Dan Robertson

Basically I think BTS had the tungsten rounds penetrate, at slope as though they were full caliber rounds. this is usually a penetration of (cos angle)^(2/1.41) due to their smaller size the sabot rounds tend to bounce off sloped armour. Beyond thirty degees is where we assume this takes place. From a test firing of APDS rounds against slopes pf 0 30 and 60 degrees we can see that the actual value beyond 30 degrees should be (cos angle)^(2/1.1) I don't know about APCR but they could be even worse due to the light full size jacket bouncing the round straight off the target without even allowing the tungsten core to strike. Post war APDS L25 and beyond are single piece tungsten-nickly alloy, these do not bounce off as much. they react as (cos angle)^(2/1.25)

I see no reason why materials other than steel, should be used in the construction of tanks. After all we now have infantry helmets which are made of reinforces nylon which are stronger than their steel predessors, but light enough to wear all day. I think that with the increasing cost and sophistication of warfare we are going to get tanks which are the technical equivalent of fighters jets on the ground. This will mean that we can afford to use more exotic materials in them. Steel is basically used in most applications because it is cheap and easy to make. It's properties are in fact nothing special wood for example is much strong than steel of equivalent weight. Carbon fibre is in a different league with the same strength as a hardened steel but 1/5 the weight. As for radar sensors sysytems like Jstar and ASTOR are used to pick up things like armour advances. Plastic vehicles would not show up nearly as much. Also on vehicles like MBT's the armour would still be composities but they would be mounted on plastic or carbon fiber frames. If we change the turret for an unmanned version and move the crew into the hull, and then make the vehicle entirely out of composites and titanium there in no reason why we can't half the weight of a MBT.

Combat missions Aparently this is a game show. Wonder what inspired the name............. http://www.combatmissions.com/

I have fired the British Armies LAW 94 from the prone position. To fire it from the prone position you must place it on your shoulder but be careful not to have the back blast any where near your feet. To do this you aline your body about 30 degrees to the left of the target. The ideal launch point is on a reverse slope where you can fire it prone, but you feet ate very much lower so you don't have to worry about them. This may be different with the Bazooka or shreck because their MV's were much less than a more modern weapon, so presumably required more elevation.

I discovered the site a few months ago. I has plenty of data but a great deal of it is conflicting. However I found the comentaries on each entry usually picked this up. What was also interesting was the reports to shafe at the end of it about the 17pdr and 77mm verses the tiger. I took a look at some of the data and got a slope modifier of cos 60 ^(2/1.1) as the modifier for the APDS. However the German 88 APCR seems to have a modifer cos 60 ^(2/1.4) I think this may be wrong. It is possible that these figures were generated by calcualtion. BTW what are the slope effect on the German 75/48 75/70 88/71 APBCHE that is.

<BLOCKQUOTE>quote:</font><HR>Originally posted by Mr. Johnson-<THC>-: Its quite obvious that a better pilot in a older plane can beat a newbie in the F-22 Raptor. What excactly that reason is, is up for debate. Maybe those in power just don't understand how things work at a military level. <HR></BLOCKQUOTE> Got to say that it would be very hard for the best pilot in the world to beat the F22 in a fight. The technology level is way a head of even the Eurofighter and the various prototypes the Russians come up with. Even if the F22 was readily detectible it still has the power and super cruise mean it's no escape zone is significantly smaller than fly any enemy plane, and the missiles at medium ranges make the difference. Not dog fighting. By this argument you would prefere the US army to field M60's verses T80's or exported Challengers and Leclercs.

The multichambered gun was constructed by the Germans in WWII to shell London because by the late war German planes had a life span of minutes in British airspace. It wouldn't have worked though because the gass pressure would have chosen the path of least resistance which is to compress the air down the tube rather than move the shell up the barrel. As for the balistics, that was quite a good explaination. With the WWII projectiles the objective was to ahieve the highest energy per area to achieve the maxium penetration. So gun power to penetrate armour is proportional to it's volume and pressure, and inversly proportional to the square of it's diameter. Thus the engineer will try and produce the best combination of bore and lenght to produce the required power. However most usually the bore of the weapon is set, by president or the vehicle it must fit it. In which case the engineer tries to get the highest velocity possible out of the weapon. This can be done by making the weapon longer, and giving it more power. Or by increasing the pressure and using the propellant more efficiently to produce a steadier push up the barrel. A good example of the is the British 17pdr. It was a 76.2mm L 55 gun (barrel is 76.2 X 55 long) and had similar power to the German 75mm L70, and vastly superior power to the American 76.2mm L53. Gun power itself it slightly more complicated to measure, than it would seem. The Kinetic energy imparted to a round is not the true measure of this. This is because the gun must also push gass up the barrel at speed too. Thus it is best to standardise weapons performance by comparing what weight of shot a weapon would throw at a given speed. I choose 1000 meters persecond. ((Muzzle velocity/1000)^0.45)*mass of round You can use this to predict what will happen if you fire a differnet shell from the same gun. By finding the power of the intial gun and then working back throw the formula with a different mass.

<BLOCKQUOTE>quote:</font><HR>Originally posted by rexford: We use U.S. HVAP slope effects for all tungsten core, since tungsten brittleness makes slope multipliers greater than steel.<HR></BLOCKQUOTE> From some data I got from Britwar site I found that the modifier for APDS over 30 dregrees is (Cos Angle)^(2/1.1) under 30 (Cos Angle)^(2/1.37) and over 30 degrees for a modern tungsten alloy APDS (ie 105 and 120) (cos Angle)^(2/1.25) BTW the I am looking at the velocity curve for APCR, in the game it seems that they have far too great penetration at the muzzle and then drop off at too greater weight, I haven't looked into it yet fully though.

I described this feature of the game on a earlier post but. Some people had problems understanding what I was on about. So I have modified some pictures as an example. The Red areas are significant because they are facing the front of the vehicle. In fact on the tiger II they account for a significant perportion of the front of the vehicle. They are 80mm thick. The compound angle of the two slopes towards the front of the vehicle is about 71@. This results in a LOS thickness of 250+mm, taking the slope modifiers used in the games for a conventional shell and a APDS round this gives a thickness 393mm conventional 615mm tungsten of constants (1.41 and 1.11) Or unpenetrable from this angle. By non APFSDS rounds. AS can be seen from the picture it shows that at best you should only have a 40% chance of a head on penetration of a TigerII. However conversly at an angle there will be greater chance due to armour less sloped when viewed front thaat angle. So the question is, is this modelled in the game? And if it isn't will it be in CM 2? [This message has been edited by Dan Robertson (edited 12-03-2000).]

My writing style is far from concise so I will try to answer a few points. I wanted to find out whether or not is was possible to do things. The tank LOS issue is odviously one which leaches too much CPU power for little gain. The next too points come from somthing very irratating. I had a tank flanking a position, there was an enemy tank less than 50m away over a crest. My tank kept on targeting a 75mm AT gun parralell to it. This weapon was in a bunker and hence no threat. So as I sent my tank to crest the hill and attack the enemy tank it insted pointed it's gun at the bunker and got killed by the enemy tank. So I came up with two ideas to stop this happening. On was th escetor search, the other was to allow an acompanying infantry comand unit to inform the tank that there is a greater threat over the hill. This happened sometimes in war, since we are simulating with the player being a good comander it should bewithin the repetior. I am in no way saying that tanks should be cabible of indirect fire or aiming on a target that is not visible. Just that it knows it is there. The armour issue is something I proper answer would solve. The situation is that the shape of the turret or the tigers 1/2 have part of their side armour that is visiable from the front. This is angled at 80degs. This works out as a LOS distance of 210mm comoponded by the angle effects this is invelerable to even 120APDS in the chieften. Using the formula the game uses. verses a conventional shell this gives about 350mm of protection, verse WWII APDS it is about 552mm The different HEAT/AP values are due to fact that in places the Tigers mantle and Turret front overlap. This works out as 200mm of steel. However as two thiner plates together this is less effective against AP. There is an entire thread on this. A barbed wire entanglement is quashed by a tank passing over it. It is still sharp but is less effective it is artilery which has no effect. The casualties issue is just somthing I made up I think actually it would not make the better. However I would change the AAR to take into account that some casualties would be captured dependant on who won.

I though I would ask what is possible for CM 2, and at the same time put forward ideas for CM2. Tanks 1. Tanks are to be considered as part of the ground so block LOS allowing friendly fire, and infantry to shelter behind them. 2. An arc of fire comand which tells the tank to scan for targets in a sector (particulary usfull for flanking manovers. 3. Tank infantry co-operation. A comand unit should be able to designate targets to a nearby tank that the tank itself cannot see, therefor the tank can target the enemy crest a hill and fire imidiatly. Similar to the way a comand unit can identify tagets to nearby morters. Comand tanks would also be a good idea doing much the same thing. 4. The tank could do with more cases of damaging, that is vision block hits which reduce but do not totally remove to abilty to fire. Gunnery/armour. 1. I am pretty sure that this will be even more acurate than previously, but what I would ask for is that the tank crews shold be able to range by MG and by bracting. 2. As far as I can tell the CM armour model models a tank as two boxes turret and hull. However certain tanks like the tigers have turrets which a significat perportion of the front of the turret is actually the side of it at a very steep angle. For example the Tigers side armour is at 80 degrees when seen from the front. This needs to be modeled becase this area is invulnerable to conventional rounds. 3. There should be seperate values for HEAT and AP round for each tank. The Tiger for example has 140mm verse AP but over 200 in places against HEAT. Equiptment. Crews should be able to leave heavy weapons and re-ocupy them. Within bounds crews of similar weapons should be able to take over firing different weapons. So for example the crew of a 88 could leave it under bombardment and then re-ocupy it afterwards if there was enought of them and the weapon itself was workable. The same should be the case with MG's and morters. Fortifications and buildings. Bunkers should be considered like buildings in that a unit should be able to ocupy them. For example the crew of an MG bunker should be able to leg it if they are under firefrom at tank. A concrete bunker should still be able to function as a bunker even if it recieves a penetration as an infantry squad could still fire their weapons from within. Trenches as well as large buildings would be nice.Also barebed wire should be made ineffective by a tank running over it. Soldiers. The causalty issue should changed for example there should some difference between death and injury. An injured soldier could drop from his unit but remain staitionary but still armed. If his unit retreated they would have to pick him up and tkae him back or moral would drop. To carry him back would remove one weapon while the unit is moving. So you may have soldiers who are Moving unarmed. Armed unmoving unmoving unarmed these injured could be moved into units when there are more than one of them, a moving casualty could forexample move a nonmoving one. Coments, questions? Dan Robertson [This message has been edited by Dan Robertson (edited 11-27-2000).]

Kip I take it that you use the de marre formula used in this game. Using this and the data on shell weight and Mv from the wargamer site. I have made a spread sheet of some of the most comon guns from WWII. Using de marre and a velocity loss formula of my own (which is not scienfic but works!)From my spread sheet 3.6 is a pretty good figure for relating t/d to energy per mm The 85mm MV 792 Shot 9.2 kg Now Russian shells are meant to have better performance against slope compared to Westurn guns. However the 85 does not it seems to have a cofficeint of 1.4 like the 76mm. (this is based on the penetration figures) The 85 should penetrate 130mm vertical at 1000meters or 112 at 30deg. Stats say,105 and 85 respectivly 76 Mv 792 shot 7kg should penetrate at 1000m 112 at 30 stats say 92mm. 17pdr Mv 884 shot 7.71 kg should penetrate at 1000m 132mm at 30deg stats say 130. 88mm L71 Mv1000 shot 10.2 should penetrate at 1000m 175mm at 30deg stats say 165mm So basically the constant needs to be changed slightly for every gun. On the subject of testing the US test were possibly easier than the British but their weapon performs worse by a considerable margin. In percentage terms. 17pdr =101.53% over 76mm =121.7% over 88mm =106% over 85mm =130% over this shows that amunition performance needs to be taken into account. I read about a test of the 76 verses the 17pdr in which the 17pdr knocked hell out of the 76. In was noted in the test that the 76mm rounds were of poor quality compared to those of the 17pdr. So therefor I would say that the 85mm over estimation is due to both a more demanding test criteria and also poor shells compared to the 17pdr which was premium AT weapon. (and of course my velocity loss formula! which is based on stats from the 120 L44 firing) and the other thing which must be remembered is that the 17pdr was pure solid shot where as the other shells have an explosive filler which degrades penetration but guarentees kill if the target is penetrated. For an idea of what I am on about go here. http://www.wargamer.org/GvA/background/pentypes17.html

I have to say it SHOULD mean the difference between a US tank hunter which with a turreted gun is meant to find tanks and destroy them using it's ability to spot the other tank first. And German tank destroyers which could not fire on the move and were at a dissadvantage to a tank in a meeting engagement. They were defencisive weapons and relied on tanks coming to them

Why not allow a utility where you could change the armour and gun varibles of the various tanks and guns to what ever you believe to be correct? This would, I believe reduce the number complaints that things are unrealistic. Obviously this would be easier to do with armour because that is a single number. With the guns you could simply put in a modifier to increase penetration by X percent of the calculated penetration. Or would this allow players to hack the code and copy the game engine? [This message has been edited by Dan Robertson (edited 10-23-2000).]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Supertanker: I'm in the middle of reading "Death Traps: The Survival of an American Armored Division in World War II." by Belton Cooper (thanks to whoever recommended this, it is a great book). Cooper's duty was to coordinate the recovery and repair of damaged equipment with Combat Command B of the 3rd Armored Division. He says their loss rate of tanks was 580%, and is very critical of the Sherman, saying it was inferior in every way to the German tanks. When the Pershings arrived, he was quite pleased. I don't know how accurate his recollections are, but he did see plenty of knocked-out armor to judge things by. Cooper's unit received only one Super Pershing, and he was trained as a naval architect, so the task of adding armor to it fell to him. See pp. 230-234. He writes that they found a German steel-fabricating shop, and it had several pieces of 1.5" thick boiler plate which they attached to the Super Pershing. "We wound up with four inches of cast armor on the original glacis plate and two inch-and-a-half pieces of boiler plate with an air gap in between. We thought that even though the boiler plate was softer, the lamination and the lowered angle of incidence would help German projectiles ricochet." [He says earlier the added plate was angled at 52 degrees.] "We then cut a section from the faceplate of a knocked-out German Panther and trimmed it to three and a half inches thick by five feet long by two feet wide. We cut a large hole in the middle to accommodate the gun tube and two smaller holes on each side to accommodate the coaxial machine gun and the telescopic site." My favorite part is his story of testing the T15E1 gun, which he says had a muzzle velocity of 3,850 fps, "some 600 feet per second grater than the 88mm KwK43 gun mounted on the German PzKw VIb King Tiger." [i don't know if those numbers are accurate.] They used a knocked-out Jadgpanzer IV as a target, glacis plate toward the Super Pershing. "The distance to our target was approximately a mile and a half." The first shot was a hit. "When it hit the target, sparks shot about sixty feet into the air, as though a giant grinding wheel had hit a piece of metal. [Paragraph] When we looked at the target, I was dumbfounded. The 90mm projectile penetrated four inches of armor; went through a five-inch final drive differential shaft, the fighting compartment, and the rear partition of the fighting compartment; penetrated the four-and-a-half inch crankshaft of the Maybach engine and the one-inch rear armor plate; and dug itself into the ground so deep that we could not locate it. Although we had been told by the ordnance officers from Aberdeen that the tank gun could penetrate thirteen inches of armor at a hundred yards, it was still difficult to believe this awesome power. We all realized we had a weapon that could blast the hell out of even the most powerful German Mark VI Tiger."<HR></BLOCKQUOTE> 13 inch is an overstatement. Thats 330mm of armour. The Most powerfull version of the 90 could penetrate 240mm at 500 metres. Problible slightly more at 100 metres. Slightly better than the 88 fireing similar ammo, APCR. The MV difference stated between the US90 and the German 88 was that for the 88 on the tiger. Either way the big guns from the end of the second world war were all over kills for the tanks of the time, epecically firing tungsten rounds.

I have a specific acount of a tank hitting another in combat. The occastion was after the breakout of Normandy. In what was to be the largest tank engagement on the westurn front. The engagment was at close range between British Cromwells and German heavies. The Cromwells charged the Germans from dead ground at a distance of 300 metres. One of the British accounts tell of how he hit a panther at short range from the flank, because he was traveling so fast the tuuret of the panther turret could not track him and he hit the vehicle in the side with his 75, a K-Kill. (has this every happened in the game?) Another Cromwell was set on fire by a crew compartment penetration by a tiger, the driver insted of stopping and abandoning the vehicle. Accelerated and hit the Tiger tank with sufficent force to roll it over. The Tiger was itself consumed in the blaze, the crew probliby sevrely injured by the impact could not esacpe as the Tiger was rolled on to it's roof. Of course one must remeber that the cromwell was just about the fastest WWII tank and at 30 tonnes was not particulary light. So the impact would have been pretty imense. Still this is more than desperation this is the driver of the stricken tank realising he is dead anyway and taking some Germans with him.

I hope you could answer these questions, if I am asking anything which is commercially sensitive please tell me. What I would like to know is if a piece of software could be made that would allow the users to customise vehicle. That is to alter the parameters of gun, armour, and engine. The reason would be so that other vehicles could be simulated even if the vehicle shown did not look like that. I would also serve to take away on complains about the realism of the vehicles. If you are unhappy with the vehicle you could simply change it. For example a chieftain tank could be simulated by a Panther, with 400mm of frontal armour, fast traverse, gyrostabiliser, and the guns penetration upped by about 2.5. (That and all the other differences) So my question is, is this possible? Whether or not would depend on how you are modelling the combat and how vehicles are represented. I looked at the penetration charts on the website. Now these show the kill percentages of tanks hitting each other. Is this the way it works in the game? Are the percentages calculated in advance and put in tables which the computer accesses during the game? Or is each shot calculated as to where it will hit and then the computers works out what will happen? If it works by the second means it would be relatively easy to change armour and gun variables, for the first method it would be very much harder. Also the units themselves are they extrapolations from a single basic model or are they each individually coded? I ask this because I would quite like to model a post war infantry squad, which could be modelled by 7 soldiers carrying BAR’s and one carrying an MG42. This would accurately model a squad carrying FN FAL and MAG’s. Of course they would be just as mobile and less visible than their wartime colleagues. I think this would make for some interesting simulations and also some amusing confrontations.. Thanks, Dan