"...did our high-tech equipment really work? Beyond our wildest expectations"
General Norman Schwartzkopf, It Doesn't Take a Hero (Bantam, 1992)
On 10 May 1940, German forces attacked into Belgium and Holland. Blocking their way was the Belgian fort of Eben Emael, accepted as one of the most powerful single fortifications in Europe with a garrison of 1,200 men. It was rendered inoperative in less than two hours by a German force of only 56 men armed with man-portable weapons.
How was this Achieved?
The accepted wisdom at the time, and still prevalent, is that the element of surprise gained by the use of gliders, and the use of emerging technology, in the shape of the 'hollow-charge', were the reasons for success. The Commander of this 'Lilliputian detachment', Lieutenant Rudolf Witzig, supported this view in his own account of the raid.
In March 1991, I was taking a party of soldiers in a guided tour over the Belgian fort of Eben Emael, with the help of the Belgian 'Friends of Eben Emael' (FEE) an association of veterans and local historians. At one point during the tour on the outside of the fort, the party was grouped around one of the steel cupolas that formed the basis of the fort's armament. Standing on the cupola, to address the group more easily, I gave a short explanation on the theory of the 'hollow charges' used by the Germans in their attack, and pointed to the characteristic marks left on the armour plate from their operation. One of the soldiers then asked what sort of effect the charge had on the men working inside. I indicated the veteran standing to one side, and said 'Why don't you ask him? He was inside one of these turrets during the attack.' The soldier did so; but the veteran merely shrugged expansively and said 'I suppose it made me more religious . . . ' He then pointed out that the 'hollow charge' had not in fact knocked out the turret, but merely temporarily jammed the traversing mechanism. The knockout blow came from a number of smaller conventional charges 'thrown down the barrels of the guns'.
This account was a surprise and appeared to be quite opposite to the accepted view. It was not, however, the first time that it has come to light. It has been mentioned, and dismissed as apocryphal, in other accounts of the attack on the Fort. But if this veteran's account did turn out to be true, it raises a number of interesting questions. Why has there been this tendency to exaggerate the value of technology? If it was not the use of some 'secret weapon' that contributed most to the defeat of the Fort in 1940, then was it something else?
Planning and Training
In 1939 the German Army Group B was given the task of planning the breakthrough of the Belgian defences between Venlo and Aachen in a lightning operation, and destroying the Belgian forces before they could occupy the defensive line constructed across the centre of Belgium.
When the Army Commander, General von Reichenau presented his operational plan to Hitler and the Supreme Army Command (OKH), in October 1939, the Fuhrer was not satisfied with the idea of taking the bridges over the Meuse and Albert Canal by the advance guard of the 6th Army. He was concerned that the defenders would have enough time to blow the bridges. This would slow down the mechanised units, allowing the Belgians time to withdraw as they had in 1914 and extend the enemy front as far as the coast. The whole operational concept hinged on the destruction of Fort Eben Emael and the capture of the Albert Canal bridges, at the very beginning of the campaign.
On 27 October 1939, General Kurt Student, Commander of 7 Fliger Division was ordered to visit the Fuhrer, 'alone and without delay'. On arrival, the thoroughly puzzled General was immediately led in to see Hitler. At the far end of the long walnut panelled room, the Fuhrer raised his eyes and beckoned the General to look at the map on his desk. 'For the war in the West . . . ' Hitler paused, seeming to consider how to begin, ' . . . I know you have made some tests with gliders. You have some in your Division. I have a job for you and I want to know if you can do it. The Belgians have a fort here . . . The top is like a grassy meadow. They have heavy artillery in cupolas and casemates. I think some of our silent gliders could land on top of the fort and your men storm the works. Is that possible?'
To Student the idea sounded both incredible and simple. He said that he was not sure and would have to go away and think about it. He returned the next day, still not sure. He said to Hitler, 'It may be possible under very special circumstances: the landing must be made in daylight, or at least morning twilight and not before; and I am uncertain about the amount and type of explosives needed to be used against the fortifications.'
Hitler then revealed that German munitions experts had developed a new and fantastic explosive charge, the Hohlladung or 'Hollow Charge'. It was capable of blowing a hole in any known military armament, be it steel or concrete. The problem was that it weighed 50kg and could not be fired from a gun, but had to be emplaced, fused and exploded, by two or three men. If it could be placed like this, nothing could withstand it.
Student had been considering how a few glider loads of men could really capture such a vast fortification with conventional explosives. With the hollow charge the whole operation took on a new meaning and chance of success. The combination of gliders and hollow charges seemed unbeatable to him. Hitler then said 'I order you to take Fort Eben-Emael. All aspects of the operation must remain absolutely secret. The code name for this operation will be GRANIT' (Granite). Later Student was to say that this 'was perhaps the most original idea of this rich-in-brain-waves man'.
Now that the decision had been made, the preparations for the attack went ahead. General Student carefully screened his airborne forces and selected Hauptmann S. A. Koch, a highly talented officer, renowned for his incredible ideas and schemes, to lead the attack. On 3 November 1939, Koch Storm Detachment was formed in Hildesheim, composed of a number of units. These were formed into groups, including GRANIT who consisted of 11 gliders, two Officers and 88 men.
The GRANIT force was formed from the Engineer Detachment of the Division, under the command of Lt. Witzig. This was the only parachute unit composed entirely of sappers. Many of these had long records of disciplinary infractions, but they were all individualists with a reputation for fearlessness. Amongst them were some of the best pre-war amateur glider pilots.
This detachment was constantly moved around under a bewildering array of codenames. Glider practice in the Hildesheim area was carried out on only the smallest scale. When necessary, the gliders were dismantled and moved about in furniture vans. Despite their extensive sport experience, most of the pilots had never seen the DFS 230 before, and they entered into an intensive training programme. By March 1940 they could take off at night, towed by a JU-52 aircraft, and cast off to land within 20m of the target. They used a piece of terrain in Stolberg that was similar to the plateau at Eben-Emael.
Each section, one glider, was given two emplacements to destroy, with plans to take over another section's task, should it fail to arrive. The glider pilots were also fully integrated into the sections. Practice assaults and trial demolitions were carried out on Polish fortifications near Gleiwitz. Secrecy was of paramount importance. From November 1939 until May 1940, for six months, the men of the operation were virtual prisoners. No mail, no leave, no contact with other units and all parachute insignia was removed from their uniforms. Two men, found discussing the operation with men of another unit, were sentenced to be shot, but were reprieved to take part on the day of the operation. Eventually, trains moved the planes by night to two airfields near Cologne. The hangars were continuously guarded and surrounded by barbed wire. Even the base commanders were not told what was going on in the hangars.
The operation was scheduled to start at 0300hrs on 10 May 1940. Two Luftwaffe personnel who were curious, and were found wandering in the vicinity of the hangars the evening before, were arrested and held until the operation was over. By 0335hrs on 10 May 1940 all of Witzig's gliders had taken off and their tow planes circled to gain height before following the route marked by searchlights and signal beacons.
The Fort
Before World War I, the Belgian fort designer Henri Alexis Brialmont had identified the 'Gap of Vise' as being of vital strategic importance, and stated that the decision not to construct a fort in this locality was one over which the Belgian nation would 'weep tears of blood'. The events of 1914 proved him right. Later, during the con-struction of the Albert Canal (1927-29) a cutting was driven through a hill in the area, known as the Kaster, over 80 metres deep. This feat of engineering, equal in magnitude to the cuts at Suez and Panama, was to connect the canal to the Meuse River. This produced a site with the near-vertical walls of the cutting to the northeast, a natural cliff to the south and unparalleled views towards Germany. With the lesson of the First World War behind them, and the engineering works producing near-ideal conditions, the Belgians decided to construct a fortification near the village of Eben Emael. The Fort was constructed in only three years (between 1932 and 1935) at a cost of Bf 24M (1935 prices), and occupied an area of 75 hectares.
The armament consisted of two batteries, one for protection of the fort itself, and the other designed to cover the vital bridges over the Meuse and Albert Canal. The latter was made up of a number of cupolas and casemates. The three cupolas had all-round traverse. Two of them were of the 'disappearing' variety, capable of being completely retracted between firings. In addition to these real cupolas, three fake cupolas (identical to the largest) were added as a deception plan to confuse attackers. The four casemates each consisted of three-gun batteries with a limited arc designed to cover specific bridges. The defensive battery included anti-aircraft positions and machine-gun emplacements on the roof of the fort, as well as a defensive ring of blockhouses and outworks.
The fort itself benefited from the latest technology. It possessed a sophisticated fire-control system and network of outlying observer stations to co-ordinate defensive fire tasks. The chemical threat was addressed with a protection system of unparalleled ingenuity, involving purified air overpressure maintained in the gun positions and a huge filtration chamber. Gas-tight doors separated the various parts of the fort and each section had, in theory, three separate modes of communication with the command post. The fort was supported by six massive generators and even had its own deep borehole well.
The Assault
As dawn was breaking on 10 May, the German gliders landed on the surface of the fort. Despite the months of planning and training, there were a number of potentially fatal mishaps. One of the gliders was damaged at the take-off and another, carrying Witzig who was commanding the operation, was forced to land near Cologne due to the towing cable breaking. The wind changed; the gliders could not be released until they had passed into Dutch airspace, where they were detected and fired on by the anti-aircraft batteries around Maastricht. This alerted the Belgian defenders, who were already at their posts after an alert had been called at 0030hrs. In addition the Belgian deception plan worked perfectly and the Germans wasted 30 per cent of their force attacking the dummy cupolas.
The Belgians, however, had problems of their own. The fort itself was regarded as something of a punishment posting, and was not popular. The full garrison was indeed 1,200 men. However, this was made up of about 200 technicians and support staff and 1,000 gunners. These were split into two week-long shifts, with the off-duty shift billeted at Wonck. They had no transport and it usually took over an hour to march the 6km to the fort, and in the past few months of the 'Phoney War' a great many alerts had been called, all of which turned out to false alarms - until now. The total of 500 gunners actually in the fort was further depleted by sickness (the fort was not a particularly healthy place to work) and the policy of allowing fathers with large families, and those from agricultural areas, extra time off at home. In fact, on 10 May 1940 the total garrison was only 883. Furthermore, much of the administration for the garrison was carried out from two wooden huts situated outside the main entrance. In the event of an attack, classified documents and other materials had to be moved into the fort's command post. The men allocated to this task were the crews of the machine gun emplacements on the upper level of the fort. Despite this, the commander of the fort, Major Jean Jottrand acted swiftly. When he heard the sound of the anti-aircraft batteries firing he ordered the transfer of papers and the demolition of the huts that limited the arcs of fire for the outer blockhouses. When the demolition guard at the nearby bridge at Kanne contacted him, because they were unable to contact their superiors, Jottrand ordered them to open fire even though this was exceeding his orders. Despite not being under his command, they obeyed him and eventually destroyed the bridge in the face of the attacking German ground forces. Jottrand did organise a number of counter-attacks, but these were ineffectual. The soldiers moving the documents into the fort were the crew on the machine-gun emplacements on the roof, so were absent from their posts for the vital moments that they were needed. The Fort commander did not have formal communication links with the surrounding ground units and, anyway, they were not under his command. Any requests for assistance were supposed to be relayed through the superior headquarters at Liege. The off-duty shift at Wonck was contacted and ordered to attack, but the Germans on the Fort called down Stuka and artillery attacks and the attack petered out. Only 12 men reached the fort 'unwounded and capable of mounting an attack'. They were used in counter-attacks, but after running out of their stock of grenades Jottrand called them back.
What About the Hollow Charges?
While all this was going on, however, it is generally accepted that the German hollow charges were making short work of the Belgian guns and emplacements. But was this really the case? I am an Ammunition Technical Officer (ATO) by training, and not unfamiliar with the effects of explosives. I examined the other turrets and casemates during this visit, and later. In only one case, out of a total of 14 gun positions, was it possible that the hollow charges achieved the destruction of the gun concerned. In all other cases the demolition was achieved either by a smaller conventional charge. These were placed near the barrels of the guns themselves, or by wedging the hollow charge at an angle in the embrasure and relying on the force of the explosion rather than the hollow charge effect to destroy the gun. The charges only appear to have been truly effective in shattering the tiny observation cupolas that were mounted on the top of some of the emplacements.
In the days after the attack, the alarmist contemporary accounts of German secret weapons, spies, and sabotage were easy to understand. One newspaper even offered the fantastic theory that Germans, living in that part of Belgium, had managed to stack explosives in caves under the Fort so they only needed to detonate them when the attack started. Later speculation focused on the Belgian consortium, United Enterprises, which received the contract to build the Fort. They sub-contracted some of the work to German firms. Not surprisingly, this led to much speculation about espionage, despite the fact that their work was limited to the canal walls. In any case the Belgian Government, of course, made details of the armament of the Fort, as well as its level of protection public. How else were they to provide a deterrent to any potential attacker?
In the final analysis, the fort itself was the embodiment of the latest military defensive technology and the only readily acceptable explanation for its defeat was the invention of some more advanced technology that made resistance impossible. Furthermore, the comprehensive German security precautions and unusual treatment of the Fort's garrison after the attack (they were completely isolated in a separate prison camp for six months) did nothing to dispel the rumours and mythology that built up.
But, if it was not the advantage of technology that proved the deciding factor, what did?
On 10 May 1940, the German Paratroopers of Assault Force GRANIT were some of the finest soldiers in the world. They had a great many advantages on their side: the rigorous physical selection, the months of practice attacks and training carried out in the strictest secrecy, and the long record of fighting and other disciplinary infractions that is supposed to demonstrate aggressiveness and high morale in a unit. There were additional factors. The German soldiers believed themselves to be superior to their enemy. The invasion of Poland had been a stunning success, the latest in a line of German political and military triumphs. The enemy were 40 year-old conscripts, wearing uniforms little changed from the last time the German Army had defeated them. They were armed with Belgian copies of German First World War rifles and had received minimal infantry training. The Belgian leadership lacked focus and direction. They were unprepared for war, both physically and morally.
Latecomers
When the tow cable snapped on his glider, forcing Lt. Witzig down, most normal men would have accepted that their part in the operation was over. Witzig, however, did not allow this setback to deter him. He hijacked a bicycle from a passing civilian and set off to his base. After meeting up with a German unit, he commandeered transport and drove to the airfield some 70km away.
There he picked up a spare cable, a set of wheels for the glider (these were jettisoned on take-off) and arranged for a new JU-52 tug aircraft from the airfield at Goetersich. He then took off and flew back and landed where his glider had been forced down, the JU-52 was capable of landing on unprepared fields. In the meantime his men had not been idle. They cut down the hedges dividing the fields, allowing room for the landing and take-off. When Witzig arrived they fitted the cable, lifted the glider onto the new wheels and took off again for the Fort. They finally arrived only two hours late. By then, however, it was all over.
Yet they were not content to rest on their laurels. They took on the Fort's garrison itself, 80 men against 800. They blasted their way into Maastricht 1 & 2, and MG Nord by wedging hollow charges at an angle in the embrasures of the guns. In Maastricht 1 the gun was thrown back off its mounting, and the surviving crew fled down to the safety of the interior of the Fort. The Germans then squeezed through the hole caused by the explosion and into the casemate. The dismounted gun had blocked the door to the telephone point, trapping two of the Belgian gun crew, and these were freed by the Germans. The attackers then decided to press on after the retreating Belgians. The connection to the intermediate level of the Fort is via a steel spiral staircase that winds its way around the ammunition hoists, over a vertical distance of 40 metres. The Germans made their way down the stair to the intermediate level, and up to the blast doors.
These blast doors were heavy gas-tight double steel doors, 2 metres apart and closing towards each other. Between the locked doors were 20cm slots in the concrete, into which fitted a number of steel 'I' beams completely blocking the passage. Sandbags were available to fill up the remaining space between the beams and the second set of doors further backed these. Finally the doors themselves were capable of being locked. This formidable arrangement was supposed to defeat any attempts to get into the interior of the Fort.
German soldiers carried hollow charges all the way down the winding stairs, to the blast doors. It is worth remembering that the charge alone weighed 50kg, and the steel stairs are too narrow to allow two fully equipped soldiers to pass each other. At the bottom they set the fuses and retreated to the surface. How long was that fuse? Lt. Witzig states that the standard fuses were only 10 seconds. The soldiers must have fitted non-standard fuses, something that is always to be avoided in the heat of battle, where a simple slip would cause instant disaster or embarrassing failure. Neither of these happened, and the resulting explosion, confined as it was deep underground, had only two routes for the expanding gases to escape; up the shaft containing the stair and ammunition hoists, and through the blast doors. Behind the doors in Maastricht 1 were six Belgian soldiers on guard. They were killed instantly as the door and the steel beams were blasted across the passage. Also in the corridor were a number of drums containing a chlorine-based disinfectant. These burst sending the smell of chlorine, via the forced air system, throughout the Fort. The concussion and the smell of gas caused a panic among the remaining defenders.
Unfortunately for the Germans, the force of the explosions also destroyed the steel stairs and ammunition hoists, leaving them an impassable mass of twisted metal, preventing access to the intermediate levels. Nevertheless they continued to attack the various embrasures until they ran out of explosives.
Even the crew of the glider that was damaged on take-off did not return to base, but instead commandeered various vehicles and joined the ground forces for the link-up attack. Some crossed the canal in advance of the attacking forces, over the wreckage of the demolished bridge at Kanne. One of them, Private Walter 'P' Meier, stole a bicycle and cycled right up to the fort, where his comrades who didn't recognise him promptly fired on him.
He returned to German lines with a copy of the 'Orders for the Day', taken from a notice board outside the main entrance, and 121 Belgian prisoners (the POW Camp receipt for the prisoners he attached to his battle report to prove he hadn't been slacking).
The Belgians, in contrast, limited themselves to ineffectual counter-attacks (despite outnumbering their foe by odds of 10:1) and calling down artillery fire onto the superstructure of the Fort.
Conclusions
Operation GRANIT was a plan based on the technological possibilities of the hollow charge. It was carried out with overwhelming success, despite the fact that this technology proved almost completely ineffectual, because of the fighting qualities of the German attackers, and the lack of those qualities in the Belgian defenders. Ultimately, the Germans were simply better soldiers than their foes.
But if this was the case, why did even veterans of the assault feel compelled to exaggerate the value of the technology, and why we are still doing so 50 years later?
I feel the answer lies in the fact that western society has a technological foundation. We are used to technology, and technical explanations are easy for us to understand. We find comfort in machines, lacking as they are supposed to be in 'human failings' and they give us confidence. Also, in the post-colonial era, there is a natural unwillingness for a westerner to compare himself with his enemy man to man, person to person. It smacks of arrogance, overconfidence and ultimately racism. It just isn't done.
Furthermore, the soldier is well aware that, although technology is only one factor in the reason for victory, it is a factor over which he has little control. It is within his power to change the emphasis on training, organisation and doctrine but it is the politician that will ultimately decide whether he receives the latest piece of equipment or not.
If this is true of the victors, then it is doubly so of the losers. It is only human nature to put the blame for failure on something over which you have no control. Thus we end up with both sides appearing to agree on the reason for success, when the reality was somewhat different.
In the end it is inevitable that technology will receive inflated importance. It is also only natural that accounts of the event will pay less emphasis on long and complicated explanations about morale, aggression, team spirit and esprit de corps, in favour of a sophisticated illustration showing the way a hollow charge is supposed to work. Technological factors can never be ignored, but Operation GRANIT offers a classic example of how their significance has been greatly exaggerated and served to obscure the real reasons for the success of the operation.
Which brings me back to the quote by Swarzkopf at the start of this article. Did our high-tech equipment really work 'beyond our wildest expectations'?
Editorial note
The opinions expressed in this article are the author's own and in no way represent the views of Her Majesty's Government.
by Major T N Mouat MBE RLC
Further Reading
Dunstan, Simon, Fortress 30: Fort Eben Emael: The key to Hitler's victory in the West (Osprey, 2005)
Marix Evans, M., General Military: The Fall of France: Act with Daring (Osprey, 2000)
Quarrie, Bruce, Warrior 38: Fallschirmjäger: German Paratrooper 1935-45 (Osprey, 2001)
Shepperd, Alan, Campaign 3: France 1940 (Osprey, 1990)