Shooting the War

The German Super-Guns of the WWII

The German super-guns
The heaviest field equipments seen during the war were the German self-propelled howitzers generically known as ‘Karl Morsers’. These were of two calibres, 540-mm and 600-mm, mounted on the same type of carriage. Six carriages were made and the exact disposition of barrels between them is in some doubt; the carriages were numbered I to VI; Vehicle V was captured by the US 1st Army and found to have a 540-mm barrel, yet photographs captured later showed this same carriage to have a 600-mm barrel. It is probably safe to assume that three of each calibre were made. The date of introduction is also a little vague, but it seems fairly certain that the 600-mm version was introduced in 1942 and the 540-mm in 1944.
The carriage of ‘Karl’ was a simple rectangular box, divided into three compartments. The first held the Mercedes-Benz engine and transmission; the second carried the gun; and the third held the carriage raising and lowering gear. After driving into position on its tracks the engine was used to drive the lowering gear, which rotated the anchorages of the suspension torsion bars so as to allow the chassis to be lowered to the ground until the suspension and track were relieved of the weight. For long-distance moves the gun and recoil system were removed from the carriage, dismantled, and loaded on to spec,a -,a e•s, the carriage was then winched on to a special tank-transpor-er. For very long distances the complete gun and carriage assembly could be slung between two railway flat wagons by means of special trusses.
In the use of railway artillery Germany virtually had the field to herself. This class of weapon is really the prerogative of the Continental nation with a well-developed rail system by which it can readily deploy them to any front. In contrast, Britain and the USA, while possessing railway guns. used them solely as mobile coast defence units, since the problem of transporting two or three hundred tons of railway mounting across the Channel was not a trick to be undertaken lightly. Indeed, the British and American weapons were almost entirely relics of the First World War which had been in mothballs. 1940 saw a few more mountings hastily cobbled together from available spares and hurried to cover the Channel, just as in similar fashion American guns were mobilised and deployed in 1941. In 1944 reports from France indicated that heavy railway artillery might be of use in demolishing strongpoints to be expected in the final assault in Germany, and designs were hastily prepared by the Americans for a number of 16-inch guns, but within a few weeks it was seen that heavy artillery of this class had been rendered superfluous by the quality and quantity of air support available, and the demand was cancelled.
The German army had a vast range of railway guns from 150-mm upwards, but two were really outstanding and deserve closer examination. The first was the 28-cm K5(E)—Kanone, Model 5, Eisenbahnlafette —which became their standard super-heavy railway gun and was probably the finest design of its k;nd in the world. The basic arithmetic and paperwork had been done in the late 1920s and early 1930s, and work began on the gun in 1934. (It is worth noting that every German railway gun was designed and built by Krupp— Rheinmettal did design two, but they were never made.) First, a 150-mm barrel was produced for tests; it had been decided that to obtain the great range demanded, a conventionally rifled barrel was out of the question. A design was prepared with 12 deep grooves and having a shell carrying 12 ribs, or splines, to match. The theory behind this was that the engraving of a conventional copper driving band on the shell gave rise to very high pressure in the gun chamber; by using the spline and groove method to spin the shell, this resistance was removed, and the shell would step off more smartly, allowing a bigger propelling charge to be used without over-straining the gun. The 150-mm test barrel proved that the theory was right, and a full-calibre 280-mm barrel was built.
The mounting was a simple box-girder assembly carried on two six-axle bogies, with the front bogie slung so as to allow the front of the box-girder to be swung across it for aiming the gun. For large angles the whole weapon was mounted on a special portable turntable built at the end of a short spur of track laid at the desired firing point. Each gun was supplied with a special train which included wagons for carrying the turntable, light-antiaircraft guns for local defence, air-conditioned ammunition wagons, living quarters and kitchen for the gunners, and flat wagons to carry their entitlement of motor transport.
By 1940 eight of these complete equipments were in service, and production continued throughout the war, 25 being built in all. The German gunners called them ‘Slim Bertha’, but to the Allies in Italy one at least became famous as ‘Anzio Annie’.
With the 561-pound pre-rifled shell the gun could reach to 68,000 yards. A rocket-assisted shell was later developed which increased this range, with a certain loss of accuracy, to 94,000 yards. Finally, the Peenembride Research Establishment designed a 300-pound dart-like projectile which was fired from a special 310-mm smooth-bore barrel and which ranged to 170,000 yards. Although coming too late for general issue, these ‘PeenemOnde Arrow Shells’ were issued for troop trials in the field, and some were fired against the US 3rd Army at ranges of about 70 miles.
The second railway gun, ‘Gustav’, was the biggest gun the world has ever seen —the Krupp-designed 800-mm Kanone. The idea was conceived in 1937 of a pair of super-guns; they were of quite conventional design, except for their immense size. Too large to be moved in one piece, they were transported piecemeal in special trains and assembled at the selected sites by travelling cranes. When assembled, the mounting straddled two sets of standard-gauge rails, with 80 wheels taking the 1,350-ton weight. An armour or concrete-piercing shell of 7 tons was propelled by a 13/4-ton charge to a range of 23 miles, or a 5-ton high-explosive shell to 29 miles. The first equipment, ‘Gustav’, was proved at the Rugenwalde range in March 1943, in Hitler’s presence. The only record of its use was at the siege of Sebastopol; the gun was sited at Bakhchisary and fired some 30 to 40 rounds. One shot is recorded as having penetrated through 100 feet of earth to destroy a Soviet ammunition dump at Severnaya Bay. The subsquent history of the gun is unknown (it was presumably captured by the Red Army).
The second equipment, ‘Dora’. so far as is known, never left the proving ground, though what happened to it at the end of the war is a minor mystery (some ammunition and a spare barrel were found at Krupp’s proof establishment at Meppen near the Dutch border).
The detachment necessary to man. maintain, and give local protection to Gustav was 4,120 men strong. commanded by a major-general. The actual fire-control and operation of the gun demanded a colonel and 500 men, and the construction or dismantling of the weapon took between four and six weeks. A long-range ‘PeenemOnde Arrow Shell’ was developed for Gustay. but, so far as is known, was never fired. This was to weigh 2.200 pounds and range to 100 miles. There was also a proposition to mount a 520-mm gun on the same carriage to fire rocket-assisted shells and ‘PeenemOnde Arrow Shells’ to a range of 118 miles for cross-channel bombardment, but this never got past the drawing-board.
If it is accepted that it is not a good idea to tamper with a good gun design in the middle of a war, then the only way to render the gun more effective is to improve the ammunition, and this technique was frequently adopted during the war. And in no field is this seen to greater effect than in the battle against the tank. The reason for this is fairly self-evident: personnel targets remain more or less the same—once the anti-personnel projectile is perfected it can stay as it is. On the other hand, once a new anti-tank projectile appears, it is only a matter of time before the enemy put thicker armour on his tanks.
At the outbreak of war there were two types of anti-tank projectile: the armour-piercing (AP) shot, and the AP shell. The difference is basic. Shot are solid, with no explosive filling, and rely purely on their speed to smash through the armour and do damage inside the tank by their impact, the fragments of plate they knock off during penetration, and their own effect when they penetrate the plate and bounce around inside the tank. AP shells, on the other hand, have a small cavity filled with high explosive and are fitted with a fuse in the base. The shell penetrates, similarly to shot, by brute force, but the fuse is activated by the impact and, after a short delay to allow the shell to pass through the plate and enter the tank, the explosive is detonated, shattering the shell into fragments and adding to the shot-like damage already caused. On paper the shell is the better proposition, since there is the bonus of the explosive filling. But paper figures tend to be deceptive, and in fact the shot is probably the more practical projectile, because the high-explosive (HE) cavity weakens the shell, and the fuse is precariously supported against the hammer-blow of impact. Britain held firmly to the shot theory for anti-tank work, though many years of experience in producing AP shells for naval use was available. Several other nations preferred AP shell, bewitched by the HE bonus.
Most of the belligerents entered the war with a plain shot or shell and relied on throwing it hard enough to penetrate the opposing tanks. So long as the target was relatively lightly armoured this was successful; but, naturally, each side began to increase armour thickness on each succeeding generation of tank. The quick answer to this was to increase the gun charge or even the calibre, and thus throw the projectile harder, but there comes a time when the impact is too much for the projectile, and instead of piercing, it merely shatters on the outside of the target without doing any damage.
The answer to this was to protect the tip of the shot or shell with a softer cap, which tended to spread the impact stresses over the shoulders of the projectile, instead of concentrating them into the tip. This preserved the piercing action to higher velocities, and the gun was again winning the battle. The next move belonged to the tank designers who made their armour thicker, and so it went on until the projectile was once more shattering, cap or no cap. At this point the projectile designers were faced with a new problem: if it was futile to throw the projectile harder, might it not be possible to throw a harder projectile? And what was harder than an armour-piercing projectile? Tungsten carbide, a diamond-hard alloy, provided an answer, but it was about one-and-a-half times as heavy as steel, so that it could not easily be made into a projectile. Furthermore, it was expensive and in short supply.
The first application of tungsten to an anti-tank projectile was by the German army in their 28-mm Schwere Panzerbuchse 41, a weapon with a unique tapered barrel. The shot consisted of a small core of tungsten carbide held in a light alloy casing of 28-mm calibre. As the shot was fired down the gun barrel, so the calibre diminished and the light alloy casing was ground down, until it emerged as a 21-mm shot. This squeezing enhanced the velocity and changed the ratio of shot diameter to weight. The velocity reached was 4,000 feet per second, and, on impact with the target, the hardness of the core was impervious to impact shock and penetrated successfully.
About the same time—late 1940—a similar idea had been put forward by a Mr Janacek, a Czechoslovakian weapon designer working in England. While his idea was still under consideration, a specimen of the German weapon was captured in North Africa and flown home for trials: the idea was seen to be feasible. The British version was in the form of a taper-bore adapter to be fitted to the existing 2-pounder gun, together with a special tungsten-cored shot, known under the code name of ‘Littlejohn’, an Anglicised version of Janacek. The advantage here was that the adapter could be removed to permit firing normal explosive shells, but could be refitted quickly for the special shot, whereas the German design required a special pattern of high-explosive shell to be developed, a difficult feat in such a small calibre. The ‘Littlejohn’ attachment and its shot were not used in towed artillery, since by the time they were ready for service the anti-tank units were armed with 6-pounders, but it was used on 2-pounder and American 37-mm guns mounted in armoured cars.
To use tungsten in a conventional gun, a different approach was needed. The first attempt, for the 6-pounder, was the ‘AP Composite Rigid’ (APCR) shot, a tungsten core mounted in an alloy sheath of approximately the same dimensions as the conventional steel shot for the gun. By virtue of its light alloy content the APCR shot was somewhat lighter and thus had a higher velocity when fired. Unfortunately the ratio of weight-to-diameter was unfavourable, giving a poor ballistic coefficient or ‘carrying power’, and while the short-range performance was impressive, the velocity soon dropped, and at ranges over 1,000 yards, steel shot was just as good, sometimes better. Some German weapons were also provided with the same type of projectile, and one was designed for use in the Soviet 76.2-mm field gun which the Germans captured in large numbers and converted into an anti-tank gun. Unfortunately for them, by early 1942 the shortage of tungsten in Germany began to be felt, and in the middle of that year a ban was placed on the use of tungsten in ammunition; what scarce supplies there were had been earmarked for machine tool production, not for throwing about the Russian steppes. After strong remonstrations, the 5-cm Pak 38 anti-tank gun was specifically exempted from this ban, since at that time it was the only weapon capable of stopping a Russian T-34 tank, provided it was supplied with tungsten-cored shot.
Although the 6-pounder APCR shot seemed reasonably successful, it was not the ideal answer. The ideal, in fact, sounded ridiculous: what was wanted was a shot which in the barrel was large-calibre and light, so as to pick up speed quickly and leave the gun at high velocity, but which outside the barrel should be small in diameter and heavy, so as to have good ‘carrying power’ and keep up its high velocity for a long range. These two conflicting requirements were fused into one projectile by two British designers, Permutter and Coppock, of the Armaments Research Department. Even before the 6-pounder had received its APCR shot they were at work, and in March 1944 their ‘AP Discarding Sabot’ shot was provided for the 6-pounder. In this design, the tungsten core is contained in a streamlined steel sheath or sub-projectile; this in turn is carried in a light-alloy framework or ’sabot’ of the full gun calibre. On firing, this sabot holds the sub-projectile centralised in the bore and gives the whole thing the combination of light weight and large area which is wanted for velocity. But firing actually ‘unlocks’ the sabot, and as the shot leaves the gun muzzle, so the sabot is thrown clear, allowing the sub-projectile to race to the target at velocities of the order of 3,000 feet per second. Now, since the sub-projectile’s sheath is virtually a skin round the tungsten core, it follows that the weight is high in relation to the cross-section—the ideal condition for good carrying power and thus long-range performance. A similar projectile for the 17-pounder followed in September 1944, and one was under development for the 20-pounder tank gun when the war ended.

ARMOURED BALANCE IN 1939 BEFORE WWII

German, French, British, Americand and Russian Tanks and Weapons Before WWII in 1939

The tank was to be decisive in the coming campaign.
But the Germans did not have more or even markedly
better tanks than the Allies. They just used
them more imaginatively
Although the end of the First World War in November 1918 seemed outwardly to symbolise an Allied victory and total defeat for the German army, it did not in fact reflect the real balance of fighting power at the front nor illustrate the state which the revolution in warfare had reached. For in the last months of that war the Germans were still retiring in good order towards their homeland. Indeed they were beginning to stabilise the front as the offensive power of the Allied armies declined as a result of their losses and of the difficulties they were experiencing in maintaining men and material at increasing distances from their bases. Indeed, it was becoming progressively harder to drive the war-winning weapons –artillery and tanks –to the front, and there maintain them to fight in mass. And without their presence a relatively thin screen of machine-gunners could delay and hold up infantry and cavalry for sufficiently long to enable successive lines of defence to be prepared in the rear. By the beginning of November 1918, the Allied progress was getting slower and more feeble.
Yet the turning point had come in August and September when the defeats inflicted on the Germans signalised the failure of their own offensive, and underlined the war-weariness of the nation and army. The most decisive of these defeats occurred at Amiens on August 8, 1918, when 430 British tanks –in conjunction with cavalry and infantry –broke through the German lines, and thus convinced General Ludendorff, the controller of the German military machine, that the war had to be ended. The British tanks, fighting in close co-operation with the cavalry and infantry, did not penetrate much deeper than the forward German defences, but their employment in such numbers, carrying them forward 5 miles in one day, administered a shock to the German soldiers and their leader from which they did not fully recover.
The tanks of 1918 were neither fast enough nor sufficiently reliable to break through the enemy lines and then penetrate
deep into his rearmost tactical areas. But the tanks under construction for use in 1919 were meant to be capable of doing this very thing, and the Allied plans for that year were based on this kind of strategy. Against these new, faster, and more reliable machines, the Germans would have only been able to deploy conventional artillery, a number of inefficient light anti-tank rifles, and a few clumsy tanks of their own.
For Ludendorff had rejected tanks, thinking it unlikely that the early, slow, clumsy vehicles would ever become viable weapons of war. Anyway, when given new machines, armies take a long time to acquire the techniques necessary to keep them running and to use them to their best effect, so the lead which the Allies had built in two years could not be overtaken in a few months.
Atrophy
Thus the First World War ended at a moment when victory in the field was not clear-cut and its causes not sharply delineated. Many Germans were in no doubt that the surprise use of tanks, in large numbers in the least-expected sectors, had been a paramount factor in their defeat. General von Kuhl, who had been a staff officer in the army group attacked and defeated at Amiens, wrote ten years after the event that, in achieving surprise, the most important and decisive factor had been the tanks.
But the Allies were not similarly convinced and, gripped by inertia linked to their own war-weariness, were content to allow their military thinking to atrophy after 1918. As for the French, for over 20 years they persisted in a policy that compelled tanks to act merely as an adjunct to infantry on the one hand, and as a substitute for cavalry in the scouting role on the other. They envisaged all offensive operations taking place in a manner similar to those of 1918, and so locked themselves behind the fortifications of the Maginot Line, developing a purely defensive mentality. They could not believe that a war of manoeuvre fought by tank
armies would take place on their soil. Their tanks were therefore organised into battalions, the bulk of them (33 of between 45 and 60 tanks each) ordained to work in small groups in conjunction with infantry divisions.
The experiments carried out by the French army, starting in 1932, were based on their existing cavalry divisions. There evolved from these experiments three light mechanised divisions –with a fourth being formed in May 1940–each with 220 tanks, armoured cars, and a brigade of infantry. But this well-balanced force the French threatened to squander because the old cavalry doctrine dictated that it should be employed as a dispersed screen, or advance guard, ahead of the Allied armies when these advanced beyond the frontier to meet the Germans in Belgium.
After the destruction of the Polish army in September 1939, largely as the result of action by German tanks in conjunction with aircraft, the French hastily began to form four new tank divisions in which the machines were heavy ones and the infantry few in proportion to tanks. These were still not proper armoured divisions: their envisaged role was to breach a front through which other conventional formations could pass. They were thus merely an extension of the policy which tied tanks to infantry, and were not conceived as a balanced formation capable of driving deep into the enemy rear to strike at his nerve centres and his supplies–the very heart of his war-making capacity.
The British did not suffer from the same stagnation as the French, but in 1918 the nation that told itself that it had won the war, also persuaded itself that it could rest on its laurels. The heavy losses of tanks in the last few months of the First World War made a case for those who argued that the machine could not replace the horse as the agent of the decisive, mobile arm; the sentiment generated by a lifetime’s comradeship with the horse was strong–and so rejected change. Moreover, the formidable bills incurred in the manufacture and running of tanks, when presented to taxpayers who had had enough of war, were striking deterrents to new construction and expansion.
The ‘Tank Idea’
Nevertheless, real progress was made in Britain. The discovery that tanks and armoured cars offered a cheaper and better way of policing the more turbulent parts of the Empire encouraged experiment. And the persistence of a few enthusiasts projected the ‘Tank Idea’ as an element in warfare that intruded beyond the tactical battle into the realms of strategic decision. The names of Captain Liddell Hart, Generals Fuller, Lindsay, Broad, Pile, Hobart, and Martel appear at the head of the short list of pioneers who envisaged armoured forces becoming the decisive element in war, as well as being a straightforward economy of force when compared with the old horse and foot armies.
These men designed and trained tank units and formations that were unique both in their concept and technical proficiency. By the end of 1934, Hobart, as commander of the 1st Tank Brigade, had conclusively underlined what Broad and Pile had demonstrated in earlier years, namely that a mobile tank force could out-manoeuvre conventional forces by advances of prodigious length. And they showed that tanks could dominate the infantry of the day. These men were not dreamers. They were practical soldiers who based their judgements on the bitter experience gained by witnessing four years of slaughter during the First World War. They were often impatient with those who could not or would not understand, and who, by their slowness of mind, could not keep up with the pace demanded by mechanised forces.
Hobart, above all, with a ruthless driving force that he used to push his ideas ahead, would not permit the speed demanded by tank action to be slowed down by artillery, cavalry, and infantry units that were unable to keep up with his machines and their tempo of operation. By his requests for outstanding efficiency and speed, he frightened his more conventionally minded colleagues.
Eventually, there came about a reaction, accusing Hobart of demanding an all-tank army to the exclusion of the traditional arms. This was not entirely justified, since Hobart and his staff are clearly on record as having said they wanted infantry and artillery suitably mounted in armoured vehicles to go with their tanks; but the impression had been given they wanted an army based on armour, and the forces of reaction were quick to seize on this for use as a brake on the progress of the tank enthusiasts.
The traditionalists were also successful in acquiring political support; the Financial Secretary to the War Office, Duff Cooper,
stated in Parliament in 1934: ‘The more I study them [military affairs] the more I become impressed by the importance of [horsed] cavalry in modern warfare.’ In 1935 Duff Cooper became Secretary of State for War.
The traditionalists also insisted that some tanks should be designed and set aside for work in conjunction with the infantry, rather in the manner of the French. Thus Britain began to develop armoured forces of two kinds: the fast moving, all-arms groups, that were the genesis of future armoured divisions; and tank battalions designed for infantry work, equipped with so-called `I’ tanks.
But by investigating the entirely new problems inherent in mechanised forces, the British did train a small cadre of experts whose knowledge and experience were to be invaluable when war, and the need to expand, came. On the other hand, when at last, and too late, it was decided in 1937 to give tanks to a large number of cavalry regiments —instead of expanding the existing Tank Corps — another temporary brake was placed on improvements in quantity and quality at a moment when time was short in the race to catch up with German rearmament. Thus only a small proportion of the British tank units that went to war in May 1940 were experienced and imbued with an insight into mechanised warfare.
Of the British armoured forces ready for action in Europe in May 1940, there was only one armoured division and this was still training in England. In France there was a formation known as the 1st Army Tank Brigade comprising two battalions of the new ‘1′ tanks designed for close co-operation with the infantry. Of these units —the 4th and 7th Battalions, Royal Tank Regiment—the latter arrived in France on May 1 and was not as well-trained as the 4th. In addition there were with the BEF seven cavalry light armoured regiments mounted in light tanks: Their tasks of reconnaissance and co-operation with the infantry divisions were akin to the traditional cavalry role.
German enthusiasm
The restraints imposed on the French and British after 1918 were totally different from those imposed on the Germans. Because the Treaty of Versailles forbade Germany to have her own tanks, she was reduced to carrying out a few sporadic and subversive experiments, mostly under cover in Russia. But because the Germans had been defeated, as they thought, by the tank as much as any other weapon, they were more anxious than anything else to acquire knowledge of mechanised armoured forces. The same traditional reactions that beset the British innovators held back the progressive German soldiers too, but with the advent of Hitler the political atmosphere became the reverse of Britain’s.
As he cast aside the restrictions of Versailles, Hitler gave his enthusiastic backing to the soldiers whose ideas and experience were devoted to tanks. Those generals who had been associated with the early tank investigations — Guderian, Thoma, Lutz, Brauchitsch, Blomberg, and Reichenauwere now brought to the fore.
These men possessed imagination and insight, the appreciation of the strategic and psychological effect of deep thrusts, and the zest for speed and decision demanded by the nature of armoured operations. They were unanimous and generous in their acknowledgement of the profit they gained after studying, and often copying, the British experiments (Guderian is said to have toasted Hobart’s name in champagne after a successful German tank exercise before the war). They paid little attention to the French—not even to de Gaulle, who had published a short work on the ‘Army of the Future’. As a result, by 1936 the Germans were catching up fast in numbers and quality of machines, and had taken a clear lead in organisation and application over the British and the French, who two years before had been ahead in every department of armoured warfare.