In the 1920s and 30s, influenced by the positional warfare of World War I,
the major military powers of Europe constructed systems of fixed fortifications.
It was thought that fortifications would be able to protect a country’s borders, or specific, crucial regions, from invasion.
These fixed defenses were integral to the strategic planning of France, Germany, and the Soviet Union.
Each country developed fortified areas in their own way,
combining bunkers, infantry and vehicle obstacles, medical units, communications systems, and many other elements.
Engineers and planners did their best to anticipate any potential enemy attack.
We have decided to rate each defensive line in terms of length, degree of complexity at the time of construction,
and how well each one held up when put to the ultimate test: enemy invasion.
First off, let’s see which defensive line was the longest.
Length: 3rd place.
According to the Treaty of Versailles, Germany was banned from having any kind of defensive structures on its borders.
Nevertheless, when the Nazis took power in 1933, they began constructing lines of fortifications.
In 1934, the first gun emplacements appeared on the border of the country that posed the greatest threat to Germany at the time - France.
These fortifications formed the basis of Germany’s West Wall, also known as the Siegfried Line.
The Siegfried Line was built to protect the borders from a French attack.
However, the very first gun emplacements could withstand only bullets and light artillery fire.
In 1936, the construction of larger and more heavily armed defenses began.
The Siegfried Line stretched along the borders with France, Luxembourg, and Belgium, and part of the border with the Netherlands.
The total length of the line was about 630 kilometers, putting the Siegfried Line in third place in our rating of the longest defensive lines!
Now let’s see which line takes second place.
Length: 2nd place.
France was deeply scarred by the horrors of World War I and looked at Germany as a possible future threat.
The construction of a French defensive line began in 1929.
The person most responsible for the construction of the defenses was André Maginot, the French Minister of War.
The total length of the line along the border with Germany was more than 360 kilometers until 1936 - much shorter than the Siegfried line.
However, the Line continued north along the borders with Luxembourg and Belgium to the Atlantic Ocean.
In addition, the Maginot Line also stretched south along the borders with Switzerland and Italy.
The total length of European portion of the line was about 750 kilometers.
The total cost of the Maginot Line was about three billion euros in today’s currency, going to show that it was not all that expensive.
As well as the fortifications along the German and Italian borders there were also sister-fortifications on the island of Corsica and in Tunisia.
The Tunisian portion, known as the Mareth line, is, to an extent, part of the Maginot Line.
So, Germany’s Siegfried was 630 km long, and the French Maginot Line was 750 km.
But is that really long?
Let’s find out by comparing them to the Stalin Line.
Length: 1st place.
After the Russian Civil War ended, the Soviet Union saw itself as besieged by the hostile capitalist countries of the world,
presumably led by Great Britain and France.
It began to fortify its borders.
The construction of a chain of fortifications began in 1928.
These fortifications were to stretch from the Baltic Sea to the Black Sea
and had to protect the most important industrial cities and regional centers of the USSR.
At first, there were 13 fortified areas and 8 more were added over the next 10 years.
By the beginning of the Great Patriotic War, there were 22 fortified areas in the defensive line.
Their total length was 1800 kilometers, more than one and a half times the length of the Siegfried and Maginot Lines combined!
So, the Stalin Line convincingly occupies first place as the longest defensive line.
Which line was the most advanced and complex from an engineering point of view?
Let’s find out!
Fortification Complexity: 3rd place.
Ninety percent of the emplacements of the Stalin Line were equipped with machine guns.
When construction began, it was thought that these emplacements would be used to defend against attacks by infantry and horse cavalry.
By the mid-1930s, the most widely used gun emplacements were machine-gun and cannon bunkers.
They typically had 2 to 4 Maxim machine guns, crewed by 10 to 12 troops.
Some two-storey bunkers were built.
The weapons were emplaced on the upper storey, while the lower held supplies and living space for the personnel.
Some bunkers had 76 mm guns.
The opening through which the cannon fired, known as the embrasure,
was often protected by an armored shield that would be raised and lowered by a hoist.
In large bunkers, there were warehouses for weapons, ammunition, and provisions.
Such a fortification might have a crew of 30 troops.
Telephone communication systems were set up to coordinate action between gun emplacements.
For vision, all-round view periscopes were used.
Large fortifications were equipped with air filters to allow personnel to survive a gas attack.
In the most important sectors, multiple pillboxes were built so that they could support each other with fire.
Sometimes, they were connected with each other by tunnels.
However, the Soviet Union did not manage to fully complete the planned emplacements of the Stalin Line.
Inspections in early 1939 found some serious design flaws.
Some bunkers were ineffectively positioned; they did not have sufficient fields of vision and could not deliver long-range fire.
Some fortifications appeared to be flooded.
There was not enough electrical equipment to supply power to all fortifications.
Some pillboxes had no camouflage and some did not even have the required top layer of soil.
The quality of the concrete was also inconsistent.
So, despite the planned immensity, the Stalin Line loses out to the German and French lines in terms of infrastructure and equipment.
That’s why we rank the Stalin Line third in fortification complexity.
What line comes in second?
Let’s find out!
Fortification Complexity: 2nd place.
Compared to the Soviet fortifications, the Siegfried Line was significantly more imposing.
You’ll understand why it captures 2nd place in our ranking.
The Siegfried Line was designed to be a much more rugged system of barriers, obstacles, and fortifications.
When passing through it, an advancing army was to be constantly impeded and worn down until it finally became exhausted.
The first barrier line was relatively weak.
It consisted mostly of tree obstacles, wooden anti-tank teeth on narrow roads,
and other barriers covered by advance posts and machine-gun detachments.
Generally, the first line of defense was not designed to inflict heavy losses on the enemy,
but to force the enemy to put its forces into assault formation, attack and, by doing so, lose time.
There would be individual earth-timber bunkers between the first and second lines at key points such as crossroads, bridges, and small villages.
These would engage enemy forces, inflicting losses and causing more delays.
The second line of defense consisted of anti-tank barriers and concrete emplacements: pillboxes and bunkers.
This line was quite robust but still passable.
The enemy forces might break through but then they would again face individual fortifications at key points.
Behind these would be the third and strongest line of defense.
This system of defenses would sap the attacking enemies of his momentum, bogging them down and inflicting mounting casualties.
At the critical moment, German forces would counter-attack and defeat their adversary.
The Siegfried Line fortifications that were built first were mostly earth and timber, and sometimes concrete.
The walls were 30 to 60 cm thick.
There also were more robust bunkers with the frontal wall about one meter thick.
Among other obstacles, there were multiple rows of barbed-wire entanglements and wooden, metal, or concrete anti-tank obstacles.
After 1936 and up to the beginning of the war, the Germans devoted significant resources to the construction of fortifications.
The walls of some structures built during this period were 2 to 3.5 meters thick.
The thickest walls were designed to withstand a hit by a 520-mm anti-concrete shell or a 1000 kg aircraft bomb.
23000 trucks were used in the construction of the Siegfried Line.
About 4500 rail cars were unloaded every day.
3500 buses took people to the construction sites.
In addition to bunkers, key avenues of approach were guarded by the concrete anti-tank teeth known as “dragon’s teeth.”
They stretched for dozens of kilometers in multiple rows.
So, you might think that no one could surpass the German engineers in constructing complex and intricate fortified areas.
But that’s exactly what the French did!
Fortification complexity: 1st place.
The Maginot Line was made up of three types of defensive complexes: fortified areas, fortified sectors, and fortified ground.
There was an outpost line in front of the main fortifications: anti-tank ditches, barbed-wire entanglements, and small pillboxes.
Fortified areas were the most heavily protected.
These were the most likely sectors of enemy advance.
Fortified areas were defended by systems of large and small forts and individual long-range gun emplacements.
All were camouflaged and were designed to survive artillery fire, including direct hits by large-caliber shells.
The thickness of concrete flooring in pillboxes and forts was up to three meters.
According to the estimates of French military engineers,
a fire emplacement was expected to continue operating even after being hit by two 420-mm howitzer shells.
Fortified sectors were built at the secondary areas of defense.
They were not as well protected, but were still guarded by numbers of small intermediary fortifications
and several forts that could provide each other with covering fire.
The areas that were considered least suitable for enemy advance were protected by so-called fortified ground.
These consisted of a small number of pillboxes in key positions or near important objectives.
It may be said that they were built “just in case.”
Forts and big intermediate fortifications were often multistory.
Like icebergs, the greater part of these fortifications was hidden underground, with only gun and machine-gun casemates on the surface.
Some rooms were 50 meters underground!
Below the thick concrete, there were living quarters, hospitals, headquarters, electrical stations,
and storage rooms for food, water, and ammunition.
Forts were equipped with elevators, lifts, and even narrow-gauge railways to transport soldiers and ammunition.
The French were the only nation to use armored domes in their fortifications.
These domes would be opened to let the guns fire, and then closed to protect the embrasures from enemy fire.
The Maginot Line is a true masterpiece of engineering,
so it deservedly occupies first place in our rating of the most elaborate and technologically advanced war fortifications.
However, there was a kind of paradox.
The Maginot line was provided with 700 anti-tank guns but they only managed to destroy a single German tank.
German tanks passed through Belgium.
At the time the French army had five thousand antitank guns. 25 mm, 37, 75 and 47 antitank gun on wheels.
There were more antitank guns than the Germans had tanks!
However, the operative doctrine of the German forces was very good and they broke through the lines very strongly in Belgium and in the Ardenne.
So, we’ve judged which defensive line was the longest and which line was the most advanced.
Now, it’s time to see how effective these lines proved to be.
Which line presented the most effective barrier to an attacking enemy?
We’ll find it out in a few moments!
Battle Effectiveness: 3rd place.
The most sophisticated defensive line in Europe—the Maginot Line—was barely a factor in the combat of World War II.
Of course, the Germans struck where the French did not expect—the Ardennes.
This region of mountains and thick forest had been considered impassable for large troop formations,
and especially for tank divisions—the main striking force of Wehrmacht.
How wrong everyone was!
This was the weakest point of the Maginot Line.
After passing through the Ardennes, German forces engaged the small La Ferte fortification.
Its garrison held out for only two days.
During the invasion of France, the Germans engaged separate, sometimes unfinished fortifications of the Maginot Line on several other occasions.
The main part of the Maginot Line waved the white flag after the capitulation of France.
France began to fortify the border with Germany and Italy, to prevent a blitz attack from those countries
and to have enough time for the mobilization of the French army, which would take 20 days.
Another mission of the Maginot Line was to channel the enemy into passing through a neutral country, Belgium or Switzerland.
If Germany were to invade France through Belgium, then the British would enter into the war on the French side
and you’d have a multi-national conflict on your hands.
That was the political vision behind the construction of French fortifications.
So, the most fortified and developed defensive line—the Maginot Line—comes in third in battle effectiveness.
Let’s see which line managed to hold back the enemy for a bit longer.
Battle Effectiveness: 2nd place.
The massive German invasion on the 22nd of June, 1941, quickly pushed the Red Army back from the border.
The fighting reached the Stalin Line quite soon after that.
Most of its fortified areas didn’t last long against German forces.
The Ostropol and Letichev fortified areas held out for 10 days.
The Kingisepp fortified region fought for two weeks.
One pillbox in the Mogilev-Podolsk fortified area held out for a week, until all soldiers in its garrison were dead.
The most robust Kiev fortified area resisted the enemy for a month.
It surrendered only after the forces of the Southern Front were surrounded and crushed near Kiev.
The most outstanding success was the 22nd Karelia fortified area, which stretched from Sestroretsk to Lake Ladoga.
This was the only fortified area of the Stalin Line that fulfilled its mission completely.
It prevented the enemy from reaching Leningrad, the second-largest city and the main industrial center of the USSR.
So, the fortifications in the Karelia sector performed exceptionally well.
This sector, which included 196 defensive emplacements, fought from September 1941 to June 1944.
The Stalin Line fortifications weren’t designed to fight a battle in isolation.
It was assumed that the fixed emplacements would be supported by a combined-arms fighting force.
But such tactics were hard to implement at the beginning of the Great Patriotic War
(as the Soviet portion of World War II is known in former-Soviet countries)
Overall, we award the Soviet defensive line second place in our ranking of battle effectiveness.
Battle Effectiveness: 1st place.
Although the Siegfried Line wasn’t the longest or the most technologically advanced, it proved to be the hardest defensive line to defeat.
During World War II, the Siegfried Line played its role twice.
The first time was in the so-called Phoney War, when French attacks failed to penetrate even the first line of German fortifications.
After France surrendered in 1940, the Siegfried Line became useless for Germany.
All building plans were cancelled.
Workers moved to other projects.
Many of the garrison troops were used as infantry on other fronts.
Unfinished emplacements were dismantled and other bunkers were deactivated.
In 1944, after the Allies landed in Normandy, the Germans made an attempt to reactivate the Siegfried Line.
However, the structures of the late 1930s were obsolete and couldn’t provide protection against the weapons of the Allies forces.
Germany lacked the time and the resources to build new defensive structures.
Some new bunkers and concrete pillboxes were built, incorporating the turrets of the Panther tank.
Also, a network of “Tobruk” bunkers were hastily built.
These were concrete firing positions for a single soldier with a machine gun or grenade launcher.
Allied forces advanced to the German border in September 1944.
It seemed likely that they would be able to pass through this skeleton of a defensive line with ease.
However, the Germans fought tenaciously through the winter of 1944–1945.
The last chapter in the battle history of the Siegfried Line did not end until March 1945,
when the German border was penetrated in several locations.
Although the Siegfried Line didn’t entirely play the role it was designed to,
it managed to hold back the enemy longer than the Maginot Line or the Stalin Line.
That’s why we award the Siegfried Line first place in terms of battle effectiveness.
Let’s summarize:
Each fortified area had its own specific features.
The Siegfried Line was well organized and held back enemy forces twice:
during the Phoney War of 1939–1940 and after the landing of the Western Allies in Europe in 1944–1945.
The Maginot Line was much better than its competitors in technological equipment and defensive systems.
However, it was outflanked and barely saw combat.
The Stalin Line was the simplest from an engineering point of view
but, except for the Karelia sector, wasn’t able to hold the enemy back for very long.
This line was the longest defensive line of World War II.
We may wonder, what if the building of these defensive lines had been completed?
Would the course of the war have been different?
Questions like these will remain just questions.
History has delivered its verdict.