In the accounts of the Western Front during in the Great War there are innumerable instances of how accurate shelling silenced a far distant enemy gun battery, broke up an enemy attack well before it came into sight of the guns, or destroyed a village/town from a distance of many miles. Similarly, trenches and dugouts were regularly pulverised in a planned and systematic way, and, later on in the War, advancing armies were supported into enemy territory by a moving wall of shells called a 'Creeping Barrage'.
Casualty records show that 58% of the war-dead of 1914-18 were caused by shellfire, and that the vast majority of these men died on the Western Front.
Equally, our history lessons tell us how the artillery of armies, such as those at the Battle of Waterloo, could only function well when the target was in the line of sight of the guns: the gun-sight was located directly on top of the smooth-bore cannon barrel. For guns to successfully bombard the enemy whilst hidden from sight on the reverse slope of an adjacent hill was considered to be very skilful and cunning planning indeed on the part of the gunners concerned.
So, how did the gunners the Great War take the basic gunnery technology of the time and advance it to a degree that enabled far distant targets to be shelled with both extreme accuracy and efficacy using ordnance maps? And how did experience gained on the battlefield during the Great War create this new gunnery technology? In, short just how were the artillery guns physically aimed at their targets and collectively controlled between 1914 and 1918 to achieve the stunning results that were progressively achieved, particularly during the later phases of the war.
The artillery situation on British entry into the Great War
At the outset of the Great War on the Western Front, the British field artillery was usually located amongst the infantry and generally fired only at in-sight targets. It also largely depended on the Shrapnel Shell. The standard British 18-pounder shrapnel shell contained 374 metal (lead and antimony) balls of 13mm - 0.5-inch; 40 to the pound - fired from a long barrelled field gun with a range of 5,000+ yards. The 13-pounder contained 236 balls.
In effect, the shrapnel shell was a sort of massive airborne shotgun. On open ground it was lethal to both the infantry and the cavalry. In the early days of the War, its capacity to successfully cut through concentrations of barbed wired was limited due to the use of inappropriate fuses.
At the start of the Great War, High Explosive Shells (H.E), producing powerful explosions and multiple lethal metal splinters (around 500 per shell), were not considered to be as effective against troops in the open as shrapnel shells. And, in any case, they required a much more difficult and protracted manufacturing process that was only in limited availability in 1914/15. Indeed, such were the production problems, it was only in October 1914 that HE shells were tested in the standard British 18-pounder field gun.
By the end of 1914, due to the appalling casualties in all the belligerent armies, open warfare had given way to the subterranean life of trench-warfare. The non-availability of large quantities of the HE shells quickly became an operational problem as shrapnel lost most of its efficacy as the infantrymen disappeared into trenches and underground shelters.
Thus, even when the efficacy of the HE shell in trench warfare had finally became evident to the British Expeditionary Force (BEF), the full operational requirements of H.E. shells only became available for the larger set-piece battles of the Western Front from 1916 onwards (e.g. The First Battle of the Somme in July 1916). But even then there were still constant complaints from the soldiery about the large numbers of faulty shells - the much-hated 'duds'.
Also, in 1914, the British Army had only 1,352 artillery guns, very few mortars, only limited numbers of howitzer-type heavy guns, and no specific-purpose anti-aircraft guns. Reserves of shells of all calibres were limited and the UK manufacturing base small. Consequently, during 1914/15 on the battlefields of the Western Front, it was quite the normal practice to ration shells to a daily quota per battery.
The British artillery gun battery
At the outbreak of war in 1914 both the British horse and field artillery (R[Royal]HA and RFA) were, as usual, formed into 'batteries'. The RFA battery was equipped with six QF (Quick Firing) 18-pounder field guns whilst the RHA had six QF 13-pounders. The BEF when it left for France had six QF 18-pounder guns, or 4.5-howitzers, per battery. However, the Territorials the New Army units had only four BLC (Breech Loaded, Converted) 15-pounder guns or BL 5-in howitzers. From 1916 onwards these four gun field batteries were converted to 6 guns and in 1917 the howitzer batteries were similarly raised in strength. (The complex Brigade, Divisional and Garrison Artillery organisation is beyond the scope of this article, as are the obsolete artillery pieces recycled to meet the desperate shortages of firepower of the early years on the Great War).
Commanded by a major, the batteries were manned by five officers and approximately 200 men.
Each battery was subdivided into Sections, commanded by a lieutenant gunner with two guns each. The Sections were further divided into Sub-sections of a single gun under a sergeant gunner.
The normal deployment of the British gun battery in the field in 1914 was a straight line, i.e. the barrels of the guns were aligned in parallel and aimed at the same range as the principal or pivotal gun. The other guns in the battery followed the line of aim of the principal gun. So, theoretically, the shells of all the guns fell in a close group around the fixed point set by the principal gun. In certain circumstances, due to concealment and operational requirements, the guns were staggered or grouped in smaller sections of two or more guns.
From 1915 onwards the batteries were commonly massed along lines parallel to the Front Line to provide supporting fire for an offensive attack at densities of one gun for less than every 10 yards of frontage.
The principles of aiming (or orienting and laying) an artillery gun
There were two main principles involved in the orienting and aiming (or the so-called 'laying') of all artillery guns in the Great War. (There were also several other variable parameters that had to be taken into account - but more about these later).
The two main principles were:
The 'azimuth', or the direction that the gun was oriented on the ground based on the horizontal plane, with north = 0 degrees, and south = 180 degrees.
- The 'elevation', in degrees, - i.e. always less than 90 degrees but, in practice a maximum of 70 degrees - at which the gun barrel had to be aligned in a vertical direction to achieve the desired range; in other words the distance the shell had to travel to its target. The range/distance that some larger calibre shells travelled could be positively affected by an increase in the explosive power of the propellant in terms of quantity or efficacy.
The reference azimuth was determined by the use of a periscopic panoramic sight called by the British a 'Dial Sight'.
Before the required elevation of the gun could be calculated the gun sight was levelled to the horizontal plane by a coloured bubble spirit level. Using this as a base line, the elevation of the gun barrel was then ascertained by an clinometer attached to the gun barrel that measured the angle at which the barrel was vertically inclined in degrees and seconds. The estimated range or distance that a shell would cover for a given elevation, in a particular type and model of gun, was provided in a tabular form. However, with some types of guns the clinometer was graduated in distances - i.e. yards - instead of angles making the range tables unnecessary.
The battery guns, were aimed to 'Spread Out' (distributed) or 'Focussed' on a single point (concentrated).
Alternatively, the guns were fired to 'Sweep and Search' an area by incremental changing of the setting of the guns. The 'Sweep' changed the direction of each shell whilst the 'Search' changed the range. In practice instead of using the actual readings on the inclinometer and the dial sight, the appropriate handwheels that activated the British guns were usually turned by a set amount, say, two turns per degree.
The setting up of an artillery battery
Firstly the Battery Leader (a lieutenant) under the overall directions of the Battery Commander established exactly where the gun battery was to be located. This left the Battery Commander free, when this was required, to undertake the necessary observation work required to zero the guns of his battery onto its target(s) and command the shelling of the target(s) assigned to it.
The co-ordinates of the battery's position on the battlefield were determined by the Battery Leader from an ordnance map of the area concerned using protractor and a prismatic compass. This information was plotted onto his Artillery Board - a sort of working table for plotting gunnery information on an ordnance map of the area concerned and formed the basis for firing his guns. Obviously, the more accurate the ordnance map was the easier it became to get an accurate placing of the battery. Extending forward from the centre of the battery an imaginary 'zero line' against the reference azimuth was created and all the guns of the battery would set their dial sights to the 'centre point' of this line making all the gun barrels in line.
From 1915 onwards, once the gun line of a battery was established, survey pickets (or aiming posts) were installed 50 to 100 yards in front of, or behind, the gun-line. These were four-foot long steel stakes, painted in black and white banding, that were hammered into the ground and clearly in view from the guns. Attached to the stake was a card that gave an accurate reading of the Aiming Point (AP): a distinctive topographic feature in the enemy area that the battery was assigned to cover. From this survey picket the AP readings could be made to give the exact location of the pivotal gun in the battery. As the war progressed these survey pegs became standing operational procedure for the British artillery and they became known also as Bearing Pickets and more colloquially as 'pegs' or 'BP's'.
The role of an Artillery Observer(s) changed as the war progressed. In the early days of 'open warfare' it was the BC whom was largely responsible for co-ordination the targeting of his guns directly from his own gun-line. As trench warfare became the dominant status on the Western Front, so the location of the respective BC(s) was suitably moved ahead of the gun-line into an Advance Observation/Command Post. This was located on a nearby hilltop, a tall building, or often in the trenches in the Front Line in direct collaboration with the infantry commanders. He provided the 'Firing Data' for the batteries in his battery command post by telephone, or visually using signal flags or special daylight lamps. Later in the war these observations were increasingly made from the air from an observation balloon or aircraft and passed on by radio. Increasingly, the necessary gun control information was derived directly from aerial reconnaissance and aerial photographs.
However, this primary compilation of the firing data was subject to modification due to various factors. This was known as the 'Correction of the Moment'. It comprised of parameters such as: the direction of the wind; the atmospheric pressure; the ambient temperature at ground level, and along the trajectory of the shell; the presence of rain/hail/sleet/ snow and the altitude of the target. Also, when necessary, the effect of wear on the rifling of the barrel of the gun had to be calibrated and compensated for. These factors were, as far as possible, incorporated in the calculations.
This modified data was conveyed to the commander of one of the guns of the battery and a 'Registration Round' was fired at the target. The Observer would follow the fall of the shell and any necessary calculations were made to adjust the accuracy of the gunfire. The Battery Leader/Commander was informed of the final settings by the Observer, or his telephonist/signaller, and the new settings plotted on the ordnance map or plotting table. The necessary action would then be taken to fire the battery's guns accordingly. The Observer would continue to plot the fall of the shells on the target and pass on new instructions as required using the so-called 'Clock-Ray (hands of the clock) code'.
To maximise surprise, batteries of guns were often zeroed onto an alternative target and when all were firing in a properly co-ordinated way, new settings would be given so the all the batteries' shells struck the true target.
Another approach that was perhaps used more often than would be admitted by the higher echelons of the artillery commanders was 'Area Bombardment'. Here the batteries concentrated their firing on a given 'Box' or 'Zone'. The principle being that there were known targets in this specific area and if enough shells fell in the box at least some of the targets would be hit.
As seen above, as the war moved on, the preparation of the firing data of the British batteries was generally under the control of Artillery Observers in a Command Post (and not the actual on-site gunners themselves). More senior artillery officers commanded and co-ordinated the overall deployment and the larger concentrations, such as the gun batteries that participated in the mass barrages and became a dominant feature of the Western Front. It meant that that the firing data supplied from the Observer/Command Post was applied to the azimuth and elevation sights and the guns laid accordingly.
This fire control system was called 'Indirect fire'. This enabled the guns to fire at targets even when they were not visible from the gun site. A prime example of this co-ordinated and extended barrage was the 'Preliminary Bombardment' (also known as 'Hurricane Bombardment'). It preceded the set-piece battles on the Western Front, such as the First Battle of the Somme, where the Preliminary Bombardment involved 1,400 guns firing 1,500,000 shells; it lasted eight days and nights of almost continuous gunfire. This was an incredible feat of planning, organisation and co-ordination. However, its tactical efficacy at this time was another matter.
Even more astounding feats of gunnery were achieved as the war progressed: in particular, the cutting of concentrations of barbed became easier with the introduction of the Model 106 percussion fuse which exploded the HE shell on immediate impact with the wire, or the ground surface immediately beneath it. Thus the HE blast and splinters would be concentrated on the wire and not absorbed by the ground as the shell penetrated deeply into it.
As will be seen, as the fighting on the Western Front progressed from a mobile war to a static war, and back again to a mobile war. Accordingly, these tactics and their technology also changed rapidly.
Perhaps, the most skilful and dangerous application of this new artillery technology was the development of the 'Creeping Barrage'. In this sophisticated tactic the guns laid down, with precise timing, a wall of shellfire in front of advancing 'Friendly' troops. This line of fire then progressively moved into enemy territory matching the predetermined marching speed of the infantry. This could be 50 metres per minute when the going was good, but down into single figures when the going was really bad. As it often was on the muddy and shattered battlefields of the Western Front. The idea of the creeping barrage was to keep the defending troops in their dugouts or, at least, persuade them to keep their heads down in their trenches as the 'friendly' troops advanced towards them.
The mixture of shells in a British creeping barrage was something like one-third shrapnel, one-third HE and the remainder smoke.
When the creeping barrage was carried out correctly, the effect on the enemy troops was often dramatic, if not always decisive. When it went wrong many casualties could occur among the 'friendly' advancing troops - certainly to an extent and frequency that would not be acceptable today. The organisation of such a complex gun aiming and shell delivery schedule has been likened to orchestrating a complex musical score.
There is some controversy about whom, or even which nation, first deployed the creeping barrage on the Western Front. But there seems general agreement the first British unit to use it was the 15th Division at Loos in September 1915. It was certainly deployed by the British at the First Battle of the Somme in 1916. However, considerable refinement and practice was required before it became in any way a decisive tool.
One of the major activities of the British gun batteries on the Western Front was the 'silencing' of the batteries of the enemy, leaving its troops without defensive and offensive gunfire. In this field two highly technical developments by the British in 1917 greatly enhanced their success rate. These were the accurate long distance location of the enemy batteries by the detection of their muzzle flashes ('Flash-spotting') and the detection of the guns from vibrations generated during firing of the shells ('Sound-ranging'). For this purpose the BEF established special Field Survey Companies using trigonometric determination for the former and directional microphones that determined the locus of the report and the actual flight of the shell in the latter. In 1918, at Amiens in August, 95% of the German guns were identified before the battle began, and in September, at the Canal du Nord, British counter-battery fire was 80% successful; both initiatives represented crippling blows to the Germans. Inevitably, in due course the Germans introduced flash-less powder that made the flash-spotting technique redundant.
Photo-reconnaissance and mapping
Additionally, almost daily photoreconnaissance by Allied aircraft provided excellent up to date information about the deployment of the German artillery and possible intelligence about their intentions. It also facilitated the production of huge numbers up-to-date and highly accurate military maps for gunnery and other tactical purposes.
By 1917, techniques had been evolved whereby the aiming of shells on a target could be reliably predicted solely from a map, or an aerial photograph, and, as already indicated, frequent aerial sorties were made to map and up-date the situation on the entire battlefield.
Thus, the vulnerable Artillery Observer was no longer so essential for reliability in the shooting of the artillery guns, and pre-registration and ranging shoots became largely unnecessary.
Deployment of other shell types
Earlier, from 1916 onwards on the Western Front, the inefficient deployment of poison gas clouds from the discharge of high-pressure steel cylinders was slowly overtaken by the more precise placement of the explosive poison gas shell. Increasing of numbers of these gas shells were fired with, as always, the Germans in the van. However, the British did tend to persist with their preference for generating and dispersing ever-larger poisonous gas clouds from cylinders. Reputedly, some of these British generated gas clouds blew into Germany itself.
Similarly, smoke shells containing white phosphorous were used to create smoke screens to obscure military operations, and illuminating star shells were widely used for nighttime activities, including signalling.
During the Great War on the Western Front, the long practised art of artillery fire became revolutionised by technology. After many trials and set-backs, by mastering this art the British artilleryman was able to dominate the battlefield of the Western Front in the final months of the war, and play a major role in bringing an Allied victory.
From a modest British strength of 1,352 artillery pieces in 1914, the British gun strength on the Western Front rose to nearly 12,000 by the Armistice in 1918; all controlled by a sophisticated gunnery cadre of around 550,000 well-trained officers and men.
Whilst many of the British field guns on the Western Front were manoeuvred by horse power throughout the Great War, increasing numbers were transported by internal combustion engined, 'Caterpillar' tracked, tractors. The modified gun carriage on the Mark II 60-pounder introduced in 1914 made the all-up weight too much to be moved by horses, so the lighter Mark III carriage was introduced and became the standard.
Many of the new tanks that increasingly dominated the battlefield carried mounted artillery guns for both offensive and defensive purposes.
This article is an attempt to present to the non-specialist, in relatively simple terms, the extremely complex topic of the use artillery on the Western Front in the Great War. If there are any errors or oversimplifications which could be corrected to make the subject material easier to read, or understand, by the non-specialist, the author would be grateful if this could be conveyed to the webmaster of the WFA. Accordingly, suitable corrections, or modifications, will be incorporated in the text.
Should the reader wish to see examples of the various artillery pieces mentioned, many examples, some in full colour, are to be found on the Web. Just type in a brief description of the piece (e.g. WW1 18-pdr British artillery gun) into your search engine.