Did the US test the 88/L71?

[scotsman]

A very, very rough and ready formula for figuring point blank range is MV + 10% = point blank range. ALL projectiles will fall 16 ft in the first second of flight. Gun is aimed so that projectile never rises more than 4-5 feet above line of sight at close range and max point blank range is when projectile falls 4-5 feet below line of sight, depending on size of tank target. ALL projectiles will fall 48 feet in the second second of flight. It is in this just over point blank range area that high velocity guns really show to advantage. An 800m/s gun not only has 330 metres more "BP" range than a 500ms feild gun but at 900-1000meters is only slightly into it's second second of flight as apposed to the end of the 2 seconds for the feild gun. This may mean a drop of 25 ft or so for the 800m/s gun vrs 64 feet of drop for the 500m/s gun.

 

Any gunner with any smarts should have figured this into their point blank setting. Although they might shave a bit on the close range hight. Don't want to shoot over if they get close;) although if the tanks get to 3-400meters the 3.7 guns are in a bit of trouble;)

 

Correct - back to any gunner worth his salt and knowing what he is doing will have his battle zero settings for the most likely range(s) of engagement. Its really nothing to do with physics Ken...its how the gun cmdr has prepared his gun and crew to fight and action. I am assuming he is smart enough to use at least some of his time in knowing the lay of the land around his gun(s). If has been given a secondary AT mission that almost certainly includes getting range to known landmarks getting these down on his rangecards, along with assigned kill zones to the guns.

 

Certainly when tanks get close to any gun position thats an issue...but I am always amazed in rereading the WWII after action reports by gunners in the western ETO just how close the majority of engagements actually were...

[scotsman]

All very nicely put, but, you know, firing ranges in Germany and the US are relatively flat and easy. Fighting from terrain hastily occupied or from the march may not conform to one's favorite setup. We will leave your definition as DP=fire can be put on two or more kinds of target. This makes almost any weapon dual purpose, mind you, rifles to rockets.

 

We do range cards in tanks as well, but would never fire on a tank target with them, unless in fog or somehow unable to have visual, and then only if it would not reveal own position while firing 'blind.'

 

The reason that the US and UK did not make other arrangements/mods for their AAA for AT use is that they were not so employed as a matter of course. I already pointed out the exigencies for them that provided the motivations. Allied forces rarely operated at such a short string after 1941.

 

I would never count on engaging opposing tanks at 600m as a routine. over 1200m a first round hit cannot be guaranteed for most of these guns. I have seen plenty of multiple kilometer LOS landscapes in W. Europe.

 

You are most certainly counting upon a mostly flat world.

 

Repeating the matra over and over again doesn't make it true Ken....granted my definition of DP is liberal in that any weapon which engages secondary target sets is DP as far as I am concerned. I am OK with that....weapons that have second instrument sets/software/etc specific to an alternative target set are simply better suited/more effective in the secondary mission, and thus more 'DP' than they might be in some arbirtrary baseline condition. As such I divorce effectiveness somewhat from the actual ability to engage in the mission....

 

No-one is assuming a flat world here...the US and British Armies spent tons of effort and money on reducing the data of WWII in the post WWII environment to arrive at things like average range distribution. Certainly you can find given areas and shots over a Km throughout the engagement area...but an average is exactly that....an average of all engagements with the TO....some longer some shorter. All the data which I am familiar with certainly points to average ranges we have discussed.

 

As you well know the number of positions from which such shots are available are also very limited...typically not every company/platoon in the same battalion will be enjoy such terrain even if it is present in the battlespace. That was certainly my own experience...a constant battle between tanks and ATGM for 'the best' available terrain...and frequently 'the best' was far less than ideal...

[scotsman]

This one strikes me as truly wierd. Does anybody thing Germany of today bears much resemblance or has the same topography vs. Germany of 1944-45? Urban sprawl, anybody? In any case, Germany was the location for only a short period of WWII for ground fighting, and there was little call for Allied AT guns, let alone AAA pressed into such service.

 

Rommel's harried AA cdr in No Africa apparently differed in his opinion. Of course, by 1943, there were lots of dedicated 88mm AT guns entering service, perhaps reducing the imperative overall. We really do not know how many guns were modified from what you consider DP mountings.

 

If we want 'pure' WWII data we may as well stick with the cardioid shot distribution for range/angle, which certainly confirms the sort of ranges we have discussed.

 

Certainly the areas have changed with time...there is a historic comparison or two made within the study, with note made of the fact that long range engagement space actually -decreased- with time as urbanization and population continued to increase....so as time moves forward it seems the cross compartmentation issue in the battlespace gets worse, and the number of long range shots decrease. (which makes sense when you think about)

 

Again, its obvious that the winning side was less pressed and thus had less need to use their AAA in such a role as the war moved to its conclusion. Nevertheless it still happened, at the battle of the bulge for the US, certainly in Holland for the Brits according to interviews, definately during the Normandy campaign prior to the breakout as noted by both the germans and allies.

 

Also - not really trying to comment on the entire 88mm thing one way or another....simply pointing out what my own digging on the 3.7" has revealed...

[scotsman]

I was wondering about point blank range when it comes to 3.7 at range between 500 to 800 meters.

 

Muzzle Velocity 2600. Exactly how much does it drop at that range. According to my ballistic tables(For rifle bullets) for best Ballistically Efficient projectile, at 500 meters my 30-06 drops 69 inches with a velocity of 2900. So if the 3.7 acts in the same way, then at 500 meters it should drop somewhere between 72 to 80 inches.

 

So if a gunner places his reticle on Center of mass and pulls the trigger, he will miss "short". Point and shoot without regards to elevation attention will mean firing too low. This is if his sight is perfectly bore sighted. Did 3.7 crews zero their detachable Direct Fire Sight before shooting? A 500 meter zeroe would be the best under the relative short ranges of Northwest Europe.

 

Can anyone elaborate about Sight zeroing for the 3.7? This would make a great deal of difference in snap shot accuracy. Also would determine the efficiency in transferring the gun between AA to AT role.

 

C.G.

 

It was noted in several HAA regimental histories that in the time before normandy, they were cycled though a DF shooting range. Frequent additional comments from the Royal Engineers that they hated DF 3.7" shoots as they invariably tore up the ranges. I would assume the weapons were correctly sited for such shoots prior to shipping to normandy.

 

I assume that if a gunner have recent DF experience with his weapon, and some minor elevation offset is required for a given range below a 1000 meters, that he will in fact be aware of where the reticle needs to be to obtain a hit on an exposed tgt. Obviously a defilade tgt is a different kettle of fish for such a shoot. Minor variation in exposure due to microterrain issues wouldnt be a driver I shouldnt think...

 

I think its useful to point out that in WWII, it can and frequently did still come down to a degree of gunner skill...instrumentation and sights are simply tools to the desired end. If they were the end in and of themselves then the bofors kerrison predictors would have been the be all and end all...they weren't...until power pointing, slaving to radar, and better computers came along...

 

I contacted larkhill in an effort to save some of the original 3.7" course material to answer some of these questions but unfortunately didn't have much luck on that score. I had much better luck in talking to WWII and immediate post WWII 3.7" gunners themselves....Research continues as time and opportunity presents itself.

[Argus]

1/ On separate training and elevation. I think we can all agree its not ideal, single laying is always the way to go. But as for tracking a rapidly moving target, I can't help noticing that not only the majority of manually worked naval guns (including those without directors) but also the majority of WWII light AA guns (Bofors etc) operated with separate layers and trainers.

 

At least in naval mounts providing a set of open sights in addition to the telescopes, as seems to be the case with the 3.7", was pretty common on on 3" and upwards QF guns. The open sight allows both men to get roughly on target then fine lay with with the telescopes, and IIRC even the 2pdr and 25pdr had rifle sights in addition to teles (not sure about 6pdr and 17pdr).

 

2/ From memory the 25pdr AT drill had the layer at his sight with elevation and traverse wheels (foot trigger), gun commander with a pair of binos and one of the loading numbers manning the trail handspike for rapid traverse.

 

shane

[Ken Estes]

....granted my definition of DP is liberal in that any weapon which engages secondary target sets is DP as far as I am concerned.

....

As such I divorce effectiveness somewhat from the actual ability to engage in the mission....

 

Well, there we have it. End of story.

[C.G.Erickson]

Correct - back to any gunner worth his salt and knowing what he is doing will have his battle zero settings for the most likely range(s) of engagement. Its really nothing to do with physics Ken...its how the gun cmdr has prepared his gun and crew to fight and action. I am assuming he is smart enough to use at least some of his time in knowing the lay of the land around his gun(s). If has been given a secondary AT mission that almost certainly includes getting range to known landmarks getting these down on his rangecards, along with assigned kill zones to the guns.

 

Certainly when tanks get close to any gun position thats an issue...but I am always amazed in rereading the WWII after action reports by gunners in the western ETO just how close the majority of engagements actually were...

 

Yes but what I am asking is how they set zero with fixed sights. Did 3.7 have that capability for Direct Fire sight?

[DKTanker]

Repeating the matra over and over again doesn't make it true Ken....granted my definition of DP is liberal in that any weapon which engages secondary target sets is DP as far as I am concerned.

Interesting. So if a rifleman engages a tank with his rifle, the rifle is now dual purpose anti-personnel / Anti-tank? Absurd, maybe, but it fits your definition.

[Ken Estes]

Interesting. So if a rifleman engages a tank with his rifle, the rifle is now dual purpose anti-personnel / Anti-tank? Absurd, maybe, but it fits your definition.

 

 

 

Then there's always the DOD dictionary of mil terms:

dual-purpose weapon

(DOD) A weapon designed for delivering effective fire against air or surface targets.

http://www.dtic.mil/doctrine/jel/doddict/data/d/01785.html

 

perhaps does not apply to British Army. zzzzzzz

[Lieste]

Then there's always the DOD dictionary of mil terms:

 

http://www.dtic.mil/doctrine/jel/doddict/data/d/01785.html

 

perhaps does not apply to British Army. zzzzzzz

 

 

Well here you may have a quibble over effective and efficient.

 

A PaK35 37mm AT gun may be ineffective against a KV1, but it is still an AT gun.

A PaK40 75mm AT gun is effective and efficient against a mid war tank.

A FlaK18/36 88mm AT gun is effective but may be less efficient against a tank target.

A 3.7" HAA will also be an effective AT gun. The question is how efficient the pointing devices etc are. They may not need to be *very* sophisticated, just sighting down the gun tube prior to loading, and adjusting BOT may be all that is required at close range (and if a tank is heavily armoured enough to require the use of heavy AT guns, you probably don't have the luxury of attempting to attack it at extended ranges anyway).

[Ken Estes]

What part of 'designed for' do you not understand?

 

"just sighting down the gun tube prior to loading, and adjusting BOT may be all that is required at close range" does not even merit comment.

 

No point in comparing obsolete weapons effectiveness vs. efficiency vs. targets that did not exist at introduction. The 37mm did just fine through 1939,

most of 1940.

[Kip Swanson]

Then there's always the DOD dictionary of mil terms:

http://www.dtic.mil/doctrine/jel/doddict/data/d/01785.html

 

 

Interesting. So if a rifleman engages a aircraft with his rifle, the rifle is now dual purpose anti-personnel / Anti-aircraft? Absurd, maybe, but it fits DoD definition.

[Mobius]

A PaK35 37mm AT gun may be ineffective against a KV1, but it is still an AT gun.

No. It started out as an AT gun but ended up as a door-knocker.

[Ken Estes]

Interesting. So if a rifleman engages a aircraft with his rifle, the rifle is now dual purpose anti-personnel / Anti-aircraft? Absurd, maybe, but it fits DoD definition.

In what way? designed for or effective fire?

[Kip Swanson]

In what way? designed for or effective fire?

 

3.7" AP is "designed" for and "effective" in armor penetration. It's high explosive ammunition is "designed" for and "effective" against aircraft targets.

[Typhoid Maxx]

Interesting. So if a rifleman engages a aircraft with his rifle, the rifle is now dual purpose anti-personnel / Anti-aircraft? Absurd, maybe, but it fits DoD definition.

 

It is in the Serb army, kid; hear the order “airplanes” and according to the Rules of Service you drop on your back and fire your AK directly in the air...

[jwduquette1]

As I recall the same sort of text can be found in US Army Infantry field manuals from WWII -- FM 7-10 or 7-20. Basically if enemy aricraft are attacking you everthing is supposed to directed at them -- rifle fire -- BAR fire -- LMG -- etc.

[Lieste]

If the enemy armour is immune to frontal fire from your AT weapons, then they are ineffective as antitank weapons, and the enemy armour can operate with relative impunity.

 

If you can destroy any target with frontal fire from a reasonably comfortable range (say outside effective small arms range for example) then you have an effective antitank weapon. It might require more than one shot to obtain each hit, which reduces it's efficiency somewhat, but even the threat of such a weapon may be highly effective at deterring enemy tanks. Ideally you have a weapon with absolute accuracy in range-finding, pointing and low shot-shot dispersion, but this is not absolutely required for a credible threat.

 

While this may not be good enough to qualify as an 'effective AT gun' from your 20:20 vision here and now, I'm sure the crews of Tigers or Panthers having to face it thought it effective enough.

 

 

 

Similar to the US view of the V-75 SAM - not a very effective weapon by modern reckoning - huge numbers fired for very few hits, but it was sufficient to bring a halt to overflights by the U2 by shooting one down, and demonstrating that it was not immune.

[Mobius]

As I recall the same sort of text can be found in US Army Infantry field manuals from WWII -- FM 7-10 or 7-20. Basically if enemy aricraft are attacking you everthing is supposed to directed at them -- rifle fire -- BAR fire -- LMG -- etc.

Yes, unless if the infantry thought they were hidden enough not to be seen by the aircraft. (Just read some of 7-10 yesterday.)

[hojutsuka]

As I recall the same sort of text can be found in US Army Infantry field manuals from WWII -- FM 7-10 or 7-20. Basically if enemy aricraft are attacking you everthing is supposed to directed at them -- rifle fire -- BAR fire -- LMG -- etc.

I remember reading a long time ago a pre-World War II Japanese book, a sort of "know your Imperial Japanese Navy" book for kids. There were descriptions of what naval actions were expected to be like, and when aircraft were sighted approaching the ship, men would be ordered out on the deck, where they would lie down on their backs and prepare to engage the enemy aircraft with their bolt action rifles...

 

Hojutsuka

[rmgill]

Interesting. So if a rifleman engages a tank with his rifle, the rifle is now dual purpose anti-personnel / Anti-tank? Absurd, maybe, but it fits your definition.

 

I think effectiveness is part of the equation.

 

A PIAT is just an anti-tank weapon but it made a useful mortar and could sometimes be used on infantry targets. It was an EXCELLENT tool for making mouseholes in buildings for urban combat and was VERY good at removing snipers from hard to hit spots (trees, towers, attics) which were otherwise hard to deal with using any other direct or indirect man portable infantry weapons.

 

A 3.7, when used against tanks was a MOST excellent weapon. It was also useful for indirect fire shoots against land targets and was used to great effect in that way in Normandy. Certainly seems to be Dual Purpose to me. One could argue that they probably killed more Germans on the Ground than they did in the air over occupied Europe.

[rmgill]

And if they were making an AP round for the 3.7, that would certainly seem to imply a designation for the weapon to be fired at ground targets no? 3.7 batteries em-placed at fixed positions were also setup for engaging surface targets on land or sea. That's certainly a dual purpose is it not?

 

Either way, if your fuze and ammo selections included parts and materials for engaging surface targets with your Anti-Aircraft weapon, I'd argue you have a Dual Purpose design.

[alejandro_]

Again no argument there. 88mm was used successfully (or desperately whatever word you like best) as an antitank gun in France, Russia and N.Africa -- probably other places as well.

I don't agree, as 88mm was extensively used in Spain against ground targets. First units arrived in Spain on September 1936 as part of Flakbteilun F/88, counting 4 batteries of 88/56. Two were used to protect airfields in Burgos and Vitoria, the others to support ground troops. IIRC there was a specific ammo for ground targets.

 

As war progressed, 88mm were used more and more often against ground targets. During the offensive in Cataluña, 93% of shots were fired against ground targets like fortifications.

 

3 7/16" @ 55: Two complete penetrations. both projectiles fractured. Projectile fragments passing through plate. One partial penetration projectile fractured. 3334 mv two penetrations. 3310 mv on 21/2 deep partial.

 

What is the velocity drop for 88L71? is it also superior to 90mm rounds?

[binder001]

If the enemy armour is immune to frontal fire from your AT weapons, then they are ineffective as antitank weapons, and the enemy armour can operate with relative impunity.

 

Funny enough, the Panther ws functionally immune to most AT weapons of the Western Allies from the front, but it rarely "operated with impunity". It seems the Americans, British and French had the annoying habit of attacking from the side or rear whenever possible. Rarely did the actual tactical situation allow the Panthers to engage at range and use their frontal armor to full advantage for long. Mechanized combat is fluid - nobody really gets to operate with impunity for very long.

 

Gary

[Ken Estes]

3.7" AP is "designed" for and "effective" in armor penetration. It's high explosive ammunition is "designed" for and "effective" against aircraft targets.

One could say the same for the 6" /47 ammo on US WWII cruisers, but they are not considered dual purpose AT and AA guns.

 

So, since you apparently like the US DOD definition, was the 3.7" gun designed as a dual-purpose AAA and AT gun? To what extent was it employed as an AT gun...oh.