Rockets and TRPs

[Kingfish]

Gents,

I’m having trouble understanding how a rocket battery benefits from a TRP, or if they should at all. How does a FO ‘tweak’ the battery until it is on target? With regular arty each gun could be walked onto the TRP one round at a time, but with rockets the entire launcher has to be fired off (I could be wrong on that).

Also, when tweaking regular artillery the FO can at least be assured that the rounds will land within a reasonable distance to the TRP, but with rockets an extra second of burn time or a bent fin will have the rounds landing a kilometer away. With such a large impact area how will he know that the battery is locked on to the TRP?

[Pascal DI FOLCO]

I wonder if TRP really existed for Rockets...

But well, in CM, from what I know the game just give quicker firing time and less spread when a gun or rocket fires at a TRP.

I saw the spread areas somewhere, they are quite larger for rockets than for guns (perhaps 200*100 where guns have 50*100).

[Andreas]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Pascal DI FOLCO:

I wonder if TRP really existed for Rockets...<HR></BLOCKQUOTE>

It appears they did. Blackburn relates a case where a Nebelwerfer battery was found by the advancing Canadians, fully loaded and ready to fire. So the gunners who found them turned them around and fired them at the German lines. Almost immediately, the position was hit by a rocket barrage, killing about 20 and wounding a number more. The Germans had expected this to happen, had dialed in their old position and just waited for the curious Canadian gunners to pull the trigger.

[Mud]

It still might let the FO communicate the exact intended target easier, right? And in theory, the velocities of the projectiles are probably known, so maybe they precalculated an approximate trajectory to use. Sounds somewhat plausible to me.

Rocket spread is indeed huge. Set up a 500-pt QB, small map, w/ a German 300mm rocket FO. Target the enemy zone w/o LOS or TRP. Make everybody else sit tight, and watch rockets land basically all over a massive part of the map (and outside it, as well).

[Kanonier Reichmann]

I keep having this nagging suspiscion where I read somewhere that rockets in fact do not benefit from TRP's. I've searched the manual from top to bottom & can't find reference to this but perhaps I read it in an old thread involving an official BTS response to a similar question.

Does this ring a bell with anyone else?

Regards

Jim R.

[Andreas]

They certainly come in faster.

[CMplayer]

I recently fired two fire missions of 150mm rockets, one at a TRP and one not. My impression was that the TRP strike both came faster and with less spread.

[Kingfish]

<BLOCKQUOTE>quote:</font><HR>It still might let the FO communicate the exact intended target easier, right? And in theory, the velocities of the projectiles are probably known, so maybe they precalculated an approximate trajectory to use. Sounds somewhat plausible to me.<HR></BLOCKQUOTE>

But how is that any different from a FO calling in a strike w/o a TRP?

[CMplayer]

The difference is that all the calculations would be done and the guys at the front could call in the concentration when they need it by just giving the name/number of the target. It would save time.

[Kingfish]

<BLOCKQUOTE>quote:</font><HR>Originally posted by CMplayer:

It would save time.<HR></BLOCKQUOTE>

I agree, but TRPs will not only give you a faster response but better accuracy as well. That's what I'm having trouble understanding. How is a rocket battery firing on a TRP more accurate than one without? Both are firing on the same coordinates, only one got the coordinates a few minutes sooner.

Keep in mind that my questioning is based on the assumption that rocket batteries are not 'tweaked'(for lack of a better word) onto a TRP. I've always understood them to be area fire weapons, not something you can walk towards a target one round at a time. If someone has info to the contrary please let me know.

Thanks

[JacMac]

Of course a TRP would help, the deflection and elevation for any gun would be pre-calculated. Thats the point of having a known reference point. For mortars, the charges would be preset on some rounds as well. It means a fast response with no adjustment rounds necessary. We used to write the sight information down for special targets and sheaf alignments and tape it right on each gun in the section.

[ 10-11-2001: Message edited by: JacMac ]

[CMplayer]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Kingfish:

How is a rocket battery firing on a TRP more accurate than one without? <HR></BLOCKQUOTE>

Well that big iron bullseye out on the ground maybe magnetically pulls the rockets towards it?

[tiborhead]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Kingfish:

Keep in mind that my questioning is based on the assumption that rocket batteries are not 'tweaked'(for lack of a better word) onto a TRP. I've always understood them to be area fire weapons, not something you can walk towards a target one round at a time. If someone has info to the contrary please let me know.

Thanks<HR></BLOCKQUOTE>

That sounds about right to me. Although I don't really use many rockets, or TRPs for that matter (I usually attack ), I've always understood that rockets are, by design, rather inacurate.

[John Kettler]

Kingfish,

You appear to be laboring under multiple misconceptions here. Let me go through them with you and sort out some things.

First, in registering standard tube artillery

the usual practice was to register one gun, the base gun, from each battery, not each gun

individually. Doing it your way would've given the other guy's sound and flash ranging parties way too much information and thus compromised security.

Second, it is possible to register a multiple rocket launcher (MRL) battery, though trickier because of that annoying smoke trail many rockets have. I used to have the Soviet firing procedures for multiple rocket launchers, and these specifically described launching successive single rockets for registration, with the recommendation that this be done under cover of other support fires when possible, in order to hide what was being done.

Third, since we're talking about Nebelwerfer type weapons, I went and dug out my best reference on this, T. J. Gander's FIELD ROCKET EQUIPMENT OF THE THE GERMAN ARMY 1939-1945 (1972,Almark Publishing Co., Ltd) which says on page 17:

"The rockets were fired at 2-second intervals, and this interval had to be judged by the firer using the rotary hand generator--one turn fired one rocket."

This being the case, not only could registration procedures identical to those employed by the Soviets be used, but a solid mechanism exists by which MRLs could be taken out of spasm firing mode. In practice, though,

each battery would likely have only one target, and firing even one MRL would be enough to bring down a storm of counterfire from mortars or artillery.

To summarize, MRLs can be prezeroed, much like tube artillery, using individual rounds and making adjustments until the desired zone is hit, whereupon the other MRLs in the battery derive their firing settings from the base MRL. Similarly, having precomputed settings for MRLs works to cut fire delivery times exactly as for standard tube artillery, but nothing repeals air drag, velocity and burnout time differences. The rockets remain area weapons.

Hope this helps.

Sincerely,

John Kettler

[Kingfish]

Well, if it isn't the 'Rocket man' himself.

Thanks for the info John. I never knew WW2 rockets could be fired individually. That answers one question.

How about the second question? Considering how inaccurate rockets are, how would the FO know that the battery was locked on?

[Michael Emrys]

One small footnote. If any German rockets had fins, they were in the minority. Much more commonly, they were spin stabilized. The exhaust was expelled through holes drilled at an angle around the periphery of the base, thus imparting a spin. The gasses exiting through these holes also poduced an eerie moan, from which derived the weapon's nickname, "Moanin' Minnie".

Most of the Allied rockets (regretably absent from CM:BO) had fins, although I believe I have read that the Americans had a spin stabilized model as well.

Michael