Schweres Wurfrahmen 40 Revisited--Surprising New Data

[John Kettler]

My brother George recently shifted his wargaming focus and sent me most of his World War II land combat references, in which was a rare treasure, T.J. Gander's FIELD ROCKET EQUIPMENT OF THE GERMAN ARMY, published by Almark in 1972 and long out of print. This is a real grognard's work.

Quite some time ago, there were extensive debates about having Nebelwerfer type weapons on the board, but BTS decided the minimum range was too great to permit this. New evidence indicates the decision may need reexamination.

Page 31 of the book consists of range table extracts for the 28cm and 32cm rockets. According to them, the minimum range is 300m

for the 28 cm rocket and 400m for the 32cm rocket. Normal loadout for the Schweres Wurfrahmen 40 was 5 28cm HE rockets and 1 32cm incendiary, but the vehicle could accommodate any mix of the two rocket sizes. Page 38 lists the minimum fighting range for the 30cm rocket as 400 meters. Page 40 indicates that the trailer launch rack for the 30cm was equipped not only with the normal artillery dial sight, but also iron sights graduated from 100-1000 meters. Anyone up for an overrun attempt on the rocket battery?

Taken in aggregate, the above revelations strongly suggest that the whole issue of Schweres Wurfrahmen 40 implementation and use for direct fire in CM and CM2 needs to be reopened and seriously reconsidered.

Sincerely,

John Kettler

[Guest MantaRay]

Ya, but one source isn't always the way to go. I am sure BTS does lots of research as to why certain things work the way they do in the game. Let em get CM2 out and then make your case.

Besides, I think the arty is represented well, and if you want on board rockets, well buy a few spotters and pretend. I just cant see a NW in the scale that CM simulates.

Ray

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[RMC]

IIRC those minimum range figures were bandied about in an earlier discussion. I say if they fit the map and unit scale then put them in. It seems to me there is a lot of resistance to these things because they would potentially unbalance the game or the Nw would become a lighter version of the super tank. In CC3 and 4 these things did present a real problem. CM allows for more accurate modeling of these systems so that all of their drawbacks would be manifest as well. Long reload time or no reload at all. You get six rockets. You need LOS to target. Target can shoot back. Rockets are highly inaccurate etc.

Biggest headache I see is the need for a new and very dynamic launch animation.

[KiwiJoe]

Just because 300-400 metres is the min range that doesn't mean it was standard practice to use them at that sort of range... if at all. If you put them into CM you are forcing the player to use these weapons at min ranges ALWAYS. This wouldn't be very historically accurate IMO. I think they should be left as off board artillery in CM AND CM2 unless the map sizes are twice as big or more.

[Guest tero]

Further more you could sweep the table with one salvo of 6 rockets in the correct circumstances. The game would be over before turn 1 was finished. Where is the fun in that ? Not that it is much more fun against the 14" guns for that matter.

[This message has been edited by tero (edited 02-21-2001).]

[Mattias]

I’m with RMC on this one. These weapons were available from 1940 and onwards, not uncommon and not all all without weaknesses.

If they are judged to fit the scale of CM they should pose no more of an balance issue than a Jumbo, a VT 155mm barrage, a King Tiger or Churchill Crocodile already does.

These weapon systems are all able to dominate a situation if deployed correctly and the opponent is unable to respond, why then should the Wurfrahmen be excluded on the basis of being too powerful?

The sources I used in the old discussion pointed to a minimum range that was about double the one you point to here John but I wouldn't be surprised if yours is correct.

In favour of this view speaks, among other things, the fact that these weapons were part of the equipment used by the Pionere to clear obstacles. Something that would have to be done from the shortest possible range, because of the inaccuracy of the rockets.

I guess it boils down to arguments about why they should *not* be included, as there is ample evidence that they were there in reality and would technically fit the scale of CM.

M.

[Guest tero]

>I’m with RMC on this one.

Not really.

>These weapons were available from 1940 and onwards, not uncommon and not all all without weaknesses.

They were however not used before Barbarossa started in 1941.

>If they are judged to fit the scale of CM they should pose no more of an balance issue than a Jumbo, a VT 155mm barrage, a King Tiger or Churchill Crocodile already does.

I am afraid they will fall in the same pit with the horse drawn vehicles. Present without a shadow of a doubt but still glaringly absent because of "design considerations".

>These weapon systems are all able to dominate a situation if deployed correctly and the opponent is unable to respond, why then should the Wurfrahmen be excluded on the basis of being too powerful?

The Americans would need to get something to match it or they would feel inferior because somebody has something bigger than they have ?

>The sources I used in the old discussion pointed to a minimum range that was about double the one you point to here John but I wouldn't be surprised if yours is correct.

I think the difference is the style of firing. If there is a minimum/maximum elevation imposed by the mount the restrictions would be inherent. And one must remember that with some vehicle mounts it was possible to get near 0º elevation while the metal racks on SdKfz-251 and with the racks placed on the ground the elevation was a real issue.

>In favour of this view speaks, among other things, the fact that these weapons were part of the equipment used by the Pionere to clear obstacles. Something that would have to be done from the shortest possible range, because of the inaccuracy of the rockets.

Agreed.

[PzKpfw 1]

I think players should decide how they want to use their wpns not BTS, if it could engage at 300m then let them, maps run what 2 - 2.5k ?remeber, not all ppl playing CM play it to be historical or even want to be told how they are suposed to use this, or that item.

I'd also be interested why it's assumed anyone did extensive researech on this subject?.

Regards, John Waters

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[Jeff Duquette]

There is some great information in various British Army Operational Studies on these fellows. Apparently danger close employed by the Germans for rocket barrages was something like 600 meters. This would seemingly imply a fairly erratic dispersion pattern.

John: does your reference include firing tables? Might be interesting to look at range and deflection Probable Error. My biggest gripe with there inclusion in other, not to be mentioned tac wargames, was their uncanny accuracy, and the limited map sizes of these "other" wargames.

[tss]

Jeff Duquette wrote:

Apparently danger close employed by the Germans for rocket barrages was something like 600 meters. This would seemingly imply a fairly erratic dispersion pattern.

Not necessarily. The same 600m value was used in Finnish regulations for 152 mm guns. In practice, those guns often fired much, much closer to own troops.

- Tommi

[Jeff Duquette]

600meters for a howitzer or gun! Jeeze…were the Finnish reverting back to unrifled barrels Do you have access to the firing tables for the 152mm? Danger Close = 600 meters is quite large for most indirectly fired mortars or conventional artillery. Perhaps this was for artillery firing without the benefit of an FO, or perhaps the 600meters was the recommended set-back for training exercises.

The Allied Carpet Bombing before Cobra used a set-back of only 1000 meters (which actually turned out to be somewhat to small...just ask General L. McNair).

Even with the rudimentary FO and FDC control existing during WWI, British Infantry were able to walk behind rolling barrages by 18-pounders if they maintained a distance of 75 to 100 meters from the mean range line.

[Mattias]

Ill make it easy and repost two previous posts of mine, as things hasn’t really changed, and adding BTS response at the end..

One thing though, don’t confuse the use of the Wurfrahmen with that of rocket launchers like the Nebelwerfers. With a maximum range of about 2000 meters these are primarily direct or at least low fire angle weapons. As inaccurate as they are they definitely better than the current off board representation of rockets in CM, as can be seen in the figures given below.

The vehicle mounted sWF 40 could fire at targets at any range within the envelope of it’s 1925/2200 (Sprg/Brd) range, the only limitation being arming distance which could be set to almost nothing.

It was intended as a Pioneer weapon for clearing of obstacles or for “simple” bombardment. As the former task requires accuracy this must have been done at close range.

However it “looks” like the six-pack of launchers mounted on, for example, the Sd Kfz 251 was unable depress the launchers below 14-15 degrees when all six were in place.

Enter game considerations:

I cannot see how anything less than the fully loaded vehicle on a bombardment mission could be modelled in the game. The game, as it stands today, simply isn’t flexible enough to, usefully, model the pioneer missions envisaged for it in real life.

If this is the “truth” the vehicle would be limited to +14 to +50 degrees

In order to achieve a certain range you could move the vehicle to a spot where the ground is sloping slightly up or down in order to get an elevation outside of the limitations of the mountings. Alternatively you could hit a target at a higher elevation than yourself, or something really tall, like a big building, in which case the target could be very close.

However, back to the game:

My impression is that this is not modelled in the game or would require extra coding. I shan’t dwell on it as I don’t know anything about it but it is my impression that a sWF would be limited to operating from “flat” ground when the trajectory of the projectiles is calculated, no matter the inclination of the vehicle. Would be happy to be wrong though.

So, where does this leave us in game terms?

Considering the limitations mentioned above the vehicle mounted sWF 40 could be added but would be limited to bombardment missions at ranges of app:

1000 to 1925m for the 28cm Sprg

1200 to 2200m for the 32cm Brd

Considering that map sizes of 2x2 km does not appear to be extreme it is tipping on the edge of being an on board weapon system rather than an off board one.

I have a range chart supplied by an Australian friend but am sadly lacking in ability, thus I cannot post it here. But as an example of the “accuracy”, consider this:

At maximum range the 50% zone of the 28cm rocket is. 80m in length and 90m in breadth. At 1000 meters it is 150 in length and 30 in breadth

The same figures for the 32cm Brd is 100/110 at max and 180/40 at 1200 meters.

Just realised I too had the same figures as John posted originally:

Two classics, Field Rocket Equipment of the German Army 1939 - 1945 by TJ Gander and Deutsche Raketen-Werfer, Podzun-Pallus-Verlag.

28cm min 300m max 1925 m

30cm min 400m max 4450 m

32cm min 400m max 2200 m

The minimum range is taken from the range tables of the frames (sWuG 40 and 41). The 251 was fitted with the sWF40 frame and rated with the same ranges.

TJ rates the 30cm as having a higher range of 6000m but I believe this applies to the 15cm rocket when fired from the same launcher.

The 15cm had a max of 6900 m. You could use them at shorter ranges, but you would start to suffer from the effects.

And finally, BTS (both by Steve) response:

1.

Since this resurfaced, and there was no commentary made by us originally, I will make some comments now...

At best this is a borderline on-map weapon (six pack version). If the map is at least 3500km deep perhaps. But anything smaller and it is a definate no. Think about it. If the map were 2000km deep (which is pretty deep BTW) then the HT would have to sit on the map edge and fire at stuff on the opposite edge. Not much flexibility or purpose here and impossible to use if the map wasn't very deep at all.

We don't include things like the 120mm mortar on map for exactly the same reason, or any other form of nebelwerfer for that matter. So these are certainly not going in. There is really no benefit game wise, unless you are in the CC3 direct fire camp. We aren't

Also, how would we handle the ammo situation? I mean, how many rockets could be stored INSIDE the 251? None? So if they were on the map they would be a one shot deal, and that doesn't seem either realistic or usefull.

Sorry, no go.

2.

What you are talking about is introducing a feature that can only work using special, and perhaps artificial (i.e. not historically accurate) situations. They really have no place on a CM sized battlefield other than to make people go "cooooool". Which is probably why they were put into CC3

There are probably 100 other features and vehicle models that are far more worthy of our time than this.

M.

[This message has been edited by Mattias (edited 02-21-2001).]

[This message has been edited by Mattias (edited 02-21-2001).]

[This message has been edited by Mattias (edited 02-21-2001).]

[Scipio]

Originally posted by John Kettler:

Taken in aggregate, the above revelations strongly suggest that the whole issue of Schweres Wurfrahmen 40 implementation and use for direct fire in CM and CM2 needs to be reopened and seriously reconsidered.

We have Wurfrahmen in CM??? Have Imissed something?

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[Mattias]

Scipio,

CM models, I assume, FO's for the "pure" artillery rocket systems:

15cm NbW 41 (6900 meters)

21cm NbW 42 (7850 meters)

30cm NbW 42 (4550 meters)

The rockets discussed for possible on map deployment have max ranges around 2000 meters.

However, as the 30cm rocket could be fired from Wurfrahmen (Schweres Wurfgerät 41) as well I guess you could say we have them in CM. Sort of indirectly

M.

[Jeff Duquette]

Matthias, great post. Thanks. One question regarding the following info:

You Indicated:

I have a range chart supplied by an Australian friend but am sadly lacking in ability, thus I cannot post it here. But as an example of the "accuracy", consider this:

At maximum range the 50% zone of the 28cm rocket is. 80m in length and 90m in breadth. At 1000 meters it is 150 in length and 30 in breadth.

That seems odd that the max range has a larger 50% zone than the 1000meter range zone. Did you transpose the figures?

Anyway just as a comparison: a 155mm-AM-2 firing M107 HE and using charge 5 green bag at a range of 6,000 meters, the 50% zone (for range probable errors…ie length) is only 15meters. Deflection probable error (ie width) for the above 155mm scenario, 50% zone, is 4meters

So there is a huge difference in dispersion between conventional artillery, and rocket artillery. This shouldn't be much of a mystery.

[Mattias]

Jeff,

Your question made me wonder but, no, it seems to be the numbers from the chart.

The further you shoot, the less dispersion you get in length and the more you get in breadth.

In any case, I have E-mailed the full chart to you, perhaps you can get put it up here on the chat?

M.

[M Hofbauer]

What we need to keep in mind is that while there has always been discusion about just what the minimal theoretical and practical range is, it is a fact that the maximum range for the 28 and 32cm rockets were barely over 2km. This makes it obvious that they could very well be included in CM if people wanted it in.

This is also a big difference of these weapons to the 15 and 21cm rockets, which could be considered artillery weapons with their ranges of 7 to 8 km. The 28/32cm Nb.W.Gr. fall somewhere inbetween being neither a real artillery asset nor a real demolition weapon. Their limited range, large destructive force, high inaccuracy and mass use suggest they are something remotely like a short-range impromptu carpet bombing of a special kind.

As to their use - someone suggested they were not used before Barbarossa. They were, but indeed only *few* Nb.W.Gr. 28/32 were used before the invasion of Russia, to be more exact, 3,212 were used until March 1941. Another 1,032 were used during the campaign in the Balkans.

When operation Barbarossa was launched against the USSR, usage skyrocketed (sorry for the pun). Total usage on the russian front until the end of 1941 was 11,268 Nb.W.Gr. 28/32.

Still rather pathetic number. In 1942, 46,230 and 10,190 of the Nb.W.Gr. 28 and 32 respectively were used, in 1943 this rose to 103,510 / 15,650.

Now, even the 1943 figure is pathetic of you compare it for example with the ammo usage of the regular artillery pieces, for example the common leichte Feldhaubitze leFH 18 fired over 26 million rounds of ammo in 1943.

1944 saw the climax in Nebelwerfer- rocket use, with a total of nearly 220,000 of both types fired - still pethetic when compared to for example over 31 million rounds of 105mm ammo fired by the leFH 18 during the same time.

Therefore, whether these rockets will be shown on-map or off-map, I hope to see the rarity factor (if there's gonna be one) applied not only to tanks and guns but to artillery as well.

P.S: It's "Schwerer Wurfrahmen", Wurfrahmen is male, "he", d e r Wurfrahmen.

P.S.2: I just realized Mattias made a very interesting post in the meantime....

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[Guest tero]

>600meters for a howitzer or gun! Jeeze…were the Finnish reverting back to unrifled barrels

What do you mean by reverting ? We had still some in operation in 1940.

Due to ammunition starvation in the -30's our artillery developed fire methods that were VERY accurate.

For example, during the summer of 1944, if the FO went off the air (which was quite often as communications relied on telephone lines) the artillery would habitually fire at the sound of the guns as they had several (sometimes dozens in a few square kilometers) preplotted targets registered and they knew where the friendlies were within a few meters. Even firing blindly on known friendly positions on purpose was not unheard of.

[Jeff Duquette]

Mathias:

Thanks for emailing that info. I'm at work at the moment, but look forward to taking a look at it when I get home. I still think that something smells "fishy in Finland" with the rocket dispersion data. Typically, an increasing range to target will also result in an increasing range probable error.

Example: 155m-AM-2 firing M107 HE using 4G charge:

<UL TYPE=SQUARE>

Range____Range Error____Deflec. Error

2000m________8m______________1m

3000m________11m_____________2m

4000m________14m_____________3m

5000m________18m_____________4m

6000m________23m_____________5m

7000m________28m_____________6m

Note: Range probable error would be 50% dispersion along the axis of fire (length of 50% zone). Deflection is the 50% zone to the right or left of the line of fire (50% zone width).

[This message has been edited by Jeff Duquette (edited 02-21-2001).]

[Mattias]

Exactly my thought as you mentioned it Jeff.

Just wondering if it can't somehow be explained by the rate of decent and varying speed of the rocket propelled projectile, as opposed to a grenade fired from a gun.

For example, how long does the engine burn? Could this mean larger error in length at short distances? Just toying with the idea.

Something connected with Rexfords 75L24 vs. 75L70 posts?

I'm all ears.

M.

[Jeff Duquette]

"Something connected with Rexfords 75L24 vs. 75L70 posts?"

Yeah that's got to be it

[Jeff Duquette]

Wow...I appologize Matthias. I stand corrected. This certainly appears to be a copy of authentic TFT for 28/32cm Rocket Projector. The 50% zones do infact decrease with range.

[John Kettler]

I'll never get all the "who saids" right, but I shall attempt a coherent reply anyway.

First, I clearly indicated in my post that the information originally derived from the German range tables for the 28/32 cm rockets, extracts of which were presented in the book. The original source was thus German official.

The minimum range at which I have 50% zone

zone data for either is 600 m. For the 28 cm a 140 mil elevation with a drift correction of +10 mils yields a 50% zone 160 m long by 20 m wide. For the 32 cm the numbers are 118 mils elevation, +10 mils drift correction, 170 m x 20 m. Very nearly identical.

Though I lack the mental focus right now to even attempt typing the table, I will say that generally speaking out to 1600m both types are generating 50% zone shapes typical of direct fire engagements. For the 28 cm it's 110 m x 60 m; the 32 cm is 150 m x 60 m. The 32cm's direct fire zone actually goes out to 1800 m, but we'll simplify the discussion by assuming all launchers are set to provide the same range.

Given the above, it looks to me as though the Schweres Wurfrahmen 40 could, if on the board, deliver direct fires out to 1600m without any problem, with hit probablity being tied to target width and height. Outside that range the impact pattern begins to circularize, more nearly resembling the behavior of mortars. At that point, I'd say we're in FO land.

The Schweres Wurfrahmen 40 was specifically designed to provide heavy, mobile firepower where and when needed by the panzers at the point of contact, though, which is why I'm arguing for its inclusion in CM and/or CM2. It was used for direct fire engagements against fortified positions and in streetfighting at places like Stalingrad, but certainly could be used for indirect fire as well.

At its max range of 1925 m, the 28 cm is elevated to 698 mils, has a drift correction of +48 mils, and produces a 50% zone that is

80 m x 90 m. At 1800 m the pattern is 80 m x 80 m, or circular and starts to diverge more in azimuth than range.

The 32 cm at its max 2200 m and 800 mils of elevation, +60 mils for drift, produces a 50% zone 100 m x 110 m.

The other rocket type I mentioned, the 30 cm, was specifically described as having conventional artillery sights and direct fire sights graduated from 100 m to 1000 m. It was a separate matter which I mentioned only because it was pertinent to my main point, which was to show that the Germans did and could use powerful rockets for direct fire. This point is equally valid for the Russian Katyusha. On several occasions Katyusha batteries were attacked by German armor and responded by lowering the launch rails and letting fly volleys of rockets right into the ranks of the panzers.

That's all I have for now.

Regards,

John Kettler

[Mattias]

Jeff,

If you look again I think you'll find that the 50% zone actually, as one would expect, grows with range. It is the shape of the zone that changes.

John, I think all numbers are more or less on the table when it comes to the historical real life interpretation of this weapon system.

Putting it into CM is another matter though as it seems to stumble on a few of BTS's famous steps of inclusion, not adding anything substantial to the game seemingly being the biggest.

Being a friend of details I'd very much like to see it included and firmly believe that CM could represented it in a correct, none CC, manner.

I understand BTS point of view though.

M.

[John Kettler]

Interesting discussions! Bumping this now in the hope of getting some reaction from BTS.

Regards,

John Kettler