Setting up Target Reference Points

[noob]

Does anybody know how long it would take for a force to create TRP's in real life, i'm currently running an operation and i want to be able to utilise TRP's in the game but i have no idea how long a force has to occupy a section of terrain unmolested to create them.

[Chainsaw]

I have no clear answer to that, but my guess is within 15mins if you have a FOO with you. a TRP is a zeroed area, which means that it has been fired at by spotting rounds from the battery supposed to fire at the area and they then saves the cordinates/settings for that area.

So the only thing a FOO need to do is call in spotting rounds, just like if he was calling in a normal mission and then tell the bty to save it as codename "M1" or something like that.

My personal opinion is that scenario creators really miss out on TRPs as they are used plenty in both attacks and defences. Im going through 2 ESSEX war diary and there is constantly new "TRP" added when they move into a new position, often named M1, M2, M3 etc or named like "RATS" "BOX".

[noob]

Thanks for that information, what you say is interesting and i think i could do something with that, one other question would be about TRP's out of the LOS of a spotter, so for instance if a force occupies an area of 1 x 1 km and is unmolested for 2 hours would it be reasonable to assume that the spotter could go on a tour of the area marking out TRP's in areas outside the LOS of his forces main line ?

[Chainsaw]

Honestly don't know about that. You have to see the spotting rounds to zero in 100% so the FOO would have to move in the dead space outside own lines to be able to do that. Sounds kind of risky to me to risk a FOO that way?

On the other hand, just read a book about 43rd Wessex Divison and during one of the battles the FOO party was dug in 100-200yds forward of the infantrys position

When a FOO with a unit comes to a new place, the first thing the FOO does is get coms to work with bty and locate his own position so he can be ready to fire. Then he looks at the map together with the CO and IO to get a picture of the enemys situation and COA (Course of Action) and from there starts planing TRPs. Plenty of grey areas I cant really answer to. guess I need to read up more on the RA side of the British Army

But for your operation you could do it the easy way and just say for example "if FOO in loc > X time unit gets X TRP" And then assume the FOO had time/possibility to check the TRPs himself/with a patrol.

[Chainsaw]

A good link when it comes to British RA:

http://nigelef.tripod.com/maindoc.htm#FIRE%20PLANNING

That whole site is outstanding source and if you want to get into detail you should sit down and read it all

[Michael Emrys]

...one other question would be about TRP's out of the LOS of a spotter...

In the case of an Allied force, I think it would be reasonable to assume a pretty good chance that a spotter plane could call in the rounds for a TRP. But then that information would have to coordinated with the force on the ground—i.e. the plane's observer and the FO on the ground would have to agree on the map location of the TRP, and that might not be a simple or automatic procedure.

Michael

[Broadsword56]

Certainly for the German side I think there should always be a hefty set of TRPs, just about everywhere they might be fighting. That's because they had months to prepare their Normandy defenses and the fallback line of strongpoints and resistance nests, and had been living and patrolling and training in the area long before it became a battlefield. So IMHO the German side should get TRPs for just about every crossroads, farm complex, town, hilltop and any other tactically meaningful spot of ground, regardless of the battle type or length of time the FOO had been there.

[Broadsword56]

For the Allies, I think TRPs are more a function of:

1. How long the unit has been in the area -- any unit that's been someplace overnight, for example, would always have dug foxholes for a night perimeter and set up at least some TRPs around their position.

2. What kind of assets and HQ level support is involved in the unit's current action.

In a meeting engagement or a hasty attack, an American unit wouldn't have any TRPs, IMHO.

A more deliberate attack with some attached assets would get some TRPs.

And if it's part of some larger operation that involved planning by Division HQ staff, aerial recon, and is more of a setpiece attack that represents the division's main effort, I'd say there should be a lot of TRPs with that -- expecially in the case of the British, where they used those massive preplanned rolling barrages of 25-pounders with the infantry following 300 yards behind.

(To do that, you'd want to set up a whole parallel string of TRPs so the FOOs could call in a new medium mission/medium duration every 3 minutes to "lift" the barrage 300 yards to the next line)

[noob]

Certainly for the German side I think there should always be a hefty set of TRPs, just about everywhere they might be fighting. That's because they had months to prepare their Normandy defenses and the fallback line of strongpoints and resistance nests, and had been living and patrolling and training in the area long before it became a battlefield. So IMHO the German side should get TRPs for just about every crossroads, farm complex, town, hilltop and any other tactically meaningful spot of ground, regardless of the battle type or length of time the FOO had been there.

That makes perfect sense, i will utilise that in my artillery rules for the Axis forces, thanks for the input.

[YankeeDog]

Bear in mind that a lot depends on what kind of asset you're talking about. Very often, the first thing an infantry company would do on gaining ground would be to register targets for the organic mortars and -- the 60mms and/or 81mms. So in the case of these assets, TRPs would probably be established in less than a half hour from the gaining of the new objective. But heavier, longer-ranged assets might take much longer to register. In the case of registering TRPs on newly gained ground, a lot depends on whether the artillery batteries are moving up to a new position or not.

On defense, the opposite can happen. That is, if a force on defense falls back a click or two to a new defensive line, the heavier assets to the rear may already have targets registered in front of the new MLR, but the lighter mortars may need to re-register as they will have had to change position in the retreat.

Unfortunately, in CM TRPs are one size fits all (advantaging everything from MGs to Battleship guns), so you have to make some compromises. But it is important to consider what support assets are being depicted in the battle before estimating what a reasonable number of TRPs might be.

In regards to the Germans generally being in well-prepared defense and having a lot of TRPs, I would say this is generally true. However, I think an important qualifier on this is that German artillery assets in Normandy were subject to a hell of a lot of counterbattery fire and air interdiction, which among other things forced them to reposition frequently. This might disrupt any registered fire plans (or simply render support assets completely unavailable at certain times/places). This was probably more significant for the heavier artillery assets than light stuff like mortars, which are easier to conceal and can shift position quickly.

[noob]

For the Allies, I think TRPs are more a function of:

1. How long the unit has been in the area -- any unit that's been someplace overnight, for example, would always have dug foxholes for a night perimeter and set up at least some TRPs around their position.

2. What kind of assets and HQ level support is involved in the unit's current action.

In a meeting engagement or a hasty attack, an American unit wouldn't have any TRPs, IMHO.

A more deliberate attack with some attached assets would get some TRPs.

And if it's part of some larger operation that involved planning by Division HQ staff, aerial recon, and is more of a setpiece attack that represents the division's main effort, I'd say there should be a lot of TRPs with that -- expecially in the case of the British, where they used those massive preplanned rolling barrages of 25-pounders with the infantry following 300 yards behind.

(To do that, you'd want to set up a whole parallel string of TRPs so the FOOs could call in a new medium mission/medium duration every 3 minutes to "lift" the barrage 300 yards to the next line)

As far as Allied forces go, given one operational turn represents two hours real time, i think a force that has occupied a hex and been unmolested for a full turn would have the opportunity to drop spotting rounds but only on targets with a LOS from the main defensive line, thanks again for the input.

[noob]

Bear in mind that a lot depends on what kind of asset you're talking about. Very often, the first thing an infantry company would do on gaining ground would be to register targets for the organic mortars and -- the 60mms and/or 81mms. So in the case of these assets, TRPs would probably be established in less than a half hour from the gaining of the new objective. But heavier, longer-ranged assets might take much longer to register. In the case of registering TRPs on newly gained ground, a lot depends on whether the artillery batteries are moving up to a new position or not.

On defense, the opposite can happen. That is, if a force on defense falls back a click or two to a new defensive line, the heavier assets to the rear may already have targets registered in front of the new MLR, but the lighter mortars may need to re-register as they will have had to change position in the retreat.

Unfortunately, in CM TRPs are one size fits all (advantaging everything from MGs to Battleship guns), so you have to make some compromises. But it is important to consider what support assets are being depicted in the battle before estimating what a reasonable number of TRPs might be.

In regards to the Germans generally being in well-prepared defense and having a lot of TRPs, I would say this is generally true. However, I think an important qualifier on this is that German artillery assets in Normandy were subject to a hell of a lot of counterbattery fire and air interdiction, which among other things forced them to reposition frequently. This might disrupt any registered fire plans (or simply render support assets completely unavailable at certain times/places). This was probably more significant for the heavier artillery assets than light stuff like mortars, which are easier to conceal and can shift position quickly.

For the sake of simplicity i'm going to allocate one TRP to each artillery battery, if the mortars want to use them fair enough, as for creating limitations on Axis artillery, in future operations i'm going to allow the players to use the air support available in the operational game, which will force the Axis to either stack any AA assets around them or move them which will create the movement penalties you mention as it takes a full operational turn to set up and fre after movement so any artillery that is forced to move will be out of action for at least 2 operational turns or 4 real life hours, thanks for the info.

[MikeyD]

CM:BN has a new artillery option in the game -'harrass'. Used in conjunction with TRPs its supposed to represent denial of movement artillery missions. You pick a choke point on a map (intersection for example) and fire blind to those map coordinates at a low ROF to dissuade the enemy from transiting the area. TRPs do seem to lend themselves to abuse in the game, though, combining blind targetting with "eye of God' player overview of everything going on. In real life artillery was tied to its radio/land line net and there wasn't always an omniscient observer available to order the optimal artillery strike at just the right moment.

[Michael Emrys]

However, I think an important qualifier on this is that German artillery assets in Normandy were subject to a hell of a lot of counterbattery fire and air interdiction, which among other things forced them to reposition frequently. This might disrupt any registered fire plans (or simply render support assets completely unavailable at certain times/places).

In addition to that, both sides were moving formations around to different parts of the line as new formations became available, or old ones needed a rest, or the main point of attack was shifted. Any time a formation with its supporting artillery was moved, the new units would need to go through the TRP acquiring procedure all over again.

Michael

[JonS]

Any time a formation with its supporting artillery was moved, the new units would need to go through the TRP acquiring procedure all over again.

They shouldn't do, if they've any pretense towards calibration and professionalism.

Target records should, in principle, be able to be shared between incoming and outgoing fire units, as long as both sets of guns are calibrated (that is; firing at a known difference to the ideal standard represented by the tabulated firing tables), and both sets are on the same level of survey when they fire on the targets.

The incoming guns would probably need to fire a series of registration missions to confirm survey and establish the corrections of the moment (ie, what way is combined effect of the wind blowing in various directions at different altitudes, and differences in humidity and air density, and several dozen other factors that affect where the bombs land), but the outgoing guns would have had to do that anyway.

Even given that, though, incoming guns would probably end up with a different set of recorded targets because the tactical situation would be different, their stance could be different, the enemy and its stance could be different, and simply that different commanders view ground differently, and make different deductions from that, which leads to different requests for recorded targets.

But none of this has anything to do with CMBN

[gunnulf]

Certainly for the German side I think there should always be a hefty set of TRPs, just about everywhere they might be fighting. That's because they had months to prepare their Normandy defenses and the fallback line of strongpoints and resistance nests, and had been living and patrolling and training in the area long before it became a battlefield. So IMHO the German side should get TRPs for just about every crossroads, farm complex, town, hilltop and any other tactically meaningful spot of ground, regardless of the battle type or length of time the FOO had been there.

Not so sure that logic applies universally. Certainly if you are talking about the first few days after D-Day in defence of static positions, but after that the majority of German forces in Normandy would have come in from elsewhere. Additionally TRPs are effectively calculations of bearing/distance from batteries to the target point and again while in the first days your logic applies after that then battery locations would be relatively newly established. That said it would be standard to begin the registration process whenever a defensive position was established.

[Michael Emrys]

They shouldn't do, if they've any pretense towards calibration and professionalism.

Target records should, in principle, be able to be shared between incoming and outgoing fire units, as long as both sets of guns are calibrated (that is; firing at a known difference to the ideal standard represented by the tabulated firing tables), and both sets are on the same level of survey when they fire on the targets.

That assumes the incoming guns are sited in the same locations as the outgoing ones. Is that known to be the case? Always? I for one do not know, but I have been proceeding on the assumption that the incoming batteries might well want to develop their own sites for various reasons, including avoiding existing counter battery fire, changes in lines of supply, adjusting to changes in the front lines, etc.

Michael

[Lt Belenko]

In addition to that, both sides were moving formations around to different parts of the line as new formations became available, or old ones needed a rest, or the main point of attack was shifted. Any time a formation with its supporting artillery was moved, the new units would need to go through the TRP acquiring procedure all over again.

Michael

I think an Arty unit in WWII would stay in place with a few exceptions. Threat of being overrun, being out of range as front line moved forward, being subject to counter battery fire/bombing, or getting ready for an offensive. In WWII units were pushed pretty hard and stayed in the line for a long time.

[JonS]

That assumes the incoming guns are sited in the same locations as the outgoing ones.

Actually; no. It doesn't. Edit: it shouldn't. As long as the new and the old are on the same survey state then they should be able to share data.

'Survey state' has a technical meaning that involves a lot of detail, but for the purposes of this discussion consider it to mean 'used the same maps, and the same survey instruments, to the same level of accuracy.'

Surveying batterys and regiments in so they were all on a common survey state (specifically so they could share data and all fire accurately on the same targets without individually adjusting on to each one) was one of the main roles of the RA Survey Regiments. Eg, 4th Durham Survey Regiment. That's basically the same technical problem as one fire unit replacing another, regardless of whether they occupy the same literal positons or not.

Eidt: again, this has nothing to do with CMBN

[JonS]

I think an Arty unit in WWII would stay in place with a few exceptions.

Yeah, pretty much. Blackburn's memoirs contain a map showing the locations his bty and regt occupied in Normandy, including a couple that were overlooked by the enemy. What's surprising to me is how seldom they moved - basically they only moved when the frontline advanced away from them, and they needed to displace forward to continue to provide support.

There are some partial explanations for the lack of movement, that don't apply to the Germans; the Canadians pretty much advanced in a straight line south from JUNO until they got to Falaise, and they weren't switched from one flank of the beachhead to the other and back again, as some of the British divisions were. The British half of the beachhead was heavily congested, so often there just wasn't anywhere else for the guns to go to, even if they'd wanted to move (and at times they most definately did!). The German artillery was completely dominated, and unable to mount an effective CB effort, meaning that by-and-large Allied gun positions were unmolested - evidence of that can be seen in photos of the period in which camoflage is notable by its absence.