N-L-M

FINAL SUBMISSION: XM-2240 RED FOX [Fullbore autism warning] Upon receipt of the technical requirements for the light tank competition, the design team at GF&M once more decided that the spec was extremely conservative. It was decided that a light vehicle, capable of being used in direct wars of maneuvering and in the assault against Deseret forces, as well as in a defensive ambush role against Californian forces, was more than possible. To allow good strategic mobility, and low maintenance for long-range independent operations, a lightweight wheeled chassis was chosen, based on pre-war experiences by South African forces in Angola and Namibia. Combined with the success of pre-war French armored cars (AML, EBR, ERC, VBC, AMX-10), and the export and service success of the pre-war British vehicles (Saladin, Fox, Ferret), it is clear that wheeled vehicles have the ability to operate in rocky desert and mountainous terrain (as long as the going doesn’t get too sandy), with limited support or maintenance. For armament, it was quickly determined that the minimum calibre gun which would remain relevant against high-end threats throughout the life of the vehicle is prohibitively large at roughly 100-110mm, forcing the tank to be bigger and heavier than it otherwise needed to be. The minimal calibre to remain relevant against light vehicles (such as light tanks, APCs, IFVs and older tanks), however, is much more reasonable: a 30-35mm autocannon. To defend against the high-end threat, a pre-war invention is resurrected: the anti-tank guided missile (ATGM). Systems and crew comfort features were inspired by (and in some cases shared with) those in development for the Norman medium tank, saving time and development money. Mobility: Suspension is double wishbone on the front 2 axles, with steering; the front-most axle steers all the way, the second axle only steers roughly half. The rear axles have Christie-style suspension, with the springs tucked away in the groove on the outside of the hull. All axles are powered through drive systems reminiscent of that of the ERC; the engine and transmission sit in the rear of the vehicle. Survivability: Armor is 10mm high hardness steel facing on 60mm aluminium LOS throughout the 60 degree frontal arc for both hull and turret; for the sides, 5mm steel facing on 30mm aluminium LOS; and the rest (sides, back and belly) 30mm aluminium. The belly is V-shaped, at 10 degrees from the horizontal, to allow good performance against mines. Smoke grenade launchers as on Norman, 24+24 for 4+4 salvoes of instantaneous smoke. The entire vehicle has a very low profile, and is capable of firing ATGMs from turret-down positions with only the optics and box launcher exposed. Automatic IR-detection fire suppression fitted as standard; room for spall liners is available. Mounting points for light-weight ERA when available are also integrated onto the vehicle. Thin sheet-steel (2mm) stowage boxes over front and above wheels, around left and rear of turret, set off HE rounds at sufficient standoff to avoid having the armor cave in. [not in model] Firepower: A. Armament. 1. The main gun is, basically, a Bushmaster III, chambered in 35x230mm, with full dual-feed first-round-select semiauto/automatic fire capability, at around 200 RPM. Ammunition is belted in 2 boxes underneath the turret crew seats; 100 rounds of AP and 500 rounds are carried (50/250 ready). Ammo types: AP, HE/HEI (APDS, APFSDS in development) 2. 1 M240 coax. The coax has a ready box with ~2500 rounds ready, with an additional 2500 stowed. 3. 1 M240 commander’s MG. Commander’s MG has 600 rounds on mount with extras stowed on the sides of the turret in unarmored boxes [not pictured] 4. The main armament elevates from -10 to +30 degrees, and is fully stabilized in a similar manner to the Norman’s armament. 5. The ATGM box is raisable, and carries 4 missiles; it is armored against light arms fire (10mm steel) and can elevate and depress to the full extent of the main sight. Additional missile canisters can be stowed on the sponsons (not ready to load from within) 6. There are in fact 2 different versions of the basic MCLOS missile on offer, differing by the details of the guidance system. B. Optics. Same as Norman, minus loader. C. FCS. 1. Same as Norman for guns. Smaller hydraulic unit needed for the much smaller and lihter turret. 2. For missile: Missile is controlled in current variants by gunner using a joystick. Space has been allocated for a reticle seeker feeding off of the gunner’s optics and electronics to allow SACLOS systems to be fitted. Details on missile system expanded in later section. It is not recommended that a firing mechanism be fitted for the commander to fire the missiles in MCLOS versions. For best accuracy it is recommended to point the launch tube directly at the target before launch. D. Radio. A more powerful radio is fitted in the Red Fox, with more options. It is suggested that this radio also be fitted in command variants of the Norman. Crew comfort: As on Norman, with smaller water tank and reduced power AC unit. Upgradeability: 1. Same as on Norman, minus ammo. 2. Missile easily upgraded to SACLOS. 3. Gun very capable of accepting newer advanced ammunition types. 4. Main armament can be replaced with low-pressure 90mm gun (styled after the pre-war Cockerill) to create an infantry fire support platform. Estimated stowage: 30-40 rounds, HE/HEP/HEAT. [I ran out of time so the modelling is woefully incomplete on the vehicle, but the general outline is available]. Mass of turret: 0.8 tons Mass of hull: 2.2 tons Engine: ~200HP diesel. Features as on Norman (air compressor/starter, large radiators) Estimated mass: 0.6 tons. 500L fuel, 0.4 tons. Transmission: smaller version of that on the Norman, 4 speeds forwards, 4 reverse. mass: probably around 2 tons (including drive shafts). Suspension: Probably around 2 tons. (including tires) Armament mass: probably around 2.5 tons including mantlet, ammo and ATGM box. Mass of extras: 3 tons. Total estimated mass: 15 tons. Dimensions: Length, gun forwards: 6.0m Length, hull: 5.0m (wheel to wheel, maximum) Width, OA: 2.75m with ATGM launcher. Width over tracks: 2.5m Ground clearance: 450mm to bottom of V, 580mm to top of V hull. Height, turret roof: 1.95m Height, overall: 2.3m to top of commander’s sight Wheel diameter: 1.1m Wheel hub diameter: 0.5m Wheel width: 300mm As an additional note, the secrets of multi-alkali photocathodes and cascade image intensifiers are known to the engineers of the EL-OP subsection of the Electronics Division. The Cascader Mark 1 is expected to be in field trials soon. While too large for infantry weapons, tank gunnery integration is expected to proceed rapidly. (This refers to first-generation image intensifier equipment, intended for integration in both tanks) Likewise, IR detectors and spin scan reticles are being developed; conscans will soon be in development as well. Their use in SACLOS systems as well as anti-air applications will be apparent soon. (These reticle seekers will be used for automatic missile detection and aiming in SACLOS, and target detection in anti-aircraft applications) And now, the moment you’ve all been waiting for: MISSILE TECH EXPLAINED As a forewarning, this is going to be fullbore autism, and I strongly recommend you read up on gyros, control theory, and missile guidance before you read the explanation. Useful links: http://www.shorlandsite.com/images/landroversmissileselliott.pdf Contains useful info on the development of British first generation ATGMs. And missiles on Land Rovers, which are cute. http://www.dtic.mil/dtic/tr/fulltext/u2/b807471.pdf Scientific Advisory Commission report on guided and homing weapons, May, 1946. http://www.tpub.com/neets/book15/63e.htm Gyro basics. https://sci-hub.tw/https://ieeexplore.ieee.org/document/1104289 Non-minimum-phase dynamic systems. The following is based on my knowledge of control systems and missile guidance, as well as basic knowledge of human reactions and as-built 1st gen ATGMs. The problem is as follows: we want a missile to fly along the line of sight, to the target, despite target maneuvers and outside disturbances. For this, we track the missile, and send commands to the missile to correct for its heading, to maintain the missile along the line of sight to the target. As long as the missile can be made to always be on the line of sight, and is moving faster than the target, a hit is guaranteed. This is the basic premise of CLOS guidance. To ensure aerodynamic stability and direction-keeping despite manufacturing flaws and inconsistencies, the missile is lightly spun around its axis throughout flight by its fins. These are on an adjustable base, so as part of the SACLOS upgrade the spin can be disabled. There are a few points to address in this regard- 1. How is the missile tracked? 2. How are the commands given? What do they mean? 3. How are the commands sent and how are they interpreted? 4. How are the commands carried out? The answers will be given for 3 systems- a. classic MCLOS b. classic SACLOS c. The BGM-1A and BGM-1B missiles let’s start. 1.A: operator tracks target and missile through sight. 1.B: Operator tracks target by centering sight on it; guidance system detects missile location relative to crosshairs through spin or later conscan reticle similar to those in early A2A missiles. 1.C. Same as traditional MCLOS 2.A. Manual Joystick, usually acceleration command to the missile, command intensity proportional to joystick deflection; force feedback. 2.B. automatic, often bang-bang, to center of crosshairs, usually acceleration. 2.C. Manual Joystick, proportional, velocity control. 3.A. From joystick take-off, through amplifier, through wires, direct to gyrostabilized commutator (in spun missile), to actuators on open loop. 3.B. From detector output, through wires, direct to gyrostabilized commutator (in spun missile), to actuators on open loop. 3.C. BGM-1A: From joystick take-off, to flight control box, Through wires, direct to gyrostabilized commutator (spun missile), to actuators on open loop. BGM-1B: From joystick take-off, to flight control box, Through wires, direct to gyrostabilized commutator (spun missile), to autopilot in missile; autopilot operates actuators on closed loop with horizontal and vertical rate gyros to achieve fixed angle for given command. 4.A. TVC or rear control surfaces. 4.B. aerodynamic control surfaces, front or rear. 4.C. Front control surfaces. The disadvantages of classic MCLOS are that it was difficult to use, and required great skill, as the acceleration commands combined with rear steering missiles. These missiles exhibit extremely unintuitive steering mechanics, with delayed response, and inverse response: rear steering throws the aft end of the missile in the opposite direction to point the missile towards the target, which means the whole missile moves the wrong way until sufficient wing lift can be generated to push the missile in the intended direction. This is extremely unintuitive for the user and takes a lot of practice to accurately predict; frontal control on the other hand is minimum-phase and intuitive- the missile goes where you want it to, and goes there faster for the same control authority. Likewise, acceleration feedback is not intuitive for human beings; we are not used to it. Speed feedback is however within the abilities of humans to handle reliably, and therefore the autopilot has been chosen to perform this duty, greatly easing the use of the missile system by humans and thereby improving accuracy, within the limits of established technology. Example of front vs. rear steering. Note the rear-steered missile going the wrong way initially. This is very confusing and leads to overcompensation in all except the well trained and highly skilled. The differences between the flight control of the BGM-1A and BGM-1B are as follows: The BGM-1A has a single inertia gyro, spinning on a horizontal axis normal to the missile’s axis. This gyro stabilizes the commutator to allow the proper splitting of command to the surfaces despite missile spin. Velocity control is achieved through matching to an internal simulator in the flight control box. This receives the command, and relays it to both the missile and the internal missile flight estimator (a reduced 3-variable (local sideslip angle, turn rate, and heading) first order differential solver. The system is linked to an internal PID controller aimed at bringing the missile velocity across the line of sight to the value dictated by the command joystick input. The missile itself, in flight, is controlled on open loop, and therefore velocity errors are liable to accumulate throughout flight. With a flight time of only around 20 seconds to maximal range (4000m), however, this is not considered to be too great a risk. This flight control box also forms the basis of the built-in missile simulator; hooked up to a driven mirror assembly with HUD-style reflector plate in the gunner’s sight, it can be used to project a dot representing the gunner’s view of the missile tracer flare onto the gunner’s sight. This can be used to practice missile firings as many times per day as is desired, to maintain high skills with minimal support and minimal live-firings of practice missiles. The BGM-1B has an additional gyro in the missile, this one a displacement gyro with its rotation axis aligned with the missile body. The angle take-offs from the 2 gimbal frames are fed through the (larger) commutator, to allow the missile to know what its attitude is compared to that it had at launch. When firing this missile, the flight control box only controls the gain of the joystick (less sensitivity at short range as speeds across the line of sight have greater angular rates), and the missile itself contains a PID autopilot, controlling the servomechanisms by gyro feedback to maintain constant bearing displacement relative to launch. The size of the bearing displacement is linear as a function of the control input, as that results in proportional velocity control along the line of sight. The BGM-1B is a slightly more expensive missile, but the increased accuracy thanks to reduced drift more than justifies the cost difference. The BGM-1B, thanks to its design, retains a modicum of accuracy in case of a wire break, as it seeks to maintain a 0 bearing relative to launch in that plane. For this reason it is highly advised to point the launcher directly at static targets before launch. Both missiles are fairly modular; the warheads are easily removeable and upgradeable, as are the rocket motors, flares, and batteries. MCLOS missile tech better than was available pre-war is possible with the current industrial ability, as it involves no tech not present in the 1946 survey, and transistors improve reliability and significantly shrink the volume needed for guidance electronics. The better understanding of the control problems involved and the man-machine interface allows the design of more reliable more accurate missiles than were available pre-war. TL;DR: Missiles work and better than any MCLOS missile built IRL. Tech Specs of the missile: Diameter: 160mm Length: 1300mm Length of launch tube (including launch gas generator): 1500mm Wingspan: 550mm Wing type: wrap-around fin, thin sheet steel with forming springs; sprung fold-out Monobloc canards. (As on AT-4 Spandrel and AT-5 Spigot) Gyros: 1 free for commutator inertial stabilization, BGM-1B: extra displacement gyro for angle feedback control. Gyro spin-up mechanism: Compressed air start, no sustain. Servo actuation mechanism: Electrical servo-controlled compressed air actuators. Velocity: ~200-250m/sec [ss.11 was 220 m/s, clearly this is a controllable speed] Range: 4000m, wire limited. Time to max range: 16-20 sec. Warheads: Antitank: Precursor 60mm HEAT, main 160mm HEAT, precision formed, crush-cone fuze, base detonated with wave shapers. Anti-structure/ Anti-ship: Precursor: none. Main: 160mm blast-frag. Current development of variants includes: a. CEV (light breaching equipment, smoke screening equipment, fascines, light digging equipment) b. ARV (winches, light crane) c. APC/IFV (similar in concept to Alvis Saracen with small cannon/MG turret) d. SPAA (VADS-like turret, with twin 20mm autocannon, 1 Vulcan cannon or 1 35mm revolver cannon, and basic air search and ranging radars; missile pod replaced with SAMs (Sidewinder-style) when available). e. Fire support vehicle- 90mm low pressure main gun.

I'd add that launcher-based APS need space for the launchers. With only 2, they need good firing arcs, which means they need to be high and get in the way of the turret's gun arcs. Look at the Trophy on the regular Namer, and consider how much that installation would get in the way of the turret's arcs.

You're missing 2 important points with that line. The first is that BAE are not the OEM of the MCT-30. It's not their design to modify, that's Kongsberg's job. BAE are offering integration onto the CV90 they sell. The absence of APS integration on current-production MCT-30 does not prove it to be impossible. The second is that the D series is not ready for mass production. At all. They say it'll integrate APS, but they don't have anything more than mockups of Iron Fist on the thing. And Iron Fist is also not production ready. I want a source on the claims that the MCT-30 is too small and doesn't have enough power.

1. To the best of my knowledge the current projected future versions of the Brad (A4, and perhaps A5 as well) are intended to retain the existing turret. While a testbed with the MCT-30 exists, the thousands-strong fleet will not be rearmed any time soon. 2. The MCT-30 has been successfully integrated on the Stryker. The operational requirement was to get that into service ASAP, and that seems to have succeeded. The MCT-30 can probably be modified later to carry APS equipment, if the designers were even semi-competent (and I believe they are competent). What turret with integrated APS existed at the time of selection? How many could be fielded right now? MCT-30 was the right choice at the time and still is. 3. The MCT-30 is now in the army's supply train and training. They know its quirks and it's cleared for service. So why wouldn't the Marines go for that for the new ACV? Again, i'd be very surprised if it isn't upgradeable. No, the US Army is trying to get results fast and at low cost. The Brad turret is going to be around for quite a while, so integrating an APS on it is important; but it is getting old and a bit outdated, and the MCT-30 is the best option available to the US for quick fielding-there are already active Strykers with the things in Europe. No turret currently in mass production has integrated APS, so getting turrets now and fitting APS later isn't a bad choice.

There are a few tricks that separate gasoline and diesel (and AFAIK supercharged and naturally aspirated) 2 stroke engines. The problem with 2-stroke engines is that the moment the down-stroke is done, the entire cylinder has to be scavenged and filled with clean air (and fuel, for gasoline engines). And the cylinder is full of hot gas above atmospheric pressure. So on small engines, the crankcase and piston are used as a pump, with the piston sliding also playing the role of the valves. On the up stroke air is drawn into the crankcase, on the down stroke it gets pressured and then pumped into the cylinder, ready to work. This of course means you have a lot of air going through your crankcase and can't just spray oil on it, but mix it in with the fuel. You can also get iffy performance thanks to questionable scavenging, rich mixture (if its a diesel, the fuel is injected directly, regardless of the scavenging efficiency), and so on. In larger 2-strokes, the overpressure problem is solved with a blower of some kind, usually an engine-powered supercharger (turbos don't work at low speed, but external blowing is also possible), which allows the crankcase to not be used for air pumping. This means it can be lubricated like a normal engine. Additionally, with some cam-operated valves, and careful arrangement of the system, good axial scavenging can be achieved. Linear scavenging is even more useful for cylinders with a high stroke to bore ratio; such as are found on opposed-piston engines. These are tempermental beasts, but when properly tuned put out a lot of power for their weight and volume. The Napier Deltic took this to a whole new level, and it worked pretty well, but was very hard to maintain. With modern CFD and CAD, the precise arrangement of ports, timing, and dimensions can be found to make this work reliably and efficiently.

Are those all new builds, or are they remanufactured?

Cost. Same as with the Abrams, there are a lot of vehicles in service, and the budget isn't infinite, and therefore low-cost upgrades are desired. Low cost implies minimal changes in structure and fittings. Brand-new turrets with built-in APS are quite a bit more expensive than APS upgrade packages, and usually involve longer lead times, not a good thing for the current European focus.

FINAL SUBMISSION: XM-2239 NORMAN [ooc: this is written from a timeframe at which only a few prototypes have been built and tested, mass production awaits selection. Square brackets denote ooc comments] Classified: top secret for Cascadian eyes only When General Foundry and Mechanics (henceforth, GF&M) received the brief from the Cascadian armored corps on the requirements for a future armored fighting direct combat vehicle, medium (henceforth, medium tank), and future armored fighting direct combat vehicle, light (light tank), focus was immediately concentrated on the larger requirement of the pair. It was quickly realized that the requirements fell significantly short of the state of the art; and that said state of the art permits the development of a vehicle not only superior to the requirements in every regard, but capable of matching the requirements of the future as well, thus ensuring the safety and freedom of Cascadia for generations to come. Intelligence gathered from neighbouring states set the basic offensive and defensive requirements; the larger mechanized and armored forces of California to the south, and the more mobile and dynamic, but lighter, forces of Deseret to the south-east. Protection requirements for the medium tank were set by existing and projected future enemy weapons, as detailed in report (REDACTED). Likewise, the performance characteristics of the main armament were set by the current and projected protection of vehicles in the possession of the neighbouring states, as detailed in report (REDACTED). Upon receipt of the above reports and requirements, GF&M’s Archival Division in conjunction with the engineering divisions (Mechanical, Electric, Aeronautic, Automotive, and Ballistic) conducted a survey of the current engineering state of the art, in particular with regard to the ability to construct large complex assemblies to an exacting standard. From this survey, it was determined that the current industrial base is roughly the equivalent of that available in Tank City, Michigan, circa 1950. Likewise it was determined that the state of the art from an electronics standpoint is roughly equivalent to that available in the same time period. Theoretical knowledge available, however, significantly exceeded that level; the divisional chief engineers all have archival clearance and are well-educated on the finer details of the achievements in their respective fields all the way up to the Ultimate War. While the state of the art does not support the immediate manufacture of prewar equipment, many lessons were learned in the past through trial and error, which is estimated to have saved years and many cycles of iterative design and testing in the development of the medium tank. Following the industrial survey, the archival division conducted another study; this one historical, examining the vehicles produced pre-war with similar industrial capabilities, as well as the evolution of design from that point to the onset of the War. Individual designs were examined based on archival evidence throughout their lifetimes, noting their technical-tactical characteristics as well as more subjective factors such as efficiency of design and manufacture, maintainability, upgradeability, crew comfort, battle efficiency and so on. Following this survey, it was found that the pre-war Soviet tank T-55 is well within the capability of the industry to construct, and other than minor dimensioning issues more than outmatches the required specifications. While this design had many flaws, and by design was not optimized for the nature of the Cascadian environment, it was chosen as a baseline as it was evaluated to offer more potential than the other possible baselines (Centurion, M-48 Patton), mostly due to small dimensions, reputation of maintainability and reliability, and efficient layout. From this baseline, a series of improvements were suggested by the Archival Division to the engineering divisions, to better suit the medium tank to the Cascadian environment, as well as to apply the lessons learned throughout the service lives of the vehicles studied. The list of suggested improvements was as follows: 1. More compact, autofrettaged gun of ~4” calibre. 2. Crew water stowage. 3. Increased crew working volume. Specifically, improved head space for loader. 4. Improved gunnery optics (including the installation of a rangefinder). 5. 8-10 degrees of gun depression. 6. APU of roughly 1-2 cylinders (2-4 HP) 7. Basic air conditioning 8. Spaced armor arrays 9. Reversed turret crew (gunner and commander on right, loader on left 10. More, better accessible, ready ammunition racks. In the bustle with blowoff panels, if possible. 11. Improved hatches (sprung) and access. 12. Desertised larger air intakes and filters. 13. External coil spring suspension, with return rollers. 14. Improved protected external stowage. 15. 2-channel gunner’s sight, with periscopic mirror head. 16. 2-axis stabilizers, with the gunner’s line of sight being stabilized independently of the main gun, with the gun following the sight, to allow accurate observation and quick firing from the short halt, as well as the use of the coaxial MG on the move. Such a system also allows the implementation of fixed-angle loading, easing the loader’s work without affecting the gunner’s observation of the target. 17. Separated hydraulics, in the turret bustle. 18. Commander’s MG useable under armor. 19. Infantry telephone in rear sponson. 20. Ammunition loading hatch near ground level. 21. Automatic fire suppression. 22. Over-barrel fitting for either spotlight (white light or IR) or .50 BMG. 23. Thicker front hull for mine resistance. 24. Roof machine gun for both loader and commander. 25. Frontally removable gun, with separately removable barrel, for faster and simpler field maintenance of the weapon system and to allow easier modification and upgrading of the vehicle throughout its service life. 26. Making the Commander’s cupola a hunter-killer system. This involves the use of an independently driven cupola, with independently stabilized optic, and slew-to-cue control of the turret, allowing the commander to find, range, and pass over targets to the gunner, greatly increasing the battle efficiency of the vehicle. 27. Fitting of indirect fire equipment. As the gun on the tank is liable to be one of the larger guns available in any given setting, the ability to conduct indirect fire when possible is considered to be a great advantage. 28. Boiling Vessel, allowing the crew to heat their food and that of any infantrymen, boosting morale and reducing fatigue. 29. Ammunition load of roughly 40-50 rounds for the main gun, and roughly 5,000 rounds of secondary ammunition 30. Improved suspension damping and increased wheel travel. 31. 6 wheel stations per side 32. Volume allocation for more advanced electronics, including but not limited to image intensifiers, ballistic computers, and so on. 33. Improved transmission, with emphasis on reverse speed. 34. Fittings for tank riders, should doctrine require. 35. Design for upgradeability, particularly with regard to electronics and armor technology. 36. Drive system packaged as powerpack to allow easier repair and maintenance. With the above list of changes, the resulting vehicle bears only a mild resemblance to the venerable T-55 upon which it is based, and yet maintains many of the classic features which made its forbearer a success. The resulting vehicle entered iterative development and prototyping; In the basic stages of which it was found that all the desired improvements could not only be fulfilled, but even exceeded; The resulting vehicle has greatly improved protection in the frontal 40 degree arc for the hull and 60 degree arc for the turret, along with having all the main gun ammunition safely stowed in separated compartments with blow-off panels, keeping the crew safe. The greater weight of the vehicle compared to the T-55 is compensated by use of a more powerful engine of similar size, a more advanced transmission, and longer track contact along with more wheels, reducing the mean maximum pressure. Despite HVAP being the standard AP ammo, it was decided not to optimize the gun around that ammo type, as very soon APDS and APFSDS will be available, and will completely eclipse HVAP. The features of the vehicle are as follows: Mobility: 1. 600HP (750HP with supercharger) V-12 diesel engine [T-55 engine, uprated to the historical KV levels, with supercharger it’s at T-72 levels] 2. Mechanical-Hydraulic cross-drive 12 speed transmission, 6 forwards, 6 reverse, with good mountain fighting ability [Stolen off of a Pz 61] 3. 1500L diesel fuel, stowed outside crew compartment 4. 4 HP APU exhaust acts as engine compartment heater in cold weather. 5. Small air compressor fitted to engine and compressed air tank allow starting in extreme weather without batteries, along with easy cleaning of the air filters at routine intervals. 6. Enlarged engine bay relative to T-55, to house larger radiators and fans, improving cooling capacity in desert environments. Air is exhausted downwards behind the vehicle, M60 style, to avoid the “rooster tail” effect of the original T-55. 7. Rotary dampers on each swing arm hub and linear dampers on first, second and last swing arms. 8. Vertical travel of roughly 400mm up, 150mm rebound 9. Ground clearance of 540mm Survivability: Low profile- 2.32m turret roof height, 2.66m top of commander’s sight, extremely low profile in hull-down positions. Frontal arc - no less than 200mm LOS base steel* with air gap and another 60mm LOS spaced hard steel layer, or angles exceeding 80 degrees from normal. Lower glacis- 30mm hard face, 500mm fuel tank, 50mm back face at 20 degrees from normal. Sides- crew compartment armor at least 40mm LOS with 20mm high-hardness plate welded on hull, 100mm on turret, with spaced 30mm, Non-crew compartment-40mm side armor. 20-5mm spaced skirts on hull. Sponson boxes- 30mm armor on frontal boxes, 10mm on rear boxes. All-around armor- no less than 30mm steel for direct and air fire, 30mm front floor, 20mm rear floor. Mounting points for explosive reactive armor are available on the external faces of the spaced armor arrays.** All ammunition separated from the crew behind blow-out panels. Instantaneous (WP) smoke grenade launchers- 24 ready, 24 stowed. (4+4 salvos of 6) [launchers on the turret flanks, not modelled] Automatic IR-detection fire suppression system in crew and engine compartment. While not fitted as standard, the crew compartment is spacious enough to allow the fitting of spall liners when the technology to make them reliable and not a fire hazard is around. *The base steel is not homogenous; on the turret cheeks and sides, and on the hull front, it is an arrangement that can only adequately be described as “inverse Stillbrew”. The armor comprises a 50mm thick base layer, with the secondary casting bolted on with a rubber interlayer in the middle. The purpose of this arrangement is not to increase protection (although it should a bit), but rather to aid upgradeability- when better armor gets developed, it is intended that the thick steel facing plates be swapped for more weight-efficient armor. The volume needed for these arrays is already available, as the spaces of the spaced armor. The stowed equipment in those pockets will be displaced to less critical locations. **It is intended that with the steel armor replaced by NERA arrays and the external face topped with ERA, that the total armor array will be ERA-hard armor-NERA-backing steel armor. Such an array is reminiscent of the T-72BV turret and could quite reasonably be expected to handle tandem HEAT and moderately advanced APFSDS constructions. This drastic improvement in protection could easily be a simple part of a midlife upgrade, with the chosen construction methods. Firepower: A. Weapons: 1. Dual stabilized (sight following) 105mm L/51 autofrettaged gun with brass cases, fitted with fume extractor and thermal shroud. [basically an M68 with a slightly larger case]. Ammunition natures: APCBC [BR-412D with slightly higher velocity] HE Smoke-WP [unless it really doesn’t work with horizontal stowage] HVAP [T29E3 at lower velocity than from the gun T5E1] Stowed ammo: 56 rounds, of which 16 ready in bustle; the rest behind blast doors and equipped with blowoff panels in the hull. 2. Upgradeable to 125mm L/45 gun, when available, intended to use combustible-body stub cases [basically slightly larger NATO 120, there’s room in the turret but the gun isn’t industrially feasible yet] Stowed ammo: ~42-45, of which ~10 ready in bustle; the rest behind blast doors and equipped with blowoff panels in the hull. 3. 1 coax M240 Stowed ammo: 6,000 rounds, of which 2000 ready. 4. 1 M240 on commander’s cupola, fireable under armor. Stowed ammo: 2400, of which 600 ready. 5. 1 M240 on skate mount [modelled as pintle] for loader. Stowed ammo: 2000, of which 200 ready. 6. 1 M2 HMG over barrel (optional) Stowed ammo: 1300, of which 100 ready. B. Optics: 1. Dual-channel 2-axis independently stabilized gunner’s sight with extension for commander. 2. Gunner’s secondary direct-vision telescopic sight. 3. Commander’s fire control cupola: single-channel (selectable) main independently stabilized optic, with secondary coincidence rangefinder channel. 5 periscopes allow all-around vision, slew-to-cue feature. 4. 3 periscopes for loader improve situational awareness. 5. Commander’s hatch with open protected position in development. C. FCS: 1. Range-finding stadiametric reticles. 2. ballistic cam computer with automatic feed in from commander’s rangefinder, automatic superelevation. 3. Gun follows sight (with offset based on superelevation from ballistic computer) 4. Hydraulic control- 15 deg/sec elevation, 40 deg/sec traverse (basic turret), 30 deg/sec (fully up-armored). Pump, accumulator and reservoir are separated from the crew, in the bustle, and the system is fitted with a pressure-loss automatic cutoff to prevent the hydraulic fluid spraying everywhere in case of a rupture. 5. Commander has override handles. For the external machine guns, spare ammunition is carried in belt boxes in the spaced armor of the turret. 12 boxes of .50 can be carried in the frontal pockets, with 100 rounds linked each; and 9 7.62 boxes in each side of the turret, with 200 rounds linked each. The commander’s cupola has a 600-round ring ammo box around the cupola [not modelled]. Crew comfort: 1. Air conditioning. Operating armored vehicles in the desert without this feature is torture, to say the least. In the bustle, between the hydraulic unit and the ammo rack, sits a powerful air conditioning unit. Rated at 3 HP, this is enough to properly cool down the fighting compartment even with moderate air leakage. While currently no requirement for NBC exists, such an air filtration system could be merged into the aircon unit. When firing, the blower fan is directed into the fighting compartment and not the aircon radiator, to clear out the gasses. Aircon also aids in maintaining the life of electronic components, an important feature for such an electronically-rich vehicle. With flow reversal, the aircon unit heats the crew compartment during the winter, with none of the dangers of a fuel-powered crew heater. 2. Drinking water. There is a tank for drinking water installed, aft of the turret. With a capacity of 240 litres, this allows the tank to operate in the desert and support infantry for extended operations without supply. Additional external stowage is of course possible. A small water container sits directly in front of the aircon vents, allowing the crew to drink at a comfortable temperature. (The main water tank sits up against the engine firewall and will likely get a bit too hot for comfort.) 3. Boiling Vessel. Allows cooking MREs for the crew and infantry, and hot drinks during the winter. 4. Height. All seats are adjustable and suitable to the above-average Cascadian recruit. The loader’s position is arranged in such a way that most of his duties can be performed sitting down. There is sufficient headroom and elbow space in every crew position, and using the equipment requires no contortionisms. 5. Ammo loading hatch- allows loading ammo into the tank from ground level, and not from roof hatches, results in less tiring and quicker loading. 6. Fume extractor on the barrel greatly reduces the flow of gas into the fighting compartment when the gun fires. Upgradeability: 1. Overbuilt, easily upgradeable suspension. Allows weight growth, at cost of increasing ground pressure. 2. Armor upgradeability, as explained in armor section. Current armor is fairly inexpensive, and allows inexpensive upgrading at a later date, allowing fairly cheap buildup of forces and allows use of more mature armor when the upgrade occurs (as current reactive armor arrays developed at GF&M are fairly crude). Current armor more than outmatches current and projected enemy weapons. 3. Powerpack dimensions, and those of engine bay, allow upgrading with bigger and better powerplants and transmissions as they come available. The engine bay is 200mm longer and 200mm taller (at the hump) than that of the T-55, to allow better cooling and more upgradeability. It is expected that upgrade powerpacks with 1000HP transversely mounted engines with automatic transmissions, as were available pre-war for the T-72, will be possible for a late-life upgrade. 4. Spare internal volume for more vetronics. 5. Frontally removable gun, allows easy maintenance and upgrading. 6. Configurable ammo racks inside blowoff bunkers allows depot-level reconfiguring for different calibres. Vents were not modelled due to lack of time. Mass components: Turret structure: 6.0 tons, includes internal subdivisions and basket Turret spaced: 1.8 tons, includes partitions Hull structure: 13.8 tons, includes suspension mounting points and internal subdivisions. Hull spaced: 1.92 tons, includes sponson stowage boxes. Suspension: 4 tons. Tracks: 3.3 tons, based on T-72 track links. Armament: 1.3 tons Ammo: 1.5 tons Fuel: 1500L, 1.23 tons. Engine, cooling and accessories: 1.5 tons Transmission: 2 tons Extras: 6 tons, includes 0.5 tons electric systems, 0.5 hydraulics, 0.3 tons water, 1 ton structural components, 0.3 tons for the aircon system, 0.5 tons for fittings, 0.4 tons of crew, and a margin of 2.3 tons for things unaccounted for. Total, loaded: 44.3 tons. Dimensions: Length, gun forwards: 8.7m Length, hull: 6.3m Width, OA: 3.3m Width over tracks: 3.24m Ground clearance: 540mm Height, turret roof: 2.33m Height, overall: 2.66m Idler height: 0.84m (relevant for vertical step climbing) Track contact length, zero penetration: 4.38m Track width: 550mm Roadwheel diameter: 686mm Extra notes: 1. The gun uses brass-cased ammo as semi-combustible case tech does not seem to be ready for prime-time with 1950 tech, as evidenced by the problems with the ammunition of the US 152mm gun on the M60A2 and Sheridan in the 1960s; The combination of good rigidity needed to hold large propellant loads onto big heavy projectiles (like 105mm APCBC) and good burn characteristics would seem to be beyond current tech, and therefore extremely risky to develop. 2. As brass-cased ammunition was chosen, 105mm was the logical caliber to use, as it is the largest caliber which can still be relatively easily man-handled in the confines of a turret, when brass cased full-bore AP rounds are used. 3. The future 125mm intended for the mid-life upgrade is intended to be stub-cased combustible, smoothbore, with APFSDS as the primary anti-armor round. It is expected that by the time the gun is ready and needed, the technology will have progressed sufficiently to allow higher pressures and reliable strong combustible case bodies. As the ammo stowage is already compartmentalized, this ammunition will pose no greater risk to the crew. 4. The tank, with its current weight, is train-deployable fully loaded. The weight margins ensure that when upgraded it will still be transportable in MLC-45, without loaded ammunition, fuel, crew, and other extras. 5. Current development of variants includes: a. CEV (similar in concept to M728 CEV, with 155mm demolition gun/low velocity howitzer) b. Bridgelayer (Similar in concept to M60 AVLB, with bridge designed for MLC 70-80) c. ARV (similar in concept to M88 ARV, with a crane) d. HAPC/HIFV (similar in concept to Achzarit with small cannon/MG turret, axial instead of transverse engine) e. SPAA (Shilka-like turret, with twin 35mm guns, and basic air search and ranging radars; plenty of space for more advanced electronics when available) 6. The compressed air starting system connects to a pneumatic joint in the engine bay, to which air-powered tools can be attached. Current supplied tools as basic vehicle equipment include a pressure blower for cleaning air filters and the like, a pneumatic bolt-driver, a pneumatic jack, and other assorted goodies. 7. A coincidence rangefinder was chosen, as no low-risk practical alternative could be thought up. It is intended to be replaced as soon as possible with a laser rangefinder, and an additional laser rangefinder to be installed in the gunner's FCS suite. A coincidence rangefinder takes around 10-12 seconds to range effectively; with the rangefinder in a separate mount, the commander can range a target while the gunner engages a different one, allowing high-speed hunter-killer operation.

I'm pretty sure the original Stokes Mortar had a better safety record.

I believe the correct term for that is "giving them just enough rope to hang themselves".

I'd also add that Drummond is probably waaaay off base with the armor- we've seen the M1A2C prototypes running around with pretty large weight simulators, I highly doubt they're moving to a lighter armor package. I also doubt better IED armor is on the table when TUSK works pretty damn well and the focus is rapidly shifting back to high end war. Also, while the new gun and autoloader are nice features, they don't actually add that much capability to the vehicle for their cost. Trophy and AMP capability are far more important, and Trophy isn't exactly cheap. And finally, smaller turret!? The hell is he smoking? Smaller turret would have to be new build, which is not cheap, would decrease volume needed for systems (though without the loader there is more space available for juggling around), and if width reduction is involved would by definition reduce ammo capacity and squish the loader into the gun. Drummond is a hack.

Just to elaborate on this- In a direct-vision block, you have a single* block of glass through which you look, with a short overall distance. In a simple unity periscope, you have 2 reflective components (whether they be mirrors or prisms), and the optical path is pretty long. Looking through a periscope is like looking through a pipe- your field of vision is much narrower than you'd expect, unless you have some special optical trickery* (like submarine periscopes, which have built-in telescopic lenses and split-lense rangefinders and shit). Also, generally speaking, flat vision blocks** are easier to control dimensionally in manufacture than prism heads, leading to less optical fuckery like distortion and abberation and shit. Prism-based periscopes may also have more glass than vision blocks, whixh impedes light transmission and gives a darker image. *Many modern periscopes have larger objective prisms than eye prisms to reduce the "looking down a pipe" effect. ** may actually be several layers.

http://tass.com/defense/1022432 After an awful lot of delays and redesigns, the second Lada sub, Kronshtadt, has been launched.

The amplifiers are the bit that benefits from transistors, as opposed to vaccum tubes. What the wiring inside each amp block looks like I'm not sure, I'm not very well aware of how exactly the internals of amplifiers work. I have a few friends who are electrical engineers, I'll ask one. Edit: wiki has a pretty good rundown on the internals. https://en.wikipedia.org/wiki/Operational_amplifier

Thanks to the miracle of asset reuse, the Red Fox is more detailed than it has any right to be. The gun is a 35mm autocannon, and the cupola and optics (and hatches) stolen from the Norman. The render may not get significantly more complex than the current state, as I lack the time. Regarding the missile, a few notes which popped up: >The intent is to have an MCLOS missile broadly analogous to the AT-5 Spandrel (Though with a larger missile body), easily upgradeable to SACLOS when the tech arrives without loss of capability relative to a purpose-built SACLOS like the AT-5. >The missile is lightly spun to maintain direction throughout flight without requiring constant operator input >I'm also intending for an MLU to replace the rocket motors and warheads >There's space in the nose for a precursor, and the warhead sits a bit further back than is good for it with existing HEAT tech, because a 160mm HEAT warhead even at standoff greater than optimal will kill things pretty dead, and later warheads will benefit from the standoff. Regarding the concept- light tanks are not intended to go toe-to-toe with MBTs or heavy tanks. The 35mm allows the destruction of anything short of a medium tank from the front, and mediums/MBTs at close range from the sides and rear. The missiles are intended to allow self defense and ambush capability against the heaviest vehicles the enemy can field, as well as the destruction of fortifications and strong points, in the absence of heavy enemy armor.

Might actually be the way to go, if I decode to have my servos air-powered like they are on the TOW. The TOW is however bang-bang, which doesn't work well with human control. We'll see.

Yes. humans are not good at correcting non-zero side accelerations. Also the PID control is fully realizable with solid-state electronics, which are now available. No need for steampunk.

PID per Ziegler-Nichols from operator command to servo command, servos on open loop. Where, of course, the full deflection of the operator's joystick would translate to full deflection of control surfaces at launch, decreasing with flight time to allow better accuracy. Space in the turret has been cleared for the SACLOS conscan device, when such a thing will be ready. Also, there's a damned good reason I'm not going with TVC.

The tail is fixed, and the canards are monobloc control surfaces. The lines on the fins are just a result of how I defined them.

SS.11 was indeed an inspiration. And it even has a SACLOS upgrade (Harpon) and a few other details I intend to borrow. But it too suffered from the major flaw in the control layout of first-gen ATGMs, which is why I haven't copied its aerodynamics. Also friendly reminder that Azon, Fritz-X, Razon, and other WW2 guided bombs were also MCLOS. As previously stated, I will be exhaustively justifying the ability to build this system.

The basic form of the Red Fox is now in. Current plate thicknesses are not indicative, and the tires are just for show.

Secondary armament for the Red Fox light tank/scout car is in: Yes that is a guided missile and yes I will be exhaustively justifying why I believe it to be feasible with the existing tech. The ATGM is MCLOS and easily converted to SACLOS; space will be reserved in the turret for the guidance equipment. The aerodynamic setup is reminiscent of the AT-5 Spandrel, and has been chosen to avoid the most common problem of MCLOS ATGMs as built before the war, and will also be exhaustively discussed in the final submission. Exact dimensions are still liable to change.

Plant is far more important, followed by screw. But flow noise isn't insignificant, and evenly-spaced holes can cause easily-recognized tonals.

All those flooding holes... that thing is unlikely to be particularly quiet.

https://sci-hub.tw/https://arc.aiaa.org/doi/10.2514/3.19908 " The development of radar homing missiles "