In World War Two the Germans made use of huge railway cannons, Dora and her brother Gustav were the biggest and most effective ever made.  These railway cannons were colossal feats of engineering, they could fire shells from one country to blow targets up in another...and they often did!

For all her power and magnitude, Dora only ever fired a total of 48 shells in combat. It took a whole regiment of two thousand men a total of six weeks to assemble the gun ready for firing, as it had to be assembled on site on a double row of special railroad tracks.


In 1937, Hitler wanted a huge cannon that could destroy enemy targets such as an enemy fortress or garrison at long range. The criteria required that the shell had to penetrate 7 meters of steel reinforced concrete or at least one meter of hardened armor plate, over a range of 25 miles.

The Maginot line was considered to be a worthy target, with the ability to blast it, whilst still within their own lines was too much of a temptation.

A temptation so great that Hitler initially ordered three such guns to be built, regardless of how much manpower and resources they would use up in the process.

Krupp Steel industries was given the job of creating these huge guns and Professor Erich Muller worked out the mathematics needed to manufacture them. He arrived at a caliber of 80cm - 31½ins with a shell of 7 tons and a barrel length of over 30 meters.

They  would have to be on a railway carriage split into two separate parallel tracks to disperse the weight, estimated at over 1,000 tons.  The barrel would only be able to have vertical movement, so the tracks had to be curved for the carriage to move along, for sideways elevation.



The actual range achieved by Dora was 51,000 yards - 29 miles.  She had a   crew of 250 for the actual firing and a crew of 2,000 for full operation, including loaders, train drivers, assembly workers, canteen workers, armed guards, mechanics, electricians and track maintenance.

To operate, Dora was similar to the running of a Battleship inland, a colossal team effort all just to fire a big shell over distance.  The biggest worry for the crew of Dora would have been attack from the air, so the gun would have needed high security, the best camouflage techniques and to have constantly been kept on the move.

It would have been a great psychological win for the allies to have bombed her, the location of the gun could have been sent by the resistance.  Everything about Dora was massive including her ammunition, this consisted of a seven or eight ton, 31½ inch diameter shell.

The shear weight of the shell meant that the gun had a very slow rate of fire, two rounds per hour with everybody working flat out was the limit. It was a big operation indeed to crank this thing up, but was it really worth it?


The shells for Dora and Gustav, including the one ton charge, were seventeen feet long. It needed a full ton of charge to send the seven ton shell over twenty-five miles from the one hundred foot long barrel.  On test firing, the shell  proved to be able to penetrate thirty feet deep into earth, making a crater over ninety feet across.

The velocity of the shell was 2,700 feet per second, the barrel was estimated to have a life of about 150 rounds, weighed 400 tons and the breach block where the shell was inserted weighed over 100 tons.   Dora stood five stories high, over 20 feet wide, 141 feet long and weighed 1,323 tons.  To say she was big would have been an understatement, she was absolutely mammoth, a mountain of steel.  This mountain of steel had to be maintained on a 24 hour basis, the cost in man hours must have been terrific.

To get some scale of the shells size, on the left is an image of an average sized guy  standing next to one of Dora's seven ton shells, that is currently on display at the Imperial War Museum in the UK.

If the Germans had utilized these weapons to their best advantage then they may have made a difference in the tide of war.  As it turned out though, they had little impact in one sense, even though they had great impact in another.

The only real downside was all the resources these huge railway guns used just to fire off a few big shells.  The means did not really justify the ends and as impressive as all of these huge guns may first appear, they were just too colossal to be used in anything but a specialist capacity.


At the beginning of January 1942 the gun was ready to go fully operational. Two railway engines were attached to the front of the gun carriage, one on either side, to slowly pull the carriage forwards on its curved track.

This movement gave the gun the side elevation. The engines had a special ultra low gear to be able to move the carriage forward an inch at a time, for the best possible accuracy.

I could imagine the scene "...up a bit...down a bit...left a bit...right a bit...ok...Fire......Achtung!..we missed!  "

In the image below Adolf Hitler pays a visit to review the massive railway gun, this is actually an image of Gustav, the twin gun of Dora. The photo is impressive with people around it to give it some scale, however, the real thing must have been awesome to gaze upon.

Dora was loaded slowly with huge winches and electrically powered rams by a crew of two hundred and fifty.  The initial target for Dora was Sevastopol on the Eastern Front and in June 1942 the big gun opened fire. The Dora railway gun was only fired over a five day period.

A small spotter plane like a Storsch was used to fly over the target area and report back via radio with information on where the shells were landing.  The trajectory with the relevant distance, gun elevation with projectile weight, velocity and other ballistics properties were mathematically and geographically worked out with slide rules, pencil and paper to accurately hit the target. The only calculators they had in those days was the old grey matter!

Gustav attacked coastal gun batteries at a range of sixteen miles.  It took eight shots to completely destroy these targets, Fort Stalin was destroyed later that day with only six shots.

Fort Molotov was destroyed with seven shots on June 6th, 1944.  Nine rounds were fired at The White Cliffs Of Severnaya Bay and a lucky shot hit an underground ammunition store and the whole Fort was completely destroyed. One of the shots missed the target and sunk a large ship in the harbor, the shell burst must have been absolutely devastating.

Seven shots were fired the next day in the same vicinity at nothing in particular,  but was again used to more worth some days later when Fort Siberia was hit with five shots and destroyed as was Fort Maxim Gorki.  As we can see, Dora did actually have some success and destroyed several large targets with only a few shells.  So we can assume that these big railway guns did at least have some use, even though it was rather limited.


The barrel of the gun was worn out after only fifty shots or so and not the one hundred and fifty as projected.  So Gustav had to be dismantled and shipped back to Germany to be refitted with a new barrel sleeve, this took weeks and weeks to do, costing valuable time, effort and money.  Germanys resources at this time was extremely pushed as it was and now a whole factory was needed for her refit.

Dora and Gustav  did indeed destroy several targets but were they worth the resources to actually accomplish this?  If I had  been Hitler in World War Two, I would not have wasted my resources on this project, I would have had another 1,000 Tiger tanks built instead. Maybe its just as well that he was an idiot with logistics as well as tactics.

Dora was only fired several more times after the refit, this was due to the fact that she had to be disassembled, transported and re-assembled for every new target in different parts of enemy territory and the railway tracks had to be laid down for it each time.

What a waste of time, money, manpower and overall resources, just for a few shots at the enemy.  The total accomplishment of these guns was in respect quite small and did nothing to alter the course of the war for its optimistic owners.  If anything,  a pair of cannons like these would be more trouble than they were worth.


As World War Two was drawing to its inevitable conclusion of total victory for the allies, the Germans were in full retreat.  As they retreated, they destroyed every piece of equipment that they could not take back with them, nothing could fall into enemy hands. The destruction of their equipment included the biggest cannons the world had ever seen...Dora and Gustav.

One gun was destroyed with explosives in 1945 near Metzenhof, Bavaria by its crew as the allies were advancing.  This marvel of engineering on the most colossal scale ever seen was rigged with explosives and then detonated, the resulting explosion blew the cannon to bits.

The whole train carriage was also destroyed, absolutely nothing was allowed to fall into enemy hands.

A pile of twisted metal and a big wrecked 80cm barrel was all that was left of one of the two guns.  Gustav, the other big railway cannon was discovered in pieces in Russia in the same year, she had also been blown to pieces.

That was the end of the huge railway cannons, they have never been built since as they have never been needed since.  One is left wondering if they were ever needed at all, maybe their psychological value was more than their real worth.


The famous Paris Gun  that shelled Paris in World War I, had a caliber of only 22cm - 8.6 inches, but had a fantastic range of seventy-six miles. 

Paris Gun at Altenwalde Range.  The guns barrel is positioned at 60 degrees. 

The name Big Bertha was soon attached to any railway gun though, even though the Big Bertha gun herself was actually a 420mm  or 16.5  inch mortar which had a range of  only  nine miles.  With the end of World War Two also saw the end of the big railway cannons, they were not deemed worth the maintenance as I have stipulated throughout this page.

These huge railway guns also presented a large target to be bombed.  Why bother when you can fly a few hundred strategic heavy bombers over the target, do a bit of carpet bombing and yield the same results.


Below is a 1/6th scale model of Dora that was home-made by Mr. Peter Shaw, in only four and a half months! Even at 1/6th the original size, the scale of this Dora railway cannon is absolutely huge.

Imagine a model company making plastic kits in this scale, the box it would come in would be as big as a house and need a forklift truck to get it to your garden!  I have no further information on this model, but please do click on the above image to find out more.



Page created February 22nd 2002.  Updated December 9th 2012