Engines of War

by Christian Wolmar

  The Dunkirk debacle was the nearest the war got to the British mainland, which meant that again the railways were not involved in front-line combat but on the Continent they played their now traditional role as the core of the logistics of war, a function which Hitler had fatally failed to grasp. Hitler was a car fanatic who understood their technology and how the engines worked, and had consequently focussed his country’s transport infrastructure effort on the Autobahnen, the world’s first motorways, rather than on building up the capacity of the railways. That was understandable given that it was very much in keeping with the Zeitgeist as railways were seen as an old-fashioned technology and the National Socialist emphasis on modernization naturally led them to embrace motor cars. The National Socialists did build innovatory diesel trains like the streamlined 100 mph Fliegende Hamburger (‘Flying Hamburger’), but it was the Volkswagen Beetle and the white Autobahnen which were their showpieces.

  This emphasis on rubber rather than steel tyres would severely constrain Germany’s war effort. Worse, Hitler compounded the error by focussing on the roads rather than on the vehicles which were needed to run on them. Yet it was the railways which kept the German economy functioning. According to a study of the German economy before and during the war, ‘the dependence on transportation was multifaceted and self-reinforcing. It was the very heart of the Reich’s military might.’1 And it was the railways which were at the heart of the system, as they carried 90 per cent of the coal that was the basis of the nation’s industrial output and 75 per cent of all freight.

  One surprising aspect of the German Army in 1939 was the limited extent to which it was motorized. The British had dispensed with the horse apart from ceremonial duties, but the Germans surprisingly had made less progress in converting their army to motor vehicles. This was partly because of Hitler’s lack of attention to detail, which meant he focussed on the more sexy hardware like tanks and aeroplanes, but was also a result of the German motor industry’s inability to meet army requirements. According to van Creveld, ‘of 103 divisions available on the eve of the war, just 16… were fully motorised and thus to some extent independent of the railways’.2 The rest of the army marched on foot while their supplies were, for the most part, carried in horse-drawn wagons as lorries could not cope with the demands of the army and, in any case, there were not enough of them. In the technological conditions of 1939, an astonishing ‘1,600 lorries would be required to equal the capacity of just one double-track railway line’.3 Worse, trucks use up vast amounts of road space and require more fuel and people than an equivalent railway, greatly elongating the army’s ‘train’, which meant that in relation to payload, ‘the railway maintained its superiority at distances of over 200 miles…however great the effort, there was little chance that motor vehicles would relieve, much less replace, trains as Germany’s main form of transportation in the foreseeable future.’4

  Hitler’s focus on motorizing his army and his failure to see it through left the railways suffering from comparative neglect, with the result that there were fewer locomotives and wagons available in 1939 than there had been at the outbreak of the First World War. To a large extent, the marching German armies depended on scavenging trucks from the local populace – a move that increased antagonism towards the invaders – and, equally unpopular, even from their own civilians.

  While the German invasions of Poland, and France and the Low Countries in 1939 and 1940 respectively, were astonishing victories, they exposed weaknesses in the Army’s logistics. German advances were characterized by having two sections, a small rapid motorized advance party which quickly took over vast swathes of territory but lost contact with its supply line, and a much larger, slower-moving rear. This tactic was fine in these early assaults since they were successfully concluded rapidly enough not to require reinforcements and the prolonged maintenance of supply lines. In Poland, the destruction of the railways by the retreating Poles had been so complete that it was only the rapid surrender of their army that prevented a logistical bottleneck for the Germans, who lost about half their trucks to the atrocious roads on which they were wholly reliant. By January 1940, the supply organization at Army HQ (OKH) was forced to resort to horse-drawn transport to make up the shortfall in available trucks. In France, the logistical failings did not escape Hitler’s notice since they contributed to the decision of the Germans not to press home their advantage in their sweep through northern France. The armoured spearheads speeding over the Meuse towards Paris progressed faster than expected and, as the railways had all been destroyed by the French, lost contact with their supply lines, leaving a gap between the two flanks. Hitler called a halt to allow for the supply lines to be re-established, which is why the British Expeditionary Force was able to escape from the beaches of Dunkirk, an event which contributed much to the Allies’ morale. Although the sabotaged railways were reinstated as soon as possible, there were too few Eisenbahntruppen to carry out the work quickly enough or to work the lines efficiently. There were frantic calls to requisition ‘all the lorries of Germany’ but by the time they arrived the Dunkirk beaches had been cleared. Again, as in Poland, had the French not crumbled so quickly, the split between the two parts of the army could have been exploited by the Allies and the Germans would have been forced to stop and consolidate.

  It was the invasion of Russia in the summer of 1941 where the logistical failings were to be cruelly exposed. In truth, however, Operation Barbarossa, the name given to the massive plan to invade Russia, was always doomed to suffer the same fate as all previous attempts to overcome the Great Bear. The Germans decided on a rather muddled three-pronged attack on a vast 1,400-mile front aimed respectively at Leningrad (formerly St Petersburg, then Petrograd), Moscow and Kiev, involving more than 3 million men, five times the number that Napoleon had at his disposal, and the largest invading army raised in the history of warfare. The basic orders for the operation, which van Creveld calls ‘a rambling and confused document’, provided for an advance to the line Dvina-Smolensk-Dnieper, respectively 600, 700 and 900 miles away from the point of departure. Yet, each army group only had one railway line to supply it during the advance, with motorized transport expected to do the rest. It was simply impossible because of the massive shortfall of motorized transport. Not only was the fleet of trucks a ramshackle collection of vehicles of 2,000 different types largely purloined from occupied countries, but to replace rail with road movements to reach Moscow would have required ‘at least ten times the number of vehicles actually available’.5 Operation Barbarossa was overwhelmed by the logic of its supply constraints and its failure changed the course of the war.

  There was, therefore, no alternative to using Russia’s sparse railway network and that was fraught with difficulties. Locomotives with boilers that kept functioning in the arctic conditions would have to be produced and track relaid because of the change in gauge between Germany and Russia. In other words, as Len Deighton puts it, ‘the speed of the advance would be limited to the speed at which a new railway could be built’.6

  The plan for the German advance was therefore drawn up in the light of these logistical constraints. To be successful Russia had to be conquered before winter and to achieve that a series of optimistic assumptions were made by the German HQ. It was to be the apogee of the blitzkrieg method of warfare, the strategy that combined tanks, infantry and air power in a single overwhelming attack concentrating tremendous force at points of weakness in order to overcome the enemy quickly. The plan for Barbarossa envisaged the rapid motorized units of all three army groups speeding 300 miles into Russia and then pausing while new railways were built and supply depots created to prepare for the final assault further east. To this end, remarkably, the Eisenbahntruppen, charged with repairing and converting the railway, were sent ahead as part of the advance party, even before the territory where they were expected to work was properly secured. This contradicted normal military practice. As van Creveld puts it, ‘instead of the logistic apparatus follow
ing in the wake of operations, it was supposed to precede them, a procedure probably unique in the annals of modern war’.7 Such expediencies were a measure of the desperation of the Germans, who grasped that the successful invasion of Russia depended entirely on their ability to supply their armies. And they couldn’t. The attack was launched on 22 June, rather later than seemed wise given the short Russian summer. Military historians argue about whether the start had been fatally delayed by Hitler’s last-minute decision to invade the Balkans to get the Italians off the hook in Greece, where they were being beaten by a poorly equipped Greek army, or whether he always intended to begin the invasion on the longest day of the year. Initially, the Germans met only feeble resistance from the shell-shocked Russians, allowing the fast advance units to reach their targets within days. However, the unmetalled roads proved to be even worse than expected, and deteriorated in the face of unusually heavy rainfall during the first week of July. A quarter of vehicles had failed within three weeks of the start of the campaign. On the railways, the difference in gauge meant the invaders were heavily reliant on using captured rolling stock but the Russians took away the best locomotives and destroyed the rest, leaving only a few wagons and coaches behind.

  Not surprisingly, the Eisenbahntruppen could not cope with the scale of their task and were beset by a host of difficulties. Undermanned and lacking requisite skills, they failed to carry out conversions and repairs thoroughly, tending only to provide the tracks without installing such vital equipment as platforms, workshops and engine sheds. They were forced to travel by road but were not given the priority they needed because the officers of the combat regiments did not understand the importance of their task. Changing the gauge was a slow and cumbersome job and proved to be the major obstacle for the efficiency of the lines of communication. While captured wagons could be adapted to standard gauge, it was impossible to convert locomotives and therefore, effectively, the Germans were always having to contend with two separate railway systems. At the point of change of gauge, which was advanced into Russia as quickly as possible and therefore had to be moved frequently, huge bottlenecks built up, at times delaying loads for two or three days.

  Railways tend to have their own particular characteristics and the Russians had built theirs with lighter rails and fewer sleepers, with the result that the lines, even once converted, could not cope with the more modern but heavier German locomotives which were used on the sections where the gauge had been changed. German engines struggled in the winter, too, as they had not been built to withstand the extreme temperatures. Unlike the Russian engines, their pipework was external and in the harsh climate of the Russian steppe, far colder than anything ever experienced in Germany, the pipes quickly froze and burst, putting the locomotives out of action.

  Shortages of fuel, both coal and petrol, were a perennial problem. Russian coal was inferior and therefore needed to be mixed with some imported fuel in order to power the German locomotives. To compound the supply difficulties, Russian petrol had such a low octane value that it was unusable for German vehicles. Even the horses were of the wrong kind. To pull their heavy wagons, the German army relied on strong draught horses, which proved unsuited to the cold conditions and required enormous quantities of forage. Amazingly, in order to ensure supplies could be carried, half the infantry divisions were equipped with small hand carts, Panje wagons, which meant the world’s most modern army was dependent on a transport method familiar to Christ.

  Each of the three German armies was accompanied by two armoured trains. The Wehrmacht had been rather unenthusiastic about armoured trains, especially after their failure during the invasion of Poland, where attempts to use them to spearhead attacks on key railway crossings over rivers were stymied when the Poles simply blew up the bridges. The Poles themselves deployed five armoured trains, which proved effective in several encounters with German Panzer (armoured) units, but three of them were destroyed by the Luftwaffe, demonstrating their vulnerability to air attack. Nevertheless, the Wehrmacht decided that they would be useful in the initial stages of Barbarossa to seize railway bridges and then, after conversion to the wider Russian gauge, to protect the long stretches of railway line from attacks by partisans, which as the Germans advanced deeper into Russia increased in both severity and effectiveness. The Germans used not only their own armoured trains but several captured from the Soviet forces, who had started the war with a far bigger fleet but lost many in the early battles of Barbarossa. Some of the trains used by the Germans were even protected with armoured cars, mostly French Panhards, converted to rail use and sent out in front of the train to reconnoitre the line and draw any fire.

  Of the three armies that invaded Russia in theory the northern group led by Field Marshal von Leeb, which headed towards Leningrad, had the easiest task as it only needed to cover a distance of 500 miles from East Prussia. And at first, helped by the good road and railway network in the Baltics, which had been prosperous independent states before their occupation by the Soviets in 1940, progress was remarkable, with the motorized units covering 200 miles in just five days. However, as the convoy headed north-east, the forests became denser and the roads fewer, and the supply trucks became entangled with the huge infantry columns marching ahead of them. Soon airlifts had to be organized to keep the forward troops supplied and although by 10 July the leading armoured troops led by General Max Reinhardt were within eighty miles of Leningrad, and were in the process of overwhelming the outer defence line of the city, launching an all-out attack proved impossible because the infantry was strung out over the Baltics and the tanks could not operate in the heavily wooded terrain. This was typical of many similar offensives in the Second World War in which the attacking armoured forces ran ahead of their logistical support that then failed because it was predominately road-based. By then the Eisenbahntruppen had converted 300 miles of railway but the railhead was still well behind the front and in any case the line was in such poor condition that it could only accommodate one train per day. The armoured troops therefore had to wait for supplies to arrive by road and for the transport situation to improve, and consequently the opportunity to take Leningrad swiftly was lost. Moreover, Russian resistance stiffened with numerous partisan attacks on German supply lines, making life difficult for the invaders, and in August heavy rain turned the roads into quagmires. By September, Hitler, recognizing that Leningrad could not be taken quickly, ordered the withdrawal of the Panzer tank unit, Panzergruppe 4, to join the assault on Moscow, leaving the Luftwaffe with the impossible task of trying to take the city. Van Creveld concludes that the strategy of the attack was fatally flawed at the outset: ‘It seems certain that Army Group North’s best chance for capturing Leningrad came around the middle of July, when Reinhardt’s corps had penetrated to within eighty miles of the city. At this time, however, supply difficulties ruled out any immediate resumption of the offensive.’8 By the time any attack was possible, the citizens of Leningrad had built a series of fortifications, including anti-tank ditches, trenches and reinforced concrete emplacements that proved all but impenetrable during the siege, which lasted two and a half years and became one of the most deadly in human history.

  The middle group, aimed at Moscow and led by Field Marshal von Bock, was by far the strongest force. While initially its supply difficulties were the least pronounced of the three army groups because it straddled the main Warsaw-Moscow railway that remained undamaged, they were to play a crucial role in the army’s failure to reach Moscow. Indeed, the progress of the central army group was initially even more impressive than that of its counterpart to the north. The strategy was to create a series of pincer movements with Smolensk, about halfway to Moscow, as the target for the first stage of operations, but the usual difficulties of roads being blocked by streams of infantry and of insufficient railway capacity soon became apparent. There was a shortage of petrol exacerbated by the higher consumption of lorries on the atrocious roads and of spares, especially tyres, whereas on the railw
ays there were the customary bottlenecks at the gauge changeover points. However, by and large there was reasonable progress until the Germans attempted to build up a supply base for the final attack on Moscow. Then it became clear that there was insufficient capacity to launch the assault on the Russian capital. Bock needed thirty trains per day to build up stocks whereas, at best, he was getting eighteen. Just as in the north, Hitler then changed the game plan, diverting resources – a tank unit, Panzergruppe 3 – to the south, along with 5,000 tons of lorry capacity, to ensure that Kiev could be taken. It was a terrible mistake. While Ukraine was important in terms of resources – wheat, coal and oil – Moscow was the centre of the nation’s communications and had the Germans been able to block it off, the Russians would no longer have been able to use the rail lines to transport troops between the north and south.

  With the help of the extra panzers, Kiev soon fell but then another mistake resulted in the move eastwards being undertaken too hastily. Already the south group, which had been charged with taking Kiev and then crossing the Dnieper to capture the coalfields of Donetz and invading the Crimea, had been beset by wet weather that knocked out half its motor transport. Progress was also slowed by fiercer resistance from Russian partisans than faced by the other two groups. Once Kiev had been encircled, the eastward move resumed on 1 October but it was greatly hampered by the destruction of the bridges over the Dnieper, which forced supplies to be shipped across the river. The Germans took over sections of the Russian railways but they were in a poor state and during October barely a quarter of scheduled trains arrived at the two easternmost railheads. Chaos on the Polish railways further back on the line of communication added to the supply difficulties. Therefore, the decision to resume the offensive proved premature as, without any effective railway support, there was no hope of reaching the Donetz Basin with its mineral riches before winter set in. Although the Germans captured Rostov in late November, their supply lines were overextended and they subsequently lost the town, the first time the German advance had been successfully repelled.