Colin Williams Posted January 15, 2014 Share Posted January 15, 2014 That was RO11 not I that was correct.He meant me, although I make no exclusive claim to correctness, having been schooled on this topic by Rich before! It is thus written in the Book of Hunnicutt in reference to the M2 Medium Tank - "The main armament was a short barreled 75mm gun installed in a rotor at the right front of the hull. This weapon was an adaptation of the unsuccessful 75mm gun T6. The latter was a most improbable weapon, a low velocity antiaircraft gun. As modified for tank use, it was redesignated as the 75mm gun T7" Link to comment Share on other sites More sharing options...
DougRichards Posted January 15, 2014 Share Posted January 15, 2014 That was RO11 not I that was correct.He meant me, although I make no exclusive claim to correctness, having been schooled on this topic by Rich before! It is thus written in the Book of Hunnicutt in reference to the M2 Medium Tank - "The main armament was a short barreled 75mm gun installed in a rotor at the right front of the hull. This weapon was an adaptation of the unsuccessful 75mm gun T6. The latter was a most improbable weapon, a low velocity antiaircraft gun. As modified for tank use, it was redesignated as the 75mm gun T7" Thus spake the prophet, and it was good. Link to comment Share on other sites More sharing options...
R011 Posted January 15, 2014 Share Posted January 15, 2014 I stand corrected! Thanks! Link to comment Share on other sites More sharing options...
Richard Lindquist Posted January 15, 2014 Share Posted January 15, 2014 Colin was quite correct. The 75mm M2 Tank Gun was developed according to OCM 16640 on 24 April 1941, using the T5 75mm AA Gun as its starting point. The T5 was (as theT5 indicates) the fifth attempt by Ordnance to develop a 75mm AA Gun, all of which were unsuccessful (the idea was for a medium range gun to fit the zone between the proposed 37mm and proposed 90mm (Ordnance was full of proposals in the 1920s and 1930s). The only commonality it had with the M1897/M1916/M1917 75mm Field Guns was the cartridge and projectile. Otherwise, new barrel, new breech, electrical solenoid firing, and a new recoil mechanism. Rich: I believe that Ordnance was working on a spectrum of 37mm to 75mm/3in to 105mm. This then changed to 40mm-90mm-120mm (90mm selected because it was the largest single loading round a man could vertically hand ram). Link to comment Share on other sites More sharing options...
sunday Posted January 15, 2014 Share Posted January 15, 2014 (edited) That low-velocity AA gun bit intrigues me. The Navy had a 5''/25 AA gun, and a 5''/51 gun used in BB as secondary arty, and went to unify them in the dual-purpose 5''/38 of WWII fame. They used the short 5'' as AA gun because of being more wieldy and offering higher train rates. So the prospect of a low-velocity AA gun is not so strange as Hunnicutt states, I think. Edited January 15, 2014 by sunday Link to comment Share on other sites More sharing options...
Rich Posted January 15, 2014 Share Posted January 15, 2014 Colin was quite correct. The 75mm M2 Tank Gun was developed according to OCM 16640 on 24 April 1941, using the T5 75mm AA Gun as its starting point. The T5 was (as theT5 indicates) the fifth attempt by Ordnance to develop a 75mm AA Gun, all of which were unsuccessful (the idea was for a medium range gun to fit the zone between the proposed 37mm and proposed 90mm (Ordnance was full of proposals in the 1920s and 1930s). The only commonality it had with the M1897/M1916/M1917 75mm Field Guns was the cartridge and projectile. Otherwise, new barrel, new breech, electrical solenoid firing, and a new recoil mechanism.Rich: I believe that Ordnance was working on a spectrum of 37mm to 75mm/3in to 105mm. This then changed to 40mm-90mm-120mm (90mm selected because it was the largest single loading round a man could vertically hand ram). T5, T6, whatever...I probably should have consulted Hunnicutt in the first place. Ordnance was working on the 37mm M1 AA Gun for a while, it finally deployed in mid-1941. Ditto the 75mm. It in fact was the first AA deployed by the U.S. Army and those were basically M1897 on a truck mount, then also M1916 were used, but neither worked very well. That is why they went to the 3" Coast Artillery guns, deploying first the M1917 and then the M1918 3" AA. There was also a 105mm AA developed in the 1920s, but it was not well regarded and was only deployed AFAIK to the Canal Zone. The need for a 90mm AA was identified during the early 1930s and work continued for some time, while the 120mm requirement was made in 1939 IIRC (have to check the Ordnance Catalog). 40mm was a wartime decision based upon the simplicity of construction of the Bofors; it was easier to build than the Colt-Browning 37mm and was considered more reliable to boot. However, that decision wasn't made until 1942-1943 and the 37mm stuck around on the M15 SP mount until the end of the war. Link to comment Share on other sites More sharing options...
Rich Posted January 15, 2014 Share Posted January 15, 2014 That low-velocity AA gun bit intrigues me. The Navy had a 5''/25 AA gun, and a 5''/51 gun used in BB as secondary arty, and went to unify them in the dual-purpose 5''/38 of WWII fame. They used the short 5'' as AA gun because of being more wieldy and offering higher train rates. So the prospect of a low-velocity AA gun is not so strange as Hunnicutt states, I think. What was strange was that they had been experimenting with the 75mm as an AA gun since 1917 and none of them had been very successful. The notion was that there was an altitude zone between about 5000 feet and 15000 feet where the existing light and heavy AA didn't work well, so an intermediate caliber was required. The Germans thought the same and so developed their unsuccessful 50mm medium Flak piece. In practice though, especially with the modern radar director systems, it was found that the 90mm was equally effective pretty much everywhere above about 3000 feet, which finally killed the reason for the "medium altitude" gun. Link to comment Share on other sites More sharing options...
DougRichards Posted January 15, 2014 Share Posted January 15, 2014 That low-velocity AA gun bit intrigues me. The Navy had a 5''/25 AA gun, and a 5''/51 gun used in BB as secondary arty, and went to unify them in the dual-purpose 5''/38 of WWII fame. They used the short 5'' as AA gun because of being more wieldy and offering higher train rates. So the prospect of a low-velocity AA gun is not so strange as Hunnicutt states, I think. What was strange was that they had been experimenting with the 75mm as an AA gun since 1917 and none of them had been very successful. The notion was that there was an altitude zone between about 5000 feet and 15000 feet where the existing light and heavy AA didn't work well, so an intermediate caliber was required. The Germans thought the same and so developed their unsuccessful 50mm medium Flak piece. In practice though, especially with the modern radar director systems, it was found that the 90mm was equally effective pretty much everywhere above about 3000 feet, which finally killed the reason for the "medium altitude" gun. The British did likewise with a series of 57mm / 6pdr guns, also unsuccessfully. Link to comment Share on other sites More sharing options...
bojan Posted January 15, 2014 Share Posted January 15, 2014 Soviets and Swedes hit a jackpot post-war with 57mm. Link to comment Share on other sites More sharing options...
nigelfe Posted January 16, 2014 Share Posted January 16, 2014 (edited) However, in the 1950s Vickers did develop a MAA gun for army use above 40mm L70 and up to 25,000 feet. It fired 20 second bursts at a rate of 50 rpm, with VT fuzes as an option. It was also 4 inch calibre. They proposed a twin barrel version but this was not supported. Edited January 16, 2014 by nigelfe Link to comment Share on other sites More sharing options...
Colin Williams Posted January 16, 2014 Share Posted January 16, 2014 Reading through the M2 and M3 parts of Hunnicutt's Sherman book again to check on the origin of the 75mm gun reminded me to be a little easier on the poor hapless interwar British Army. The interwar US Army may have been small and underfunded, but at least it devoted sufficient resources to keep the tank designers experimenting and moving forward. In 1930 the British were still ahead of everyone else in tank design with the A6/Medium III effort, and then they were practically immobilized due to budget cuts and strategic/doctrinal paralysis. They finally started working on the A9 in 1934, and the first production model only came off the assembly line in early 1939. During that same period of time the Germans had designed, prototyped, and started large scale production on both the PzIII and PzIV. Link to comment Share on other sites More sharing options...
Tony Evans Posted January 16, 2014 Share Posted January 16, 2014 (edited) @ Tony E I think the problem is that your memory is playing tricks with arty fire control terminology or are trying to change their meanings. I think you've forgotten the term 'Direction', being the bearing between Observer and target and the line to and along which 'Target Grid Corrections' are ordered by the Observer. As I described in my previous post Polar Coords are a different matter all together, and since you don't seem to have had the benefit of a LRF you may not have fully understood what PC was. All this artillery terminology was standardised starting in the mid-1960s with a QSTAG, which later became a STANAG. This is what all the English speaking schools of artillery teach to when it come to artillery fire orders, even the infantry manage to understand and apply it to their mortar fire control. I have controlled arty fire from several nations including the US Army in both training and operations, I know the USMC uses the same procedures. You need to do some studying up. The following examples are from a recent manual, but they track very closely with what I was taught almost thirty years ago. Note that in all cases that "Direction" is always the observer-target direction, and that it is the direction along which subsequent shifts are plotted. Also, note that the Polar mission example above is a compass polar with eyeball range estimation. There's a separate Laser Polar mission that uses slant range and angle from horizontal, rather than estimated distance and up/down shift. Edited January 16, 2014 by Tony Evans Link to comment Share on other sites More sharing options...
Rich Posted January 16, 2014 Share Posted January 16, 2014 Reading through the M2 and M3 parts of Hunnicutt's Sherman book again to check on the origin of the 75mm gun reminded me to be a little easier on the poor hapless interwar British Army. The interwar US Army may have been small and underfunded, but at least it devoted sufficient resources to keep the tank designers experimenting and moving forward. In 1930 the British were still ahead of everyone else in tank design with the A6/Medium III effort, and then they were practically immobilized due to budget cuts and strategic/doctrinal paralysis. They finally started working on the A9 in 1934, and the first production model only came off the assembly line in early 1939. During that same period of time the Germans had designed, prototyped, and started large scale production on both the PzIII and PzIV. That may be true, but the financial constraints on U.S. Army Ordnance were remarkable and the resources were tiny. Total funding to Ordnance for the 18 year period from FY 1920 to FY 1938 averaged less than $1.4 million per year. In 2012 dollars that is equivalent to about $31.5 million, about enough to pay for redecorating the Chief of Ordnance's office today. Link to comment Share on other sites More sharing options...
richard g Posted January 17, 2014 Author Share Posted January 17, 2014 Off topic, a bit of an extension of the original topic but meh it's my topic. Of all the Western Allies it's the US in my opinion which got it wrong the most. Everyone else was actually in a war which narrowed the focus considerably while the US was in a unique position, able to sit back and learn the lessons at not cost to itself. If it wanted to. Instead it threw poorly trained and led infantry into battle with little sharp end support and no apparent concern for casualties. 90% of the total in uniform and 'in support', 10% getting shot at and taking the bulk of casualties. This from a country that wanted to invade Europe in 1943 and blamed the British for stalling until 1944. Instead of quality the US relied on quantity, much like one would think a totalitarian state would do. While overwhelming US industrial power should have been used to take the place of manpower up front where the human casualties were. Link to comment Share on other sites More sharing options...
Richard Lindquist Posted January 17, 2014 Share Posted January 17, 2014 Instead it threw poorly trained and led infantry into battle with little sharp end support and no apparent concern for casualties. 90% of the total in uniform and 'in support', 10% getting shot at and taking the bulk of casualties. This from a country that wanted to invade Europe in 1943 and blamed the British for stalling until 1944. Why don't you try to develop a force structure with your "sharp end" deployed half a world away and see how many men it takes to maintain and support someone at the "sharp end". After the Yom Kippur War, a lot of ninnies were running around marveling at how the Israeli tanks were supported directly from their depots without intervening maintenance units. I said that would work for us if we could fight all of our wars within a 150 mile radius of Red River Army Depot. Link to comment Share on other sites More sharing options...
Ken Estes Posted January 17, 2014 Share Posted January 17, 2014 How tiresome of you. US forces are not in offensive action against Axis powers on the ground until Aug/Nov 1942, taking the cue from your 'thrown into battle' notion. The actions in the Philippines, Wake and Guam were non-voluntary, sort of like the UK/CW at HK and Singapore, where others who had been at war since 1939 had very little to show for it, nor were they supported at all by the govts that dispatched them. The 1st Marine Div landed at Guadalcanal on 7 Aug 1942. It fought holding actions against growing JA reinforcements, by September numerically superior, until the latter were defeated and retreated in disorder by the end of the year. The follow-on offensive by other US/AU forces retook the Solomons chain during 1943. Nov42 saw on the other side of the globe the North Africa landings at Casablanca, Oran and Algiers. As in the case of Guadalcanal, these were the first time in WWII combat for the US ground organizations involved and they revealed nothing by way of organization and preparation that was defective, just the usual range of foul-ups that accompany military operations at all times. These modest operations were completely successful in aim and strategy and the French forces rallied in short order to the Allies, giving the Allied side about a qtr/million extra troops for the grinds that lay ahead. So, no sacrifice of untrained, badly equipped unsupported troops into the offensive, from the outset. Show us what you have. Link to comment Share on other sites More sharing options...
JW Collins Posted January 17, 2014 Share Posted January 17, 2014 (edited) Is that ratio for support vs front line troops correct however? Seems a bit high going by the rule of thumb I've heard that you have 3 in support for every 1 at the front. By the time the Normandy landings occured the Army had learned many hard fought lessons in North Africa and Italy. But as always there was some poor judgement on the strategic level and certain factors weren't considered in planning. The British were no better prepared for dealing with the bocage terrain and everybody had to adapt to that situation. While not matching a fully equipped Grenadier unit in terms of firepower (with squad level MG42s or MG34s) an American infantry unit was still pretty well equipped. The semi-auto M1 Garand is standard, every rifle platoon had a MG section of two M1919s, Thompsons, BARs and rifle grenades are relatively common. Airborne troops got a lot of specialized equipment to meet their needs. The US Army also has as many AFVs as can be shipped into theater, numbers and replacements that the Germans don't have. Although the designs were outdated/outclassed in certain respects a mediocre tank is better than none at all. Artillery support was certainly not lacking, and the types of ammo and fuel shortages the Germans frequently sufferering from weren't as much of an issue. Then there are enough fighter-bomber sorties being flown by the USAAF and RAF to cripple German movement and severely limit the options of any Panzer division. Despite the numbers of IL-2s the Soviets fielded, German armor was able to operate more freely on the Eastern Front to perform localized counterattacks and other actions. Edited January 17, 2014 by JW Collins Link to comment Share on other sites More sharing options...
DougRichards Posted January 17, 2014 Share Posted January 17, 2014 Off topic, a bit of an extension of the original topic but meh it's my topic. Of all the Western Allies it's the US in my opinion which got it wrong the most. Everyone else was actually in a war which narrowed the focus considerably while the US was in a unique position, able to sit back and learn the lessons at not cost to itself. If it wanted to. Instead it threw poorly trained and led infantry into battle with little sharp end support and no apparent concern for casualties. 90% of the total in uniform and 'in support', 10% getting shot at and taking the bulk of casualties. This from a country that wanted to invade Europe in 1943 and blamed the British for stalling until 1944. Instead of quality the US relied on quantity, much like one would think a totalitarian state would do. While overwhelming US industrial power should have been used to take the place of manpower up front where the human casualties were. You may have started this topic, but it is not your topic, it is owned by all those who have read and contributed. Link to comment Share on other sites More sharing options...
Ken Estes Posted January 17, 2014 Share Posted January 17, 2014 What's amazing is that once the US plan for the 89 division army and the Army Air Forces was agreed to, there were few if any disruptions because of bad strategy, operational miscues or other setbacks. Strategically, the NA campaign served to get forces into action against the Germans, in favorable conditions. The Sicily and Salerno landings were essential to knock Italy out of the war and gain the airbases of the Foggia Plain. The drive beyond that, even to Rome was likely a questionable strategic choice [we gave in to the Brits], but Normandy and So. France worked well, and the 60 days holdup at Normandy presaged a drive to the German border that more than caught up with the timetable. The general advance into and across Germany was also proven correct, as was the decision to not drive to Berlin and otherwise upset the occupation plan. The lost time Sept-December was almost unavoidable given the logistic tail, and Monty's error in not clearing the Scheldt after Antwerp made it certain. The Bulge was a lucky hit by the Germans but in the end left both their army and LW hobbled for 1945. The Pacific War went very well, gaining momentum in 1944. One can argue about this or that island assault being necessary or not, but the dual drive west and the advanced timelines really upset the Japanese defense shift and we were there too soon almost everywhere by their calculations. So, unlike others we could speak about, there were no clear strategic blunders or operational setbacks in the US record of WWII, once the war began for it. Howzzat? Link to comment Share on other sites More sharing options...
Shortround6 Posted January 17, 2014 Share Posted January 17, 2014 Poorly trained? Perhaps but then it was the army with the fastest and largest expansion in numbers during the war. this forum post sums it up pretty well http://www.battlefront.com/community/showthread.php?p=1128518 It also takes 2-3 years to get the US industrial power geared up and producing. Unless FACTS can show otherwise the US troops probably had the most "sharp end support" of any army on average (not isolated incidences) during the war. Better food, better medical, better transport, more artillery support, more air support. Link to comment Share on other sites More sharing options...
mnm Posted January 17, 2014 Share Posted January 17, 2014 Link to comment Share on other sites More sharing options...
Colin Posted January 17, 2014 Share Posted January 17, 2014 How tiresome of you. US forces are not in offensive action against Axis powers on the ground until Aug/Nov 1942, taking the cue from your 'thrown into battle' notion. The actions in the Philippines, Wake and Guam were non-voluntary, sort of like the UK/CW at HK and Singapore, where others who had been at war since 1939 had very little to show for it, nor were they supported at all by the govts that dispatched them. The 1st Marine Div landed at Guadalcanal on 7 Aug 1942. It fought holding actions against growing JA reinforcements, by September numerically superior, until the latter were defeated and retreated in disorder by the end of the year. The follow-on offensive by other US/AU forces retook the Solomons chain during 1943. Nov42 saw on the other side of the globe the North Africa landings at Casablanca, Oran and Algiers. As in the case of Guadalcanal, these were the first time in WWII combat for the US ground organizations involved and they revealed nothing by way of organization and preparation that was defective, just the usual range of foul-ups that accompany military operations at all times. These modest operations were completely successful in aim and strategy and the French forces rallied in short order to the Allies, giving the Allied side about a qtr/million extra troops for the grinds that lay ahead. So, no sacrifice of untrained, badly equipped unsupported troops into the offensive, from the outset. Show us what you have.The US forces in NA did suffer some setbacks, not surprising as it was their first real taste of mechanized warfare. To be fair, they did a remarkable job in getting their act together after taking one in the nuts, a trait as I recall the Germans remarked on (British better at defense, but took longer to recover once broken, than the US troops). did the US get to really try out their TD doctrine there or were the weaknesses lost in the noise of all the other stuff they were busy learning? Link to comment Share on other sites More sharing options...
Marek Tucan Posted January 17, 2014 Share Posted January 17, 2014 (edited) I would say lost in the noise, do not forget that TDs were presented mostly by the 75mm-armed Carriers... Err Halftracks, not by the turreted provisional vehicle (M10) or the TD corps wet dream (M18) and infantry AT gun was 37mm. Then again, not all German tanks were Tigers. I would say the main lessons were a quick shakedown of totally bad officers. And tuning of artillery-infantry-armor cooperation and communication. It also proved the effectivity of TOT technique that haunted Germans ever since (asnd was much more effective than distributing howitzers in penny packets) Another part of the Kasserine Pass problem were French troops. Not to imply they did not want to fight - but that they did not have anything to fight with. If you have to ask your allies to give you at least their helmets so that enemy thinks you may have AT guns... Was US Army in NA inexperienced? Sure. Made mistakes? Sure! Did they have same level of support as two years later? Sure as hell not. BUT: Without lessons from Africa, many issues would float up too late. And one major point... Even with all the deficiencies and provisional solutions (like Hlaftracks as weapon carriers pushed into roles beyond their capabilities) the US Army in Africa had much better direct support overall than Germans or Italians. While concentrated armored fist with artillery concentration looks impressive... it also meant that twenty kilometers away infantry had to be stripped of the armor and arty support for much longer time. Edited January 17, 2014 by Marek Tucan Link to comment Share on other sites More sharing options...
Ken Estes Posted January 17, 2014 Share Posted January 17, 2014 Kasserine Pass is part of the Tunisia Campaign, which had distinct problems and learning curves apart from the landings in NA. The way was bloody, but there were no errors of strategy, nor were US forces unsupported, or untrained. They were still inexperienced. Tactical procedures and coordination were problematical. This is what I referred to as "the range of foul-ups that accompany military operations at all times." It was a major lesson that US forces had much to learn before the Germans would be beaten. Despite the tactical defeat, the operational momentum was not altered and the 2 Axis armies surrendered several months later. Link to comment Share on other sites More sharing options...
Rich Posted January 17, 2014 Share Posted January 17, 2014 Is that ratio for support vs front line troops correct however? Dear me, but that does seem to be yet another argumentum ad ignorantiam...go figure. In terms of the ground component of the U.S. Army (excluding the Army Air Forces and odds and ends like WAC, Warrant and Fight Officers, and Branch Not Assigned) the ratios for AGF versus ASF were: 31 DEC 41 - 867,462/435,76931 DEC 42 - 1,939,917/1,857,04231 DEC 43 - 2,451,007/2,735,03631 MAR 45 - 2,753,517/3,095,020 Note also that the ASF also provided support for the AAF, which troops were not counted as AAF. Subtracting that substantial component would reduce the ratio even more. As Richard Lindquist has already noted - and as should have been immediately obvious - there was a very good reason for the expansion of the ASF; the last time I checked, Occupied France was not across the English Channel from the U.S., it was across the Atlantic Ocean. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now