) when the engine is active in Fighter Mode. This engine also required the use of some custom parts by the booster for the engine to be viable (due to differing size as compared to the intended ATF-401), these custom parts where considered acceptable due to their low complexity.

From a propulsion standpoint the upper station is non-usable in full guardian or Battloid modes, and the lower station retains usability in all modes. From a weapon standpoint they are usable in all modes. Placement of the upper station has the unit locked to the mecha's left arm for non-fighter modes (basically think of a stretch version of the OSM model/toykits extra-missile pod), and the lower station remains in position as if it was on the Beta's docking arm (giving the impression of stubby tail in Battloid). It should be noted that the upper station also precludes the use of a gunpod (as stored on the Shadow Fighters or OSM toy/model).

The Six-Arm Booster entered service in late 2023 after a short development. The unit served adequately into the early 2040s before being replaced by the "more capable" Beta Fighter after it entered production and wide spread distribution. An upgraded version of the selected 6-Arm Booster was proposed to compete with the Beta Fighter program, but was unable to compete with the feature bloat requirements being added as the program requirements evolved, which they might have been able to meet had they been allowed to evolve the system into a more FAST PACK setup with additional modules (preliminary plans exist, but where not allowed to continue due to political pressure).

A pure weapon pod variant based on the 6-Arm booster was also produced in smaller numbers that replaced the upper arm MM-60 station, engine and fuel tank with a 4-shot 275mm Medium Range Missile Launcher (no reloads), and brought back the forearm stations for an extra 10x short range missiles (the extra SRMs can only fire in Fighter Mode and only above 1000ft/300m altitude). The weapon pod variant was not as well received, while it's medium range missiles where a welcomed addition, they came with the cost of a hefty weight penalty (-5% to speed in atmosphere per) since the pod did not come with engines. This tended to force the use of a "weapon pod" paired with a standard booster (no speed penalty in atmosphere).


Length (m): 2.62m
Width (m): 0.8m
Height (m): 0.8m
Dry Weight (kg): 951.9kg
Engine Statistics: see chosen engine

AFT-401 Engine
Fuel Capacity: 16 Protoculture Cells (assuming each has 4L capacity)
Operating Time: 32minutes (OR Palladium RPG Time as Alpha Endurance)
Delta-V-single: 4.714kps (Or Palladium RPG Speed of Mach 2.9)
Delta-V-dual: 8.916kps (Or Palladium RPG Speed of Mach 5.6)
Delta-V-single & variant pod: 4.419kps (Or Palladium RPG Speed of Mach 2.8 )

Logan Engine
Fuel Capacity: 211.7 liters of SLMH
Operating Time: 34 minutes (Or Palladium RPG Time as Logan Endurance)
Delta-V-single: 6.949kps (Or Palladium RPG Speed of Mach 4.3)
Delta-V-dual: 13.105kps (Or Palladium RPG Speed of Mach 8.2)
Delta-V-single & variant pod: 6.514kps (Or Palladium RPG Speed of Mach 4.0)

MDC by Location: use relevant Alpha arm locations

Weapon Systems:
1x MM-60 Upper Arm Station as found on a regular Alpha per Booster

Design Notes:
1. Delta-V assumes the Booster and Alpha are both in standard payload configurations. This is also strictly the Delta-V provided by the booster and does not include the Alpha's inherent Delta-V capacity (what ever it turns out to be)
2. All numbers should be considered rounded
3. Dry Weight of the Booster/Weapon Pod is calculated assuming the mass breakdown of the Alpha is the same as a human male (5.7%)
4. The upper station's viability comes from: 1. the OSM model/toys have an upper arm missile pod and 2. the heavy gunpod used by the later shadowfighters have to connect somewhere (of course this feature could be model specific, but I am going with the idea it isn't)
5. The 4x 275mm MRM variant is possible, actually by area you could get a few (6) more missiles in, though length of the missile precludes much of anything else in the pod (landing gear and avionics are doable I think, definitely not an engine or fuel tank). I went with a smaller number so the missiles have some clearance from each other.
6. The Logan Engine Thrust value is based on the uRRG, dimension measurements used in calculations are from OSM lineart (IINM) found in the 1E RPG (Bk4 pg57) or AotSC pg78. All other values are calculated so that the Specific Impulse was close to the VF-1 engine (since they are the same type, they should be similar), though given 2E RPG endurance figures the Logan engine might be more efficient. How the capacity calculated here compares to the base Logan capacity I do not know.
7. Palladium RPG Speed Assumes 1mile/sec = 1 Mach Speed in conversion
8. FYI IF the AFT-401 engine could be modified (or assumed for baseline) to use SLMH as efficient as the Logan/VF-1 engine (non-overboost), Delta-V and operating time is ~3x more than what is assumed for pure PC variant listed.


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