Priests and 25 pounders in Normandy

I'm sure there's an Operational Reseach report that looked into the 'many small bangs are better than fewer big ones', essentially validating it in the context of suppression/neutralisation.

The post-war increase in field artillery to 105/155 was, I believe, primarily to increase range. However, there is also the oft-stated justification that 155mm was capable of disrupting armoured formations. This school of thought seems to track back to a Panther in Normandy being immobilised by having its track cut by a splinter during a medium artillery stonk...

Of course, bigger projectiles mean bigger payloads which opens up the possibility of submunitions to reinvent the concept of many small bangs, though from fewer, bigger guns. Then you've got (had?) MLRS adopting a similar philosophy with it's 'clear a grid square' capability.

 

This is an interesting discussion.

As far as 50th Division goes, that outfit had multiple tasks on D-Day, so many it was brought up to four infantry brigades for the assault. It had to get inland to deal with several objectives, some of them in opposite directions, so having three SP regiments which could get off the beaches to accompany the infantry and armor and deploy more quickly made sense.

50th Div also had a full battalion of American M12 155mm SP guns attached, the only complete American ground combat unit under British command in NEPTUNE. This was in the nature of an experiment to see if the M12 could serve as a tracked equivalent of medium artillery in British service, possibly for use with armored forces. I think we had a document about this on the website at one time. Anyway, the M12s did well enough when they were with 50th Div, but in the end of course the M12 was not adopted for British service. I kind of wish they had been; they proved very useful to the US Army in fortification busting on the Siegfried Line.

Interesting to hear of at least one case of a Sexton KO'ing an enemy tank. I wonder how they did it; the 25 pdr, unlike the 105, did not have a HEAT round and the standard 25 pdr AT shot was not especially formidable. Plunging fire, perhaps? I had a reference in my book about 50th Div Sextons doing that.

The 25 pdr-vs-105 debate is one of those apples-and-oranges things. The 25 pdr's virtues were range, speed and accuracy of fire, and fairly easy handling of the towed piece. The 105 had the more destructive HE as well as HEAT for anti-armor emergencies. In my idle moments (call me Justin Eidelberger) I have been designing a notional WWII Allied army with a mix of British and American equipment. The 1944 divisional TOEs have both the 105mm and 25pdr, 105 field regiments for the heavy trench-smashing work and 25 pdrs for longer range shooting. Yes, it complicates the ammo supply somewhat, but on the other hand you get more tactical options.

 

As noted above it is a difficult direct comparison. The 105-mm US round came in at 33 pounds to the 25 pounds of the British 25-pr, so one-for-one could deliver a greater HE content, while the 25-pr had a little longer reach. Conversely, the standard RA 25-pr Bty had eight guns while the US 105-mm Bty had four (except in Armd Div when it was six, all SP). Resultantly a British/CW Bty could deliver a greater salvo than a US, or indeed German one, again on a one-for-one basis. However concentrations could be augmented by lots of non-Div units in both RA and US practice. In the immediate post-war I think the US was moving to a standard six guns for 105-mm Btys in Inf and Armd Divs.

I think Nigel Evan's site might have some info on 'bursting power' of the 25-pr to other guns, I'm sure I posted on a similar thread 'somewhere' not too long ago.

British Artillery in World War 2

Gary

 

M1s and 30-06 Brens for all?

 

The U.S. Army had seen little requirement for the M12 initially so production was limited to just 100 examples (plus 100 M30 cargo carriers); consequently they were in very short supply by the time their usefulness was fully appreciated. 74 M12s (& 74 M30s) were remanufactured and modernised before being sent to the ETO in 1944. By my reckoning the attached documents from WO 229/52/26 account for 91 M12s so I presume the remaining 26 went to the ETO also. The correspondence also gives a sense of how jealously these few M12s were being husbanded by 12th Army Group in November 1944, clawing back those from Italy and most from 6th Army Group, so the British may have been unable to get their hands on any even if they had wanted to.

 

Nice info on the M12’s guys, however back to M7’s and towed 25pdrs…

Nup, I’m NOT comparing US Artillery organisation/doctrine to British Artillery organisation/doctrine. This all about Brit/Canadian Regiments ‘trading in’ their 105mm equipped M7’s for towed 25 pdrs. Again, the objective reason at the time was ammunition supply.

An extract from “Assault Division” (by Norman Scarfe ex 76th Fd Regt, RA) proves it wasn’t just a bunch of winging colonials who had a bad attitude…

“During the afternoon a hot and dusty 76th Field Regiment rejoined the Division and 8 Brigade from the area of Bayeux; there they had spent a week hastily refitting with 25-pounders in place of the cherished Self-Propelled 105 mm.s with which they had landed on Queen Red Beach. Each of the Field Regiments had to make this deeply regretted exchange in turn as the Americans were experiencing a shortage of 105 mm ammunition and could supply us with it no longer…”

The 13th Fd Regt RCA’s cartoonist was spot on. Compared to a 105mm the 25 pdr could really be described as a peashooter.

It’s all about weight of shell, AND, weight of explosive filler therein. Its all about mathematics and reality, not theory. Again, this is NOT about comparing US units with Brit units here. This about the same Brit/Canadian units using the same operational methods, with different equipment…

At 33 lbs the US 105mm HE shell was 30% heavier than the 25pdr HE. Importantly the 105 had more than two and half times more explosive filler. The 105 had a considerably higher lethality/destructive effect.

The job of a Brit/Canadian Forward Observer was (in simplistic terms) to ‘kill the bastards’ on the other side (or at the very least keep their heads down). With a more effective shell you do more damage. It’s not rocket science.

The practical fire rate of both weapons was 3 rounds per minute. Both guns could be fired at faster rates. I don’t believe for a micro second that the gunners of 13th Fd Regt RCA (et al) were told they could ‘take it easy’ because the 105 was a heavier round than the 25 pdr!

As for range, the 25pdr could indeed out-range the 105. When using supercharge, that is. The 25 pdr was indeed a sturdy design, however firing supercharge for prolonged periods and/or high fire rates was just asking for problems. Meanwhile the 105mm mounted in the M7 had an elevation of just 35 degrees – limiting its range whilst the vehicle was on level ground. However, all you need is a reverse slope with a gradient of around 8-10 degrees, and voila, you’ve got maximum range for your 105.

But how often were units engaging targets at maximum range anyway (ie. 13,400 yards for the 25 pdr)? Radio equipment of the period had theoretical maximum ranges, but in reality (in the rolling terrain of Normandy, for example) you’d invariably end up being closer to the ‘bad guys’ than you’d like to be. Close indeed, where counter battery fire was a threat – where having a bit of armour protection was a damn good idea (ie. M7).

And, of course they had a fully tracked vehicle, with good cross-country performance (ie. M7).

It’s no wonder the British and Canadian Regiments, who had to actually fight the battle, not theorise about artillery doctrine, were loath to lose their M7’s.

Arty

ps. And, of course, it took another twenty odd years for the Brits to finally move on from the 25 pdr to a 105. It was not only about increasing the range, but importantly, increasing the lethality/destructive effect of the shell.

 

It begs the question: did any units exchange Priests for 25-pr Rams and leave their opinions?

 

One of the candidates has been mention, 19 Fd Regt RCA moved from M7 to Sexton, so they retained their SP status throughout. Likewise 5th Cd Armd Div switched its SP Regt from 105-mm to 25-pr when they transferred from Italy to NWE; I'm not sure if that was 8th or 17th Fd Regt? I know there are a ton of Cdn War Diaries on line now, I've never gotten myself acquainted with the reference system for finding them but perhaps someone knows if 19th are among them? It would be nice to have a user report that wasn't in satirical format.

Actually found the 19 RCA WD, after a bit of trial and error;

War diaries : T-16428 - Héritage

Gary

 

War Diary of 19 Cdn Fd Regt:

24 Aug 44
New 25 Pr S.P.'s (Ram) drawn at 0900 hrs and 105mm equipment turned in. Day spent in checking new equipment for deficiencies and in cleaning up guns and S.P.'s. All Regtl transport also being overhauled. Sig and gun stores were drawn and issued to batteries.
Weather - mostly fair with showers in afternoon and envening.

25 Aug 44
Maintenance of vehicles continued, as was checking over of new equipment. Trainin on new equipment carried ou with the assistance of IG and his staff. One S.P. was badly burned when it caught fire while some welding was being done. It wil have to be replaced. Bath parades were held in the afternoon.
Weather - fine and very warm

26 Aug 44
Maintenance on vehicles and guns being continued. In struction on Gun Drill, Laying, and equipment carried out under supervision of I.G. and his staff. One S.P. was received to replace the one previouly burned. Bath and Dental parades were held for personnel. Gnr. Bowkay tried by F.G.C.M. at FONTAINE-HENRY. Lieut. Blackwell joined the Regiment as reinforcement Officer. Capt. V.O. Hertzman, new M.O.? arrived.


The War Diary continues in the same neutral tone, including on 9 Sep 44 when "The new guns were fired for the first time at 1430 hrs and the Air OP reported that all guns were shooting together."

Unless the "accidental" burning of one of the Sextons the day after they were received is interpreted as a more or less unconscious act of revenge, I could find nothing thus far in the War Diary expressing any opinion about the relative merits of Priests and Sextons...

I'll continue checking the War Diary around the period when they first switched from Sextons to Priests on 18 Oct 43.

Michel

 

War Diary of 19 Cdn Fd Regt:
17/10/43
(...) Lt-Col. Clarke, Commanding 19 Cdn S P Regt R C A went to 2 Corps H Q, R.C.A. and was there informed that this unit would exchange locations and formations with the 8 Army Fld Regt R C A. This entailed a move from Eastbourne to Bournemouth which was to take place the following Thursday. It also meant that the unit which had been detailed for mobilization with 5 Cdn (Arm'd) Div since Nov 1942 was to go to the 3 Cdn Division as an S.P. Regt.
(...)
18/10/43
(...) The 25 Pdr S.P. Mounts were handed over to 23 Cdn S P Regt R C A. This unit to receive 105 mm S P Mounts at new location.
(...)
25/10/43
Due to the lack of equipment the training of personel was somewhat curtailed. 105 mm units were not availabe for some days.
26/10/43
Regt was informed that it would receive this day 13 Ram Tanks as O P and G vehicles. These arrived from Bordon by transporter about 2200 hrs 26 Oct 43.
Tanks were unloaded and assigned 4 per Bty and one to R H Q.
(...)
3/11/43
(...) Word was received that this unit would take over 12 S.P. 105's from the 8th Army Fd Regt RCA.
(...)
10/11/43
Drawing of the vehs began and some of them were found to be in rather poor shape and missing quite a few tools etc.
(...)
22/11/43
Loading of S P's and Ram tank OP's commenced at 0900 hrs. It was discovered that due to the turret for the .5 Browning on the 105 mm on a Sherman chassis, it was impossible to transport the S.P. by train.
H.Q. RCA, 3 Cdn Div notified to this effect and arrangements made to transport the S.P's by transporters.
(...)
26/11/43
The personnel seem to be grasping the new type equipment quite well and the change from 25 Pdr to 105 mm is taking place with little apparent difficulty.

Again, no positive or negative word about the change of equipment here, which is perhaps less surprising than in Aug/Sep 44 when the relative performance of the guns could be assessed under actual battle conditions.

Michel

 

The Development of Artillery Tactics and Equipment makes a brief reference to the harder hitting power of the 105 when the Priest first came into use in the desert. However, I've found a bit on late-war policy which is rather interesting:


I've not found a direct comparison of the two yet...

 

Ah yes I forgot the 19th Fd Reg RCA - going from Sextons to Priests and back again to Sextons later. I'm sure they were asking: "And just what are we using next week?"

Meanwhile, an extract from WO 291/113 studying the Lethal effect of artillery fire. If you look at these figures closely you might be disturbed to see that both the US 105 and 75 were seemingly more lethal than the beloved 25 pdr.

 

I couldn't resist adding one more pic from 13th Fd Regt RCA's history. It's slightly little off topic, however I do like the fact that the Regimental cartoonist had a good grip on reality!

 

To what extent was the 25-pr shell 'built to a budget'? How much was lethality compromised to get enough good shells instead of not enough of the best? It's the production end of the argument above, I suppose.

Wasn't one of the 4.5 or 5.5 shells particularly poor?

 

My understanding of the 4.5" is that it had a thick shell with comparatively little explosive filler as it was intended for counter-battery work i.e. to produce short range heavy shrapnel for damaging enemy guns.

This meant that for general fire tasks it was sub-optimal, and this is what generated dissatisfaction with it.

 

What this indicates is that the effectiveness of the 25 pdr seems to have been heavily dependent on the type of fuse employed.

 

So, from the WO 219/113 results the best performance of the 25pdr was using an instantaneous fuse. You just had to fire twice as many rounds as the 105 to inflict not quite as many casualties!

Conclusion, 25 pdr was a good gun. Pity about the ammo....

 

An interesting remark here about reaching a point where the heavier shell become uneconomical.

 

In broad terms, those other area weapons V1 and V2 caused about the same number of casualties per 'round' despite being markedly different in 'weight'.

Perhaps the 'medium artillery stops tanks' argument won because it was easier than deciding/defining the purpose of field artillery, then finding the sweet spot calibre to do it? I imagine there are some interesting debates in the RA Journal...