VT ?? allied artillery

[Bismarck]

I was purchasing my units as the allies when I noticed theres a VT next to some of the units. What does that mean?

Thank

[Kingfish]

VT stands for variable timed. It is specialized artillery rounds that explode at a predetermined distance above the ground. They are extremely lethal to infantry in the open or light vehicles. Have fun with it.

[John D Salt]

Originally posted by Kingfish:

VT stands for variable timed. It is specialized artillery rounds that explode at a predetermined distance above the ground. They are extremely lethal to infantry in the open or light vehicles. Have fun with it.

Mr. Picky would like to point out that the letters "VT" were originally merely an arbitrary (US Navy, I believe) project code for a proximity fuze. The term "Variable Time" is a back-formation, and not a very good one at that, as it is no kind of time fuze.

All the best,

John.

[jgdpzr]

Originally posted by John D Salt:

</font><blockquote>quote:</font><hr />Originally posted by Kingfish:

VT stands for variable timed. It is specialized artillery rounds that explode at a predetermined distance above the ground. They are extremely lethal to infantry in the open or light vehicles. Have fun with it.

Mr. Picky would like to point out that the letters "VT" were originally merely an arbitrary (US Navy, I believe) project code for a proximity fuze. The term "Variable Time" is a back-formation, and not a very good one at that, as it is no kind of time fuze.

All the best,

John.</font>

[Compassion]

Originally posted by jgdpzr:

Thanks for that tidbit. I have always wondered why they called it that since, as you say, it is not a timed fuse.

Lore says that it was to fool the Germans into thikning that the mechanism was something other than what it was... NOt that it makes much sense, recovering one dud gives away the game.

[Brian]

One has to wonder though, what ever happened to the German 81mm and 120mm "Bouncing Betty" fuse?

[Scipio]

Iwonder why only the Allies has 'VT' shells.

Artillery shells that explode overground where used by all nations, already in World War One.

I hope the artillery system will be dramatically revised for CM:BB - IMO it is absolutly unrealistic.

[John D Salt]

Originally posted by Scipio:

Iwonder why only the Allies has 'VT' shells.

That's pretty easy -- because only the Allies (specifically, the Americans -- credit where credit's due) developed a successful proximity fuze during the war. Ian Hogg's "German Secret Weapons of WW2" (my copy not to hand so my recollection of the title might be a bit squinty) is replete with codenames for German proximity-fuze projects that never made it into service. Like VT, they were mostly intended for air defence applications.

Artillery shells that explode overground where used by all nations, already in World War One.

Yes, but artillery shells that *reliably* provide airbursts at a useful height are another thing entirely. Most of the airburst shell fired in WW1 would have been shrapnel, anyway. Depending on who you read, shrapnel was either an effective man-killer against troops in the open, but useless at cutting wire or hurting entrenched troops; or it was a complete waste of space. The Russians continued to use shrapnel in WW2, I believe (The "Handbook on Soviet Military Forces" certainly seems to think so), and the Japanese and Italians I think continued to use it, but I think it's fairly safe to say that there wasn't any shrapnel fired in Normandy (maybe some old captured weapons with exotic Fremdgerat numbers had some).

Most wargames rules dealing with mobile warfare -- as CM:BO does -- treat field artillery as if it did hardly anything else but simple concentrations with superquick fuzes. I think that's not a bad simplification.

I hope the artillery system will be dramatically revised for CM:BB - IMO it is absolutly unrealistic.

"Absolutely unrealistic" doesn't make much sense (as I've said before, "realistic" isn't really a sensible word to use when talking about simulation, anyway). CM:BO players use indirect fire in ways that are discernably related to the ways field commanders used it. Still, I agree that I'd like to see the treatement of artillery given a complete overhaul, so that players can juggle with different kinds of fuze, perform advance fire-planning, fire proper rolling barrages, call reinforcing fires, and so on. I want to be able to put elevated OPs in church towers (it's traditional, dammit) and have the other side's artillery try to shoot them down, shooting in three dimensions (the impact point on the ground will be a fair way beyond the one on the church tower). Most of all, if I'm playing the Brits and I get bogged down by those pesky [Tigers | Panthers | 88s | SMG squads | Puppchens | 20mm Flak guns | Fallschirmjager] I want, instead of having to run away, to be able to lose the game by paying a substantial forfeit in victory points in exchange for the privelege of seeing the other side vanish in clouds of smoke and falling trees shortly after my FO yells "Uncle target!" into his wireless handset.

It occurs to me that, by assuming a fictional elevated observer at a considerable distance behind the lines, the functionality of the LOS tool could be re-used to calculate (and visualise) crest restrictions for artillery. This would give still more point to mortars and to the reverse-slope defence. It would also, AFAIK, be the first time this question had been simulated in detail in any entertainment wargame.

Oh -- and does anyone know if CM:BO simulates the fact that VT is less effective over lying snow because the burst height is higher (due to better reflection of RF energy)?

All the best,

John.

[Brian]

Originally posted by John D Salt:

</font><blockquote>quote:</font><hr />Originally posted by Scipio:

Iwonder why only the Allies has 'VT' shells.

That's pretty easy -- because only the Allies (specifically, the Americans -- credit where credit's due) developed a successful proximity fuze during the war. Ian Hogg's "German Secret Weapons of WW2" (my copy not to hand so my recollection of the title might be a bit squinty) is replete with codenames for German proximity-fuze projects that never made it into service. Like VT, they were mostly intended for air defence applications.

</font>

[Mattias]

Originally posted by Brian:

One has to wonder though, what ever happened to the German 81mm and 120mm "Bouncing Betty" fuse?

Production of the 81mm round was discontinued in 1942 due to unsatisfactory reliability. Stocks were used as long as they lasted after that.

No info on 120mm round.

M.

[Guest PondScum]

Originally posted by Brian:

R.V.Jones in his book makes the point that the "Oslo Letter" arrived at the British Embassy in Norway with a proximity fuse attached. That letter was the means by which Jones was able to know what the Germans were cooking up for a good part of the war, it revealed in detail many of their most top-secret developments. No one knows who wrote or couried the letter to Norway though.

I thought that Jones had revealed who the author was - electronics specialist in Siemens, or some such?

[Brian]

Originally posted by PondScum:

</font><blockquote>quote:</font><hr />Originally posted by Brian:

R.V.Jones in his book makes the point that the "Oslo Letter" arrived at the British Embassy in Norway with a proximity fuse attached. That letter was the means by which Jones was able to know what the Germans were cooking up for a good part of the war, it revealed in detail many of their most top-secret developments. No one knows who wrote or couried the letter to Norway though.

I thought that Jones had revealed who the author was - electronics specialist in Siemens, or some such?</font>

[Brian]

Interesting comment from this web page:

"Timed Fuzes

Mechanical or Powder-Train Timer Fuze

The shell goes off some time after it is fired. Usually, this is intended to give an air burst, which is most effective at about 20 yards above the target. However, setting the fuze correctly was tricky business. The US mechanical fuze seemed very unreliable and was only used to give a high-altitude registration burst for spotting. Wesely [2] says German fuzes were much better, about as reliable as the US VT fuze.[my emphasis]

VT (Proximity) Fuze

The VT fuze emits a radio signal and goes off when it detects enough of this signal is being reflected back from a hard object. The height of burst will increase if over dense foliage, swamp, water, or wet terrain; and it will decrease with high-angle fire.

1940's era VT fuzes had a minimum arming time of five seconds, so the VT fuze cannot be used for close-in defense. With the VT fuze, The minimum

ranges in yards for several guns is shown below:

Weapon Minimum Range (yards)

75mm Howitzer 2,200

105mm Howitzer 2,700

155mm Howitzer 4,000

8" Howitzer 6,000

240mm Howitzer 9,000"

[ April 15, 2002, 11:59 AM: Message edited by: Brian ]

[Brian]

Originally posted by Mattias:

</font><blockquote>quote:</font><hr />Originally posted by Brian:

One has to wonder though, what ever happened to the German 81mm and 120mm "Bouncing Betty" fuse?

Production of the 81mm round was discontinued in 1942 due to unsatisfactory reliability. Stocks were used as long as they lasted after that.

No info on 120mm round.

M.</font>

[Guest PondScum]

More on the Oslo report from "The Oxford Companion to World War II":

The identity of the report's author, a German physicist called Hans Ferdinand Mayer who worked for the electronic firm Siemens, remained unknown until 1989 when Jones revelaed it in his book Reflections on Intelligence, which contains the complete report. Because of his anti-Nazi stance Mayer was imprisoned in Dachau in 1943 but survived the war to become professor of astrophysics at Cornell University in the USA

Nice to see that he could do some good AND lead a good life afterwards!

From the same source, on promixity fuses:

An early version was fitted to British rocket weapons in 1940 and British research into the fuze was passed by the Tizard committee to the USA for development the same year. The Oslo report revealed that the Germans were working on a similar device, but, it seems, they never used any operationally.

This jibes with a "secret weapons of wwII"-type book that I read (and sadly gave away!) many years ago - it said that the major stumbling block with early proximity fuzes was protecting the miniature valves they contained from the shock of firing. Thus the Brits put them in relatively crude anti-aircraft barrage rockets first, since a rocket has a much lower instantaneous acceleration than a shell. It took a while to engineer them to the point where they could be fired from a gun. If I recall correctly, they also came up with a very neat liquid electrolyte battery that was activated by the shock of firing.

My guess is that the Germans had the concept first, but couldn't get the engineering right - the allies led in valve technology throughout the war.

Finally, an interesting note on the month when they should be allowed into CMBO for classical artillery use:

The Ardennes campaign, which started on 16 December 1944, brought forward the date for its use in north-west Europe by nine days and it contributed decisively to the defeat of this German offensive, artillery air bursts having a particularly devastating effect.

[Brian]

Originally posted by PondScum:

More on the Oslo report from "The Oxford Companion to World War II":

</font><blockquote>quote:</font><hr />The identity of the report's author, a German physicist called Hans Ferdinand Mayer who worked for the electronic firm Siemens, remained unknown until 1989 when Jones revelaed it in his book Reflections on Intelligence, which contains the complete report. Because of his anti-Nazi stance Mayer was imprisoned in Dachau in 1943 but survived the war to become professor of astrophysics at Cornell University in the USA

</font>

[JonS]

Originally posted by PondScum:

... If I recall correctly, they also came up with a very neat liquid electrolyte battery that was activated by the shock of firing...

I believe you are correct. IIRC it was some Canadian engineers who designed the battery - so it was a truly Allied effort to develop the VT fuse.

Incidentally - designing the battery was a non-trivial problem. The fuses need to be able to sit around safely - for years if necessary - then suddenly develop full voltage, reliably, when required. Normal batterys deteriorate too quickly to make them useful. I think the battery was the last stumbling block to be overcome before they were mass produced, and one the Germans never figured out.

Regards

JonS

[Mattias]

Originally posted by Brian:

Wurfgranate 39 would be the one you are looking for.

M.

[ April 16, 2002, 03:22 AM: Message edited by: Mattias ]