Arty spotting rounds; some observations I've done:

[Olle Petersson]

Here are the results of a test I did recently

I picked a couple of artillery spotters and studied the spotting rounds, primarily the first spotting round.

Measured factors:

- Time from order given (hit GO) to first spotting round fired (ammo drawn from the counter), T1 (min:sec).

- Time from order given (hit GO) to first spotting round hit the ground, T2 (min:sec).

(- Calculated time from ammo drawn to impact, T3 (sec).)

- (Estimated) distance from target point to first spotting round impact point, D (m).

Here are the preferences:

No HQs or TRPs present. All spotters had LOS to the target (about 600m away), each spotter fired two missions.

Spotter - Quality - T1 - T2 - T3 - D

US 8" Hwz - E - 0:09 - 0:13 - 4 - 130

US 8" Hwz - E - 0:14 - 0:17 - 3 - 190

US 8" Hwz - C - 2:45 - 2:56 - 12 - 45

US 8" Hwz - C - 3:01 - 3:09 - 8 - 145

US 155mm - E - 0:23 - 0:31 - 8 - 145

US 155mm - E - 0:09 - 0:12 - 3 - 85

US 155mm - C - 3:36 - 3:44 - 8 - 150

US 155mm - C - 3:40 - 3:45 - 5 - 50

UK 5.5" - E - 0:45 - 0:52 - 7 - 60

UK 5.5" - E - 1:06 - 1:14 - 8 - 25

UK 5.5" - C - 4:33 - 4:38 - 5 - 60

UK 5.5" - C - 6:08 - 6:09 - 1 - 30

German 15cm - E - 1:03 - 1:16 - 13 - 45

German 15cm - E - 0:51 - 0:59 - 8 - 90

German 15cm - C - 5:37 - 5:44 - 7 - 45

German 15cm - C - 5:42 - 5:48 - 6 - 40

German 21cm - E - 0:53 - 0:60 - 7- 25

German 21cm - E - 0:54 - 0:57 - 3 - 55

German 21cm - C - 5:32 - 5:44 - 12 - 85

German 21cm - C - 4:27 - 4:29 - 2 - 40

Note: Quality; E = Elite, C = Conscript

Conclusions:

(Confirmation of old knowledge)

- US is faster than UK is faster than German response.

- There's no bonus for retargeting an "old" target point.

(Stuff that's new for me)

- Spotting round deviation is not related to troop quality.

- Spotting rounds in CM are very accurate, compared to real life, where a mile off target isn't uncommon.

- Response time, even the first estimate, isn't fixed. It varies from mission to mission.

Other observations:

- Exactly two spotting rounds are fired before FFE, no matter if the spotting rounds are on target or not.

- The second spotting round has no correlation to the first round. I noticed an instance where the 1st round was 30m off target (which in arty terms is on target) and the 2nd round was 80m off target!

- In some cases the time to first impact is less than typical flight time for the shells. How range measurement, firing calculations and transfer of orders are managed within this time frame is beyond me...

Some future modifications I'd like to see implemented:

1) Larger deviation for first spotting round, somewhat dependant on troop quality. An Elite spotter will have about the same deviation as now, but Green spotters will deviate a couple of hundred metres on average, and a mile or two on rare occasions.

2) Lesser time difference in T2 between troop qualities.

3) Bracketing of spotting rounds. An Elite spotter will probably only need one round, Green spotters 4 or more, before being on target. This is what makes the major reason for the increase in time to FFE with lesser skilled spotters.

4) The larger deviation makes it probable that spotting rounds will fall on friendly troops more often. Therefore all spotting rounds need to be smoke(-flash-bang) instead of HE.

5) Take projectile flight time (sometimes more than a minute) into consideration when calculating response times.

Typical example, with good spotter: After initial calculations (30s) the first spotting round will take something like 30s to reach the target. If it's within LOS from the spotter the next round may be on it's way 10s later. Suppose that round is on target, then FFE starts at 1:50 and the first salvoe arrives on target at 2:20.

Of this time 1:30 is flight time that the spotter can do nothing to reduce.

6) Larger variation (upward) in response time for US artillery, and definately a minimum response time way more than the 12s I found. (12s is less than the time needed to transmit target coordinates...) Their spotters have no control, but request fire from a central arty staff, or whatever it's called, in the hope of receiving something.

Sometimes all artillery within range is busy. UK spotters have dedicated batteries idle for a call, German SOP I can't remember, but I think that they too have dedicated stuff.

Cheers

Olle

[Guest ciks]

Very interesting!

I hope someone at BTS takes a note on this.

[Soddball]

What I found interesting is that it isn't consistent - which is as it should be.

I can now clearly see the benefits of better quality spotters.

Can you tell me whether you were able to carry out research on green/regular/veteran/crack troops (since they are more common I would have thought) and if so whether the difference is quite so substantial?

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"Woof!Woof!"

That's my other dog impression.

[Olle Petersson]

Originally posted by Soddball:

I can now clearly see the benefits of better quality spotters.

The only major benefit (in CMBO) is a shorter response time. (Then there's the benefit of them being better at hiding and detect enemies...)

With the changes I suggest the differences will be more noteworthy in number of rounds wasted for aiming, and a larger degree of unscertainty when calling fire.

As it is now the spotting rounds are accurate enough to do the job, if you use the heavy artillery. Rarely any need to wait for the actual mission to be fired.

Cheers

Olle

[Leonidas]

Interesting stuff. I would prefer that the response times not be random, because it introduces a gamey problem: If you don't like the delay you're given from a new fire order or adjusted fire order, you can reload the file and roll the dice again. You can speed up the arty by up to ten seconds this way, if you're patient. I usually don't have the patience for this, but it's irritating to know that I could improve things a little in the game by wasting more of my time reloading files in a gamey way.

Originally posted by Olle Petersson:

The only major benefit (in CMBO) is a shorter response time. (Then there's the benefit of them being better at hiding and detect enemies...)

I thought that a major difference in spotter quality was the density of the arty pattern. More experienced spotters produce more accurate fire, IIRC.

[-Havermeyer-]

I find the spotting round silly. I mean, I bloody well drew the line to the point the rounds are supposed to drop anyway, didn't I?

[Swede]

Originally posted by Leonidas:

Interesting stuff. I would prefer that the response times not be random, because it introduces a gamey problem: If you don't like the delay you're given from a new fire order or adjusted fire order, you can reload the file and roll the dice again. You can speed up the arty by up to ten seconds this way, if you're patient. I usually don't have the patience for this, but it's irritating to know that I could improve things a little in the game by wasting more of my time reloading files in a gamey way.

With Olle's proposed modifications, the spotter wouldn't know how long it would be till FFE since that would depend on the results of the spotting rounds. The spotter would only be able to give an ETA shortly before the rounds were fired, which would be based on time of flight.

Even now when it gives an ETA for the FFE, that doesn't always seem to be very accurate. I once had a spotter indicating 22 seconds at the beginning of a turn, but then the counter stayed frozen at 22 seconds for almost the entire 60-second movie and the rounds finally arrived well into the next turn.

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Swede

Rommell, you magnificant bastard! I read your book!

-- GCS as GSP

[ADAman]

"The second spotting round has no correlation to the first round. I noticed an instance where the 1st round was 30m off target (which in arty terms is on target) and the 2nd round was 80m off target!"

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Not quite enough data here to tell but this may be closer to the way FOs are taught than you think. When I had my FO training (mandatory for all of us with crossed cannons on our collar, even if we did have the flying phallic symbol in the middle of them), I was taught to bracket the target, even if I thought my first round was pretty good. Then it was halve the interval until FFE. Using binoculars it was difficult to really tell how close the first round landed so the instructors said to adjust the second round far enough to ensure it bracketed the target. Your description doesn't say if the 80 yard adjustment bracketed the target or was truly random. If it did bracket it, there may be some method in the madness.

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Air Defense: Shoot 'em down, sort 'em out on the ground (AKA - if it flies, it dies)

[SenorBeef]

Originally posted by Leonidas:

Interesting stuff. I would prefer that the response times not be random, because it introduces a gamey problem: If you don't like the delay you're given from a new fire order or adjusted fire order, you can reload the file and roll the dice again. You can speed up the arty by up to ten seconds this way, if you're patient. I usually don't have the patience for this, but it's irritating to know that I could improve things a little in the game by wasting more of my time reloading files in a gamey way.

I thought that a major difference in spotter quality was the density of the arty pattern. More experienced spotters produce more accurate fire, IIRC.

The spotter has nothing to do with how the guns are aimed once his coordinates are set in - the battery strictly controls where each gun points exactly, so the spotter quality has nothing to do with it. Although, I suppose it would make sense if spotter quality also reflected battery quality - but in as far as CM, spotter quality only affects time to FFE.

[Olle Petersson]

Originally posted by ADAman:

Your description doesn't say if the 80 yard adjustment bracketed the target or was truly random.

The first shot was about 30m straight left of the target, 2nd round 80m to the right. So it was some sort of bracket, but in the direction most easy to adjust.

I can imagine some over-correction along the LOS, but not perpendicular to it.

Cheers

Olle

(Posting 982)

[Olle Petersson]

Originally posted by SenorBeef:

The spotter has nothing to do with how the guns are aimed once his coordinates are set in - ...

Wasn't this a matter of national doctrine?

US spotters gave target coordinates, and then someone else did the calculations.

For some other nations the spotters did all calculations.

Still, factors where the quality of all troops involved only have a minor influence are;

- radio transmissions (be it target coordinates or gun laying instructions). (US have more of these, as the FO talks to some arty coordination staff, that in turn relay data to some battery. All other FOs radio their battery directly.)

- projectile flight time.

Where troop quality does matter;

- Target aquisition. (Speed and accuracy of target location measurement.)

- Ballistic calculations. (Speed and accuracy of these.)

I can buy that the troop quality of the FO represents the average quality of the whole chain involved.

Cheers

Olle

(Posting 983)

[Olle Petersson]

Originally posted by Swede:

I once had a spotter indicating 22 seconds at the beginning of a turn, but then the counter stayed frozen at 22 seconds for almost the entire 60-second movie and the rounds finally arrived well into the next turn.

This has to do with another "flaw" in CM. The time estimate doesn't take reload time into account.

If you have some heavy artillery and fire one salvoe in a turn, and then adjust fire a bit, the timer will say 30s or so. Then reloading the guns may very well take over a minute, and the countdown won't start until the reloading is done...

Cheers

Olle

(Posting 984)

[Pacestick]

Originally posted by ADAman:

"The second spotting round has no correlation to the first round. I noticed an instance where the 1st round was 30m off target (which in arty terms is on target) and the 2nd round was 80m off target!"

The way we used to do this was 30m would be on target for 105mm. The adjuster would order one round fire(each gun in the fire unit fires one round) to confirm the beaten zone, adjust if necessary, and then order fire for effect.

As an aside, the minimum safety distance for 105mm fire from memory was 200m but the first adjusting round had to be targeted a minimum of 1000m from the nearest friendly troops and adjusted back from there. As another poster indicated, we would adjust to the observer/target line then bracket the target using a table of minimum size adjustments depending on the range from the observer to the target eg. if your first bracketing adjustment was add 800, the next would be drop 400 and so on.

[Olle Petersson]

Originally posted by Pacestick:

... the first adjusting round had to be targeted a minimum of 1000m from the nearest friendly troops ...

Why not use some less dangerous Flash-bang-smoke ammo?

When LOS is restricted beyond 500m (and the spotting round lands somewhere out of sight), what would you do then?

Cheers

Olle

(Posting 992)