Thread by @ReassessHistory

Counter-Mortar Organisations

In the run up to Overlord, Anglo-Canadian forces had prioritised building highly efficient integrated fire control systems for artillery, aiming to overwhelm their German opponents with volume of fire & relative accuracy. /1

#WW2 #SWW #History

Since 1940 there'd been a massive series of equipment, establishment, doctrinal and communications changes that now allowed almost anyone with a functioning wireless set to request accurate fire on a target.

In short, most opposition could be demolished. /2

Infantry battalions operated closely with their counterparts in the supporting Royal Artillery Field Regiment.

Each infantry brigade had 3 inf bns and had a field regiment (along with other assets) as part of it's 'Brigade Group'. As the field regiment had 3 batteries... /3

with each battery of eight guns, each battalion had it's own dedicated battery for support.

Battery commanders frequently acted as FOOs (with their small supporting team) to direct fire on near-permanent attachment to the infantry.

Each bn had a minimum of one FOO attached. /4

In truth... usually 2-3 were kicking about, with the infantry company commanders able to request fire as needed.

Some determined oppo proving too sticky for eight 25 Pounders? Mike Target requests the full regt of twenty four guns. /5

Even keener oppo? Uncle target. Full divisional compliment of 72 guns.

Well keen oppo bruv? Victor Target brings down all available corps' artillery.

These were the most frequent for an inf bns, but do escalate even higher... /6

We knew the principle 25 Pounder was actually a bit lacking in taking out dug in enemy infantry, some German troops actually claimed that 25 Pdr bombardments were really a demonstration in overwhelming psychological warfare. /7

As a result you have your AGRAs on hand, Army Group Royal Artillery, usually containing a mix of Field and Medium Regiments. The latter is where the pain is really dealt, with their 4.5" and 5.5" guns.

These weapons offer serious firepower... /8

and are really intended to boost field regiments' viability in providing effective fire.

They also provide essential counter-battery fire, ably assisted by integrated support apparatus from sound ranging and survey regts. If a German gun goes bang, they find it and... /9

medium regiments kill it.

In fairly short order German guns will be unpicked and eliminated, thus steadily reducing their ability to fire their own counter-battery fire & hit British troops.

Sharp. Clinical. Efficient. /10

A curious problem emerged that saw German mortars achieving serious killing in Normandy. In short they could fire a few rounds then bugger off before retaliatory fire could be directed.

Sneaky buggers. /11

Density of attacking troops was much higher than the defenders, highlighted during (and after) Operation Epsom by the plight of the Scottish Corridor where we crammed strength of about 4-5 divs into a bloody narrow area.

Almost every round was guaranteed to hit something. /12

German arty remained effective in this messy period, ably directed from Hills 112 and 113, and towards Carpiquet - nailing British troops on three bloody sides. /13

One solution was to reduce troop density, for infantry battalions to send large cadres of men to be Left Out of Battle (LOB), but this put more pressure on remaining forces. As a rule of thumb between 10-30% of strength was assigned LOB or so during this period. /14

But this did little to stop the enemy guns, and most important mortars firing.

Formations in Normandy had been troubled by mortars for some time and had to find a way around the problem. Concentrations by FOOs took too long to arrive and the mortar bombs kept coming. /15

British commanders pledged to send ten rounds back at the enemy for every one sent at them, but this was nothing more than a morale exercise unless they actually hit something.

Bns began assigning spotters and their own mortar OPs to scan the ground... /16

for mortars and then direct fire. The problem was, as before, a good mortar crew could lob five mortar bombs then scarper off to another dug in emplacement long before retaliatory fire could blow them to kingdom come.

Time was the essence. /17

This also conflicted with the RA's other needs for other shoots and pre-planned barrages.

The problem was this persistent nuisance fire was inflicting a substantial number of casualties on static formations and sapping morale.

The CMO oversaw improved liaison... /18

while integrating OPs and inf bn's own endeavours with the field regiments & divisional machine gun battalion's 4.2" Mortars.

Inf bns own 3" Mortars were really too short ranged to be effectively used in the CMO role. /19

Loitering Aerial Observation Posts really helped develop a database of known enemy positions - aided by Photo Reconnaissance and confirmed by infantry patrols.

So assets slither out at night and aim to beat the enemy at int acquisition. /20

AOPs have a useful side effect as the sight of an Auster trundling overhead tends to discourage German guns and mortars from firing.

In a matter of days the British conclude the German mortar superiority really stems from arty inferiority. /21

So we copy it. Racing around 4.2" Mortar Platoons on 'Nomad' shoots where they turn up in odd places to the front line and start hitting German positions.

This provokes German defenders no end and can lure them to engaging those on Nomad shoots... /22

the problem is, as we've cloned their model, the 4.2"s have long gone.

Due to the problem of density... the infantry in the area have not. Unsurprisingly Nomad shoots are not popular with infantry.

A good lure tho'. /23

The more active German mortars are, the more likely they are to be caught out esp with more eyes scanning for them.

Compass bearings were taken from suspected mortar positions & the arrival of bombs timed to offer field regiments a rough targeting area. /24

Yeah... this was crude but offered a basis to help CMOs in their role of preventing "our own troops getting 'browned off' by having to sit in their slit trenches while being mortared and shelled without any form of [infantry] retaliation.' /25

The divisional CMO compiled as much data as possible and began analysis, looking to refine methodology.

For the 3" Mortars shortcomings, these platoons were soon integrated and near-defunct 40mm Bofors guns reroled to target suspected mortars with indirect fire. /26

Analysis revealed that certain sectors would be routinely bombed at particular hours, so defences and readiness could be stepped up.

The Germans were predictable in this regard (as they found the British oddly enough)... /27

CMOs also managed to drop time on response massively to within 45 seconds of a mortar being sighted to engagement with retaliatory fire.

Massively reducing the window for German crews to engage the British and safely race away, reducing viability. /28

Prisoners are increasingly screened with mortar crewmen identified and asked a specific series of questions about their experience - and cross-reffed with CMO data.

Intelligence, data and constantly improving systems underpinned the CMO model. /29

So were CMOs that effective?

Tricky.

German mortar fire certainly decreases as they improve, but so does British density in the core sectors as gains are made elsewhere and we have more ground to cover.

Thus the incoming harassing mortar bombs became less effective. /29

These were cheap organisations that evolved in field to deal with a troubling threat and remained on hand for the campaign throughout NWE, oft using near-defunct weapons systems to achieve goals.

They undeniably did manage to save lives and discourage enemy mortars... /30

but to what extent? Harder to judge.

As the campaign becomes more mobile in August this problem becomes a rarity - but.... within a matter of days of introducing CMOs the German use of mortars for harassing tasks starts to reduce - a trend which does follow through July. /31

German density is also decreasing as their formations are more stretched out, although various mortar units do continue to flit about sectors and give an enhanced impression of strength.
In short, more work is needed on German experience of CMO & how they shifted tactics. /thread