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N-L-M

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  1. Tank You
    N-L-M got a reaction from Toxn in Competition: Californium 2250   
    Tread is the distance between the *centers* of the tracks, ie how far apart their centerlines are.
  2. Tank You
    N-L-M got a reaction from Lord_James in Californium 2250- final submissions   
    ATTENTION DUELISTS:
    @Toxn
    @LostCosmonaut
    @Lord_James
    @DIADES
    @Datengineerwill
    @Whatismoo
    @Kal
    @Zadlo
    @Xoon
    detailed below is the expected format of the final submission.
    The date is set as Wednesday the 19th of June at 23:59 GMT.
    Again, incomplete designs may be submitted as they are and will be judged as seen fit.
     
    FINAL SUBMISSION:
    Vehicle Designation and name

    [insert 3-projection (front, top, side) and isometric render of vehicle here)



    Table of basic statistics:

    Parameter

    Value

    Mass, combat


     
    Length, combat (transport)


     
    Width, combat (transport)


     
    Height, combat (transport)


     
    Ground Pressure, MMP (nominal)


     
    Estimated Speed


     
    Estimated range


     
    Crew, number (roles)


     
    Main armament, caliber (ammo count ready/stowed)


     
    Secondary armament, caliber (ammo count ready/stowed)


     

     
    Vehicle designer’s notes: explain the thought process behind the design of the vehicle, ideas, and the development process from the designer’s point of view.

    Vehicle feature list:
    Mobility:

    1.     Link to Appendix 1- RFP spreadsheet, colored to reflect achieved performance.

    2.     Engine- type, displacement, rated power, cooling, neat features.

    3.     Transmission- type, arrangement, neat features.

    4.     Fuel- Type, volume available, stowage location, estimated range, neat features.

    5.     Other neat features in the engine bay.

    6.     Suspension- Type, Travel, ground clearance, neat features.

    Survivability:

    1.     Link to Appendix 1 - RFP spreadsheet, colored to reflect achieved performance.

    2.     Link to Appendix 2- armor array details.

    3.     Non-specified survivability features and other neat tricks- low profile, gun depression, instant smoke, cunning internal arrangement, and the like.

    Firepower:

    A.    Weapons:

    1.     Link to Appendix 1- RFP spreadsheet, colored to reflect achieved performance.

    2.     Main Weapon-

    a.      Type

    b.      Caliber

    c.      ammunition types and performance (short)

    d.     Ammo stowage arrangement- numbers ready and total, features.

    e.      FCS- relevant systems, relevant sights for operating the weapon and so on.

    f.      Neat features.

    3.     Secondary weapon- Similar format to primary. Tertiary and further weapons- likewise.

    4.     Link to Appendix 3- Weapon system magic. This is where you explain how all the special tricks related to the armament that aren’t obviously available using Soviet 1961 tech work, and expand to your heart’s content on extimated performance and how these estimates were reached.

    B.    Optics:

    1.     Primary gunsight- type, associated trickery.

    2.     Likewise for any and all other optics systems installed, in no particular order.

    C.    FCS:

    1.     List of component systems, their purpose and the basic system architecture.

    2.     Link to Appendix 3- weapon system magic, if you have long explanations about the workings of the system.

    Fightability:

    1.     List vehicle features which improve its fightability and useability.

    Additonal Features:

    Feel free to list more features as you see fit, in more categories.

    Free expression zone: Let out your inner Thetan to fully impress the world with the fruit of your labor. Kindly spoiler this section if it’s very long.


     Example for filling in Appendix 1
  3. Tank You
    N-L-M got a reaction from Toxn in Californium 2250- final submissions   
    ATTENTION DUELISTS:
    @Toxn
    @LostCosmonaut
    @Lord_James
    @DIADES
    @Datengineerwill
    @Whatismoo
    @Kal
    @Zadlo
    @Xoon
    detailed below is the expected format of the final submission.
    The date is set as Wednesday the 19th of June at 23:59 GMT.
    Again, incomplete designs may be submitted as they are and will be judged as seen fit.
     
    FINAL SUBMISSION:
    Vehicle Designation and name

    [insert 3-projection (front, top, side) and isometric render of vehicle here)



    Table of basic statistics:

    Parameter

    Value

    Mass, combat


     
    Length, combat (transport)


     
    Width, combat (transport)


     
    Height, combat (transport)


     
    Ground Pressure, MMP (nominal)


     
    Estimated Speed


     
    Estimated range


     
    Crew, number (roles)


     
    Main armament, caliber (ammo count ready/stowed)


     
    Secondary armament, caliber (ammo count ready/stowed)


     

     
    Vehicle designer’s notes: explain the thought process behind the design of the vehicle, ideas, and the development process from the designer’s point of view.

    Vehicle feature list:
    Mobility:

    1.     Link to Appendix 1- RFP spreadsheet, colored to reflect achieved performance.

    2.     Engine- type, displacement, rated power, cooling, neat features.

    3.     Transmission- type, arrangement, neat features.

    4.     Fuel- Type, volume available, stowage location, estimated range, neat features.

    5.     Other neat features in the engine bay.

    6.     Suspension- Type, Travel, ground clearance, neat features.

    Survivability:

    1.     Link to Appendix 1 - RFP spreadsheet, colored to reflect achieved performance.

    2.     Link to Appendix 2- armor array details.

    3.     Non-specified survivability features and other neat tricks- low profile, gun depression, instant smoke, cunning internal arrangement, and the like.

    Firepower:

    A.    Weapons:

    1.     Link to Appendix 1- RFP spreadsheet, colored to reflect achieved performance.

    2.     Main Weapon-

    a.      Type

    b.      Caliber

    c.      ammunition types and performance (short)

    d.     Ammo stowage arrangement- numbers ready and total, features.

    e.      FCS- relevant systems, relevant sights for operating the weapon and so on.

    f.      Neat features.

    3.     Secondary weapon- Similar format to primary. Tertiary and further weapons- likewise.

    4.     Link to Appendix 3- Weapon system magic. This is where you explain how all the special tricks related to the armament that aren’t obviously available using Soviet 1961 tech work, and expand to your heart’s content on extimated performance and how these estimates were reached.

    B.    Optics:

    1.     Primary gunsight- type, associated trickery.

    2.     Likewise for any and all other optics systems installed, in no particular order.

    C.    FCS:

    1.     List of component systems, their purpose and the basic system architecture.

    2.     Link to Appendix 3- weapon system magic, if you have long explanations about the workings of the system.

    Fightability:

    1.     List vehicle features which improve its fightability and useability.

    Additonal Features:

    Feel free to list more features as you see fit, in more categories.

    Free expression zone: Let out your inner Thetan to fully impress the world with the fruit of your labor. Kindly spoiler this section if it’s very long.


     Example for filling in Appendix 1
  4. Tank You
    N-L-M got a reaction from LoooSeR in Californium 2250- final submissions   
    ATTENTION DUELISTS:
    @Toxn
    @LostCosmonaut
    @Lord_James
    @DIADES
    @Datengineerwill
    @Whatismoo
    @Kal
    @Zadlo
    @Xoon
    detailed below is the expected format of the final submission.
    The date is set as Wednesday the 19th of June at 23:59 GMT.
    Again, incomplete designs may be submitted as they are and will be judged as seen fit.
     
    FINAL SUBMISSION:
    Vehicle Designation and name

    [insert 3-projection (front, top, side) and isometric render of vehicle here)



    Table of basic statistics:

    Parameter

    Value

    Mass, combat


     
    Length, combat (transport)


     
    Width, combat (transport)


     
    Height, combat (transport)


     
    Ground Pressure, MMP (nominal)


     
    Estimated Speed


     
    Estimated range


     
    Crew, number (roles)


     
    Main armament, caliber (ammo count ready/stowed)


     
    Secondary armament, caliber (ammo count ready/stowed)


     

     
    Vehicle designer’s notes: explain the thought process behind the design of the vehicle, ideas, and the development process from the designer’s point of view.

    Vehicle feature list:
    Mobility:

    1.     Link to Appendix 1- RFP spreadsheet, colored to reflect achieved performance.

    2.     Engine- type, displacement, rated power, cooling, neat features.

    3.     Transmission- type, arrangement, neat features.

    4.     Fuel- Type, volume available, stowage location, estimated range, neat features.

    5.     Other neat features in the engine bay.

    6.     Suspension- Type, Travel, ground clearance, neat features.

    Survivability:

    1.     Link to Appendix 1 - RFP spreadsheet, colored to reflect achieved performance.

    2.     Link to Appendix 2- armor array details.

    3.     Non-specified survivability features and other neat tricks- low profile, gun depression, instant smoke, cunning internal arrangement, and the like.

    Firepower:

    A.    Weapons:

    1.     Link to Appendix 1- RFP spreadsheet, colored to reflect achieved performance.

    2.     Main Weapon-

    a.      Type

    b.      Caliber

    c.      ammunition types and performance (short)

    d.     Ammo stowage arrangement- numbers ready and total, features.

    e.      FCS- relevant systems, relevant sights for operating the weapon and so on.

    f.      Neat features.

    3.     Secondary weapon- Similar format to primary. Tertiary and further weapons- likewise.

    4.     Link to Appendix 3- Weapon system magic. This is where you explain how all the special tricks related to the armament that aren’t obviously available using Soviet 1961 tech work, and expand to your heart’s content on extimated performance and how these estimates were reached.

    B.    Optics:

    1.     Primary gunsight- type, associated trickery.

    2.     Likewise for any and all other optics systems installed, in no particular order.

    C.    FCS:

    1.     List of component systems, their purpose and the basic system architecture.

    2.     Link to Appendix 3- weapon system magic, if you have long explanations about the workings of the system.

    Fightability:

    1.     List vehicle features which improve its fightability and useability.

    Additonal Features:

    Feel free to list more features as you see fit, in more categories.

    Free expression zone: Let out your inner Thetan to fully impress the world with the fruit of your labor. Kindly spoiler this section if it’s very long.


     Example for filling in Appendix 1
  5. Tank You
    N-L-M got a reaction from Lord_James in Bar / Cage armour + LASSO + RPGnet   
    Nope. The cage neutralizes the piezo fuze of RPGs by shorting the inner cone and the outer cone (vua crushing the outer inwards). Missiles with full width fuzes will detonate, and while the jet may suffer a bit from the increased standoff it's still gonna function.

    For example, the OG TOW warhead, which as you can see has a full width crush fuze. And has terrible built in standoff, so a cage would likely improve its performance.
  6. Tank You
    N-L-M got a reaction from Toxn in Competition: Californium 2250   
    No, sometime next week, sorry. Update soon.
  7. Tank You
    N-L-M reacted to LoooSeR in Jihad design bureau and their less mad opponents creations for killing each other.   
    Note that in Libya troops of field marshal Haftar use silhouettes of Africa and Libya in camo patterns.

     
     
  8. Metal
    N-L-M reacted to ZloyKrolik in Your Tank Stories   
    Time for another tank story:
     
    This time it is the early '90s, I'm a TC on an M1A1 in the Oregon National Guard, G Trp 82nd Cav. Annual training at Gowen Field, Orchards Training Center, outside of Boise ID. This didn't happen to me, but I witnessed the event. We were down range on the night portion of TT VIII. My buddy Duncan was the gunner on the Platoon Sergeant's tank. This happened during Duncan's run. It was what we called the "Widow Maker": on the move, NBC environment, two targets, a BMP & then a troop target.
     
    During this engagement, Duncan's TC gives the fire command "Gunner, HEAT, PC!", the rest of the crew & Duncan react appropriately and service the target. The TC calls cease fire on the PC & gives the fire command of "Gunner, Coax, Troops!", but the loader had already loaded a new round in the main gun and had placed the main gun safety to fire. Not normally a big deal if the gunner had switched from main gun to coax, but on the M1A1 there was a switch for each of the main gun and coax, so it was possible to fire both at the same time if both were set to fire and the loader's safety was set to fire.
     
    This time at Gowen Field, on the main tank range for TT VIII, the observation tower for that range, they had a TTS thermal sight from an M60A3 rigged up in the tower with a video camera to record it for the evaluation NCO to use during night gunnery, so there was a recording of what happened.
     
    Duncan lays on the troop target, gets a range and fires. "On the Way!', BOOOM rattatttattaat! goes the main gun and coax, "Shit!" goes Duncan. 
     
    Later in the tower, I was there when the evaluator goes over that engagement with Duncan's crew., along with the video from the tower. You could clearly see the troop target as it rises on the range, hear the fire commands given by Duncan's TC and watch as a 120mm training heat round hits the left most troop target. The troop target just disappears, flies right off the target array, and then you can see the tracers from the coax strike around the troop target as it lowers back down. 
     
    The evaluator commented that while that they hit the target & it was suppressed, they engaged with the wrong weapon system, - 30 points. They were impressed that he hit the target. Later someone went down range and retrieved that target, it had a 120mm hole in it at about the level of the heart, nice shot. They later hung it up in the tower briefing room.
  9. Tank You
    N-L-M got a reaction from LostCosmonaut in Competition: Californium 2250   
    Well, now's as good a time as any for the great announcement:
     
    ATTENTION COMPETITORS:
    @Toxn
    @Collimatrix
    @LostCosmonaut
    @Lord_James
    @DIADES
    @Datengineerwill
    @Whatismoo
    @Kal
    @Zadlo
    @Xoon
    And any others I may have missed:
    The time of submission is approaching, and the DPRC is getting ready to evaluate your designs!
    Detailed submission guidelines will be posted soon in a dedicated thread.
    The date of submission is in 3 weeks from the time of posting, Tuesday the 11th of June at 23:59 GMT.
     
    Incomplete designs may be submitted as they are and will be judged as seen fit.
  10. Tank You
    N-L-M got a reaction from Toxn in Competition: Californium 2250   
    Well, now's as good a time as any for the great announcement:
     
    ATTENTION COMPETITORS:
    @Toxn
    @Collimatrix
    @LostCosmonaut
    @Lord_James
    @DIADES
    @Datengineerwill
    @Whatismoo
    @Kal
    @Zadlo
    @Xoon
    And any others I may have missed:
    The time of submission is approaching, and the DPRC is getting ready to evaluate your designs!
    Detailed submission guidelines will be posted soon in a dedicated thread.
    The date of submission is in 3 weeks from the time of posting, Tuesday the 11th of June at 23:59 GMT.
     
    Incomplete designs may be submitted as they are and will be judged as seen fit.
  11. Tank You
    N-L-M reacted to LostCosmonaut in Martin XB-68   
    The Martin XB-68 is, in my opinion, one of the best looking stillborn aircraft projects of the 1950s.
     

     
    Development of the XB-68 began in 1954, in response to a USAF request for a supersonic tactical bomber to satisfy the WS-302A requirement. A top speed in excess of Mach 2 was envisioned, with the aircraft conducting the bombing run at high altitude. Three companies, Martin, Douglas, and North American, submitted designs. Martin's design was assigned the internal company number 316. Initial concepts off all three entries clearly show aircraft optimized for high speed flight;
     
    Martin;
     

     
    Douglas:
     

     
    North American:
     


     
     
    (Douglas and North American images via source (1))
     
    (I am not certain if there is any connection between the design of the Vigilante and North American's WS-302A entry. Given the similar operational requirements and the timeframe, it is highly likely the A3J was as least somewhat based on the WS-302A design).
     
    As can be seen, the original design of the XB-68 had roughly 45 degrees of wing sweep. Additionally, it was to have used the J67 turbojet engine, an American version of the Rolls Royce Olympus. (The J67 was also considered for several other aircraft, including the XF-103). Both of these features would change as the XB-68 evolved. At this time, the aircraft had a maximum weight of about 96,000 pounds, and 900 square feet of wing area. Two crewmembers sat in tandem in a highly streamlined cockpit.
     
    The Martin 316 was selected as the winner of the competition in 1956, and selected for further development. At the time, plans were for the aircraft to enter service in the early 1960s. As the design underwent further development, several changes were made. The J67 engines were discarded, and replaced with J75 turbojets. The exact reasoning behind this was unknown, but the J67 (built by Curtiss-Wright) had a very troubled development and was ultimately stillborn. In contrast, Pratt & Whitney's J75 was successfully used in several other aircraft, including Martin's P6M that was also being developed in the 1950s. (The dihedral on the stabilizers of both the P6M and XB-68 shows common Martin influence).
     
    The second change was moving to a less swept, trapezoidal wing, rather than the swept wing of the initial design. Studies in the NASA Langley wind tunnel (4) showed that a wing swept at only 19.2 degrees had less drag at high mach numbers than the 45 degree sweep wing, due to the thinner airfoil that could be used. The result was an aircraft that resembled another 1950s aircraft intended to operate at Mach 2 at high altitudes; the F-104 Starfighter.
     

     

     
    The design of the XB-68 was finalized by approximately 1957. The final aircraft had a maximum takeoff weight of 100,000 pounds, with a wing area of 875 square feet. (3). With a length of 109.8 feet, but a wingspan of only 53 feet, it was more than twice as long as it was wide. Using the two J75s, top speed at the maximum altitude of 57,250 was to have been 1357 knots, roughly Mach 2.35.
     
     
     

     

    However, when fitted with a water injection system, the XB-68 could have reached altitudes in excess of 60,000 feet, and a slightly higher top speed. According to (3), this limit was imposed by the structure of the aircraft (likely aerodynamic heating).
     
    The primary armament of the XB-68 was never fully decided on; according to (3), up to 8,500 of bombs would have been carried in a rotary bomb bay (this was the payload over a short range, at maximum range the payload would have been limited to about 4,000 pounds). Given the time and the aircraft's intended mission,  munitions could have included the Mark 7, Mark 10, and Mark 28 nuclear weapons. The XB-68 was also to have been equipped with a 20mm T171E2 rotary cannon mounted at the extreme rear of the aircraft.
     
     
     
    The XB-68 made it as far as mockup form, before being cancelled in the late 1950s;
     

     
    With how ambitious the XB-68 was, the aircraft would likely have not entered service until the mid-1960s. A development time of over a decade, while short today, was a relative eternity in the 1950s. Another problem was the development of surface to air missiles such as the S-75. The development of these missiles, and the Soviet deployment of them in Europe would have placed the XB-68 in severe danger. Granted, the XB-68 would have performed well at low level. Source (3) indicates it was projected to achieve Mach 1.25 at sea level, and the high wing loading (114 lb/ft2, vs 148 lb/ft2 for the F-104) would have given it excellent stability at low level. While the similar looking F-104 suffered severe accident rates in the low level strike role, the XB-68 would certainly not have been given to green West German crews. However, the F-104 was much cheaper, and had an air to air capability which the XB-68 lacked. However, it is possible that the XB-68 could have found a niche as a low level penetration bomber with superior range to the F-104. In this role it would have been soon eclipsed by the F-111, which first flew in 1964, around when the XB-68 would have entered service.
     
     
     
     
     
    Sources:
     
    (1)https://www.secretprojects.co.uk/threads/usaf-weapon-system-302a-tactical-bomber-competition.22864/
    (2) https://www.secretprojects.co.uk/threads/martin-model-316-xb-68-tactical-bomber.479/
    (3) http://www.up-ship.com/apr/v0n0.pdf
    (4) https://digital.library.unt.edu/ark:/67531/metadc64207/m1/2/
     
     
  12. Tank You
    N-L-M reacted to Walter_Sobchak in US Politics Thread: Year 2 of 1000 of the TrumpenReich   
    It's interesting to see my congressman, Justin Amash, in the national news.  Amash represents the 3rd congressional district of Michigan, which includes Grand Rapids, my home (the 3rd district used to be the 5th district, most famously represented by Gerald Ford.)  Amash is getting quite a bit of news coverage for being the first Republican congressman to call for the impeachment of Trump.  For those that have followed Amash, he has been a pretty consistent critic of Trump, so this is no surprise.  Anyhow, since I live in his district, I thought I might make some observations regarding his tenure as a representative.
     
    One thing I found amusing was Republican House leader Kevin McCarthy attacking Amash as voting "more with Nancy Pelosi than he ever votes with me. It's a question whether he's even in our Republican conference as a whole."  This claim is pretty absurd.  Amash is extremely conservative, although in a more traditional, libertarian fashion than the current strain of Trumpian conservatism.  Conservative vote tracking groups give Amash scores of 90-100% conservative in terms of his voting record.  One thing I will say about his voting record, he is not afraid to take unpopular positions if he thinks something violates his libertarian principles.  There have been a few times where he has been either the only dissenting vote, or one of a handful of dissenters on certain bills he sees as flawed.  He came into office as part of the Tea Party movement, and is a founding member of the Freedom Caucus.
     
    Based on my observations, he is well regarded in his own district for his adherence to his principles and his openness in explaining his votes (he has a fairly informative twitter feed).  He seems pretty immune to special interests, a rarity for congress critters.  More than once I have heard a liberal friend bemoan the fact that while they vehemently disagree with Amash's stand on issues, they respect his integrity.  I have never voted for him, and I don't plan to do so.  That said, I don't dislike him and respect the way he conducts himself as a representative.  Sometimes he may seem to be contrarian for the sake of being contrarian.  He is much more fiscally conservative than the Republican party as a whole right now, having advocated for smaller defense budgets rather than larger ones. He certainly fits more in the Rand Paul version of Republicanism than the Trump iteration of the GOP.
     
    One other thing I can say is that on the local level, his background as an Orthodox Christian of Palestinian and Syrian descent has never been an issue.  In fact, I suspect 99% of voters in the 3rd district have no idea what his ethnic background is.  It's only been in the past couple days since he has been in the national news that I have seen people mentioning it, typically in a derogatory way in comments sections.  
     
     
     
     
  13. Tank You
    N-L-M got a reaction from Toxn in Competition: Californium 2250   
    The concept of ATGMs is indeed well known, and basic conscan trackers can be fairly reliably produced. Extra advanced trickery is up to you.
  14. Tank You
    N-L-M reacted to LostCosmonaut in J2M Raiden   
    Compared to the most well known Japanese fighter of World War 2, the A6M “Zero”, the J2M Raiden (“Jack”) was both less famous and less numerous. More than 10,000 A6Ms were built, but barely more than 600 J2Ms were built. Still, the J2M is a noteworthy aircraft. Despite being operated by the Imperial Japanese Navy (IJN), it was a strictly land-based aircraft. The Zero was designed with a lightweight structure, to give extreme range and maneuverability. While it had a comparatively large fuel tank, it was lightly armed, and had virtually no armor. While the J2M was also very lightly built, it was designed that way to meet a completely different set of requirements; those of a short-range interceptor. The J2M's design led to it being one of the fastest climbing piston-engine aircraft in World War 2, even though its four 20mm cannons made it much more heavily armed than most Japanese planes.
     
     

     
    Development of the J2M began in October 1938, under the direction of Jiro Hirokoshi, in response to the issuance of the 14-shi interceptor requirement (1). Hirokoshi had also designed the A6M, which first flew in April 1939. However, development was slow, and the J2M would not make its first flight until 20 March 1942, nearly 3 ½ years later (2). Initially, this was due to Mitsubishi's focus on the A6M, which was further along in development, and of vital importance to the IJN's carrier force. Additionally, the J2M was designed to use a more powerful engine than other Japanese fighters. The first aircraft, designated J2M1, was powered by an MK4C Kasei 13 radial engine, producing 1430 horsepower from 14 cylinders (3) (compare to 940 horsepower for the A6M2) and driving a three bladed propeller. The use of such a powerful engine was driven by the need for a high climb rate, in order to fulfill the requirements set forth in the 14-shi specification.
     
    The climb rate of an aircraft is driven by specific excess power; by climbing an aircraft is gaining potential energy, which requires power to generate. Specific Excess Power is given by the following equation;
     
    (Airspeed*(Thrust-Drag))/Weight
     
     
     
    It is clear from this equation that weight and drag must be minimized, while thrust and airspeed are maximized. The J2M was designed using the most powerful engine then available, to maximize thrust. Moreover, the engine was fitted with a long cowling, with the propeller on an extension shaft, also to minimize drag. In a more radical departure from traditional Japanese fighter design (as exemplified by aircraft such as the A6M and Ki-43), the J2M had comparatively short, stubby wings, only 10.8 m wide on the J2M3 variant, with a relatively high wing loading of 1.59 kN/m2 (33.29 lb/ft2) (2). (It should be noted that this wing loading is still lower than contemporary American aircraft such as the F6F Hellcat. The small wings reduced drag, and also reduced weight. More weight was saved by limiting the J2M's internal fuel, the J2M3 had only 550 liters of internal fuel (2).
     
    Hirokoshi did add some weight back into the J2M's design. 8 millimeters of steel armor plate protected the pilot, a luxurious amount of protection compared to the Zero. And while the J2M1 was armed with the same armament as the A6M (two 7.7mm machine guns and two Type 99 Model 2 20mm cannons), later variants would be more heavily armed, with the 7.7mm machine guns deleted in favor of an additional pair of 20mm cannons. Doubtlessly, this was driven by Japanese wartime experience; 7.7mm rounds were insufficient to deal with strongly built Grumman fighters, let alone a target like the B-17.
     
    The first flight of the J2M Raiden was on March 20th, 1942. Immediately, several issues were identified. One design flaw pointed out quickly was that the cockpit design on the J2M1, coupled with the long cowling, severely restricted visibility. (This issue had been identified by an IJN pilot viewing a mockup of the J2M back in December 1940 (1).) The landing speed was also criticized for being too high; while the poor visibility over the nose exacerbated this issue, pilots transitioning from the Zero would be expected to criticize the handling of a stubby interceptor.
     

    Wrecked J2M in the Philippines in 1945. The cooling fan is highly visible.
     
    However, the biggest flaw the J2M1 had was poor reliability. The MK4C engine was not delivering the expected performance, and the propeller pitch control was unreliable, failing multiple times. (1) As a result, the J2M1 failed to meet the performance set forth in the 14-shi specification, achieving a top speed of only 577 kph, well short of the 600 kph required. Naturally, the climb rate suffered as well. Only a few J2M1s were built.
     
    The next version, the J2M2, had several improvements. The engine was updated to the MK4R-A (3); this engine featured a methanol injection system, enabling it to produce up to 1,800 horsepower for short periods. The propeller was switched for a four blade unit. The extension shaft in the J2M1 had proved unreliable, in the J2M2 the cowling was shortened slightly, and a cooling fan was fitted at the the front. These modifications made the MK4R-A more reliable than the previous engine, despite the increase in power.
     
    However, there were still problems; significant vibrations occurred at certain altitudes and speeds; stiffening the engine mounts and propeller blades reduced these issues, but they were never fully solved (1). Another significant design flaw was identified in the summer of 1943; the shock absorber on the tail wheel could jam the elevator controls when the tailwheel retracted, making the aircraft virtually uncontrollable. This design flaw led to the death of one IJN pilot, and nearly killed two more (1). Ultimately, the IJN would not put the J2M2 into service until December 1943, 21 months after the first flight of the J2M1. 155 J2M2s would be built by Mitsubishi (3).
     
    By the time the J2M2 was entering service, the J2M3 was well into testing. The J2M3 was the most common variant of the Raiden, 260 were produced at Mitsubishi's factories (3). It was also the first variant to feature an armament of four 20mm cannons (oddly, of two different types of cannon with significantly different ballistics (2); the 7.7mm machine guns were replace with two Type 99 Model 1 cannons). Naturally, the performance of the J2M3 suffered slightly with the heavier armament, but it still retained its excellent rate of climb. The Raiden's excellent rate of climb was what kept it from being cancelled as higher performance aircraft like the N1K1-J Shiden came into service.
     

     
    The J2M's was designed to achieve a high climb rate, necessary for its intended role as an interceptor. The designers were successful; the J2M3, even with four 20mm cannons, was capable of climbing at 4650 feet per minute (1420 feet per minute) (2). Many fighters of World War 2, such as the CW-21, were claimed to be capable of climbing 'a mile a minute', but the Raiden was one of the few piston-engine aircraft that came close to achieving that mark. In fact, the Raiden climbed nearly as fast as the F8F Bearcat, despite being nearly three years older. Additionally, the J2M could continue to climb at high speeds for long periods; the J2M2 needed roughly 10 minutes to reach 30000 feet (9100 meters) (4), and on emergency power (using the methanol injection system), could maintain a climb rate in excess of 3000 feet per minute up to about 20000 feet (about 6000 meters).
     
     
     
     
     

     
     
     
     
     

     
    Analysis in Source (2) shows that the J2M3 was superior in several ways to one of its most common opponents, the F6F Hellcat. Though the Hellcat was faster at lower altitudes, the Raiden was equal at 6000 meters (about 20000 feet), and above that rapidly gained superiority. Additionally, the Raiden, despite not being designed for maneuverability, still had a lower stall speed than the Hellcat, and could turn tighter. The J2M3 actually had a lower wing loading than the American plane, and had flaps that could be used in combat to expand the wing area at will. As shown in the (poorly scanned) graphs on page 39 of (2), the J2M possessed a superior instantaneous turn capability to the F6F at all speeds. However, at high speeds the sustained turn capability of the American plane was superior (page 41 of (2)).
     
    The main area the American plane had the advantage was at high speeds and low altitudes; with the more powerful R-2800, the F6F could more easily overcome drag than the J2M. The F6F, as well as most other American planes, were also more solidly built than the J2M. The J2M also remained plagued by reliability issues throughout its service life.
     
    In addition to the J2M2 and J2M3 which made up the majority of Raidens built, there were a few other variants. The J2M4 was fitted with a turbo-supercharger, allowing its engine to produce significantly more power at high altitudes (1). However, this arrangement was highly unreliable, and let to only two J2M4s being built. Some sources also report that the J2M4 had two obliquely firing 20mm Type 99 Model 2 cannons in the fuselage behind the pilot (3). The J2M5 used a three stage mechanical supercharger, which proved more reliable than the turbo-supercharger, and still gave significant performance increases at altitude. Production of the J2M5 began at Koza 21st Naval Air Depot in late 1944 (6), but ultimately only about 34 would be built (3). The J2M6 was developed before the J2M4 and J2M6, it had minor updates such as an improved bubble canopy, only one was built (3). Finally, there was the J2M7, which was planned to use the same engine as the J2M5, with the improvements of the J2M6 incorporated. Few, if any, of this variant were built (3).
     
    A total of 621 J2Ms were built, mostly by Mitsubishi, which produced 473 airframes (5). However, 128 aircraft (about 1/5th of total production), were built at the Koza 21st Naval Air Depot (6). In addition to the reliability issues which delayed the introduction of the J2M, production was also hindered by American bombing, especially in 1945. For example, Appendix G of (5) shows that 270 J2Ms were ordered in 1945, but only 116 were produced in reality. (Unfortunately, sources (5) and (6) do not distinguish between different variants in their production figures.)
     
    Though the J2M2 variant first flew in October 1942, initial production of the Raiden was very slow. In the whole of 1942, only 13 airframes were produced (5). This included the three J2M1 prototypes. 90 airframes were produced in 1943, a significant increase over the year before, but still far less than had been ordered (5), and negligible compared to the production of American types. Production was highest in the spring and summer of 1944 (5), before falling off in late 1944 and 1945.
     
    The initial J2M1 and J2M2 variants were armed with a pair of Type 97 7.7mm machine guns, and two Type 99 Model 2 20mm cannons. The Type 97 used a 7.7x56mm rimmed cartridge; a clone of the .303 British round (7). This was the same machine gun used on other IJN fighters such as the A5M and A6M. The Type 99 Model 2 20mm cannon was a clone of the Swiss Oerlikon FF L (7), and used a 20x101mm cartridge.
     
    The J2M3 and further variants replaced the Type 97 machine guns with a pair of Type 99 Model 1 20mm cannons. These cannons, derived from the Oerlikon FF, used a 20x72mm cartridge (7), firing a round with roughly the same weight as the one used in the Model 2 at much lower velocity (2000 feet per second vs. 2500 feet per second (3), some sources (7) report an even lower velocity for the Type 99). The advantage the Model 1 had was lightness; it weighed only 26 kilograms vs. 34 kilograms for the model 2. Personally, I am doubtful that saving 16 kilograms was worth the difficulty of trying to use two weapons with different ballistics at the same time. Some variants (J2M3a, J2M5a) had four Model 2 20mm cannons (3), but they seem to be in the minority.
     

     
     
    In addition to autocannons and machine guns, the J2M was also fitted with two hardpoints which small bombs or rockets could be attached to (3) (4). Given the Raiden's role as an interceptor, and the small capacity of the hardpoints (roughly 60 kilograms) (3), it is highly unlikely that the J2M was ever substantially used as a bomber. Instead, it is more likely that the hardpoints on the J2M were used as mounting points for large air to air rockets, to be used to break up bomber formations, or ensure the destruction of a large aircraft like the B-29 in one hit. The most likely candidate for the J2M's rocket armament was the Type 3 No. 6 Mark 27 Bomb (Rocket) Model 1. Weighing 145 pounds (65.8 kilograms) (8), the Mark 27 was filled with payload of 5.5 pounds of incendiary fragments; upon launch it would accelerate to high subsonic speeds, before detonating after a set time (8). It is also possible that the similar Type 3 No. 1 Mark 28 could have been used; this was similar to the Mark 27, but much smaller, with a total weight of only 19.8 pounds (9 kilograms).
     
     
     
    The first unit to use the J2M in combat was the 381st Kokutai (1). Forming in October 1943, the unit at first operated Zeros, though gradually it filled with J2M2s through 1944. Even at this point, there were still problems with the Raiden's reliability. On January 30th, a Japanese pilot died when his J2M simply disintegrated during a training flight. By March 1944, the unit had been dispatched to Balikpapan, in Borneo, to defend the vital oil fields and refineries there. But due to the issues with the J2M, it used only Zeros. The first Raidens did not arrive until September 1944 (1). Reportedly, it made its debut on September 30th, when a mixed group of J2Ms and A6Ms intercepted a formation of B-24s attacking the Balikpapan refineries. The J2Ms did well for a few days, until escorting P-47s and P-38s arrived. Some 381st Raidens were also used in defense of Manila, in the Phillipines, as the Americans retook the islands. (9) By 1945, all units were ordered to return to Japan to defend against B-29s and the coming invasion. The 381st's J2Ms never made it to Japan; some ended up in Singapore, where they were found by the British (1).
     

     
     
    least three units operated the J2M in defense of the home islands of Japan; the 302nd, 332nd, and 352nd Kokutai. The 302nd's attempted combat debut came on November 1st, 1944, when a lone F-13 (reconaissance B-29) overflew Tokyo (1). The J2Ms, along with some Zeros and other fighters, did not manage to intercept the high flying bomber. The first successful attack against the B-29s came on December 3rd, when the 302nd shot down three B-29s. Later that month the 332nd first engaged B-29s attacking the Mitsubishi plant on December 22nd, shooting down one. (1)
    The 352nd operated in Western Japan, against B-29s flying out of China in late 1944 and early 1945. At first, despite severe maintenace issues, they achieved some successes, such as on November 21st, when a formation of B-29s flying at 25,000 feet was intercepted. Three B-29s were shot down, and more damaged.

    In general, when the Raidens were able to get to high altitude and attack the B-29s from above, they were relatively successful. This was particularly true when the J2Ms were assigned to intercept B-29 raids over Kyushu, which were flown at altitudes as low as 16,000 feet (1). The J2M also had virtually no capability to intercept aircraft at night, which made them essentially useless against LeMay's incendiary raids on Japanese cities. Finally the arrival of P-51s in April 1945 put the Raidens at a severe disadvantage; the P-51 was equal to or superior to the J2M in almost all respects, and by 1945 the Americans had much better trained pilots and better maintained machines. The last combat usage of the Raiden was on the morning of August 15th. The 302nd's Raidens and several Zeros engaged several Hellcats from VF-88 engaged in strafing runs. Reportedly four Hellcats were shot down, for the loss of two Raidens and at least one Zero(1). Japan surrendered only hours later.

    At least five J2Ms survived the war, though only one intact Raiden exists today. Two of the J2Ms were captured near Manila on February 20th, 1945 (9) (10). One of them was used for testing; but only briefly. On its second flight in American hands, an oil line in the engine failed, forcing it to land. The aircraft was later destroyed in a ground collision with a B-25 (9). Two more were found by the British in Singapore (1), and were flown in early 1946 but ex-IJN personnel (under close British supervision). The last Raiden was captured in Japan in 1945, and transported to the US. At some point, it ended up in a park in Los Angeles, before being restored to static display at the Planes of Fame museum in California.
     
     

     
     
    Sources:
     
     
    https://www.docdroid.net/gDMQra3/raiden-aeroplane-february-2016.pdf#page=2
    F6F-5 vs. J2M3 Comparison
    http://www.combinedfleet.com/ijna/j2m.htm
    http://www.wwiiaircraftperformance.org/japan/Jack-11-105A.pdf
    https://babel.hathitrust.org/cgi/pt?id=mdp.39015080324281;view=1up;seq=80
    https://archive.org/stream/corporationrepor34unit#page/n15/mode/2up
    http://users.telenet.be/Emmanuel.Gustin/fgun/fgun-pe.html
    http://ww2data.blogspot.com/2016/04/imperial-japanese-navy-explosives-bombs.html
    https://www.pacificwrecks.com/aircraft/j2m/3008.html
    https://www.pacificwrecks.com/aircraft/j2m/3013.html
    https://www.pacificwrecks.com/aircraft/j2m/3014.html
     
     
    Further reading:
     
    An additional two dozen Raiden photos: https://www.worldwarphotos.info/gallery/japan/aircrafts/j2m-raiden/
     
     
  15. Tank You
    N-L-M reacted to Laviduce in French flair   
    After feedback, it might be best to differentiate between different types of "special armor" regions. I am very certain the turret bustle special armor (orange) is not the same as the primary special armor (red) or the side front hull special/spaced (?) armor (green):
     
     
     
     
     
  16. Tank You
    N-L-M reacted to Stimpy75 in Turkish touch   
    After a little bit research
    İn 2020 15 tanks will be produced
    and in 2021 another 25
    After these 40 vehicles the new ones will get domestic engine/transmission
    The first batch of 250 will be delivered very quickly. Qatar has also ordered 100 Altay s.
    So planning/wishing looks good,but we have to wait for next year how realistic that will be. 
    Complete 1000 are planned in 4 batches with each batch new version like a la Armata is planned.
  17. Tank You
    N-L-M reacted to Ramlaen in Bash the F-35 thred.   
    https://seapowermagazine.org/lockheed-develops-rack-to-make-f-35a-c-a-six-shooter/
     
     
  18. Tank You
    N-L-M reacted to Laviduce in French flair   
    The HL-70 CIV, HL-60 GPS and periscopes (bright green):
     
     
     
     
     
     
     
     
    Gun elevation mechanism (blue) and turret traverse mechanism (salmon):
     
     
     
     
     
     
     
  19. Tank You
    N-L-M reacted to Laviduce in French flair   
    Here is a diagram with the crew (blue) and special armor volumes (red) highlighted. Spaced armor (i.e. mantlet, heavy side skirts, right front hull, etc.) is not highlighted:
     
     
     
     
     
     
     
     
     
     
     
  20. Metal
    N-L-M reacted to Stimpy75 in Turkish touch   
    i am really exhausted
    my feet are killin me
    first i will try google pics
    if it doesnt i have to upload them to imgur
    feel free to share them(except for tanknet.forum! F.U. tanknet!)
    https://photos.app.goo.gl/hSSBM66MUsiYTteC8
  21. Metal
    N-L-M reacted to Lord_James in Competition: Californium 2250   
    I started drafting up the IFV and APC versions: 
     
    APC (SH-1A) 
    Crew: 4 + 10 
    Armament: either 23mm + 7.62mm machine guns in a low profile turret, or a 107mm recoilless rifle and 7.62mm coax (and 12.7mm spotting gun), with below armor reload. 
     
    The SH-1A is a modified version of the SH-1T MBT, trading the large turret and ammo racks for a small, 2 person turret and 10 dismount seats. It still incorporates the same armor cavities, but with a lighter array utilizing more spaced components and no special materials (non steel). The crew consists of the Driver, the Gunner and Commander in the turret, and a thespian assistant who removes spent MG and autocannon shells, or loads the RR if that turret is equipped. A third turret is in the works, similar to the RR turret, equipping an ATGM with under armor reload potential. 
     
    IFV (SH-1V)
    Crew: 5 
    Armament: 2x 45mm autocannons (SM-7 or NS-45 derivatives / maybe 4 if I think I can fit them) + 4x 107mm RRs + 107mm mortar (same as SH-1T) + 2x 7.62mm MGs (coax and commander’s MG). 
     
    Also based off the SH-1T, the SH-1V is a heavily armed supplement vehicle to armored forces in the DPRC. Fulfilling a role similar to the ancient BMPT, it is designed to assist infantry and act as heavy armor in urban or mountainous environments, and to provide rapid and heavy suppressing fire for armor groups moving through hostile terrain. The crew consists of a Driver, Gunner and Commander in the turret, and 2 thespian assistants to clear the vehicle floor of spent casings, and to reload the externally mounted RRs. As ATGMs mature, the RRs can easily be replaced with missile systems on a volumetric basis (probably 2 RRs to 1 ATGM). 
     
    Also in the drafting phase are an AA variant, an artillery variant, a heavy mortar variant, and CiC, medevac, CBRN, radio relay, EW, and others. 
     
     
    PS. SH-1(x) is the company designation for the vehicle; military designations will be given when/if these vehicles are accepted for service. 
     
    PSS. I’ve been either too busy, or unable to access the internet for the past couple of days, which has lead to delays. But I should be getting back on track later today or tomorrow, now that all of the shit is out of the way. 
  22. Tank You
    N-L-M reacted to BkktMkkt in Tanks guns and ammunition.   
    Some my models
     
     
  23. Tank You
    N-L-M reacted to Laviduce in French flair   
    For the mean time:
     
     
    Updated Special Armor Locations:
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
    Fuel Tank Locations:
     
     
     
     
     
     
     
     
    Main Gun Ammunition Locations:
     
     
     
     
     
     
     
    Crew Locations:
     
     
     
     
     
     
    Armament Locations:
     
     
     
     
     
    Powerpack Location:
     
     
     
     
     
     
  24. Funny
    N-L-M reacted to ZloyKrolik in Your Tank Stories   
    Another time when I was driving an M60A3 in the LTA (Local Training Area), I was the 2nd tank in the column as we approached a rather large mud puddle. More like a mud pit. My buddy Ray was driving the lead tank, the platoon leader's. He comes up to the hole and drives right in, not slowing down much. SPLASH! SPLAT!  The mud flew up and splattered the TC, the 2LT wasn't happy, but Ray was drenched in mud as he was driving with the hatch open. Just as they cleared the pit, I rolled up, fortunately I had slowed down as to not run into them and the mud only flowed up to, but not into, the driver's hatch. I didn't get a mud bath, but Ray did. He was covered in mud, dripping all over the place, I saw him reach into the driver's hatch and pull out his camera case, covered in mud. Luckily it was well sealed and the camera was fine. It took Ray a couple of days to clean out the interior of his tank when we got back to the motor pool. 
     
    So always slow down before driving into a mud puddle if you have your hatch open.
  25. Tank You
    N-L-M reacted to Merc321 in Your Tank Stories   
    One of my favorite memories when it comes to working on and driving my Daimler Ferret was the time I took it to an off-road park. It was very entertaining to watch the ATV and jeep guys look completely shocked when an armored car was going through mud that they were afraid to drive into. I very much have a love hate relationship with British wheeled armor. At this point in time I have one running Ferret, one that is awaiting restoration, and a Saracen that is also awaiting further restoration. The reason for my love hate relationship with them is that while they are a ton of fun to drive, maintaining them can be difficult at times, especially if you have to deal with an electrical issue. Despite the many, many, ups and downs I've had with working on British armor, it's always rewarding when you fire up the engine and take them for a drive, be it off-road or on a run into town.
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