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Jeff Duquette

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    Military History, Beer, Football (American Style!)
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    Civil Engineer

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  1. Sorry -- I did a quick search and nothing jumped out immediately. So if you all have answered this already -- sorry for asking... I used to play TOW-1 and I used to post regularly to the ToW-1 forum -- many many moons ago. As I recall I drifted from the game cause' of the multiplayer issues. Has the multiplayer stuff been resolved in ToW-2? Are there dedicated servers where ToW-2 players gather to blow each other up? I always thought ToW-1 had such amazing potential. Like Atomics old Close COmbat on steroids. But the problems with multiplayer mode and the lack of any dedicated servers made me drift onto other things. I lost interest in blowing up and being blown up by the AI. Duking it out with Human controled opposition is I think the key to these sorts of games.
  2. Don't Buy from AviaPress Web Site!! Their website claims to have a lot of very nice Russian Publications on Tanks, Aircraft, Ships, etc. However, they are notorious for not filling orders. I have ordered magazines on Russian tanks from AviaPress on three different occasions over the last two years and have only received one of the orders. The problem is they will bill your credit card or paypal account upon you placing the order rather than when they fill and mail the order. You get charged and never get your order. They do not respond to order inquires or any questions sent to them -- like “where's the stuff I paid for”. They are disreputable, dishonest, belly crawling, internet thieves. I plan on repeating this forum post on every forum I attend. Rant complete -- have a nice day. Regards J.Duquette [ May 03, 2008, 07:21 AM: Message edited by: Jeff Duquette ]
  3. ...looks rather painful. It appears like I will need to monkey with the dongel configuration, direct-x, and my anti-virus software settings. I suppose the direct-x bit has me a tad worried in how this will affect play for other games on my system. I don't seem to have any issues with other games and Vista -- to include ToW. On the Israeli teflon coating...I assume this was an LRP you are talking about?
  4. Presumably this would also imply that if one of my tanks is in a hull-down position, I won't be seeing very many hull penetrations or track hits or the like. This is the reason for normalizing penetration data into the form of t/d. An under-matching event will result in a different plate failure mode than an over-matching event. For example, blunt projectiles are very efficient when perforating under-matching plates (a low t/d event). They are much more efficient than an ogival shaped armor piercing projectile nose in low t/d events. However this advantage progressively declines as t/d increases until at a certain point the ogival nosed AP projectile becomes the more efficient penetrator. Things such as slope effects plate hardness, armor quality or armor types perform differently under differing t/d ratios. If they did not, than those graphs I posted above would be simple horizontal lines rather than curves -- i.e. a horizontal line would indicate slope effect and the like are independent of t/d (which they are not). Yes. A limit velocity -- regardless of who was conducting the trials: German, USSR, USA, UK -- is always equated with a probability of penetration or perforation. But an in depth discussion of penetration\perforation probabilities combined with a long discussion on the merits (or lake thereof) of the often cited "cosine rule" would have only succeeded in confusing the issue. Best Regards JD
  5. I see you’re a Steel Beasts fan. Great game. Although I have been unable to get Steel Beasts PRO PE to play on my super-uber gaming computer I just had built. Something to do with Vista as well as the dongle. Pretty irritating considering I paid $100 for the game. From what I've read from Nils, it sounds like compatibility with Vista isn't going to happen. So I guess I bought a $100 mini-frisbee + dongel.
  6. Are you talking about armor coated in Teflon, or projectiles coated in Teflon – ala Teflon coated bullets and body armor? As an aside Teflon is employed in multilayer EFP liners. The Teflon portion of the liner enhances secondary, or behind armor effect. The penetrator portion of the liner – be it tantalum or whatever – wraps around the Teflon during projectile formation. That’s right; the Teflon is in the interior of the EFP. Aluminum can also be employed as the “inner” layer in EFP penetrators. But the use of aluminum appears to be for its pyrophoric characteristics. Conversely the Teflon is described only as being an “energetic material” when functioning as a behind armor effects enhancement. I do not know whether this implies a pseudo-PELE behind armor effect; or whether this implies the Teflon spontaneously ignites during very high energy impacts (ala aluminum powder). I’d guess the former. I also recall reading something on another discussion forum about shaped charge liners that employ Teflon. It was indicated by whoever posted this bit, that Teflon liners provide enhanced penetration capability against ERA. But I have never come across any research papers that disscuss the use of Teflon liners and their efficiency against ERA. Even after passage of the ERA flyers, the Teflon jet would still have to perforate the primary armor shell of a tank. So I guess I’m skeptical – at least until I can find a bit more solid information on Teflon liners and ERA. Regards JD [ February 03, 2008, 07:00 AM: Message edited by: Jeff Duquette ]
  7. Not that it matters to the price of butter in Slovenia, or relative to more interesting things to yakk about regarding the recent patch. But to be clear, there really isn’t much in the way of voodoo at work with armor penetration. It’s just that it is often brought up on forums such as this one. In fact, it has come up a number of times on this forum, to include this thread. The “cosine rule” – while applicable under certain conditions of plate penetration – is really only valid under limited circumstances. What’s the cosine rule? In the way it is typically put forth – ala this particular thread – is that plate ballistic resistance to armor piercing projectiles that rely predominately upon their kinetic energy to perforate armor is somehow directly proportional to the line of sight thickness of the armor plate. This isn't really true, at least under most conditions. What is a plate’s Line Of Sight Thickness (LOSt)? Let’s say a plate has no inclination – it doesn’t slope. It’s actual thickness is the same as its LOSt thickness. If the plate is inclined at say 30-degrees, than it’s line of sight thickness (LOSt) is going to be greater than its actual thickness. The LOSt thickness is equal to the actual plate thickness divided by the cosine of the angle at which the plate is inclined. For example: If a plates actual thickness is say 77.9mm and it is inclined at 30-degrees, than the LOSt is simply: LOSt = 77.9mm/COS(30-deg) Cosine(30-deg) = 0.86604 Therefore LOSt = 77.9 / 0.866 = 90mm If a plates actual thickness is say 51.6mm and it is inclined at 55-degrees, than the LOSt is simply: LOSt = 51.6mm/COS(55-deg) Cosine(55-deg) = 0.57363 Therefore LOSt = 51.6 / 0.57363 = 90mm IMAGE-1 Actual Plate Thickness vs. LOSt As I was saying, folks often want to try and explain the superiority of an inclined plates ballistic protection capability by the plates line of sight thickness. The plate is thicker along the diagonal. Therefore it resists more. But there is more to inclined plate ballistic limit than simply the apparent thickness along the diagonal. Now let’s consider how much umph it takes for a projectile to penetrate a given plate of roll hardened armor. The following example is for circa-WWII, US-Army 90mm M82 Armor Piercing capped projectile. This is a pretty common shell that was employed by the T-26 Pershing Tank and the M-36 Jackson Tank Destroyer. The following figure is how much impact velocity the projectile requires to completely pass through a armor plate of various thicknesses and at various inclinations. IMAGE-2: 90mm M82 APC Limit velocity vs. RHA as a function of t/d How to read the above graph: The X-Axis or horizontal axis is presented in terms of t/d. t/d is simply a common means of presenting penetration data in terms of the projectile diameter or projectile caliber, divided by the thickness of the plate being attacked. For example: At t/d = 1 the thickness of the plate is simply: Projectile Diameter, d = 90mm Plate Thickness, t = 90mm x 1 = 90mm. The plate thickness at t/d = 1 is therefore 90mm. At t/d = 1.5 the plate thickness is simply 1.5 x 90mm = 135mm At t/d = 0.5 the plate thickness is simply 0.5 x 90mm = 45mm As I am talking about the validity (or lack of validity) of the often quoted cosine-rule, the t/d values for the penetration data represents the line of sight thickness of the plate rather than the actual plate thickness. For example: For 30-degrees and t/d=1 the LOSt – like that of the plate with zero inclination -- is also 90mm. However the actual plate thickness is only: 90mm x cosine(30) = 77.9mm. The vertical axis of the graph is the amount of velocity the projectile requires at impact to completely pass through the plate. For example At t/d = 1 and inclination = 0-degrees, the impact velocity required for the projectile to pass through the plate is about 1900-feet per second. At t/d = 1 and inclination = 30-degrees, the impact velocity required for the projectile to pass through the plate is also about 1900-feet per second. At t/d = 1 and inclination = 55-degrees, the impact velocity required for the projectile to pass through the plate is a smidge over 2200-feet per second. Why the cosine-rule is not always wrong, but why it is not very accurate the vast majority of the time. The following figure (Image-3) compares the ratios of velocity required for the 90mm M82 APC projectile to perforate a plate inclined at 0-degrees to that of a plate with the same line of sight thickness (LOSt) when the plate is inclined. So LOSt is being held constant between the zero degrees inclined plate and the plate inclined at either 30-degrees or 55-degrees. When this ratio of limit velocities is equal to 1 for a specific t/d value, than it can be said that the cosine rule accurately predicts the level of ballistic protection the plate provides against 90mm M82 APC. When the ratio is less than 1, or more than 1, than it can be said that the cosine rule does not accurately predict the level of protection provided by the plate at the given inclination. As the figure shows, except for a couple of very discreate points, the cosine rule doesn’t accurately portray the level of ballistic protection provided by an inclined plate in the majority of situations considered. For all the t/d values considered for the plate inclined at 55-degrees, the plate is providing much more resistance than the simple cosine rule would imply. For 55-degrees inclination, you’re always better off with the inclined plate. For the 30-degree inclination, when the LOSt t/d ratio is near 1, the cosine rule is pretty accurate. But for t/d less than 1, and 30-degrees inclination, you’re better off going with vertical armor. For t/d greater than 1, and 30-degrees inclination, you’re better off going with the inclined plate. The cosine rule can be used as a sort of ballpark figure for plate inclinations of about 30-degrees or less (depending upon the projectile type). But for greater inclination – such as 55-degrees – it can be said that the plate is providing a much greater level of ballistic protection than the simple cosine rule would predict. IMAGE-3: Ratio of Limit Velocity Required to Perforate LOSt at Inclination vs. Same Thickness of Plate at Zero Degrees Inclination. 90mm M82 APC vs. RHA. And finally – just for grins – below is a sequence of images of a projectile perforating an inclined plate. As you can see the projectile does not follow a straight line path through the plate. The projectile is subjected to several direction changes as it passes through the plate. Each direction change is resulting in rather large amount of stress developing within the projectile. But as you can see, the projectile does not follow the straight LOSt path through the plate. IMAGE-4: Projectile passage through inclined plate. Best Regards JD [ May 28, 2008, 09:23 AM: Message edited by: Jeff Duquette ]
  8. That's part of it. But you also have to consider the phase of the moon as well as local tidal conditions and the height of the pyramids.
  9. Ballistic slope effect is different and somewhat more complex than simple line of sight thickness would imply. Line of sight thickness being simply t/cos(theta)-- where(theta) is the compound angle between side angle of the shot and actual slope of the plate. Slope effect is the actual increase in limit velocity (or apparent thickness if you like) required by a projectile to perforate sloping armor. If one were comparing the limit velocity for a vertical plate with that of the same "line of sight" thickness for an inclined plate, slope effect can result in a much higher limit velocity; or the same; or even a lower limit velocity than what the simple t/cos(theta) relationship will predict.
  10. “The Heights of Courage” by Avigdor Kahalani “Duel for the Golan” by Asher & Hammel “Arabs at War” by Kenneth Pollack
  11. Go into the scenario editor and add a few friendly tanks That was the only way I could get through the scenario. But even than it was a tough one to win.
  12. I was reading something just recently about the use of Copperhead in Iraq. I can’t recall the context aside from it was urban combat going on somewhere. In this instance Copperhead wasn’t being employed against armor – rather it was being used as a precision artillery munition against a series of occupied buildings. Copperhead was mentioned specifically as well as the laser designator. I was also watching something recently on Discovery about artillery training at Ft. Sill. They were interviewing one of the battery commanders of whatever the latest SP 155mm the US Army is using, and he started talking about the ammunition ready racks and where they typically store four (maybe it was 5) copperhead rounds. It’s a rather long projectile relative to other forms of 155m ammunition, which I think was why he was yakking about it’s ready racks. The program was relatively recent – made in perhaps 2005 or 2006. The comments about the Copperhead got me to wondering if the projectile is still being employed.
  13. Great. Thanks Ergon Yes -- Agreed. This is something that requires a fair bit of preplanning and -- at least in the case of the British, would probably only be useable at the start of a scenario depicting the begining of a rather big push. For example the first few hours of Goodwood the VIII Corps advance was proceeded by a walking barrage. A player placed in the role of Company or Platoon commander (ala TOW) would typically have little or no control over preplanned fires such as a walking barrage involving the coordination mutiple batteries or even multiple battalions or regiments of artillery. But of course that is not something most players would want in their game. They require full control over many aspects of a battlefield for which in reality they would exercise absolutely no control. In terms of game applications of walking barrages, I suspect this wouldn't be much fun for the player on the receiving end. But modeling artillery effects and employment of indirect artillery within tactical wargames always seem to be such a chore for game designers. This is particularly true of material effects\destructive potential against entrenched troops. Operational assessments often point to the morale effects rather than destructive effects of prelim barrages on entrenched troops. The morale effect should be applicable both in terms of bucking-up morale of troops watching the enemy positions getting pounded, as well as acting to lower the morale of the side getting the pounding. Conversely game effects of artillery are most often limited to purely destructive effects; inflicting casualties or destroying equipment. But this is so far a field from the original topic I suppose it's best to move on, or open a new thread. [ October 31, 2007, 06:47 AM: Message edited by: Jeff Duquette ]
  14. Thnx Egon. Nothing in the way of walking or creeping barrage? The British seemed pretty fond of this form of support during attacks.
  15. Interesting material Ergon. This would be nice to delve into in a bit more detail in perhaps a stand alone thread. What was the original source?
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