Jump to content
Sturgeon's House

Atokara

Contributing Members
  • Content Count

    18
  • Joined

  • Last visited

Reputation Activity

  1. Metal
    Atokara got a reaction from Sheffield in Tanks guns and ammunition.   
    My primary reason for this is the fact that its got a proper diagram with listed lengths which is pretty hard to come by past DM33. It acted as essentially a control group to make sure I was doing proper measurements. However after cross checking with your measurements I can't find any fault in your measurements either despite them being different from mine and I have a few guesses as to why.
     
    Here is the first one. When measuring I was measuring from tip to ends of the fins. I found a diagram of 105mm Type 93 to compare against the Type 10 as there was no indication for either method and saw that the fin tips weren't included in the measurement for the Type 93 meaning that you were right with the exclusion of fins. Now this is a big problem for my control. By all accounts my numbers appeared to line up despite this error, but I went back to check anyways and found that I mis-measured the sabot diameter at 56px instead of the actual 57px and this would've tipped me off immediately to the fact that my scale was wrong. Going and measuring the cartridge diameter also shows the scale was off in a much bigger way. As it turns out that somewhere in the process of the Type 10 diagram being passed around the internet, it got stretched in the vertical axis, and when correcting for this, the exclusion of the fins got me an actually accurate scale.
     
    Basically I went into it thinking my control group was accurate, but it ended up just throwing off my other measurements. That combined with the fact that the images are so blurry means that a few pixels can make a big difference. Just switching the sabot size on DM53 from 88px to 87px changes the overall length back up to 759mm alongside OPs original estimate. With the DM53 picture being so blurry compared to the M829A3 it's not surprising that one was accurate and 1 got messed up just from image clarity. Either way I found my mistake and also what just can't be helped with such an imprecise and subjective measurement system and this is exactly why I wanted other people doing their own measurements.
  2. Tank You
    Atokara reacted to Sheffield in Tanks guns and ammunition.   
    Don't hold me on this but as far as I know, there was a picture of a brochure of DM53 posted sometime in the past on the net where it said the penetrator body was 685mm though I don't remember if it also said anything about the diameter;
     
    Regardless of this, i think comparing DM53 to Type 10 AFPSDS is a bit of a moot point and it would do us better to compare DM53 to M829A1/2 which both have 680x22mm and 690x22mm penetrators respectively in a projectile body roughly ~760mm long (though it's 779mm long in total).
     
    There's also the case of yet another, I believe Rheinmetall brochure from 2014 or so stating that the projectile body of DM53 is 745mm long (i'm assuming that they excluded the fins that extend beyond the body of the main body of the projectile.
     
    I've done my own share of estimates on DM53 and 63 in my free time and this is what I had got:
    DM53:

     
    DM63:

     
    Did an estimate for DM53 once again just a moment ago;

     
     
    In regards to the DM63 estimate, since i already had numbers for diamater and the stuff, i just did a comparison of how long fins on the 53 and 63 are, substracted the difference and that's how i got to ~770mm total length and 745mm "effective projectile length" (or perhaps it could be called in-flight length?).
     
     
    edit: just found this, i don't know where this comes from but the penetrator length matches what was said in the Brochure, diameter is a bit too high though it also matches if you count in the ribs which in my estimates were roughly 25.8mm
     

     
    And overall i think this graphic is legit; 
    DM13 estimate:

     
    DM23:

     
    DM33:

     
    They all roughly fit with penetrator length, diameter is a bit iffy cause I dunno what kind of criteria they used for diameter there.
     
  3. Tank You
    Atokara got a reaction from Collimatrix in Tanks guns and ammunition.   
    So I've seen this image used a whole lot across the internet as an estimate for the proportions of DM53 and I thought I would do my own measurements on it to see how things line up.
     
    Disclaimer: I am merely providing my own interpretation of the measurements using the same methodology as whoever originally posted the image. Pixel measuring is an inherently inaccurate measurement tool and very subjective especially on blurry images such as this as people will have different opinions on which pixels can be considered part of the rod and which cannot. I accounted for pixel bleed as best I could by ignoring the softer and less consistent outlines where it was applicable. I do not consider my measurements any more correct and encourage other people to do their own measurements to compare to as well. In the image M829A3 and DM53 are not scaled exactly the same, there is a few px difference, so the ratios for both OP and my measurements will vary between the rounds.
     
    Both DM53 and M829A3 don't have any officially published lengths, so people have gone to pixel measuring as a way to get estimates.
     
    I started with M829A3 first by taking the pixel ratio for OPs estimate of 930mm. At 696px long this gave a ratio of 1.3362. The sabot diameter is always 119.9mm which makes it an excellent scaling tool which is what I used for my measurements(here I rounded it up to an even 120mm for simplicity sake). At 90px wide the ratio I got was 1.333 repeating. At a 0.003 difference OP did a good job measuring 829A3 imo as my ratio gave me a total length of the projectile of 928mm, only a 2mm or less than 2 pixel difference in our measurements. For all intents and purposes I consider M829A3's measurements accurate as can be estimated using this method.
     
    Now onto DM53. Using OPs estimate of 760mm that gives us a ratio of 1.381818. Going off of the sabot which is 88px wide, I get a ratio of 1.3636 repeating. Now the difference here is a bit bigger (10mm or just over 7 pixels difference which I consider far outside the margin of error of 1-2pixels from M829A3) and when applying my ratio to the 550px long rod I get to total length of exactly 750mm. I actually found that OPs measurements for the diameter of DM53 lined up pretty well with mine just being a 1mm difference, but that is understandable due to the smaller pixel count of the diameter.
     
    My last issue is with how OP measured the depth that the actual penetrating rod goes into the fin section. The pic of M829A3 is a proper cross section and we can see exactly where the rod ends so there is no estimates there, however the DM53 pic isn't a cross section and OP has given his own estimate of where he thinks it might end. To find a more accurate (but not exact) estimate in the ball park of where it might end I utilized the ratio of fin length to depth that the rod goes into that section. Here I also brought in a diagram of Type 10 APFSDS and I will explain why later.
     
    M829A3 has 125mm long fins based on my measurements, 28mm or 22% of that length is overlapped by the penetrating rod.
    DM53 has 110mm long fins based on my measurement and OPs estimate puts his estimate of where the rod might end at a depth of 54mm or just shy of 50%
     
    Here I brought in a diagram of Type 10 APFSDS, because despite how secretive the Japanese are about their military equipment, we know quite a bit on this round. I used it as a control value to compare my estimates of M829A3 and DM53.
    At 748mm long for the projectile and 350 pixels across I got a ratio of 2.13714. With the sabot at 56 pixels in diameter applying my ratio gives 119.6mm which is well within the margin of error (which is expected as we already know the measurements).
     
    Now that we know the Type 10 diagram is accurate we can go back to the fins. Type 10 has 117mm long fins and a 32mm rod depth into the fin section which gives a 27% overlap (M829A3: 22%, OP's estimate DM53: 50%). And that is where my issue lies. I went ahead and gave DM53 the same overlap as Type 10 at 27% as M829A3 has a very different and longer fin design that pushes farther past the projectile body. 27% of 110mm gives 30mm and when measuring to the penetrator tip that OP estimated we get a 625mm penetrator length and an overall projectile length of 750mm for DM53.
     
    Let me know if I screwed up anywhere.
  4. Tank You
    Atokara reacted to TWMSR in French flair   
    Great idea It is so silly to put parasitic mass into design, why do not use zero-mass sabots instead? And why waste so much energy on muzzle blast? All energy should go into penetrator, it must be easy task.



     
     
  5. Tank You
    Atokara got a reaction from Lord_James in General Metallic Armor Thread   
    It uses a mix of medium and high frequency induction heating. With the device they patented, they are able to treat sections of steel up to 3m in length (which is a pretty big deal since it's usually hard to get NC steel plates that large). Talks about the quenching liquid and cooling rate to prevent cracking, but doens't mention which liquid was used, but does mention that Matensite does form in the cooling process. Talks about maintaining the correct space between the induction heater and steel plate and methodology to maintain that distance despite possible warpage from the heating process. Talks about how their methodology allows for the treatment of much thicker plates than what was normally possible before.
     
    Basically they use a combination of medium and high frequency induction to allow for better heat treatment deeper into the steel (prior to this methodology single frequency induction was primary a surface treatment and didn't penetrate and heat treat the center of the steel). While the coil is moving around and heating the plate they dump an unknown liquid onto the surface at varying temperatures appropriate to the stage to quench the metal before it is once again passed over by the coil. The rapid heating and quenching at varying temperatures allows for better crystal structure formation as only certain crystal structures form under certain temperatures and conditions so the changing variables allows for more even and diverse crystal formation. Another effect of multiple treatments in rapid succession is that the grains constantly form, break apart then reform smaller each time which allows for the extremely small grain structure required of NC steel.
     
    Video showing what induction heat treatment is like
     
  6. Tank You
    Atokara got a reaction from Collimatrix in General Metallic Armor Thread   
    It uses a mix of medium and high frequency induction heating. With the device they patented, they are able to treat sections of steel up to 3m in length (which is a pretty big deal since it's usually hard to get NC steel plates that large). Talks about the quenching liquid and cooling rate to prevent cracking, but doens't mention which liquid was used, but does mention that Matensite does form in the cooling process. Talks about maintaining the correct space between the induction heater and steel plate and methodology to maintain that distance despite possible warpage from the heating process. Talks about how their methodology allows for the treatment of much thicker plates than what was normally possible before.
     
    Basically they use a combination of medium and high frequency induction to allow for better heat treatment deeper into the steel (prior to this methodology single frequency induction was primary a surface treatment and didn't penetrate and heat treat the center of the steel). While the coil is moving around and heating the plate they dump an unknown liquid onto the surface at varying temperatures appropriate to the stage to quench the metal before it is once again passed over by the coil. The rapid heating and quenching at varying temperatures allows for better crystal structure formation as only certain crystal structures form under certain temperatures and conditions so the changing variables allows for more even and diverse crystal formation. Another effect of multiple treatments in rapid succession is that the grains constantly form, break apart then reform smaller each time which allows for the extremely small grain structure required of NC steel.
     
    Video showing what induction heat treatment is like
     
  7. Tank You
    Atokara got a reaction from Beer in General Metallic Armor Thread   
    It uses a mix of medium and high frequency induction heating. With the device they patented, they are able to treat sections of steel up to 3m in length (which is a pretty big deal since it's usually hard to get NC steel plates that large). Talks about the quenching liquid and cooling rate to prevent cracking, but doens't mention which liquid was used, but does mention that Matensite does form in the cooling process. Talks about maintaining the correct space between the induction heater and steel plate and methodology to maintain that distance despite possible warpage from the heating process. Talks about how their methodology allows for the treatment of much thicker plates than what was normally possible before.
     
    Basically they use a combination of medium and high frequency induction to allow for better heat treatment deeper into the steel (prior to this methodology single frequency induction was primary a surface treatment and didn't penetrate and heat treat the center of the steel). While the coil is moving around and heating the plate they dump an unknown liquid onto the surface at varying temperatures appropriate to the stage to quench the metal before it is once again passed over by the coil. The rapid heating and quenching at varying temperatures allows for better crystal structure formation as only certain crystal structures form under certain temperatures and conditions so the changing variables allows for more even and diverse crystal formation. Another effect of multiple treatments in rapid succession is that the grains constantly form, break apart then reform smaller each time which allows for the extremely small grain structure required of NC steel.
     
    Video showing what induction heat treatment is like
     
  8. Tank You
    Atokara got a reaction from Collimatrix in General Metallic Armor Thread   
    https://ssl.bsk-z.or.jp/kenkyucenter/pdf/mnm20191225.pdf
     
    Heres a brochure on NC steel used in the Type 10 and Type 16.
  9. Tank You
    Atokara got a reaction from Zyklon in Imperial Japanese Army Tank Nomenclature   
    Idk about IJA, but the practice has become a lot more common with the JGSDF.
     
    TKG is the most common way to refer the main cannon of armored vehicles. Basically TanK Gun. Usually it's just the XXmmTKG, but I've also seen the Type 10 cannon called 10TKG to differentiate it from the 120mmTKG of the Type 90.
     
    AFV's themselves on the otherhand really only receive this style of abbreviation from the Ministry of Defense rather than the JGSDF. ie: 90TK, 74TK, 89FV, 11CVR, 16MCV.
    https://www.mod.go.jp/gsdf/equipment/ve/index.html
     
    This nomenclature is frequently used by the ATLA as well with experimental vehicles such as the Type 90 project being named NTK and each individual prototypes for both the Type 90 and 10 being TK-X-0001, TK-X-0002, etc.
     
    From what I've seen of IJA materials, they don't seem to use the roman lettering very often and stick to katakana to denote their vehicles as I have yet to find anything showing that roman lettering was used at all. If you were to find anything, my guess that it would on the bureaucratic side of things rather than military side of things as that is more in line with how it's used in the modern day.
  10. Tank You
    Atokara got a reaction from LoooSeR in Imperial Japanese Army Tank Nomenclature   
    Idk about IJA, but the practice has become a lot more common with the JGSDF.
     
    TKG is the most common way to refer the main cannon of armored vehicles. Basically TanK Gun. Usually it's just the XXmmTKG, but I've also seen the Type 10 cannon called 10TKG to differentiate it from the 120mmTKG of the Type 90.
     
    AFV's themselves on the otherhand really only receive this style of abbreviation from the Ministry of Defense rather than the JGSDF. ie: 90TK, 74TK, 89FV, 11CVR, 16MCV.
    https://www.mod.go.jp/gsdf/equipment/ve/index.html
     
    This nomenclature is frequently used by the ATLA as well with experimental vehicles such as the Type 90 project being named NTK and each individual prototypes for both the Type 90 and 10 being TK-X-0001, TK-X-0002, etc.
     
    From what I've seen of IJA materials, they don't seem to use the roman lettering very often and stick to katakana to denote their vehicles as I have yet to find anything showing that roman lettering was used at all. If you were to find anything, my guess that it would on the bureaucratic side of things rather than military side of things as that is more in line with how it's used in the modern day.
  11. Tank You
    Atokara got a reaction from Beer in Imperial Japanese Army Tank Nomenclature   
    Idk about IJA, but the practice has become a lot more common with the JGSDF.
     
    TKG is the most common way to refer the main cannon of armored vehicles. Basically TanK Gun. Usually it's just the XXmmTKG, but I've also seen the Type 10 cannon called 10TKG to differentiate it from the 120mmTKG of the Type 90.
     
    AFV's themselves on the otherhand really only receive this style of abbreviation from the Ministry of Defense rather than the JGSDF. ie: 90TK, 74TK, 89FV, 11CVR, 16MCV.
    https://www.mod.go.jp/gsdf/equipment/ve/index.html
     
    This nomenclature is frequently used by the ATLA as well with experimental vehicles such as the Type 90 project being named NTK and each individual prototypes for both the Type 90 and 10 being TK-X-0001, TK-X-0002, etc.
     
    From what I've seen of IJA materials, they don't seem to use the roman lettering very often and stick to katakana to denote their vehicles as I have yet to find anything showing that roman lettering was used at all. If you were to find anything, my guess that it would on the bureaucratic side of things rather than military side of things as that is more in line with how it's used in the modern day.
  12. Tank You
    Atokara got a reaction from Lord_James in Imperial Japanese Army Tank Nomenclature   
    Idk about IJA, but the practice has become a lot more common with the JGSDF.
     
    TKG is the most common way to refer the main cannon of armored vehicles. Basically TanK Gun. Usually it's just the XXmmTKG, but I've also seen the Type 10 cannon called 10TKG to differentiate it from the 120mmTKG of the Type 90.
     
    AFV's themselves on the otherhand really only receive this style of abbreviation from the Ministry of Defense rather than the JGSDF. ie: 90TK, 74TK, 89FV, 11CVR, 16MCV.
    https://www.mod.go.jp/gsdf/equipment/ve/index.html
     
    This nomenclature is frequently used by the ATLA as well with experimental vehicles such as the Type 90 project being named NTK and each individual prototypes for both the Type 90 and 10 being TK-X-0001, TK-X-0002, etc.
     
    From what I've seen of IJA materials, they don't seem to use the roman lettering very often and stick to katakana to denote their vehicles as I have yet to find anything showing that roman lettering was used at all. If you were to find anything, my guess that it would on the bureaucratic side of things rather than military side of things as that is more in line with how it's used in the modern day.
  13. Tank You
    Atokara reacted to Ramlaen in General AFV Thread   
  14. Controversial
    Atokara got a reaction from Laviduce in Contemporary Western Tank Rumble!   
    Sounds like an incredibly dumb idea. Solar panels aren't even reliable in a civilian environment mounted on stationary platforms let alone vibrating military vehicles out in the desert collecting sand, dust and small arms fire. War was never a clean activity, so I don't understand the attempts to make it such. Either this is cheap pandering to the green parties in NATO aligned nations or this NATO chief is actually this brain dead and believes that this is an effective idea let alone possible. NATO just keeps wanting to justify it's dissolution, larping as "environmentally friendly" with it's tanks that are getting btfo because it's cloudy and "for some reason China didn't comply with the solar power tank act". Meanwhile half of NATO's members have a sizeable nuclear warhead stock which are less than "environmentally friendly" when used.
  15. Tank You
    Atokara reacted to SH_MM in The Leopard 2 Thread   
    When was this confirmed? Two years ago, Rheinmetall still spoke only about the possibility to adapt the L/55A1's improved technology to the shorter gun. Are you sure that you don't confuse the L/44A1 with the L/55A1?
     
     
    There aren't many mentions of the DM63+ (sometimes written DM63Plus). It was announced during a conference IDEX 2017 with an expected service readiness of 2019 while KE2020 (DM73) was expected to be ready for service by 2022. Several news outlets from that time including Jane's IHS, picked up on the story.
     
    Since then it has been rarely mentioned. Jan-Phillipp Weisswange mentioned it on his blog once in 2018. I've not seen any further information, so maybe the idea was given up.
     
     
    This is a Rheinmetall 120 mm smoothbore gun without the frontal section of the thermal sleeve and bore evactuator.
     
     
    Performance of guns is measured in kinetic energy, not by penetration.
     
    The muzzle velocity of DM63 is 1,720 m/s at 21°C; only the DM53 using its hotter (and more temperature dependent) propellant charge reaches 1,750 m/s at 21°C ambient temperature. Given the projectile weight being presuambly identical between DM53 and DM63 (no reported changes to projectile, exterior dimensions are identical), this results in a muzzle energy of ~12.4 MJ at 21°C ambient temperature. At 2,000 m/s, the muzzle energy would be 35% higher (I previously wrote 38%, but this was with a projectile weight that was off by a sligth margin).
     
    The improved penetration is also only achieved with new ammunition, not with the old DM63. As per news reports from 2017, the prototype of KE2020 (DM73) with conventional WHA penetrator existing at that time had a longer and heavier penetrator, resulting in a reduced muzzle velocity. Only when using a new - then not existing - hybrid sabot (with aluminium and composite materials) and further modifications, the muzzle velocity was expected to exceed the DM63's. However at that time several other concepts were also considered including sheated penetrators (thinner but much longer tungsten rods with steel sheat), gradient penetrators (where the thickness of the penetrator differs to increase penetration against complex targets), and even multi-penetrator designs in one catrige (one penetrator against ERA, one against the base armor) etc.
     
     
    No, he just mixed effective range for the old DM12 HEAT-FS round with the muzzle velocity of an unspecified round. The guy was not a gunner, but a Leopard 2A6 driver (so he will not receive a Leopard 2A7V tank) and he also stated that the muzzle velocity would be Zwotausendzwohundert (2,200 m/s). The video was also likely recorded before the order for the Leopard 2A7V tank was placed.
    [spoiler]
    [/spoiler]
     
    A muzzle velocity of 2,200 m/s at identical weight would result in a 62% higher muzzle energy compared to DM63 and a 26% higher muzzle velocity than even DM53. This guy just mixed up two numbers (DM12 HEAT-FS effective range of 2,200 m with the APFSDS' muzzle velocity of 1,720 m/s), because he was nervous in front of the camera. That's human nature and not an accidentally leaked secret performance gain that has been confirmed nowhere else...
  16. Tank You
    Atokara got a reaction from Clan_Ghost_Bear in Contemporary Western Tank Rumble!   
    Looks like the "human loaders are just as fast as auto loaders" is finally over. It seems like the Type 10 has two settings similar to the Leclerc's "Doublement" mode.
     
    Looking at patents for the auto loader system Japan uses, the next round seems to drop off the ammo belt onto a feed ramp. my best guess for how the 1.6 seconds is achieved is a button is pressed where immediately after the first round is loaded, a next round is dropped off and prepared. As a result you get a faster overall reload, but lose the ability to switch ammo type in between shots. Otherwise you get a standard reload of 3 seconds, but the next round isn't immediately prepared giving time to switch ammo type.
     
×
×
  • Create New...