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Monochromelody

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Everything posted by Monochromelody

  1. Monochromelody

    Tank neutral steer capability

    The neutral steer, or pivot steer, means the tank drive one track forward while the other track backward, to perform a turn-on-spot. The very first tank with neutral steer, believe it or not, is the German A7V in WWI. Here is the transmission of A7V. The transmission incorporate two independent gearbox, each connected to a 100-hp engine. The gearbox use clash gears to select speed, and bevel gear to select forward or reverse. It's easy to perform a neutral steer. Those tanks with electric transmission(St.Chamond, Porsche Tiger, etc.) can easily perform neutral steer, for their twin driving electric motors can rotate in opposite direction. And tanks with twin driving hydraulic motors(Panzer IV mit Hydrostatischem Antrieb) can neutral steer in a similar manner. As mentioned above, the simplest way to neutral steer is to have seperated gearboxes or sub-transmissions driving both tracks. US airborne tank M551 Sherridan and Ukraine T-84 Oplot are modern approach of this manner. Althought they neutral steer with tracks driving in different speed, thus they cannot pivot steer precisely on the central spot. The neutral steer capability is more common on dual-flow transmission. A dual-flow transmission, or “双流传动” in Chinese, means the power flow from engine into the transmission splitted into driving power flow and steering power flow, then they join together with mesh gears or planetaries. Control these power flows allows the driver to change speed and steer left or right. The dual-flow principle itself came up even earlier than the tank. The 1899 Vedovelli Priestley electric taxi equipped with double differential steering system, is capable of neutral steering. And the first tank with dual-flow transmission is the Schneider-Renault SRB, then evolved into the Char B1 heavy tank. The Char B1 tank's dual-flow principle is quite simple. The power splitted into two: the driving power flow into gearbox and drive the main differential; the steering power flow into the appareil Naëder, a hydrostatic pump-motor assembly, can rotate on different speed and direction. Char B1 can use appareil Naëder to control its hull howitzer precisly, this principle inspired the Swedish Strv 103 tank. And the US M1 Abrams tanks use a HSU(Hydrostatic Steering Unit) based on the same principle of appareil Naëder. (To be continued)
  2. Monochromelody

    Tank neutral steer capability

    Yes, Soviet tanks started to have dual-flow transmission after WWII, like Объект 770 heavy tank, Объект 906 amphibious tank and so on. The МТ-ЛБ transmission is similar to АТ-Л artillery tractor's transmission, which is also dual-flow transmission.
  3. Monochromelody

    Documents for the Documents God

    Sad to find out there is little information about AMX M-4's ZF transmission. ZF's official website mentioned that they converted a Entwicklung-Series tank transmission to meet French 1000-hp AMX M-4 tank design. This ZF-type transmission was widely used among early post war French heavy tank programs.
  4. Monochromelody

    Name that AFV: The New Tank ID thread

    From a Japanese magazine PANZER screenshot, it says: This is a Type 61 tank with a sort of ad-hoc spaced armour, using for target practice in exercise. The armour plates surrounding the turret and side skirts make it looks like a WW2 German Panzer IV. The crew tried to pull out a practice round stucking in the side skirt, this round was fired from a recoilless rifle. According to the vegetation of the exercise range, the vehicle was painted in a 4-colour camouflage.
  5. Monochromelody

    Name that AFV: The New Tank ID thread

    I've heard that this Type 61 tank with appliqué spaced armour was used for anti-tank rifle grenade firing practice.
  6. Monochromelody

    French flair

    Could you please tell some detail about the development of AMX 10 series AFV? Thank you.
  7. Monochromelody

    Name that AFV: The New Tank ID thread

    According to Rolf Hilmes' KPz Leopard 1 1956-2003, p.43, In year 1983, the Bundeswehr send two Leopard 1 tanks for 120 mm cannon conversion: one Leopard 1 A5 with cast turret, one Leopard 1 A3 with welded turret. And in Tankograd No.5014, p.30, The conversion of normal Leopard 1 A5 also included the preparation for installation of a 120mm smoothbore cannon, though never realised in production models.
  8. Monochromelody

    Name that AFV: The New Tank ID thread

    Leopard 1 A5 with 120 mm smoothbore cannon
  9. Monochromelody

    [Question] About AMX 10 RC transmission

    According to the gear train schematic, AMX 10RC have a triple-differential steering mechanism. This is more common on British after-war period armoured vehicle but quite rare on a French AFV. It differs from a Merritt-Brown gearbox, for the ring gear and sun gear of the steering planetary both driven in the same direction. Designed in the 1970s, the transmission of AMX 10RC shares some similarity with the TN15 gearbox of Alvis Scorpion light tank(FV101). Both of them combine the forward-reverse selector with the input bevel gears. The gear shifting part use a set of constant mesh gears with synchronizer and planet gears to have different gear reduction ratio. In total it can provide 4 forward ranges, as well as 4 reverse ranges, having the same gear ratios. When the range set to 'neutral' position, a pivot steer would be made. A pair of hydraulic-actuated disc brake is used for steering, controlled by a pair of steering levers.
  10. As we know, AMX 10 RC is a very special wheeled AFV for it's skid steering system. It can perform neutral steer, a.k.a. pivot steer or steer in place. The transmission case is similar to some tank transmission. The driver uses steering levers instead of a steerig wheel, and it's almost identical with those on AMX 10P tracked AFV. ↑wheeled AMX 10 RC ↓tracked AMX 10 P It even had a variant running on tracks: As for steering principle, there are different descriptions. Some info says AMX 10 RC use a triple-differential system, like some British tanks and AFVs. A similar skid-steering wheeled vehicle, TV1000 "Rhino" also use steering levers instead of steering wheel, and it have triple-differential system. When I looked for historical information, I found that French invented the first double-differential steering system for wheeled vehicle since 1898. And French tanks used double differential system since 1920s: Renault NC: "Cletrac" type double differential, or controlled differential. First tank using Cletrac system. Single radius. Char B1: "Naëder" type double differential, steering control via steering wheel connected to appareil Naëder(Naëder device). First production tank with hydrostatic steering mechanism. Step-less steering. Pivot steer. Somua S35: "Somua" type double differential, steering control via steering wheel connected to mechanical steering clutch. Single radius. Pivot steer. ARL 44: "ZF" type double differential, steering control via steering wheel. According to the document Notice du Char de transition, it can perform double radius steering and pivot steer. Char Lorraine 40t: "ZF" type double differential. Detail unknown. Double radius. Pivot steer. Char AMX 50: "ZF" type double differential. Detail unknown. Double radius. Pivot steer. AMX 13: "Cletrac" type double differential, or controlled differential. A more compact design, steering mechanism integrated with gearbox. Single radius. AMX 30: "Cletrac" type (1961 prototype or before), single radius; "Somua" type variant (early version AMX 30B, 5SD-200D), single radius, pivot steer; hydrostatic double-differential (AMX 30B2 upgrade, ENC-200), step-less steering, pivot steer. There's no clear evidence that French could gave up their experience on double-differential mechanism and turned to British triple-differential. I tried to look for AMX 10RC operator's handbook, but only gunnery handbook found on the internet. Any further detail information about AMX 10RC transmission would be appreciated.
  11. Monochromelody

    [Question] About AMX 10 RC transmission

    Thanks a lot! It appears to be a triple-differential steering system.
  12. Monochromelody

    [Question] About AMX 10 RC transmission

    Yes, Chieftain tank has a single steering radius for every gear, while Leopard 1 would have two steering radius for every gear, 4×2=8. And Ariete tank have 4×3=12 steering radius in total. The British prefer triple differential system for it's easier to produce and maintain, and a braking drum could probably be cheaper than a multidisc clutch.
  13. Monochromelody

    [Question] About AMX 10 RC transmission

    As far as I know, double-differential system split and transfer steering power flow by engaging different clutch(direction clutch, sometimes radius clutch), or brake certain steering planetary gear, or simply by a hydraulic pump-motor unit. Triple-differential system split steering power flow by braking either side steering planetary gear(usually sun gear), transfer steering power flow to the other side via a differential. It's much easier for a double-differential system to achieve different steering radius. For example, Single radius: Somua steering system(Somua S35), 5SD-200D(AMX 30B), CD-500(M41 Walker Bulldog), MT75(Japan Type 74) Double radius: Maybach Argus(Tiger I), ZF 4HP250(Leopard 1) Triple radius: ZF LSG3000(K1 MBT, C1 Ariete, EE-T1 Osório) Step-less steering: Naëder system(Char B1), FBTV-2B(Strv 103), SLM system(Panzer 68), HSWL 123(KJPz 4-5), HSWL 194(Marder IFV), HSWL 354(Leopard 2), S6-80(SK105), X1100(M1), TN54(Challenger 1) All these are double-differential system. Triple-differential system usually have single radius, like CD-850 series(M46 to M60), TN12(Chieftain)
  14. Monochromelody

    Tank “document” misleading

    各位最近可能在WT论坛上见过这张图片,在一些争论陆上自卫队90式战车的讨论串里: Some of you may have seen this pic recently on WT forum, in some thread arguing the protection of JGSDF Type 90: Discussion on WT forum 我就直说吧,表格里的中文注解说了,这不过是个“猜想”,GUESSING。 To be straight, the Chinese annotation in the table said it is just a GUESSING. 注解内容可能完全是编造的,但不幸的是,不同语言间的障碍使你们无法看穿这点。 This annotation could be totally nonsense but unfortunately a barrier between languages prevent you guys see throught it. 实际上,这又是一份关于陆上自卫队10式战车的文件,说的并不是90式。 In fact, again, this document itself is about JGSDF Type 10 MBT, not Type 90. 同样的花招,不一样的人,是吧? Same trick, different people, huh? ↑陆上自卫队的10式战车规格书 JGSDF specification handbook of Type 10 MBT ↑59页,附录B,性能(规定)以及诸元 page 59, Appendix B, performance (regulations) and data 下面简要说说这些性能规定如何编写、如何加密。 Let's talk about these regulations and how they were made and encrypted. 大家可能知道日语中有平假名和片假名,和拉丁语中的字母还有大写字母是差不多的。 You may know that Japanese have Hirakana and Katakana, like Latin have letters and capital letters. 正如图中所示,一些最关键的数值和描述用平假名、片假名、罗马字(拉丁字母)隐去了。 As you can see, some of the most crucial numbers and descriptions are covered by a Hirakana or Katakana or Romaji(Latin letters). 这些数值和描述被归在一起,编入附属的手册,称为“别册”。 These numbers and descriptions were collected and listed in some append book, called Bessatsu(別冊). 在查阅别册时,就好比在看试卷的答题卡。但如果把别册里面的数值和描述涂黑,你就根本不知道说啥。 When you look up to the append book, just like viewing the answer sheet of an exam paper. But when numbers and descriptions were censored, you'll never know what it said. 比如说,正面防护: For example, the frontal protection: “耐弾性 - 正面 - 正面要部は、【あ】に射距離【え】m相当存速において、貫徹されない。” 读起来是这样的: 耐弹性 - 正面 - 正面重要部位可抵御【あ】以相当于射击距离【え】米存速的射击,不会贯穿。 It read like this: Protection - Frontal - Frontal crucial part should withstand 【あ】 firing at a distance of 【え】meter speed reduce equivalent, and not penetrate. 【あ】代表某种弹药,可能是尾翼稳定穿甲弹,但不知道是量产弹种还是实验弹种。 【あ】stands for certain type of ammunition, probably APFSDS, but don't know whether it is production shot or experimental. 【え】代表某个射击距离,可以是1000、1500或2000(米),但这么远的距离,炮弹会受到风力和重力影响,故无法精确瞄准靶车的防护区域。 【え】stands for certain firing distance, could be 1000 , 1500 or 2000 (meters), but on such a long distance, shot could be effect by wind and gravity, thus cannot aim on the protection area of target vehicle precisely. 一个常见的解决方式是在更近的距离上开火,比如说200到550米,同时减少推进药量,使得穿甲弹的终点速度符合特定距离的速降。这是一种等效方法。 The usual solution is to fire from a much closer range, from 200 to 550 meters, while reducing the propellant charge so that the end speed of AP shot could match the speed drop on certain distance. This is an equivalant method. 有的人争辩说90式战车可以抵挡另一辆90式战车发射的穿甲弹(JM33),距离大约250米。这一说法源自一段未知视频片段,具体什么视频他们自己也没看过。较近的射击距离是为了能更好的瞄准,为此可能使用了减装药来模拟远距离终点速度,但也无法证明。 Some people argue that Type 90 MBT can withstand AP shot (JM33) firing from another Type 90 MBT, on a distance about 250 meters. The source of this statement came from an unknown video clip, which they have never seen. Firing on closer range is for better aim, and they could have use reduced charge to simulate a much longer range, but we cannot prove.
  15. Monochromelody

    Transmissions and final drives

    Share some less-known information about cold war period tracked vehicle transmission Mithubishi transmission MT75 for STB, later known as Type 74. The basic layout of MT75 is similar to the CD-500 transmission on M41 light tank, used by JGSDF in a short period after war. But the Japanese tank designers prefer mechanical gearbox rather than hydramatic gearbox, they use a electro-mechanic high-low range instead of a torque converter. The high-low range part is described as "1次変速"(range first stage). The steering mechanism is a single-radius, double differential type, operated by engaging steering clutch, also resemble the CD-500. ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Allison X-700 transmission, a 800-hp class transmission to replace XTG-411 on T95 medium tank in 1960s. Trials were successful but finally never adopted. The Army decided to develop a 1500-hp class transmission for XM803. X-700 then evolved into X-1100 transmission. The X-200 and X-300 were basically smaller variants of X-700. X-1100 users: M1 and its variants; Korean K9 "Thunder"; Turkish T-155 "Firtina" X-300 users: Warrior IFV; CV90 series X-200 users: M113 upgrade (A2 standard) ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Allison XHM-1500-B2, a hydrostatic-mechanical transmission developed in early 1970s. A competitor against X-1100 but less successful. Different parts were shown in different color. Orange: power input and forward-reverse shifting mechanism; Blue: hydrostatic-mechanical speed range (mechanical planetary gears were not shown in cutaway); Red: hydrostatic differential steering system; Green: output shaft and planetary gears. Hope you enjoy these pics.
  16. Monochromelody

    Contemporary Western Tank Rumble!

    With a internal fuel capacity of 1272 litre, Type-90 can travel about 300-340 km. Type-74 in comparison, can travel about 400 km when equipped with external fuel container. Exact data could depends on terrain and weather, especially in winter condition.
  17. Monochromelody

    Contemporary Western Tank Rumble!

    Simply translate the words into English, hope it will help. Another figure, posted by Wiedzmin in a thread on otvaga, shows the fuel filling port of front fuel system unit. According to a video record, about JGSDF tank training in US, they refuel a Type-10 MBT on a fuel filling port of similar location. I assume they both have similar arrangements.
  18. Monochromelody

    Compressed Air gear change systems

    As far as I know, French ARL-44 also have compressed air assist gear shifting function, from Notice du Char de transition
  19. Monochromelody

    Contemporary Western Tank Rumble!

    This illustration probably came from Japanese magazine Maru special: Tanks of JGSDF(丸 別冊 陸上自衛隊の戦車), which seems to be convincing.
  20. Monochromelody

    Contemporary Western Tank Rumble!

    original source: https://drive.google.com/drive/mobile/folders/0B8KVYt57g6q_MUk1V09wbjlsUkE/0B8KVYt57g6q_U3NBV19QVl9uWGs/18GUvRqmI8t2JmYVxpE90U5yzsCgPuDEL/0B8KVYt57g6q_aXpmNUJ2cHdDNjA/0B8KVYt57g6q_QTVHN1EyMThwRnM?sort=13&direction=a
  21. Monochromelody

    Contemporary Western Tank Rumble!

    Guys, it's not over yet. And yes, I do have the original file, but for some obvious reasons I add some watermarks. Waffentrager is doing the same thing as he did on Warthunder forum. He is just bluffing with unknown source screenshots or photoshopped fake “documents”. He deleted every post arguing the pictures' authenticity to make himself “invulnurable”.
  22. Monochromelody

    Contemporary Western Tank Rumble!

    Waffentrager YOU FAKE BULLSXXT and FXXK OFF In case you guys here cannot read Japanese: It says "Height of lens assembly is about 380 mm" May be taken from a manual of digital camera or sth. else.
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