The Story of the Twenty-five Pounder
by WL Ruffell
From about the year 1700 until the adoption by the British of the metric system of measurement in ordnance manufacture, field guns have been designated by the weight of their standard projectile. In the case of the 25-pr it is the high explosive (HE) shell.
The 25-pr also fires solid armour-piercing (AP) shot plus carrier shell, eg smoke, but these are non-standard because they weigh less than 25 pounds and do not behave in the same way ballistically.
Ordnance QF 25-pr Mark 2 on Mark 1 carriage
Callibre: 3.45 inches (87.6 mm)
Weight in action: 3968 lbs (1800 kg)
Elevation: -5° to 45°
Top Traverse: 8°
Traverse On Platform 360°
Guns have been engines of war for over 600 years. During that time succeeding generations of field Gunners have sought to improve their pieces and thus the effectiveness of their primary role in action - close support of the Infantry.
Designers of a new field gun are naturally influenced by lessons learned from experience with its immediate predecessors. Therefore, to relate the story of the 25-pr we must start with the equipments it superceded, the QF 13- and 18-pr guns, and the QF 4.5-inch howitzer, introduced in 1904 and 1910 respectively. All three remained in service until the first year of World War 2. The 13-pr was really a lighter version of the 18-pr. As it was issued to the Royal Horse Artillery only, it will not be further considered in this article.
Between the two World Wars a New Zealand Field Artillery Brigade comprised three batteries of 18-prs and one of 4.5-in howitzers, each battery consisting of six equipments, reduced to four in the peace establishment. This mixture of guns and howitzers dated back to the smooth-bore era when batteries were composite units of the two types.
The 18-pr, having a comparatively flat trajectory, was suitable only in open country with few significant hill features as in much of western Europe or Africa. When high-angle fire was required in more hilly or mountainous country the 4.5-in howitzer was employed. If the target could not be engaged by the 18-prs they 'stood easy'.
The first lesson was hammered home on the Gallipoli Peninsula. Field Artillery support should have been delivered from the beaches at the outset, but the only guns ashore by the evening of the landing were two Indian Mountain batteries plus one solitary Australian 18-pr. The former did good work but was of little use; it could not clear the crests immediately behind the beach. The one New Zealand 4.5-in howitzer battery available was not brought ashore until the day after the landing, while of the two New Zealand 18-pr batteries one arrived on 27 April, the other not until the 30th.
To be of any use at all, the 18-prs had to be man-handled up precipitous cliffs by literally hundreds of Infantry - who could have been much better employed on other tasks - in an exercise which took ten days to complete.
The positions the 18-pr Gunners were obliged to occupy were considered 'impossible' by ordinary standards. Virtually the only targets they could engage were those visible from the gun positions. To make matters worse both guns and howitzers were starved of ammunition.
Thus many of the casualties suffered by the Infantry in that ill-managed campaign were directly attributable to the dire shortage of suitable supporting Artillery. The nature of the country demanded a preponderance of guns capable of high-angle fire which the planners neglected to provide.
France delivered the second lesson. Under normal conditions, ie with the gun on a level platform, the range of the 18-pr was 6500 yards because the pole-type trail limited the elevation of the piece to 16°. Greater ranges with the Marks 1 and 2 guns could be achieved only by digging the trails down a foot for each additional 1000 yards range desired and laying by field clinometer, the maximum practicable being three feet for 9500. This exercise was irksome and time-consuming, of little use when fire was needed in a hurry.
The 4.5 carriage permitted an elevation of 45°, but the maximum range was no more than that of the 18-pr, ie 6500. Even this elevation sometimes proved insufficient to clear the crests.
Now there were occasions in France during World War 1 when attacking Infantry attained objectives beyond which their supporting Artillery were unable to engage targets, eg to deal with enemy counter-attacks, because the guns did not have the range, nor were they always able to move forward to new positions owing to the state of the battlefield which gunfire from both sides had churned into a morass in which guns and horses got hopelessly stuck. Thus Gunners were sometimes unable to provide support for their Infantry when it was sorely needed. Therefore, said the experts, field guns must have greater range and more versatile trajectories.
Development of a new field gun actually began during World War 1 and by 1918 it was ready. It was the 18-pr Mark 4 on Mark 4 or 5 carriage (both of which had a number of variations). This was not a modified Mark 1 or 2 but an entirely new gun on a new carriage which permitted an elevation of 37°30', giving a range of 11 000 yards. A number of Royal Artillery units received the new gun but with the end of the war came the inevitable restrictions on Defence spending by the British Government, so that others had to be content with the old 1904 version. Many of the latter were still in use at the outbreak of World War 2.
We in New Zealand never saw the Mark 4 18-pr, but had to put up with the older Marks 1 and 2 until the early years of World War 2. 2NZEF Gunners will remember training on them until 1941. They had been fitted with pneumatic wheels for mechanical draught, but otherwise were identical to the guns their fathers had manned in World War 1.
New Zealand Governments have never been noted for keeping defence equipment up-to-date and have always treated the Army as the Cinderella of the services.
The post-war (1920s) period saw a series of post mortems on ordnance, weapons and equipment in the United Kingdom, resulting in recommendations for the improvement of existing armament. As the 18-pr Mark 4 was not deemed suitable for further development, an entirely new equipment was proposed. It was to be a 'gun/howitzer' designed to take the place of both the 18-pr and 4.5 howitzer. Such an equipment would be capable of providing support in any type of terrain (it was thought) and a single nature of ammunition for field artillery would greatly facilitate supply in time of war.
At the same time the shell, the weapon of artillery, was examined in the light of World War 1 lessons. During that conflict Infantry on more than one occasion found on nearing their objectives that the barbed wire entanglements the Artillery were supposed to have destroyed were still more or less intact. Shrapnel, the sole projectile first made for the 18-pr in the early stages of the war, could not effectively cut this wire. HE was introduced in 1915 but the 18-pr was still found wanting. Shells from the 4.5 howitzer were much better but there were never enough of them.
Shrapnel, once considered the ultimate artillery mankiller, became obsolescent during the trench warfare of World War 1, being replaced by HE, a weapon more efficient in all respects. Not only was HE cheaper to manufacture but Officers needed less practice in its use to become proficient, an important consideration in a war in which the casualty rate among young Officers was inordinately high. It was eliminated from the Royal Artillery field branch in 1935, so the new gun could not fire it. However, in New Zealand Gunners continued to fire shrapnel for practice until they received 25-prs in 1941.
Royal Artillery experts concluded that a gun of around 3.7 inches (94 mm) in calibre with a range of at least 15 000 yards (13 716 m) firing a shell of from 20 to 25 lbs (9 to 11 kg) weight was needed to replace both the 18-pr and 4.5 howitzer.
Experiments with an 18-pr, a 22-pr, and a 25-pr were carried out in 1933, and in the same year the General Staff agreed a 25-pr be the sole field artillery equipment. In 1934, after further discussion with the War Department on specifications, the Director of Artillery (United Kingdom) ordered a pilot model.
Then arose the spectre of what has forever been the bane of the British soldier in peacetime - a tight-fisted Treasury. The holders of the purse-strings decreed that if the Gunners wanted a new field gun they would have to convert the existing Mark 4 18-prs of which there were large stocks. Now the Mark 4 18-pr, calibre 3.3 inches (84 mm), was fitted with a loose liner which could be easily removed and replaced, so at first sight conversion appeared simple; change the liner to one of larger calibre. However, 3.45 inches (87.6 mm) was the maximum to which the gun could be re-lined and at the same time retain an adequate margin of safety. So in 1935 it was officially decided to adopt a 25-pr of 3.45-in calibre. This was the 25-pr Mark 1, often referred to as the '18/25-pr', indicating conversion. Gunners who served in France and in the Middle East in the very early days of World War 2 will be familiar with it.
Ordnance QF 25-pr Mark 1 on carriage Mark 4P
First produced as the QF 18-pr Mark 4 in 1918 this gun was converted in 1935 to 25-pr by fitting a loose liner of 3.45-inch (87.6-mm) calibre. It then became known as the 18/25-pr, or more correctly, the 25-pr Mark 1 on carriage Mark 4P. The 'P' stands for 'pneumatic', the original carriage having been one of the horse-drawn type then converted to the type illustrated when Britain commenced mechanising her artillery in 1928.
Calibre: 3.45-in (87.6-mm)
Weight in action: 3570 lbs (1670.8 kg)
Traverse (top): 9°
Elevation: 15° to 37°
Range: 12000 yards (10972 m).
There was another snag: the 18-pr carriage would not stand a propellant charge powerful enough to send a 25-pr shell the desired 15 000 yards, ie it could not fire super. Consequently, a maximum range of 11 800 yards had to be accepted. About a year later, in 1936, a decision to increase the range to 13 500 carried with it approval to design a new equipment capable of firing super charge.
Early in 1938 a split-trail pilot equipment had passed technical and field tests, had been approved for introduction into the service, and a small order placed. However, at 41 cwt (2087 kg) it was rather heavy; instead the Royal Artillery favoured a box-trail carriage with a firing platform as fitted to an experimental 105-mm gun produced by Vickers in 1922. Production of the split-trail equipment was therefore held up while one of the 25-pr Mark 2 guns was fitted to the Vickers carriage. After a demonstration at the School of Artillery, Larkhill (now the Royal School of Artillery), those taking part voted unanimously in favour of the latter combination. It became the legendary 25-pr Mark 2 on Mark 1 carriage, familiar to all New Zealand Gunners who served from World War 2 to the 1960s. The Mark 2 gun first saw action in Norway in 1940, and by 1945 over 12 000 had been made.
As we have already seen, the 25-pr fell short of what Gunners felt a field gun should be capable. Nevertheless it proved a robust and dependable equipment, easily handled in action even by a reduced detachment. Its cross-country performance was good, and with reasonable care it gave excellent all-round service.
The strength of the carriage was amply demonstrated in 1943 when the first QF 17-pr anti-tank guns were mounted upon it; it easily stood up to the much more powerful piece.
The Germans appreciated a good gun when they saw one. They put all 25-prs captured in serviceable condition into service in their own forces; they formed whole regiments of 25-prs Mark 2, which they designated 8.76 cm FK 280(e) (split-trail carriage) [FK = Feld Kanone, field gun]. They were deployed for coast defence.
Few changes were made to the 25-pr Mark 2 ordnance during World War 2, the principal modifications being the attachment of a muzzle brake to ease the strain on the carriage caused by the firing of super charge (later super plus increment), and the radiusing of the corners of the breech ring to strengthen it and prevent cracking. The latter mod made the gun the Mark 2/1.
The Mark 3 gun differed in having a slower-coned shot seating to prevent slip-back of the projectile on loading, while the 3/1 was a Mark 3 modified in the same way as the Mark 2/1. The Mark 4 gun was similar to the Mark 3/1 but of new manufacture.
Towards the end of World War 2 a Mark 2 carriage with a wheel-base of reduced width was introduced to enable the gun to be towed by light vehicles, eg jeeps in the jungle, or be carried in an aircraft, but it was far from satisfactory - or popular. Every time the layer turned the traversing handwheel he skinned his knuckles on the left gun wheel. A Mark 3 version with the same wheel-base as the Mark 2 but with a trail hinged in the centre to bring the maximum elevation up to 55° was introduced for use in mountainous country, eg parts of Italy, to overcome the need to dig the trail down. It was a makeshift solution to the problem, clumsy and difficult to handle and maintain in action. Neither the Mark 2 nor the Mark 3 carriages were procured by the New Zealand Government.
In order that armoured units might be supported by field guns with the same cross-country performance as tanks, several self-propelled equipments were produced for the Royal Horse Artillery, only two of which saw service. These were the Bishop (25-pr on Valentine tank chassis) and the Sexton (25-pr on Sherman tank chassis).
Morris Field Artillery Tractor, Model 1938
When mechanisation of the RA began in 1928 field guns were towed by 'dragons', light tracked vehicles similar to the Bren carriers used during World War 2. However, tracked vehicles being expensive to maintain, in 1935 the Morris was adopted. It was sometimes (wrongly) called a 'dragon'. The vehicle illustrated is a 1938 model.
In September 1942 there arose an urgent requirement by the Royal Australian Artillery (RAA) for a gun which could fire a 25-pr shell up to 10 000 yards but be smaller and lighter than the existing equipment. It had to be both air- and man-portable, suitable for use in the difficult terrain encountered in places such as New Guinea. Designers looked at the possibility of re-designing the 25-pr on the basis that no component weigh more than 400 lbs, and that the maximum range be not less than 10 000 yards. Work progressed rapidly, and in just three months the pilot model was ready for proof. Although not as stable as the full-sized equipment it proved quite satisfactory, particularly at the higher ranges, 10 400 for Charge 3, and 11 500 for Super. Few modifications to the pilot model were necessary. The heaviest item was the recoil system at 408 lbs. More than 200 short 25-prs were produced. They were first used near Lae on 8 September 1943, and then at the landings at Red Beach. The design and production of this gun was an excellent example of how the cooperation of a dedicated team of user, designer, producer and inspector could meet an urgent operational requirement. Examples may be seen at the RAA Museum, North Head, Sydney, and at the RAEME Museum, Bandiana.
With World War 2 long over and the campaign in Korea coming to an end, Royal Artillery Gunners tried again to get a field gun with the 15 000 yards range they had sought after World War 1; they longed for that extra 1500 yards they had had to forego when accepting the 25-pr Mark 2 with its maximum range of 13 500. To the uninitiated 1500 yards may not seem critical, but it means that with an arc of fire of 120° in action a gun can cover an additional 13 square miles of territory. The significance of that figure should be obvious.
As is customary, first to be considered was the projectile, the weapon of the Artillery. Both German 88-mm and our 25-pr (87.6-mm) HE shell had proved extremely effective. The latter upon detonation breaks up into about 500 splinters, each one of which can kill or maim a man, plus a number of smaller fragments each capable of inflicting a nasty wound. It was considered rather more lethal than the 88, ideal for the prurpose for which it was intended, ie the close support of Infantry. Consequently experienced Gunners thought the 25-pr shell should be retained, but a more versatile gun designed to handle it, for, good as it was the 25-pr had its short-comings.
However, the Americans as well as other NATO countries already possessed 105-mm (4.13-in) field artillery equipments. In support of their preference for the 105 the Americans claimed that one round gunfire from their six-gun battery would put the same weight of metal upon a target as one round from our eight-gun battery. From a simple arithmetic point of view their answer is near enough, but every Infantryman knows - or ought to know - that eight bursting shells will keep more enemy heads down than six, even if the former are a few pounds lighter. Moreover, the 25-pr shell is more lethal than the American 105-mm M1 shell still currently in use. Some say it is 1.5 times as lethal.
But to insist on retaining the 25-pr would have led to unacceptable supply problems in the event of a major conflict, so Britain was obliged to fall into line. The gun to replace the 25-pr would be a 105-mm.
History now repeated itself; when the RA Gunners requested a new 105-mm gun they received the same answer as they did in 1933: the War Department had no money for new equipment. In this case the Gunners had no guns suitable for conversion - so they would have to wait.
As an interim measure in 1960 (after a two-year trial period) the British Army adopted the Italian-made Model 56 105-mm pack howitzer firing the American 105-mm M1 shell. By adopting a foreign equipment Britain avoided research and development costs.
With a range of only 10 000 metres (10 936 yards), its performance fell far short of Royal Artillery requirements, nor was its carriage sufficiently robust for the field role. For example, stub axles proved so weak the equipment would not stand long-distance towing at high speed, but had to be carried on the back of a truck. In Vietnam elevating gear boxes cracked. Gunners saw the howitzer as a possible replacement for the 4.2-in mortar, but not for the 25-pr. The New Zealand Army adopted the Italian howitzer in 1964.
In Britain development of a new 105-mm gun at last commenced in 1966. By 1975 most RA units had been issued with the " light gun ", but New Zealand Gunners did not receive their first until late in 1987. It has a range of 17 000 metres (20 000 with 'base bleed' round), has been tried and proved in every climate from Pole to Equator, and performed faultlessly in the Falklands. It should be a worthy successor to the 25-pr.
More than one author writing on war or war equipment has described the 25-pr as a 'legendary' piece of ordnance. Not always has due credit been given to the men who created the 'legend', ie the men who manned it in action.
Tragically many of the 'legends' surrounding the gun arose from its use in a role for which it was neither specifically designed nnor intended, i.e. the anti-tank role. The gun's anti-tank capability was Intended purely for emergencies; it was never intended to be deliberately employed in the anti-tank role as it was on several occasions during the Middle East campaigns of World War 2. To make matters worse, while creating some of those legends the 25-pr was not providing the Infantry with the artillery support they were entitled to expect.
Let me hasten to add the fault lay not with the Gunners but with the authorities who had failed to provide anti-tank equipments either sufficient in number or effective in performance on the one hand, or whose conservatism neglected to make the best use of other ordnance available on the other. In the latter respect a valuable lesson taught by the enemy was ignored.
For defence against tanks the Germans frequently made use of their 'famous' (some say dreaded) '88' (8.8-cm FLAK), an equipment designed primarily for the anti-aircraft role but modified for use in both the field and anti-tank roles. It was indeed dreaded by men who had endured its shells - especially the air-burst variety!
But the British had a better gun than the 88; it was the QF 3.7-in anti-aircraft gun. This equipment could have been as easily modified as its German counterpart (a few were later modified for the field role), but the British would not divert any 3.7s from the AA defence of vital points or areas, e.g. North African ports, despite the fact that they had twice as many 3.7s as the Germans had 88s. The Germans had exactly the same problems as the British, but dealt with them more realistically - to the everlasting sorrow of the 'tankies'.
War histories, unit diaries, and other accounts of the Middle East campaigns make frequent mention of the number of tanks lost by one side or the other in this or that battle, but rarely do they include the number of guns lost in action. It is not generally known that over 600 25-pr guns were destroyed or overrun and captured in these campaigns, many as a direct result of their being employed in the anti-tank role. For the German tanks soon learned to back off when confronted by 25-prs, call up their own artillery to deal with them, whittle the detachments down with long-range machine-gun fire, then move in and overrun the gun positions.
This concludes the story of the 25-pr as far as we in New Zealand are concerned, but not elsewhere. As recently as 1980 some 26 other countries were still employing the 25-pr, and many probably still are. The last major campaign in which the gun fought was the Indo-Pakistan war of 1971.