Mrsi In Actual Operations

[kaikaun]

How often has Multiple Round Simultaneous Impact (MRSI) capability actually been used in war? Has it been used even once? If so, how many rounds were typically in the salvo fired by one gun?

 

My personal impression is that MRSI has never been used in anger, only in demonstrations, but I'm not sure. Does anyone here have better information on this?

[lastdingo]

How often has Multiple Round Simultaneous Impact (MRSI) capability actually been used in war? Has it been used even once? If so, how many rounds were typically in the salvo fired by one gun?

 

My personal impression is that MRSI has never been used in anger, only in demonstrations, but I'm not sure. Does anyone here have better information on this?

 

2-round MRSI has been used during WW2 already, since some light howitzers possessed greater elevation than 45° and MRSI is even possible with 43° maximum elevation.The German army also created MRSI-like surprise artillery strikes by massing several battalions of field artillery for a time on target fire mission.

 

For more research:

http://sill-www.army.mil/firesbulletin/previouseditions.html

[kaikaun]

Thank you very much! That is a good start. So two rounds at least have been used in actual ops.

[Chris Werb]

Nigelfe will correct me, but I think the British Army did an entire Corps or maybe even Army level "Time on Target" shoot on at least one occasion in NW Europe. That was not MRSI, but it was a lot of barrels firing to achieve simultaneous impact.

[Olof Larsson]

Nigelfe will correct me, but I think the British Army did an entire Corps or maybe even Army level "Time on Target" shoot on at least one occasion in NW Europe. That was not MRSI, but it was a lot of barrels firing to achieve simultaneous impact.

 

Sounds like hill 314, during operation Lüttich, were a single US infanty batalion had corp artillery available 24/7.

Considering they could call in artillery at one of few german MSR's below the hill, the germans wanted to take the hill,

and from memory they tried to do so with divisional attacks, that were foiled by the speed,

accuracy and precision of the artillery the defenders could call in.

 

The soviets had similar experiences with the finnish artillery in 1944,

as the finns ideal method was to focus all the guns

that could reach the target and to keep the firemission short in duration.

All in the hope, that it would compensate for their lack of guns

(numbers, range and fire power) and lack of ammo.

[Chris Werb]

From Nigelfe's excellent site:

 

Timings are not entirely clear. In the early days a Victor target by 1st Canadian Corps in Italy using 668 guns (30 Canadian, British and Polish regiments) was timed at 33 minutes to time on target (which was a slow method). By the end of the war Victor targets with 1000 guns were not unusual, the British was the only army routinely using such large concentrations against opportunity targets. From early 1944 Mike, Uncle and Victor targets were used increasingly in Burma. An army (William) target was the largest but because there was no HQRA at Army level it was controlled by one corps HQRA requesting additional fire from another that was 'In Support'.

 

http://nigelef.tripod.com/maindoc.htm#Timed%20or%20On-Call?

[shep854]

I've read here and there that Allied arty was what the Germans truly feared, due to its flexibility and speed of response.

[Sardaukar]

 

Nigelfe will correct me, but I think the British Army did an entire Corps or maybe even Army level "Time on Target" shoot on at least one occasion in NW Europe. That was not MRSI, but it was a lot of barrels firing to achieve simultaneous impact.

 

Sounds like hill 314, during operation Lüttich, were a single US infanty batalion had corp artillery available 24/7.

Considering they could call in artillery at one of few german MSR's below the hill, the germans wanted to take the hill,

and from memory they tried to do so with divisional attacks, that were foiled by the speed,

accuracy and precision of the artillery the defenders could call in.

 

The soviets had similar experiences with the finnish artillery in 1944,

as the finns ideal method was to focus all the guns

that could reach the target and to keep the firemission short in duration.

All in the hope, that it would compensate for their lack of guns

(numbers, range and fire power) and lack of ammo.

 

 

Actually, number of guns and mortars was not a problem anymore for Finns in 1944 and neither was ammunition supply (unlike in Winter War). Also, major invention was from 1943 so called "korjausmuunnin" (http://fi.wikipedia.org/wiki/Korjausmuunnin (in finnish, but with Google translate you might make some sense out of it). It relieved forward observer from making complex correction calculations and allowed basically unlimited number of artillery units to participate firing same target (barring range and communication issues). Firing units with "korjausmuunnin" only needed to know coordinates of target and direction that FO was looking in angular mils.

 

As the article says, one Finnish record was hitting one enemy concentration in Tali-Ihantala battles simultaneously with fire from 21 artillery battalions and one heavy artillery battery.

 

Korjausmuunnin also allowed Forward Observer to redirect artillery fire into any additional targets in his field of view very quickly. Also, type of firing artillery didn't matter, since e.g. mortars would use same method.

[nigelfe]

Large scale planned ToT engagements were a bit difficult for UK forces before 1942 because of the need for synchronised time (synchronising by radio was an OPSEC issue), the BBC then started broadcasting time signals which greatly simplified the problem (and UK used HF not VHF radios so BBC signals were receivable). Planned engagements were theoretically feasible from about late 1915 onwards, but it wasn't until procedures for massed fire against opportunity targets were developed that M, U, V, W targets became possible. The UK system enabled authorised observers to order these massed concentrations, ordinary observers could only request them, I'm not sure which other armies (apart from Cwth & Polish) used authorised observers for massed fire against opportunity targets, in UK's case is was a logical flow-on from all observers being able to order (not merely request) the fire of their own battery. AOPs (arty offrs piloting RAF Austers) were usually authorised for a divisional artillery (72 guns). However, TOT was seldom, if ever, used with opportunity targets, because there was invariably at least a couple of ranging rounds which did away with surprise.

 

Ranging massed fire used cardinal point corrections, for single batteries corrections were on the G-T line. UK observers never had to do 'calculations', I know some armies did, it's up there with the really stupid ideas.

Edited May 16, 2015 by nigelfe

[zaarin7]

What made US Army artillery so feared was that any platoon Leutenant could call in under the right circumstances all the mortars, howitzers and guns of his division but also any mortars, howitzers and guns of the neiborhing divisions AND and Corps and Army howitzers and guns that could range in on his target.

 

In the 1920's the Army Artillery folks looked at what had been done in the war just passed. Budget's were small but were enough to design and test the controll systems and the guns and mortars that would be used in W W II.

[nigelfe]

Actually, as far as US artillery went observers could only request fire (not sure about infantry mortars). One reason for this is that in the US arty commanders were to the rear (eg in FDCs). The decision to authorise a fire request was a matter for the FDC and upwards. This system was inherently slower than the British one.

 

In the British and similar armies it was possible for an artillery observer to order large concentrations of fire, although an observer had to be authorised to do so, and not all observers were at any one time, obviously it wouldn't work if lots of observers were ordering all guns to fire at different targets at the same time (although an observer was always able to order (ie not request) fire to his own battery). This followed from the doctrine of putting arty commanders with the supported (ie inf, tank, whatever) commanders, not with FDCs as was the US practice. Being able to order fire was inherently faster than the US procedure of requesting it.

 

No sure about the Sovs, but my understanding, possibly wrong, is that a unit or formation artillery commander could order fire to the batteries/battalions/regiments under command. However, these commanders were forward in their various Command Observation Posts where they could see the battle.

 

It's helpful to remember that for artillery fire control an 'order' is not the same thing as a 'request'. The differences between the US and UK systems continue to this day, they were formally recognised in the 1965 QSTAG.

Edited June 7, 2015 by nigelfe

[Ivanjoe]

The MRSI that op is refering to isnt Time on Target but more like the Pzh2000s ablilty to fire multiple rounds at different angles and charges so that you get 3-5 hitting the target at the same time

[Josh]

I thought that was the very definition of MRSI?

[lastdingo]

The MRSI that op is refering to isnt Time on Target but more like the Pzh2000s ablilty to fire multiple rounds at different angles and charges so that you get 3-5 hitting the target at the same time

 

The effect is almost the same on the receiving end, and simple 2-round MRSI was feasible and done during WW2 as mentioned as well.

[FALightFighter]

I think that, while possible, MRSI without computerized fire control and autoloaders is more of a gimmick. Sure, when you have time to prepare and rehearse you might try it- may for a planned preparation. Most of the time, however, you're going to get going as fast as possible to get the mission completed- waiting to calculate a second set of data so that each gun can land two rounds simultaneously is a waste of time- Mass additional guns, or accept the loss of effects from the second volley to get both volleys there sooner (firing 2 volleys at the same data will only take a couple of seconds, anyway).

[nigelfe]

I think MRSI in any conditions is a gimmick! The number of rounds that can be delivered together depends on range, if range is fairly long and the target only reachable with the top charge, then the max number of MRSI rds per gun is 2. When you can get 3+ rounds onto the target in 10 secs, and it takes an enemy several seconds to react to incoming fire and take cover, why bother?

 

The other point is that there is more to a MRSI capability than a reasonable rate of fire (eg AS90, Pzh2000 and others). First, the FC computers have to be able to do it (ie automatically not with the operator initiating a separate calculation for each trajectory and noting the firing data for each gun) - which FC system can do this? Second the gun's sights have to be able to store the digital data and automatically present it in the right order - which gun can do this? Then the gun detachments have to be trained to get the propelling charges in the right order (there is definite scope for stuff ups here).

 

I actually think MRSI is one of those 'good ideas' (maybe by someone who's experience in running a gun position is zilch) but the practicalities make it a pain in the backside to actually do under operational conditions (never mind training - & GE range safety regulations almost certainly wouldn't fully allow it due to having charges prepared at the gun that could reach outside the impact area and probably needing a safety officer at every gun to triple check that the different charges were the correct ones for the different elevations).

[JW Collins]

I'd imagine that modern fire control computers on something like the Pzh2000 can set it all up without so much effort while the entire effort becomes pointless. Seems like a good way to start a fire mission on a high value target.

[nigelfe]

I wouldn't make any assumptions whatsoever. If it wasn't in the specification it wouldn't have been developed, whether or not it's been upgraded is another matter. The spec would have been written in 1988-90, and I'm not sure that the concept of MRSI had been recognised at that time.

[lastdingo]

PzH 2000 has the digital fire control to receive digital fire mission orders by radio datalink ("Adler") and do a MRSI in a time on target mission of eight (or more) dispersed SPGs with all impacts within about 1-2 seconds and the SPGs leaving the firing position before their own impacts.

Gun laying is automated for this, rate of fire is high enough, and the modular propellant system (one size only) is simple enough.

 

related

https://youtu.be/dl6JeocRsNc

[nigelfe]

IIRC Adler was and is the fire control system, ie it does the calculations for each gun and transmits actual firing data to each gun.

 

Whether or not guns leave the position (and how far they get) before the first round lands actually depends on what the times of flight are. All propellant systems are simple, but you still have to have the right number of charge bags in the right order, and mixing high and low angle trajectories means that charges for successive rounds may be larger or smaller, which increases the scope for errors.

[lastdingo]

IIRC Adler was and is the fire control system, ie it does the calculations for each gun and transmits actual firing data to each gun.

 

Whether or not guns leave the position (and how far they get) before the first round lands actually depends on what the times of flight are. All propellant systems are simple, but you still have to have the right number of charge bags in the right order, and mixing high and low angle trajectories means that charges for successive rounds may be larger or smaller, which increases the scope for errors.

 

There used to be propellant bags of different sizes in use with the howitzers of old. Some older board members may still remember those.

[Ken Estes]

Ach! That would be obsolete, not conforming to just-in-time [or not] logistics © doctrine!

[Thonar3]

IIRC Adler was and is the fire control system, ie it does the calculations for each gun and transmits actual firing data to each gun.

 

Whether or not guns leave the position (and how far they get) before the first round lands actually depends on what the times of flight are. All propellant systems are simple, but you still have to have the right number of charge bags in the right order, and mixing high and low angle trajectories means that charges for successive rounds may be larger or smaller, which increases the scope for errors.

0. Hello, Board!

1. It is currently ADLER II

2. ADLER is only exchanging data between different Artillery-Systems (MARS, Fennek, PzH2000,...), it doesn't calculate the fire-solution for the systems itself, but only feed the systems with the necessary informations.

3. MRSI was, as far as I know, effectively used by the Dutch and Germans in Afghanistan, but I need to find the reports again.

[nigelfe]

Most howitzers still use propelling charges with increments of various sizes. Modular charges have yet to be widely adopted, but since they reduce cost (in theory) then Treasuries should like them.

 

If you've only deployed a handful of guns then MRSI is probably helpful. Of course it depends on accuracy of predicted fire. It's somewhat pointless if fire has to be adjusted because the benefits of surprise, which is what MRSI exploits, isn't there. My understanding is that in Afg Pzh2000 had to always fire a couple of warming rounds if the guns were cold. This seems to be problem unique to this gun.

 

The merits of doing full calculations on the gun are debateable, processing time won't be noticeably different given up to date computers, and meteor data has to be distributed. However, if you are using gun manoeuvre areas then there are benefits. The risk is a lack of independent gross error checks on firing data.

Edited June 19, 2015 by nigelfe

[Thonar3]

If you've only deployed a handful of guns then MRSI is probably helpful. Of course it depends on accuracy of predicted fire. It's somewhat pointless if fire has to be adjusted because the benefits of surprise, which is what MRSI exploits, isn't there. My understanding is that in Afg Pzh2000 had to always fire a couple of warming rounds if the guns were cold. This seems to be problem unique to this gun.

I never heard of that before... despite there were some problems with the cooling on the FCS during hot climate... but "Warning Shots" were extensively used (mostly Illum) as "Show of Force".