Ok Battlefront it is about time for a CM: Normandy Forum

[Nicdain]

Passing from the arid lands of Syria to the temperate ones of Normandy, there is a dramatic change in vegetation, both variety and density. I wonder if this variety will be modeled in CM:N. Particularly I would like to know if the undergrowth in woods will be represented by object such as bush, scrub, etc, or they will be simply abstracted as they were in CMX1.

For what concerns trees, I suppose they will be modeled according to species present in Northern France.

Just one more question: will wheat fields be represented in 3D when crops are developed (e.g. soldiers will visually hide inside them)?

Thanks

[Michael Emrys]

What's the prognosis for graze action fuzing, please? I know the U.S. 75 mm on the Grant and Lee acquired the capability from French 75 mm ammo in Syria, so it's hardly new by Normandy. Wilson, in Flame Thrower, talks about taking out a position that way, and my 1944 FM 17-12 Tank Gunnery talks about the technique and even has an illustration of how it works. Am also interested in being able to fire HE Delay into buildings to blow them up from within instead of blowing them apart piece by piece from without.

I regret not having definite information on these subjects, but my gut level feeling based on many accounts that do not mention all these items is that while they may have existed in some form or other, aside from timed fuses in AAA units they seldom or never made it into the hands of the troops doing the fighting.

Michael

[Migo441]

Fuze grogs... Awesome!

So I've got the basics after a couple minutes of Googling.

Fuze PD (Point Detonating) - This is the VAST majority of WWII HE shells, right? It hits something and blows up with a contact primer.

Fuze MT (Mechanical Time) - This is a simple timing mechanism which will explode the shell at a predetermined time after firing. I see this would allow airbursts but how sophisticated were the timers? What intervals could you set? In practice, did many attempts with airburst missions fail* because the calculations were off or the timing granularity was insufficient? Potentially, I suppose an FO could help fine tune the settings during spotting/correction.

* I say "fail" but, of course, you still had things blowing up somewhere nearby. I suppose the poor bastards on the ground would rather have a shell blow up 300m in the air rather than hitting the ground and blowing up a couple seconds later. For just that reason, I image the arty crews would err on the side of long MT intervals rather than short.

And Kettler mentions "HE delay" for tank munitions. Is that the same as MT?

Fuze VT (Proximity Fuse, Wikipedia suggests that the initial designation did not refer to "variable time" although it kinda fits) - This seems like the first sort of smart bomb where it blows up upon reaching some form of sensing threshold that, hopefully, identifies a target. Various types of sensing were experimented with: acoustic, magnetic (mines), radio waves, light sensors, etc...

This is a big deal. This makes heavier caliber AA fire much more effective and allows reliable and consistent airbursts for arty fire.

[Battlefront.com]

We will not be simulating "shell skipping" or "ricochet" shots. We've discussed this for previous CM games and our conclusions is it wasn't used very often because the conditions which would allow this to be effective were generally absent from terrain such as Normandy. There's a bigger argument for inclusion in a North Africa game where the terrain is generally flat and hard, two of the primary variables to make this technique effective.

We have redone all the vegetation for CM: Normandy since having palm trees and dry brush wouldn't look very good

Steve

[YankeeDog]

Migo -

"HE Delay" usually refers to a fuse designed to detonate some interval of time after impact. One target type this kind of fuse is often used against is troops inside buildings -- if set properly, the shell will penetrate the exterior walls, and then detonate once inside the structure.

HE Delay is often used in direct fire situations -- a Tank firing its main gun at troops inside a building, for example. But it is sometimes also used for indirect fire.

Historically, one application of HE Delay was against troops in trenches. Airburst is probably the most effective way to hit troops in trenches with artillery, but the first use of VT against ground troops was pretty late in WWII -- by the US during the Battle of the Bulge. And as far as I know, neither the Germans nor the Russians perfected VT fuses before the end of the war. So for most of the war and for most combatants, this technology was not available. And as you note, without VT fusing, effective airburst over a target can be tricky to achieve. So artillery sometimes used HE Delay against trenches, with the idea that a hit near the trench would detonate a couple of feet underground and possibly collapse the trench. I don't think this is done so much today because VT-type technology is much cheaper and more common nowadays.

[Battlefront.com]

Apparently the best way to overcome the MT problems (before VT) was to mix MT and PD into the same barrage. Oh, say 33% MT and 66% PD. This would decrease the risk of being wrong about the MT calculations and thus wasting a lot of ammo without much effect. When VT came around (US only, though I think the Brits did use some towards the VERY end of the war) the reliability of getting it right went way up so that they could do 100% VT if that was deemed the right fit.

Steve

[Michael Emrys]

HE Delay is often used in direct fire situations -- a Tank firing its main gun at troops inside a building, for example. But it is sometimes also used for indirect fire.

It's primary use was for naval armor piercing shells. The delay allowed the shell to reach the guts of the ship before going off. AP bombs also used the same kind of fusing.

But yes, it could be used as you describe and also for the kind of skip shots that JK and SG are talking about.

Michael

[John Kettler]

I've got FM 17-12 here and will have a very groggy post later, but I wanted to quickly draw a major distinction between Fuze MT (called Time Fuzing in WW II Army FM's) and Fuze PD, which can also be set for .05 second Delay. Fuze MT, per the manual, is not normally used by tanks because its error factor makes ricochet fire against small point targets all but impossible. Fuze MT is designed to operate for the full flight of the shell or whatever lesser time of flight is set before firing. Detonation doesn't require impact, either, which is why it was the standard fuze for medium and large antiaircraft projectiles throughout most of the war. 75 mm armed tanks use Shell, M48, PD, which in its baseline mode is Superquick but can be set for Delay, thus permitting cover penetration or ricochet fire. Either way, it has to hit something in order to fuze.

Regards,

John Kettler

[Kanonier Reichmann]

When VT came around (US only, though I think the Brits did use some towards the VERY end of the war) the reliability of getting it right went way up so that they could do 100% VT if that was deemed the right fit.

Steve

Well, you included 25 pounder VT artillery FO's for the Britiish in CMBO after about December 1944 so I assumed you had some research back then that confirmed all this!

Regards

KR

[Kanonier Reichmann]

Stupid double post. My bad.

[gibsonm]

Stupid double post. My bad.

Well if "after December" means Jan - May 45 then that is pretty much "right at the end" especially if you are talking about starting in Sep 39 as opposed to Dec 41.

BTW: How's the weather over there?

Oh and 3 for 77 (if you're interested)

[Kanonier Reichmann]

I can do better than that. ALL OUT! Australia wins by 39 runs, amazingly enough.

As for the weather, about 33 degrees and sunny

Re VT artillery for the Poms. From my understanding the Yanks only used VT artillery from around the time of the Battle of the Bulge onwards (late December 1944) so the implication from my post was that their allies across the Atlantic also had access to it at or very soon after the U.S.

Mind you, I'm not trying to say that CMBO should be regarded as some sort of history source but I assumed that Steve et al wouldn't have included VT for 25 pounders unless there was some basis of fact to back it up.

Hope you're enjoying Syndney.

Regards

KR

[John Kettler]

KR,

Since you asked!

Here's a nice snippet on the introduction of VT into land warfare.

http://www.youtube.com/watch?v=FIMers1_cTU

The origins of the acronym "VT."

http://www.navweaps.com/index_tech/tech-102.htm

Here is a great excerpt on VT development, apparently quoting from formerly classified wartime memos.

http://www.history.navy.mil/faqs/faq96-1.htm

Of British field artillery VT fuzes, the relevant portion under Present Status reads: "The British Army has been supplied with AA fuzes for its 3".7 AA gun and with artillery fuzes for its principal howitzers." Obviously, this includes the 25 pdr. Confirmation of this is found on this authoritative British artillery in WW II site, just below Figure 14, where the VT fuze designators are given and the associated weapons listed. http://nigelef.tripod.com/ammo.htm Both the 3.7" howitzer and the 25-pdr use the T97, while the 7.2" and 5.5" use the T100. Date for release to ground combat seems to be same as as for the Americans, December 1944.

I close with a Canadian 25-pdr gun commander's account of preparing and firing T97 fuzed shells during the Korean War.

http://www.kvacanada.com/stories_ruthegun.htm

Regards,

John Kettler

[John Kettler]

Steve,

The above British Artillery in World War II site has a detailed explanation of the conduct of fire using Fuze MT. If that doesn't work for you, I'll dig up the title of a WW I period book I have which explains and diagrams, in astounding detail, how to conduct a shrapnel shoot using M1897 French 75s.

Regards,

John Kettler

[YankeeDog]

If anyone is interested in more details about VT fuses in WWII, the following webpage, a transcription of a document originally published in 1950, has an excellent survey of the development and manufacture of VT fuses by the U.S.:

http://www.history.navy.mil/faqs/faq96-1.htm

Some interesting tidbits that caught my eye: The very first VT fuses went into production in September of 1942 for the US Navy (much earlier than I had thought), and modifications of the first U.S. VT fuses were developed for British AA artillery very shortly thereafter. The confirmed aircraft kill with a VT fuse shell was by a US Cruiser in January of 1943. Apparently, the first VT fuses had some reliability problems and were only available for a few specific calibers (mostly heavy naval AA), but development continued rapidly and by 1944 there were a range of VT fuses available for both British and American guns. Throughout the war, the priority seems to have development for AA use, especially heavy AA calibers, but modification for Army artillery to be used against ground targets apparently began in mid-1943.

This article only mentions it briefly, but the reason that VT was not used on ground targets prior to December of 1944 was that there was great concern that the enemy might be able to recover and reverse engineer a fuse from a shell that failed to detonate if it was used over land. Unfortunately, in my quick read I could not find an exact date is given as to when or if the British land artillery used VT during the war. But British AA artillery definitely had VT in quantity, for a significant portion of the war.

Cheers,

YD

[Battlefront.com]

John K,

The above British Artillery in World War II site has a detailed explanation of the conduct of fire using Fuze MT. If that doesn't work for you, I'll dig up the title of a WW I period book I have which explains and diagrams, in astounding detail, how to conduct a shrapnel shoot using M1897 French 75s.

No need as we already know what we need to know. As KR pointed out, we've danced this dance before From a game perspective it is a simple matter of tweaking a couple of existing variables since CMx2 already has support for this stuff.

Steve

[John Kettler]

YankeeDog,

There's some great stuff on VT development in the 1947 book New Weapons for Air Warfare: Fire-Control Equipment, Proximity Fuzes and Guided Missiles, published as part of OSRD's Science in World War II series. I lucked out and got mine as a Hughes Aircraft Company library discard. Here are some places that have it.

http://www.alibris.com/booksearch?binding=&mtype=&keyword=new+weapons+for+air+warfare&hs.x=0&hs.y=0&hs=Submit

Amazingly, Amazon's got some inexpensive copies. The book review is well worth reading, seeing as how the reviewer is the son of someone who helped develop the VT fuze.

http://www.amazon.com/gp/offer-listing/B000IUC0IC/ref=dp_olp_used?ie=UTF8&condition=used

Regards,

John Kettler

[Jaws]

Well Flames of War

or

Kursk 1943 to kill the time ;p