pamak1970

A link which shows the previous memo and in addition discuss the armor doctrine http://tinyurl.com/y8bljdk

This memo does refer to tactical success for the TD and I was wondering on what basis it was said This memo comes from McNair himself as as Commander of Army Ground Forces in 1943

It is important though to point that all these tools were not supposed to be the answer countermeasure of a breakthrough, which was what the TD dogma was supposed to be. Beefing up infantry with AT or making many of them mobile following the trend of a mech infantry is one thing. Expecting those things to act as an operational reserve and counter breakthroughs is different. The belief was that the best antitant is another tank. All of these things like ITVs or even At guns in jeeps were seen more as a tool to free more tank assets from the need to support infantry. At the end the main armor thrust would be met by tanks

I was talking about something i mentioned earlier. That is the death of the TD doctrine at a time when it could easily have a mission against Soviet armor after wwii. It seems the army could not justify the existence of Tds even then.

Funny how cheap and tested solutions which worked were finally abandoned.

@ Jason In one post you talk about all these other factors unrelated to the equipment specifications that determine outcome and in your last post you use outcomes of battles to justify the quality of equipment . You are aware that even towed AT guns countered successfully the German tanks in many of these battles you mentioned. I guess according to your logic which continues to stick to the big picture and end results, towed AT weapons are not vulnerable to HE fire in which case you should start a thread trying to convince battlefront that they have to do something with the very unrealistic model they have in their games which permits players to use even mortars to silence AT guns. The point is not to find the case of German artillery destroying TDs. It is difficult to do so under the presense of air supremacy. However as i said a doctrine should apply also when no army has any significant other advantage. The point is that we can still use some type of judgment seeing a picture of a TD . The point is that we can claim that the need to combine arms and mix tanks and artillery was not in the vision of the guys who built the TD doctrine (to their defense, many others missed it also). That is why i said from the beginning that i look this all thing from a more theoritical point not sticking to specific battles. I may not be able to find mass German artillery fire killing Tds, but i can find the trend of advanced armies using combined arms concept and i do find cases of having the operational reserve forced to execute a movement to contact and even having to attack in order to counter a threat. Yes TDs were never used centrally as an operational reserve, but remember that the doctrine DID visualize them under this concept. The fact that this doctrine was not executed in practice, does not mean that we should not examine the soundness of it based on the above observations.

by the way, a little bit off topic but i would appreciate if someone has information to verify if CharB needs refueling every two hours when it operates in difficult terrain (not road movement). It is clear that the French commander asks additional time for refueling after moving just 15 to 18 km in a two hour period, but this might well be not a case of having the tanks empty. It might just be a very cautious move from the part of the tank commander who wants to be sure that he has topped his vehicles, 100% before starting the attack. On the other hand as i said, the book does talk about the high fuel consumsion of this tank when it operates in difficult terrain, giving a figure of two hours and a reference to back it up. It is just that i could not check the reference and it is possible that this number which seems very low might be the result of faulty analysis of events (the commander asks to refuel after moving for just two hours , therefore the tank needs refueling every two hours )

since i have free time tonight i continue If anyone wants an object lesson in how irrelevant the frontal superiority of a Panther over a Sherman 75 can be in the presence of such factors, please review Cole's description of the battle of Dompaire in his "the Lorraine Campaign", pages 199-200, between 112 Panzer brigade and CCL, French 2nd Armored division. Green new formations, reckless premature offensive commitment, poor battlefield reconnaissance, terrain, flanking positioning and possession of terrain features, command of the air, and effective use of SP artillery - matter. As a result, 112 Panzer has 4 Panthers left at the end of its first day in action, and is spent. Armor numbers on the ground even at the start, wipe out to losses of less than a company for the side with the lesser tanks. "But but, Sherman 75s are Ronsons and death traps and we've got 40 spanking new Panthers, they should just be fresh meat for no loss". No. How you use the weapon at the grand tactical scale, operational factors, and overall combined arms power dominate outcomes You are beating the strawman here, because i do not believe that there is a disagreement . I do not think anyone here said that better armor and guns matter more than Green new formations, reckless premature offensive commitment, poor battlefield reconnaissance, terrain, flanking positioning and possession of terrain features, command of the air, and effective use of SP artillery combined as it was the case in the battle you mentioned. THere is still though expectation that having doing my part as a member of a military unit, and having done proper training and recon and the rest against an equally capable opponent, that i am not backstabbed by a poorly designed doctrine or machine. My belief about the failure of this doctrine does not come because of the end result of particular battles since all of these factors you mentioned were present and influenced outcomes . This is why i prefered to explain from a theoritical point of you the obvious decline of the tank destroyer concept. In order to avoid misunderstandings, the above does not mean that it is useless to study those battles. On the contrary, as long as we are not fixed at seeing only the final outcome of casualty or exchange ratios and as long as we are willing to examine various other details, they can still teach us many things about proper doctrine, or arming the force. For example someone else mentioned an excellent book "the blitzkrieg legeng" and i am going to use a case from there to make my point. It is on chapter 6 dealing with the French attempts to counterattack at Sedan after the breakthough. Time is of essense for the French who have to counterattack soon since the bridghead is still fragile. Of course they do not know it yet since their reports do not give the magnitude of the problem At the end their attempt to counterattack with tanks is terribly slow. If i stop my description of events here someone might simply point to surprise or inept command and control and the like arguing that there is nothing wrong with the Char tank or the French doctrine but then the book reveals more details. Although surprise and broken communications do exist there are additional challenges because of technical and doctrinal issues. French have Char and Hotchkiss tanks and of course they want to combine them in the upcoming counterattack. However the Char tank presents some challenges. Since French saw this tank in a tactical mission role supporting infantry, it had limited range. The compo of armor (weight) fuel capacity is tailored for wwi enviroment. At the end a Char B tank needs refueling every TWO hours when it operates in difficult terrain ( The book actually gives a reference for the above). When Brocard, the commander of the 3rd Armored Division is assigned the mission to counterattack with extreme haste, he has to refuel his tanks ,( assuming the supply columns survive the German airforce), move between 14 to 18 km in two hours (among others the Char is terribly slow) and then needing another two to three additional hours to refuel again! Then the final blow comes when French hesitate to attack fast. While they advance (at wwi rates) they see French troops fleeing and talking about hundreds and even thousands of German tanks. At the end they do not have the nerve and raise to the demands of the specific situation. They decide to stop, spread and wait for the Germans , probably counting on engaging them from advantageous defensive positions. Unfortunately for them, The German effort is not pointing towards them. The Germans have already turned and advancing towards the sea at wwii rates, in a perpedicular direction to the one French are waiting. They have also the time to bring more troops on the other side and strengthen the bridgehead. The French position has become irrelevant to the demands of the situation and since they do not care on pursuing the initiative through an offensive action, they seal their fate. Of course today it is easy to talk about ineffective French commanders but taking in consideration the fog of war and the like, it is not difficult to understand even the most horrible decisions. Because if in an alternative universe the French commanders were moving with haste and happened to bump on strong German units waiting for them in the bridgehead instead of rushing towards the sea leaving a weak cover behind in the bridgehead, the same people would accuse them for inadequate recon, or stupidly aggressive attacks against a well placed enemy. Anyway my point was not to talk about the French, i just wanted to show how we can still dig for details of military operations and try to draw certain conclusions about the challenges presented by the military equipment used, in spite of the fact that we have other parameters of operational significance which are certainly responsible for the final outcome.

continuing the previous post since a lower casualty rate does not show anything about the level of protection against enemy artillery (a Sherman has obviously better protection that a TD and still has higher casualty rates according to your words ) what is the point of mentioning it in the first place? If you attempt to compare armored infantry to TD i fail to see the point. The armored infantry was not supposed to seek find and destroy enemy tanks. and its enemy was equally vulnerable to artillery and air inderdiction fire. In addition since you yourself mentions that the TDs did not have many opportunities to put in practice the doctrine they were supposed to follow, then why you use their overall casualty rates to argue that they were actually capable to do what they were supposed to do? Again let's not confuse things. The situation in west and the results there can not be used by themselves without a deeper examination to justify doctrines. Forget the arguments of air superiority , material advantage and the like. The thing is that overall at the end you have an army which can perform operational moves freely and be fully mechanized against an army which has to hide half of the day and still use mules and horses to move the rest of it. Under those conditions you have plenty of room to make mistakes as an Ally and still end up on top. I do understand your position that Germans enjoyed similar advantages of air superiority or mobility against Polish, French, Russians and so on which is of course irrelevant to the evaluation of the AT doctrine. I tent to see the latter in broader terms because the people who formulated it in the beginning were not supposed to assume that it would apply under air supremacy or any other huge advantage. A sound doctrine should apply successfully with good results even when things are on parity in other fields

Then we get the moved goalposts of TDs supposedly being too vulnerable to HE and artillery, when the debate was over the supposed lack of armor vs. armor fighting ability of the US force as planned. As a fact, personnel losses in the TD forces ran below those in the regular armor (tactical doctrine and typical use more than matching any protection difference) and personnel losses in both ran less than a third the rate seen in the armored infantry, which was already lower than the regular infantry. Nor is this remotely surprising; being behind armor of any sort protects against the cause of 70% of all personnel casualties, which is artillery shrapnel THis is the only thing i want to comment on since my belief is that for the most part anything you said related to average numbers and those types of grant statistics shows nothing about the details related to AT doctrine and machines. Talking about moving goalposts................ My understaning is that the debate is about the effectiveness of AT dogma and of the machines used to put it in practice. So vulnerability should be a part to consider in this debate. I seperated this remark because it shows once more how those types of statistics you mention are totally irrelevant to what we discuss. First of all tactical doctrine and typical use of a fighting machine ARE formulated in practice based to some extend on the vulnerability-protection of the system. So if you are naked , most probably you will not be assigned a mission putting use in the middle of heavy fight which will help you have acceptable casualty rates. In other words you can not use just the casualty rate as an indicator of level of protection without knowing the mission profiles I am pretty sure that casualty rates among artillery men or many specialists in the rear areas were lower to those of combat troops. THis does not mean of course they had better protection. You can not just compare Sherman and TD casualty rates unless you have data showing that they were assigned the same missions at similar percetages, exposed to similar levels of lethal fire. What was the percentage of overall TD missions related to indirect fire. Same question for Shermans and continue until you construct the whole mission profile. Obviously things are more complicated than you want us to believe

Critisizing Americans does not imply that i applaud Germans or English. I simply talk about Americans because the thread is about them. At the end neither approach was adopted after wwii. I assume the longer the range of the effective gun range which came as a result of tank progress, the more difficult to justify less protection for even bigger range (tank destroyer idea). After a certain theshold it does not make sense because of other factors like small likehood of finding free LOS to greater distances or identify vehicles.

We have drifted away from the original issue. I am sorry but I do not accept the logic that the winner did everything right because he simply won. The issue is as somebody else said “what if he could win faster or with less cost”. I am pretty sure you can defeat any system by swarming it with many more weak and cheaper ones, but this does not prove that you did the right thing nor it shows the cost of an alternative approach of accepting less material superiority in exchange of better quality. Nor you can use the favorite subject of “average numbers” of exchanging weapon systems or ratios of losses because all these are affected by many parameters irrelevant to US antitank doctrine and quality of US antitank or German tank systems. If Americans after a certain point had chosen to use as an antitank weapon a jeep throwing darts, they would have won with a reasonable “kill ratio” of tanks to “dart throwing jeeps”. That is because in all situations where US companies of “antitank” jeeps would had the misfortune to encounter a few enemy tanks, they would most probably abandon the mission after having a few of their jeeps destroyed and simply accept a passive secondary role letting other much more capable systems dealing with the threat. In fact after a while, seeing their obvious inability to perform any antitank mission, they would not even bother to attempt to knock out any tank. They would simply execute other secondary tasks which would be safer and tailored to their weakness to withstand fire. The end result would be to have after the end of the war, a favorite comparison of “average numbers” of US jeeps to German tank casualties. Right now we are talking about a specific thing which is the US antitank doctrine and effectiveness of US tank destroyer weapons. So let’s focus on these things and their opponents which were the German Panzers. Here are my first thoughts, saying from the beginning that I have no desire to claim that I know everything or that I am an expert but I would appreciate if somebody has issues with my thoughts to attack them with arguments instead of me with slant and nasty adjectives. The US antitank doctrine, failed in my opinion. The reason was that it made wrong assumsions which led to an overreliance on speed at the expense of protection, coupled with suboptimum armament. Let’s start first with the armament. It is wrong to make comparisons with the situation of T34’s and inability to penetrate Panthers. Everybody can understand that systems develop and naturally even the best systems may have issues in penetrating newer tank models. However let’s put things in perspective. First the T-34 was a very good design which came as a shock to Germans when it was first deployed. In this case we had the Soviets acting instead of just reacting. They gained an advantage in armament which was followed by a German answer to recapture it. Americans though seem more like reacting trying to “catch up”. So I cannot put their effort (in this specific category of armament), at the same level with the previous mentioned ones. In addition when we talk about American tank destroyers, we have a totally different demand for armament. I mean the idea behind the antitank concept is that you sacrifice in protection in order to gain an advantage in another area (like armament). If you come in the battlefield naked You better come not with just an equal or marginally bigger gun. You should come with something sufficiently big to justify your original decision to sacrifice protection and give you better chances overall to defeat an average at least German tank at the usual battlefield ranges The point is not if a tank destroyer had a bigger gun. The point is if your compo of gun armor give you a longer effective battlefield range compared to the enemy tank. If the latter in the average case scenario is still able to penetrate you at longer battlefield distances then you have a problem to accomplish your primary mission. The Americans I believe did not see it that way. They thought that speed could compensate. It could let them arrive first and engage the enemy from favorite defensive positions which could negate any possible tank advantage. Well things seems to work different . First Americans (I am talking about the antitank branch only) were incapable to understand the full effect of combined arms. It is not just tanks against tank destroyers. Where they are tanks there is going to be artillery too and infantry and a pack of different weapon systems and tank destroyers have an open turret vulnerable to every airburst . Although you as a tank destroyer expect as a member of a combined arms group to see a fellow weapon system dealing with your problem, you must still be able to protect yourself all this time which is nessesary to eliminate or neutralize at least the threat. In addition all this mobility sounds good on paper but it is difficult to materialize in practice At an operational level and as a part of a compo group you tent to move at the rate of your slower members of your team which accompanies you and at the tactical level, fire and protection matter a lot. You can not dance all around an enemy when he can still rotate his turret shoot and kill you at longer distances or when airbursts follow you Besides it does not follow in operational or tactical level that you as a reserve have some “inherent advantage” of choosing your location and wait for the advancing enemy who broke through your defense to come at a place and range of your liking.Sometimes the above may happen, especially in places where terrain restricts choice of axis of advance , like mountain terrain and the like. Very often though the enemy has simply too many choices and you can not guard against every possible course of enemy action. “He who defends everything, defends nothing”. IF you become inactive, you give the enemy the opportunity to make your position irrelevant. Fix your position with a minimum of force and maneuver to get an advantageous position towards your open flank or rear. You try to counter this by maneuvering, possibly trying to do the same thing to him. Other times the best way to stop a penetration, is by forcing the enemy to relocate forces from his original axis of advance in order to counter an unexpected threat somewhere else chosen by you, the defender(in operational terms) who decides to attack trying to get the initiative. It is much easier this way instead of trying to read the enemy’s intentions (bypassing fog of war and mirrors by his deceptive operations) and move towards his potential destination faster than him waiting to confront him there. Other times it is simply a matter of confronting him when he is exhausted not letting him time to recover from his previous effort to break your defense. The end result of all of the above is that as a tank destroyer reserve, you often have to execute a movement to contact operation at the operational level, or restore your breached defense by a swift counterattack before the enemy has time to consolidate his gains. However your tank destroyer system is not effective when it is not camouflaged or hidden waiting for the first shot . In a movement to contact environment when both forces move against each other, surprise can come easily at anytime to any of them (assuming there are no issues of air supremacy)while in a counterattack tactical scenario it is probably the attacker who is waiting for you. The reason I wrote all the above is because I wanted to show my reasoning regarding why the American antitank dogma was poor from a theoretical point of view. It is not that all of the above things I described happened in practice. Some of them did not because of other factors unrelated to the “genious” of people who gave birth to this doctrine and who were not in a position to foresee them anyway . The tank destroyer could be effective only in very specific situations against a tank. This is a very poor result for a system designed specifically to deal with enemy tanks and be vulnerable to almost everything else. As a last comment I am going to point the obvious double standards of explaining the result of a battle where tank destroyers did not perform well, in terms of “bad tactics from American commanders in the field” while taking the result of another battle like Mortain as a proof of the soundness of the American dogma. The more experienced members here can recall in other threads the arguments against the silly tactics and dogma which led to hopeless attacks against Mortain and the like. And by the way, by criticizing certain people, I do not claim that I am a “better man” or tactician or strategist than them. Same when criticize Napoleon at Waterloo, Darious at Issus and the list goes on and on…….

It will be interesting to see why the American (NATO) thought of the relative free use of nuclear as countermeasure to Soviet massive armor in the 50's? Consider for example the big disadvantages of that approach like devastation of allied territory in case of tactical nuclear weapons against Soviets in West Germany or taking the huge risk of total anihillation of big European or US cities or even countries later in case of targeting nuclear weapons at the heart of Soviet Union. Is it possible that this type of choice was forced because they did not see they had an effective conventional response at that time ? If this is the case, then it seems strange that Americans ignored a supposedly tested ,successful ,cheap and with relative minor political and strategic risks antitank doctrine at a time when they needed the most.

I do not think this is the main reason for the demise of the antitank doctrine. After 1944 it was the Soviets who had the ability to stage massive armored attacks, but still the Americans did not seem to be thrilled with the use of TDs as one relative cheap countermeasure against Soviet armor.

This thing about "fresh look" made me post one idea for discussion. Since i am not a programmer , i do not know how easy it is to do it . I leave this to the experts here. I recall many years ago, there was a request for the upcoming CMSF related to "zones of operations". In a way it was like having a player establishing boundaries between the major formations under his command and any deviation during the execution of the mission would result in some type of penalty. I wonder if we can link this idea together with probablities for mis-identification (i am talking about firendly fire) or something similar.

maintenance time during road march is absolutely vital. I do not have available right now wwii numbers for different nations (i have to dig for this and i do not have enough time). I do have right now available times for modern operations . For example http://www.globalsecurity.org/military/library/policy/army/fm/100-61/Ch3.htm Notice Daily march performance calculations assume that units march from 10 to 12 hours of each day. The remaining 12 to 14 hours are spent as follows: Maintenance: 3 to 4 hours. Deployment and camouflage: 1 to 1 1/2 hours. Movement to start line: 1 to 1 1/2 hours. Rest: 4 to 8 hours. Hot meal: 1 to 1 1/2 hours. During a march of over 1,000 km, there is likely to be at least one rest day, for essential repair and maintenance work. That is for modern (and more reliable equipment-manual of 1998) Also i have some more interesting data for specific vehicles For example http://www.inetres.com/gp/military/cv/inf/M113_variants.html XM806E1 Light Armored Recovery Vehicle "Recovery Vehicle, Full-Tracked, Light Armored (M113A1) XM806E1." The XM806E1 recovery vehicle is an M113A1 APC modified for recovery of disabled vehicles comparable in weight to the M113A1. The vehicle was scheduled for operation at Aberdeen Proving Ground for 4,000 vehicle test miles, of which 1,000 were with an M113A1 in tow. Also, 100 winch operating hours and 12 crane operating hours were conducted. Testing was under actual field conditions on missions which typify normal operational use of the equipment by troops in the field. The maintenance ratio for the test vehicle was 0.0815 hour of active maintenance time per mile of vehicle operation. Based on 4,001.2 miles of operation and 17 equipment failures, the MTBF was 235.3 miles. The total active maintenance time to repair failures was 133.2 man-hours and 46.5 clock-hours giving a MTTR of 7.78 man-hours and 2.73 clock-hours. Where MTBF =mean time between failures ..........MTTR=mean time to repair Notice especially the mean time to repair)(2.73 clock-hours). This means that a large number of vehicles falling behind during a road march, will be able to join their parent unit at the end of the day. (that is a 1969 technology by the way) There will be a small percentage of vehicles experiencing a serious problem which will not be able to join the unit and you might see them as "out of action" in the unit report. However, the real percentage of vehicles experiencing breakdown is much larger and can not be revealed by high-echelon reports about the unit's march mission. For wwii. although numbers maybe different, the concept is still the same. There are many repair jobs which will not be recorded in the unit's diary.

I suggest you visit the armchair general forums. Specifically wwii forum- " PKKA in wwii (the Russianarmy in wwii)". It has many Russian posters and a lot of them have Soviet studies (many not yet translated to English). Recently i posted a question there about the rate of repair of Soviet maintenance formations and they were very helpfull.

"Correct, but they still aren't out there with clipboards recording how many times a tank gets stuck for 5 minutes. That's my point... the statistics that matter are the same ones they were detailing... how many vehicles available this morning are not available tomorrow morning. THAT is very important, but it isn't the same thing that CM is concerned with. " Adding to this i recall in one of my books describing small unit tank actions , the case of a German attack where the company commander was forced to change four different tanks during the attack. However, the after action report of the unit for the day reports less than four tanks out of action (total losses and damaged) ). I think it was something like one total loss and one damaged. I do not recall the specific details but i do recall that i noticed the difference when i first read about the incident. Obviously (since the commander was forced to change four tanks) and since the aar gives less than four casualties, some portion of those vehicles abandoned by the commander were put back into action before the writing of the AAR.

I found the link describing in detail the Nasiriya incident and the trafficability issues. The only thing is that it is about trafficability issues of trucks of the 507 Maint company, but it is still a good read. We do not have combat vehicles here. It is the following www.army.mil/features/507thMaintCmpy/AttackOnThe507MaintCmpy.pdf On another issue, unfortunately i do not have any indication that can link high level recovery (cause of bogging issues) statistics to low level ones which can happen at tactical level and never revealed in high level reports. I only have a rough approximation of repair and recovery figures in general from a modern US manual. Without having it near me , from what i recall ( i may be somewhat off for certain numbers), it categorizes repair jobs in three groups, That is low-mid and high level. The proposed time threshold for each level is , 0-4 hours (or 0-2 not sure) for accomplishing a low level job. This is the job performed by crews and up to company support personel on the frontline. The next level is for jobs between 4-12 hours and the higher level (division and up) is for jobs requiring over 12 hours . The rule of thumb is that repair-recovery jobs are distributed about equally between those categories. One third will be accomplished at low level (and most probably will not be recorded in high level reports), another third will be accomplished at mid level support units (battalion brigade) and the last third at division and above levels. So a high level report showing x number of repair-recovery jobs by high level support units , implies actually a total of 3*X number of repair jobs occuring at tactical level. One third of those is serious enough to be forwarded to high level recovery and repair echelons. Now if we knew that this could apply also to number of bogging issues .......

as a last comment , i know i have somewhere a file about an incident in the second gulf war relative to immobilisations. It describes in detail ,hour by hour an incident of an ambush by insurgents of a support element. The element was basically composed by delayed combat units because of immobilisations and recovering vehicles which came to their assistance. The information was sufficient to calculate the percentage of initial combat vehicles which fell behind cause of terrain difficulties. It obviously includes ALL cases of immobilization occurred during the marching of a battalion strong combat force for a certain amount of miles in Iraq. Maybe it is somewhat irrelevant for the specific terrain and historical data here plus it is just one event only , but it is still neat to read. When i will have time i will try to find it and post it here.

anyway, since i guess people would want to see the other link i mentioned before go to http://www.globalsecurity.org/military/library/policy/army/fm/5-430-00-1/CH7.htm examine table 7-8 and the example where there is an attempt to determine trafficability based on the concept described in the chapter "Fifty M60 tanks (102,000 lb) and 50 M923 trucks (32,500 lb) are to be moved from point X to point Y in the area shown in Figure 7-12. Movement must be cross-country because the roadnet is heavily mined......................... " Notice there are numbers for "one pass and fifty passes" (like somebody mentioned here before about the deteriorating road conditions after the pass of multiple vehicles which can prohibit the rest of the vehicles to pass through the same terrain). Notice however that this approach does not link adequately distance travelled to probability of traverse.

From the above link Trafficability Movement of tanks was generally confined to the roads. The roads are of rough but heavy construction and have crushed stone bases. Roads, except in mountain areas are built from 5 to 20 feet above ground level and have 45 to 60 degree shoulders. Mountain roads are narrow and winding,with many sharp curves and steep grades, and have no guard rails or fences of any kind. In many instances bridges of insufficient strength had to be bypassed which was generally not difficult in the south. But bypassing often presented formidable problems in the north, where ravines and and gorges of considerable depth had to be crossed. Unfrozen rice paddies could be crossed where there was a firm bottom a foot or so below the sludge , provided that the tanks were not steered in the paddies, but prior reoonnaissance on foot was necessary to determine the depth of the sludge. Tanks could go from one paddy to another if the intervening dikes were not more than 2 to 3 feet high; higher than this, the tanks would dig In, become mired, and often throw their tracks. The rice paddies could be traversed when frozen provided the tanks did not follow in each others tracks, which might cause the solid surface to give away. In an attack demonstration, one M26 managed to climb a 2,000-foot, 30.degree slope consisting of terraced unfrozen rice paddies, but the tank threw both tracks making a slow turn near th8 top. In the north, light snow and considerable ice were encountered; these caused tanks much traction trouble. Tanks equipped with the T81 and chevron-type, steel tracks had great difficulty with skidding and sliding, particularly when trying to negotiate bends. Tanks sometimes kept one track in the shallow ditches of the mountain roads to insure staying on the road. Ths Tank Company of the 17th Infantry, in a road march from Chori to Pungsan, climbed 4,600 feet in 11 miles, with many deep bypasses of 50 to 500 feet. The first tank took two and one-half days to make this trip. Another platoon of the same company had to shovel ice and snow off the road in order to negotiate a mountain pass. The 3rd Reconnaissance Company,'with rubber-tracked M24's found the performance of these vehicles on ice and snow much better than steel tracked vehicles such as the M39. All units had to be careful to prevent an accumulation of frozen mud and snow behind the drive sprocket, which caused many tracks to be thrown." Under the above conditions and in a period of 4 months , X coprs armor units experienced (Figures in parentheres indicate total losses) Cause..................Prior to wonsan landing...............After Wonsan landing Mech failure...........46(1)..............................................54(26) Tank fire.................4(2)...............................................0 Infantry attack.........0...................................................3(3) TERRAIN..................3(1)..............................................17(17) Mines......................9(1)................................................1(1) AT guns...................4(2)................................................3(3) Mortars....................1(0)................................................0(0) Tactical abandoment...0....................................................6 PS (tactical abandoment from other parts of the document seems it does not imply cases of bogging down) Also in page 73 when there is a detailed break down of casualties by unit , it gives only one instance of "terrain casualty" as a result of "bridge failure". From the same document "These figures show the different conditions which confronted tank units in the two areas. In south Korea, 10 percent of the tank casualties became total losses; In northeast Korea, 65 percent were total losses. This was caused by lack of spare parts, the great distances separating many tank units from their ordnance supporting units , and the tactical situation. Many units could have recovered, repaired, or evacuated tanks had sufficient time been available. Many of the terrain losses, a large Item, could likewise have been recovered. It is noteworthy that only one mine casualty occurred in northeast Korea, and that only seven of the losses resulted from direct enemy action. The 100 eases of mechanical failure reported are broken down in Table II." Of course it is quite likely that those types of reports do not capture the cases of mired vehicles recovered by other tanks for example of the organic unit. I assume those "terrain casualties" were of the type where it was nessesary to call special recovery vehicles which recorded the "job" and became available as a statistical number of studies like the one presented here. Still , it gives an idea ( minimum thershold) of terrain casualties under the ciscumstances described above. The way i see it, terrain casualties in this case is a big percentage. mech failures appear in about 100 cases (and of course again we are talking most probably about serious enough mech failures which require special action outside of tank crew corrective actions). terrain failures appears in 20 cases. There are similar data for other units and that is why i pointed the link so that members can dig into it and try to establish a rough idea about trafficability and tank losses. By the way, there is another link in a US (modern) manual which gives Probability of traverse of certain types of terrains. However it does not link this probability to factors like distance traveled). It basically treats the terrain as either negotiable or not depending on soil characteristics, moisture and so on. Since the measurement of such characteristics inserts a measurement error, this creates a probability (together with the vehicle characteristics) regarding the ability to traverse the terrain by the examined vehicle). I did not post this link cause i do not think it is very helpful (although it appears at first glance to give the "ultimate answer"). However after close examination it is obvious that under this treatment the probability of traversing a certain type of terrain is the same regardless if the length of the path is 10 or 100 miles.

Trafficability Movement of tanks was generally confined to the roads. The roads are of rough but heavy construction and have crushed stone bases. Roads, except in mountain areas are built from 5 to 20 feet above ground level and have 45 to 60 degree shoulders. Mountain roads are narrow and winding,with many sharp curves and steep grades, and have no guard rails or fences of any kind. In many instances bridges of insufficient strength had to be bypassed which was generally not difficult in the south. But bypassing often presented formidable problems in the north, where ravines and and gorges of considerable depth had to be crossed. Unfrozen rice paddies could be crossed where there was a firm bottom a foot or so below the sludge , provided that the tanks were not steered in the paddies, but prior reoonnaissance on foot was necessary to determine the depth of the sludge. Tanks could go from one paddy to another if the intervening dikes were not more than 2 to 3 feet high; higher than this, the tanks would dig In, become mired, and often throw their tracks. The rice paddies could be traversed when frozen provided the tanks did not follow in each others tracks, which might cause the solid surface to give away. In an attack demonstration, one M26 managed to climb a 2,000-foot, 30.degree slope consisting of terraced unfrozen rice paddies, but the tank threw both tracks making a slow turn near th8 top. In the north, light snow and considerable ice were encountered; these caused tanks much traction trouble. Tanks equipped with the T81 and chevron-type, steel tracks had great difficulty with skidding and sliding, particularly when trying to negotiate bends. Tanks sometimes kept one track in the shallow ditches of the mountain roads to insure staying on the road. Ths Tank Company of the 17th Infantry, in a road march from Chori to Pungsan, climbed 4,600 feet in 11 miles, with many deep bypasses of 50 to 500 feet. The first tank took two and one-half days to make this trip. Another platoon of the same company had to shovel ice and snow off the road in order to negotiate a mountain pass. The 3rd Reconnaissance Company,'with rubber-tracked M24's found the performance of these vehicles on ice and snow much better than steel tracked vehicles such as the M39. All units had to be careful to prevent an accumulation of frozen mud and snow behind the drive sprocket, which caused many tracks to be thrown." Under the above conditions and in a period of 4 months , X coprs armor units experienced (Figures in parentheres indicate total losses) Cause..................Prior to wonsan landing...............After Wonsan landing Mech failure...........46(1)..............................................54(26) Tank fire.................4(2)...............................................0 Infantry attack.........0...................................................3(3) TERRAIN..................3(1)..............................................17(17) Mines......................9(1)................................................1(1) AT guns...................4(2)................................................3(3) Mortars....................1(0)................................................0(0) Tactical abandoment...0....................................................6 PS (tactical abandoment from other parts of the document seems it does not imply cases of bogging down) Also in page 73 when there is a detailed break down of casualties by unit , it gives only one instance of "terrain casualty" as a result of "bridge failure". From the same document "These figures show the different conditions which confronted tank units in the two areas. In south Korea, 10 percent of the tank casualties became total losses; In northeast Korea, 65 percent were total losses. This was caused by lack of spare parts, the great distances separating many tank units from their ordnance supporting units , and the tactical situation. Many units could have recovered, repaired, or evacuated tanks had sufficient time been available. Many of the terrain losses, a large Item, could likewise have been recovered. It is noteworthy that only one mine casualty occurred in northeast Korea, and that only seven of the losses resulted from direct enemy action. The 100 eases of mechanical failure reported are broken down in Table II." Of course it is quite likely that those types of reports do not capture the cases of mired vehicles recovered by other tanks for example of the organic unit. I assume those "terrain casualties" were of the type where it was nessesary to call special recovery vehicles which recorded the "job" and became available as a statistical number of studies like the one presented here. Still , it gives an idea ( minimum thershold) of terrain casualties under the ciscumstances described above. The way i see it, terrain casualties in this case is a big percentage. mech failures appear in about 100 cases (and of course again we are talking most probably about serious enough mech failures which require special action outside of tank crew corrective actions). terrain failures appears in 20 cases. There are similar data for other units and that is why i pointed the link so that members can dig into it and try to establish a rough idea about trafficability and tank losses. By the way, there is another link in a US (modern) manual which gives Probability of traverse of certain types of terrains. However it does not link this probability to factors like distance traveled). It basically treats the terrain as either negotiable or not depending on soil characteristics, moisture and so on. Since the measurement of such characteristics inserts a measurement error, this creates a probability (together with the vehicle characteristics) regarding the ability to traverse the terrain by the examined vehicle). I did not post this link cause i do not think it is very helpful (although it appears at first glance to give the "ultimate answer"). However after close examination it is obvious that under this treatment the probability of traversing a certain type of terrain is the same regardless if the length of the path is 10 or 100 miles.

i think the following link can be useful (not the final answer) for the question of immobilisation. It shows breakdown of UN casualties in Korea (including Sherman tanks) by all types of cause. It shows both total casualties and complete losses (write offs). It includes statistics from the period when UN controlled battlefield and from the period of fast retreat against Chinese forces. It has breakdowns (mechanical) by type of tanks (and type of mechanical failure ,table 2 page 285!) and "terrain casualties". The latter is relevant with the harsh terrain conditions in Korea. You will notice that the percentage of recoveries for mech breakdowns and terrain casualties falls dramatically during the withdrawal cause of lack of time and equipment to recover those tanks. The link is the following ( it is almost 27 MB download but it is worth waiting for it) Go to http://209.85.173.132/search?q=cache:HUgLtPJC5JYJ:www.koreanwar-educator.org/topics/reports/index.htm+the+employment+of+armor+in+korea+pdf&cd=1&hl=en&ct=clnk&gl=us scroll down and select "Employment of Armor in Korea, Vol 1, Operations Research Study (PDF File) "

Hello everybody. I have one question regarding how probability of hit works regarding AFVs. Assume you are stationed in a hull down position, against computer controll units. Is the probability of hit linked to the amount of time you are in the same position (increase over time)? In other words Do you reduce the probability of hit by enemy computer controlled units if you change locations frequently and pop up in different hull down positions nearby? I am curious about both CMx2 and CMx1 Thank you P.S I am talking about the probability of hit of a SINGLE shot fot a target popping up in a new location compared to the probability of hit of a single shot aiming Afvs which have already been fired in the past at a certain location