Landships II

I thought it might be useful as background information to look at German problems in producing armour plate for tanks, why this might be so and the implications for the potential production of German tanks at the end of the war. Not so dry a subject as it might sound as it involves blockade running and overseas intelligence operations. It may be of interest to note that much the same happened in WW2 over the supply of Tugsten (wolfram) from neutral Portugal.

The armour plate crisis

Armour plate was made from steel. Germany in WW1 produced more steel than Britain and France put together, it had copious sources of coal both from Germany’s own mines and from Belgian and French collieries in occupied territories. Although Germany’s own iron ore reserves were low yielding, Sweden supplied large quantities of high grade ore. German heavy armour plate (as used in warships) was of superior quality to that produced in Britain, France or America (one reason why production of this was specifically controlled by the Versailles Treaty) and yet in 1918 Germany was unable to produce thin armour plate in anything like the quantities necessary for more than a token tank force and the quantities of tanks ordered for 1919 were effectively nothing more than a pipe dream.

Armour plate is more than just hard steel. Very hard steel tends to shatter under the blows of shot and shell, but make the steel too ‘soft’ and it is easily penetrated. Good armour plate needs to be resilient. This can be achieved in a number of ways but these can be divided into two basic approaches; one can affect the structure of the steel through the steelmaking process or one can change its composition by the addition of other metals. Sometimes the two are combined in armour making so that a particular quality of steel is subjected to further hardening processes after the armour plate has been cut and drilled. However, as we shall see, Germany was spectacularly deficient in access to the metals needed in the production of armour plate.

In the production of heavy armour much can be done through physical processes and techniques such as casting into moulds with one surface chilled, the use of heated and chilled rollers, denching hot metal in water, oil or other liquids (including, in some processes, molten cyanide). The effect is often to produce a hardened surface with a softer (soft is a relative term) and resilient core, (the same effect is sought by master Japanese sword makers but using different, small scale, techniques). German steelmakers were very expert in these (often dangerous) techniques and significant capital investment had gone into the production of the large, very expensive and highly specialised plant necessary.

However many of these techniques could not be effectively used in making thin armour and much more reliance was necessary on the getting the right composition of steel. This can be achieved through the addition of various metals in small (but very precise) amounts. Chief amongst those used in making various forms of armour plate were nickel, chrome and manganese, the most important of which was manganese. These metals were also of enormous importance in the production of forms of steel used in artillery, shells, aero engines, machine tools and the like. Manganese was also used in non steel products such as the bronze used for ships propellers. Germany had easy access to none of these.

Nickel came from such places as Russia, Canada, Australia, the Dutch East Indies and Brazil. Germany’s pre war imports of chrome came from Spain and Turkey whilst manganese was produced in Russia, Brazil, South Africa, Australia, Gabon and India. With the exception of Turkey all of the major sources were either in Allied territory or could only supply Germany by sea routes tightly interdicted by the Allied navies. Even when Russia sued for peace its economy was in such turmoil that it would be difficult for it supply Germany even if this had been something Russia was prepared to do. Supplies of chrome from Turkey were, in part, carried on sea routes subject to attack from British and Russian navies.

Germany had to result to two methods of obtaining these strategic industrial metals, blockade running and skulduggery. Thus the metals were often purchased through front or shell companies that were in effect controlled by German intelligence officers and shipped (with false papers) on friendly neutral carriers on round about routes that finally passed through neutral countries with land borders with Germany (or very short sea links that could be protected by the German navy). Thus cargoes might pass covertly through countries such as Denmark, Holland or Sweden, often without the knowledge of the governments of those countries. Sometimes this was done with the complicity (active or passive) of individuals in neutral countries, thus German agents operating in the USA before America entered the war reported getting assistance from some German Americans and Irish Americans. There was an undercover battle between Germany and Allied intelligence over these companies and routes but over time the Allies managed to detect and plug most if not all of these. As more counties declared war on Germany the scope for the Germany agents to operate diminished. The entry of the US and Brazil into the war in 1917, for example, closed both sources and routes.

A major way of obtaining such strategic materials was the use of corrupt industrialists. In one instance between 1916 and 1917 a Swiss company was dealing in both steel and manganese. The steel was German sold on to France whilst the manganese came from French suppliers and ended up in Germany! Investigation revealed that most members of the board of the Swiss company were in fact French nationals effectively trading with the enemy in strategic materials. Amazingly no one got shot or even jailed in France (there were a number of similar cases in French industry during WW1, there seems to have been a climate of corruption in some areas of business and government). It shows how important was manganese to Germany that during a period when there was a shortage of steel in the German war industry the High Command was willing to see steel diverted to the enemy in some quantity in order to acquire the much needed special metal.

Simple blockade running continued throughout the war, U boats being sometimes used to carry small cargoes of strategic materials. German naval airships proved particularly useful in assisting surface ships in running the blockade. The airships could locate British warships and notify the blockade runner by wireless of their disposition, telling them when and where to sail to avoid interception. However in 1918 the Royal Naval Air Service became increasingly able to intercept and shoot down these aerial observers by using ship launched fighters and long range flying boats. As a result the ability of the airships to operate was greatly reduced.  A significant blow was struck with the worlds first aircraft carrier launched strike against their base destroying airships in their sheds. The effect was to tighten the blockade.

By late 1917 the German war industry was already unable to meet all the demands being made upon it. Captain Wegner of the A7V committee has described how a scheme to mass produce copies if the British Mk IV had to be abandoned as the necessary materials (mainly armour plate and man power) required could not be provided without serious depleting the supply of other weapons to the German forces. In effect the choice in WW1 was guns or tanks. Guns were chosen. Wegner indicates that a shortage of material was in part a limiting factor in the production of the A7V in 1918 and in the development of the LK series.. Other sources suggest that the delayed completion of construction of the K Wagen was also due to a lack of armour plate. Effectively by the end of 1918 German industry could not produce enough thin armoured plate for more than a few prototype tanks. Given that German steel production in general remained high up to the end of the war one can only conclude that it was a shortage of those industrial metals necessary for the production of armour plate quality steel and other needs (such as the production of manganese steel for shells) took priority for what stocks there were. In such a case one wonders from where was the armour for the five hundred plus light tanks ordered for 1919 supposed to come from?