Tactical handling of the 4.2-inch mortar in the MG Battalion (1944-45 org)

I was wondering if anyone had come across any comments or directions on the handling of the 4.2-inch mortar, with particular regard to the Machine Gun Battalion organisation introduced with WE II/240/1 of February 1944.

Without going fully down the rabbit hole concerning the organisation of support units in the Infantry Division begun in late 1942, by mid 1943 the Brigade Support Group had appeared. This included a Heavy Mortar Company with two Platoons, each of four 4.2-inch mortars. The handling of the Platoon is detailed in Small Arms Training pamphlet No.25, a copy of which I have as a reprint from MLRS books. Army Training Instruction No.7 gives some general notes on the tactical handling of the Brigade Support Group, which includes the Heavy Mortar Company as two Platoons, total eight 4.2-inch mortars.

When the Support Battalion was abolished in 21 Army Group, and a revised Machine Gun Battalion introduced, it included a fourth, Heavy Mortar Company, now of four Platoons, with a total 16 4.2-inch mortars. To the best of my knowledge, there was no ATI, MTP or other document issued giving any comments on the tactical handling of the February 1944 MG Battalion. As far as the Machine Gun Companies go, their organisation was little changed from the Brigade Support Group, and the comments in ATI No.7 were largely still applicable.

When it comes to the handling of the Heavy Mortar Company however, things must have changed somewhat. I think I have made the inference that the four Platoons could be allocated on the basis of two per Brigade, if operating 'two up', which would deliver the same weight of fire as in the old Brigade Support Group. However, I do not think I've seen any contemporary evidence for this, and the Heavy Mortar Company organisation did not have a built in ability to neatly divide into two parts (it could do but not without some complication to Admin and communication). So for those more familiar with the activities of the four Regiments undertaking the Machine Gun role, with particular reference to Northwest Europe, is there any reference to their handling of the 4.2-inch mortars? I realise these were slotted into a Divisional fire plan as required, and so things varied, I did wonder though whether there was a tendency to spilt the Heavy Mortar Company to provide two Mortar Platoons to each Infantry Brigade when working with two Brigades up?

Thanks,

Gary

 

Operational ORBATs should help. These list the allocated units and command structure (sometimes communication) for specific operations. These helped me with the use of the MG Coys. Trying to find specific references may be hard without going to the War Diaries. I'll try to find time to dig out some.

 

Off the top of my head, I recall a comment that their utility was restricted by a platoon only being able to find one OP.

 

No expertise but an interesting topic. There is no direct discussion of 'doctrine', but examples from the history of the Cameron Highlanders of Ottawa (MG) of 3 Cdn Div.

D-Day
Two Pls with 7 Bde, none with 8 Bde
Two Pls with the reserve 9 Bde

Bridgehead battles
Two Pls per Bde up

Op Windsor
'D Coy came under one command and began functioning as one Coy instead of two half Coys'. 8 Bde plus one Bn assault

Op Charnwood
Effectively a two Bde attack in two phases. Two Pls supporting initial 9 Bde assault, and then the 7 Bde follow-up. One Pl interdiction for first phase, switch to 9 Bde for second phase. One Pl supporting 8 Bde

Remainder of Normandy Ops not very specific.

Op Wellhit
One Bde attack, one Pl in support

Cap Gris Nez
One Bde attack, two Pls in support
Op Undergo
One Bde attack, two Pls in support
Could consider these as a single operation with two Bdes up

Op Switchback
7 Bde assault with three Pls
One Pl moved to reserve 8 Bde on D+1
One Pl initially with 9 Bde for diversionary attack on D+3, one Pl moved from 7 to 9 Bde when it went in

Op Veritable
Two Bdes up, support details vague other than four Pls on the initial pepperpot. Instances in the course of the battle of one or three Pls in support of a Bde

Op Blockbuster
Again a bit vague and a phased attack, but appears four Pls with the initial Bde, two Pls then switch to the second Bde, then one of the remaining switches to the third Bde

All together, I conclude that while two Pl/two Pl for a two up attack was a baseline, there was a lot of flexibility down to the use of individual Pls

 

A thought - this may be a product of the tweaks to ToEs across the board to reflect lessons learned regarding NCO junior leaders and shortage of junior officers. If, in wartime, the role of the unit was to be subdivided into individual platoons as well as pairs, each platoon commander would need a level of leadership training/experience and a rank reflecting this. This could render sub-divided command at the next level superfluous. No change in doctrine, just admin. ?
In action, the MG platoons were 'Under Command' of the unit they were supporting so needed no outside structure. I assume this was the case with the mortars too.

 

Here's the ORBAT for Operation Martlet 25-26 June '44 - 1/7DWR assault on Rauray. It shows the 'shape' of a Normandy formation. Interestingly the 4.2in Mortar pls. are 'In support' rather than a direct asset of the Bn. OC so they can choose how best to respond to a 'request', similar to the tanks, however not the anti-tank guns (this fits with reports of mis-use of M10s). From C.N.Barclay' History of the Dukes. I have seen the war diary.

 

Thanks all for the above, the ever changing allocations of 4.2-inch Pls as seen in 3rd (Cdn) Div may well show just how varied things went.

I had a look last night at ATI No.7, and SAT No.25, and the preamble in both is pretty much the same, written when the Bde Sp gp was in existence. They certainly underline the point that the 4.2-in Pls were not to be placed under command of an Inf Bn to bolster its firepower but were Bde level weapons to be used to influence the Bde battle. Likewise the Platoon was the basic fire unit, and Sections were not expected to be handled independently.

When the Bde Sp Gps went, the new MG Bn had four 4.2-in Pls for three Inf Bdes, or nine Inf Bns, giving no obvious correlation I suppose. (The US Army 4.2-in Chemical Mortar Bns made the same comment, that their 1943 org didn't mesh well with an Inf Div or Regt, but they didn't adopt a new format until late 1944).

I've found some comments from Italy, where the Sp Bns requested they be able to have six 4.2-in Pls in their Mortar Coy, as they felt that two per Inf Bde was essential. This was rejected on grounds of manpower and also the situation then prevailing regarding ammunition expenditure for the weapons. 6th Armd Div did get permission to have two MG Pls and two 4.2-in Pls in their equivalent to the Indep MG Coy used in the Armd Divs in 21 AG.

I was trying to write something on the tactical handling of the later MG Bn, but without a contemporary manual as a basis to work from it's been slow going! It does feel more like the mortars and MGs were allocated on a operational basis, though the Vickers guns remained on a pretty familiar scale under the new WE.

Gary