How did defensive artillery fire work

We’ve all seen it in the movies, a thin line of men crouched in foxholes and trenches, valiantly trying to hold off the attack with their rifles and light machine guns, while one calls up artillery fire on the telephone. And then woosh, bang, the hordes of attacking infantry are consumed in a maelstrom of exploding shells, the attack beaten back with heavy loss. But how did it really work.

Well, no doubt the defensive lines have been built taking in the advantages of the terrain where they can, bunkers, trenches and foxholes dug, wire erected in front, and most importantly, telephone cable run and radio communications established with the artillery battery/regiment positioned some miles back.

But how do the artillerymen hit the right spot. Both they and the infantry holding the line have the same maps, with various co-ordinated points marked, and when called upon, the artillery know the area they are being asked to hit.

But you’re aiming a gun/howitzer at a specific point, where as the desire is to spread your fire across, say a 400-yard-wide front, and maybe 800 yards deep. So, it is fire three rounds, and the adjust, up a notch, or rotate left/right, a notch, and fire again. And what are the other guns in the battery doing, to help spread the fire? Or are we crudely just firing at a point, knowing the variation in shell fired will provide a spread anyway?

 

There are books like Stig H. Moberg's Gunfire! British Artillery in World War II, but all essential can be found from http://nigelef.tripod.com/

 

I also cover this in Gunners in Normandy and D Day Gunners. These include historic maps with Defensive Fires marked. e.g. for the 3rd Canadian Division's fight with the 12 SS.

It is the job of the artillery officer in direct support of the supported arm (infantry or tanks) to anticipate likely enemy approaches and forming up places. There will be about three or four per company/squadron. These are passed to the command post and may be circulated across the artillery regiment, division or even corps. Firing data is calculated for these. One will have been identified as a the SOS target - on the most dangerous. The guns will be loaded and layed on the SOS target when not engaged on other missions so in the event of the calls for SOS FIRE the gun sentry can get the first rounds away in a matter of seconds while the rest of the detachments take post.

To quote Canacian gunner George Blackburn here is a flavour of what is ionvolved.

“Over in the hole that is Battery Command Post, no one speaks. They look up and stare at you a moment with red—rimmed eyes and then go back to work. For days, in incredibly dirty and cramped conditions, they’ve been working out targets and fire plans demanding extreme accuracy, calculating all the complicated data required to navigate shells to precise spots on the landscape, allowing for winds of various strengths and directions, and air temperatures and pressures at various strata above the earth through which the shells will loop on their way to the target — leaving only last-minute adjustments for the varying temperature of the propellant charges to the GPOs whenever extreme accuracy is called for. They work with pencils sharpened to fine points, on talc-covered artillery boards, which they must struggle continually to keep clean of sifting dust, their noses almost touching the surface of the boards as they strain to see what they are plotting by the yellow
glow of fading ‘lamps-electric."


"In an OP in normal circumstances, when the rumble of neighbouring artillery or local enemy activity is not interfering with your hearing, there’s a familiar sequence of sounds through which you follow your shells onto target. First comes a distant, faint thumping somewhere back behind you, then nothing for a few seconds. Suddenly overhead there’s a sinister sizzling and crackling, followed by an abrupt, split—second silence, then a fury of cataclysmic flashes erupting in the target area amidst violent black puffs of smoke and dirt. This rapidly builds without pause into a hellish cauldron that gives off the reverberating roar of the wicked, over-lapping thunderclaps that only 25—pounder shells pelting a Mike target can create.

Horrifying enough when viewed from a distance of three or four hundred yards, but until you have lived through the terrible screams of 25—pounder shells arriving on target, and experienced the distinctive, jolting whacks of their explosions around you, it is impossible to conceive of the full horror of a Mike Target to which attacking Germans are subjected again and again on a regular basis."

 

Hi

Extract from 3rd Corps Counter Battery Intelligence Reports for 22 Dec 44.

Found within 3rd Corps G Branch War Diary (WO 1270-251)

Shows the amazing level of detail gained from SHELLREPS






Hope this helps

Gus

 

Piper L-4 Grasshopper helped too.

 

Colour footage of British Artillery in action Tunisia 1943 (part of an American propaganda film by John Ford) first shows the 25 Pounder Field Guns firing.
Second (after the American Doughboys filmed in Arizona) is the view from the British OP from which the Artillery Observers issue their fire orders by radio to the Command Posts.



From my notes:
A Regiment was divided into three Batteries of eight guns.
Each Battery was split into two Troops of four guns which then split to two sections of two guns,
finally each gun crew was a sub section.

A Division could bring down fire from its three Regiments with 72 guns.
There were also independent Artillery units called AGRA (Army Group Royal Artillery)
who would supplement the Divisional fire with Field, Medium, or Heavy guns.

Gunfire would be directed and corrected by Observers either in static positions OP = Observation Post, mobile FOO=Forward Observation
Officer or AOP= Air Observer Post
They could call in fire from any number of guns from a single round to a full Army Group if necessary.
They were Commissioned Officers as they carried such heavy responsibility.

When an observer called for fire he simply asked for Gun Fire from his guns or concentrations which were coded as Mike (Regiment), Uncle (Division), Victor (Corps), William (Army) and Yoke (Army Group).
Guns also worked to fire plans, these were set up by Regimental HQ during informal firing, the settings recorded and used if the appropriate code word was used, enabling a lot of shells to be fired onto an area very quickly.

Anzio February 1944
The second phase of the German attack, this time without tanks, attacked the Recce Regiment who were defending
a line to the right of The Factory at the base of the salient.
The Recce were deployed as infantry without their vehicles and very thin on the ground,
The Germans were in battalion strength against less than a company of Recce.
Major Whatley in Recce Btn HQ and Capt Roberts with the Recce Company were in support,
helping to save them from being overrun, directing Regimental and Divisional fire for over two hours.

The enemy were in the open in broad daylight, the Artillery fire prevented them reaching the Recce lines.
Capt Roberts was so busy directing fire that he did not notice that his Recce section was withdrawing
until the attackers almost reached him.
Together with his Toc carrier crew they found themselves with Germans either side of them
coming under small arms fire before re-joining their own lines.

In the afternoon the Regt took part in a fire plan to help 3IB withdraw from the remainder of the salient
bringing the defences back into line.

I hope that goes some way to illustrate, or if necessary, simplify Sheldrake's passages from his book based on his Professional knowledge.

 

Artillery is an area weapon. Each HE round will create a butterfly shaped pattern of supersonic shell splinters at 90 degrees from the line of fire. As with any gun, the rounds will rarely go in exactly the same hole. With small arms its called grouping and is a spread in the vertical plane. With artillery its called zone and measured as a cigar shaped pattern on the ground. (a one mil variation in azimuth at 10km is 10 metres left or right. One mil in elevation or a difference of 10 m/sec in muzzle velocity might be 50 or even 100m in range)

A battery of six artillery pieces sited in an area 150 x 150m (football pitch sized) firing with lines of fire parallel - all guns on the same azimuth, is going to produce a pattern of splinters that will criss-cross an area about the same size. If you fire all of the guns at the same point, with adjustments to allow for displacement of guns from the battery centre, the rounds will land in a tighter pattern, perhaps 75m, x 75m. (The Command post has tp calculate the adjustments for each gun, adding ,say, a minute to response times.)

It is possible to adjust individual guns in a battery. This was a common practice in the First World War when, say you might want to adjust individual guns onto particular parts of a trench. (The drill is to order Battery Right N secs and the guns will fire in order, from the right N secs apart.) In WW2 and subsequently you might also carry out this procedure if you want to bring artillery fire close to friendly forces.

You could disperse artillery fire from a battery to harass an area 800 x 400, but it would not put the density of shell splinters that would force a determined enemy to go to ground. If I had to do that I'd order a linear, known in WW2 as a STONC. (Standard Concentration) This was a series points separated by 50 yards, meaning a regiment of 24 guns could create a pattern of fire 525 yards in length, and useful for creating creeping barrages. Then work from one end of the target to the other. Alternatively, if the target is big enough, maybe you need more guns. Battery target is 150 x 150; Mike (regimental= 24 guns) is 250 x 250 and Uncle (Division = 72 guns) is 350 x 350.

 

Below: Lt Col Flay OC 67th Field Regt with Col Hobson observing fall of shot on the Artillery Practice Ranges at Bou Ficha Tunisia October 1943. They were working up to battle standard after months of waiting for transport from the UK .As theirs was taken by the 51st Highland Division for the invasion of Sicily and Italy.

The two senior officers seem to be observing the shoot.
Hobson must have been on a visit, as he retired in June due to age.
He went to Allied HQ in Algeria on Eisenhower's staff. Later based in Rome, he earned an American Silver Star.
I admire their confidence in their gunners and the performance of the ammunition.

 

For the technicalities see: Royal Artillery Methods in World War 2

Are you a War Gamer by chance.
Give yourself plenty of time to absorb it all.

 

Nice photos.

What is your source for the idea that it was common to use smoke in adjustment?
It isn't something I saw in the 1980s or have read about in WW2 documents.

Smoke might be used in jungle where shell bursts might be obscured by vegetation. It is usually possible to see HE bursts unless they are in dead ground. It is more usual to adjust and record a target using HE and then subsequently use that target as a smoke target. Building a smoke screen to blind an enemy usually requires less precision than to hit it with HE

Adjusting with smoke might also present difficulties.

1. Smoke rounds are designed to produce a cloud that persists for some minutes, so if you adjust with a smoke round, the smoke from adjusting rounds is likely to obscure the target and subsequent fall of shot making it harder to hit.

2. 25 pounder smoke is a base ejecting round ejecting three smoke cannisters, so the trajectory of rounds that eject smoke over the target will not be the same as the trajectory to hit that point with HE.

3. Smoke rounds may not have the same characteristics as HE. A WP round may be heavier or lighter than HE.

Gun alignment is the job of the Gun Position Officer and his assistants, aligning the guns initially with a compass, either hand held or mounted on a director. This will be accurate within 20 mils (1 .25 degrees). The GPO also established the gun position within 50 metres. This is fine for a battery shoot, but not for multi battery missions - the Mike and other Targets. The surveyors establish the battery location to a much more accurate location/grid (5m) and azimuth within 5 mils /20 minutes. Putting all guns on theatre grid was key to the multi battery missions referred to in earlier posts. WW2 era techniques include triangulation from trig points and bearing pickets or azimuth by altitude using star fixes. (I recall my TARA sergeant once doing the latter as an exercise but he was a very clever fellow. Our survey team also had access to a gyroscopic compass and an inertial guidance system that could deliver azimuth to within 1 mil. Nowadays its all done with GPS).

 

I thought that they were using smoke in the photo due to their close proximity of the shell fall and the fact that it looked to be a bush type area, most unusual.
Ranges that I have visited in the UK are all moorland with rock and shallow peat. Fall of shot would be clearly visible.
I would expect the OP to be shellproof and a damn sight further back.
The technicalities of gunnery are a mystery to me, orienteering, radio and line laying were my limitations once a week on a Friday night.
As Bill Beadle wrote: "I believe an artillery commission needs not a little maths".
I should have known better regarding the GPO having written so much by Lt Beadle, as he was one before becoming CPO

Thanks for taking the time to provide your correction.
Withdrawn the statement in previous posting re Smioke.
Much appreciated.
.

 

Thanks for the insights. My interest is the work of the 4’th Survey Regiment and this ads to my understanding of the detailed work they did in preparation for El Alamein

 

Probably a bit late now but came across this photo of a map of Anzio showing what I think are Defensive Fire Plans.

 

Yup.
This shows defensive fires on a portion of the front north of the Moletta River.
The points marked with crosses are Defensive Fires. The lines with names are STONCS - Standard Concentrations 525 yards long designed to spread the fire of a 24 gun field regiment across a linear target - such as a road, a hedge, trench or ridge line.
The names for concentrations were picked by higher formations - usually HQRA at division. As you can see these might be variations on themes such as e.g. car makes, birds, football clubs. Some idle staff officer with time on his hands in Normandy in 1944 wrote a paper on the kinds of names to use. There is a point. Names ought to be easy for signalers to understand despite thick regional accents e.g. a cockney sending a message to a Geordie

I have uploaded copies of a couple of pages from the war diaries of HQRA 56th Infantry Division for . These mention some, but not all on the targets on the map. Maybe the map was from an earlier or, more likely, later time. The concentrations in Grid square 3580 look perfectly formed to protect 2/7 Queens.

I suspect the map is from the Artillery Regiment that was in Direct Support of 168 brigade

 

Sheldrake, your map reveals more than you might think. Much appreciated.

67th Field were in support of 36 US Engineer Regiment under 56 Div then 5th Div before returning to 1st Div for the Breakout.
The Regt was very close to the original position when they arrived on 22nd Jan 1944.

Your hunch about The Queens could be right:
From my notes:
Feb 28th very heavy mortaring same as previous. The weather had been very bad for the previous five days.
At about 1900 there was very heavy mortaring and artillery for 15 minutes then an un estimated number of
infantry crossed the river near the coast road towards the Combat Engineers wire, an SOS was called for,
Major Whatley directed fire for about an hour then all went quiet.
The Engineers went out to see what had happened but found no bodies.
A wire cutting patrol was the prime suspect, or a feint to distract attention, as the situation on the upper Moletta had been bad for some time, with various units of the Queens being cut off and attacked frequently.
This was a possible repetition of 3rd Feb when they attacked and appeared to withdraw but lay low having cut the wire, to infiltrate slowly reinforcing their position, then put in a heavy surprise attack in the morning.
36 Engineers had good defences with fifteen machine guns per company and triple wire, booby trapped with AP mines but the concern was whether they had sufficient experience to use them efficiently.
The situation was precarious, a whole system of last-ditch defences was organised and implemented, called Livingstone, Stanley and Silver lines.
The guns were calibrated.

See letter from Col Stanley OC 36 US Combat Engineer Regt. (attached).
Also AOP photocopy of a photo from A History of the 67th Field Regt. showing the Moletta

 

My grandfather (German counterbattery in WW2) told me they used airburst for the first round to adjust. After that correction it was fire for effect.

All the best

Andreas

 

There was a technique attributed to the Germans which used cross observation of an airburst by two observers to calculate a correction. British Heavy AA guns in the ground role sometimes used airburst for adjustment as the common AA fuse did not have a point detonating or graze action. What type of gun did his unit use?

 

Cannon or howitzer, varying types. He was a flash observer (Germans had dedicated batteries in the CB observation battalions, sound, flash, balloon), and they would normally try to have three, not two observers triangulate the airburst, he said with two observers it wasn't sufficiently accurate.

All the best

Andreas

 

Florence Aug Sept 1944 67th Field Regt (British 1st infantry Division)
From my notes:
The Regiment had a troop of a Heavy Anti Aircraft Regiment attached to them.
They were C Troop the 84th HAA of London Passenger Transport Board Territorials and stayed with the Regiment for some time.
It was always a frantic task for Major Kerr to find a site for them owing to their flat trajectory and very loud crack when they fired.
On a pleasant summers evening of the 22nd August the Regiment moved away to make room for American Long Toms at Galluzzo, in many ways they regretted the move as despite their noise and vibrations, they were excellent gunners and their Troop Commander was recommended for an MC on a recent occasion when they came under enemy fire.

Saturday 2nd September the Gordons sent out a large fighting patrol towards Prato. They came under very heavy fire but being out of range of their guns the FOO’s from 266 Battery called in fire from a battery of American Long Toms and C Troop of the London Transport Board Heavy Anti Aircraft Regiment at Galluzzo.
The infantry had never seen the effect of Airburst used as Artillery and were very impressed.


Edit: Derek Barton. See above, 84 HAA you may want to amend your notes for Aug Sept 1944
84 (Middlesex, London Transport) Heavy Anti-Aircraft Regiment RA (TA) - The Royal Artillery 1939-45

 

Very interesting, as this could be achieved by timed fuzes with the German artillery, or ricochet fire (Abpraller), and I presume was used quite regularly?

All the best

Andreas