For centuries, fortifications and fortresses
served as the main form of protection for those on the defensive side,
and the main obstacle for attackers.
In the 20th century, these constructions became obsolete.
The final chord in this longstanding battle
was played by a huge and remarkable German mortar
named Karl-Gerät.
World's Strangest Combat Vehicles
So, why didn't Karl-Gerät, Adam, and other giant guns
serve the purpose they had been built for?
Mikhail Lapikov will tell us how the length of the barrel
affects the gun’s ballistic range
and the devastating power of a 2-ton shell.
Self-propelled Karl-Gerät mortar
Construction of the Karl-Gerät started in 1935,
when the company Rheinmetall-Borsig
manufactured a super-heavy rifled mortar,
which was designed
to launch 4-ton projectiles over a 1 km (0.6 mile) distance.
Thus, the range of 2-ton projectiles
constituted about 3 km (1.9 miles).
The device was designed
to break through long-term defence lines,
including those of heavily reinforced forts.
The first mortar, named Adam, was produced in November,1940.
Previously, in January, a Heavy Battery 833 was created,
which included two batteries equipped with two guns each.
A small number of these devices were manufactured:
in total, seven devices were produced;
six of them saw combat.
In fact, Karl is not the official name of the device
—it was nicknamed after its designer and just happened to stick.
Thus, every mortar had its nickname:
the first two were called Adam and Eva.
The others were named after characters
from Scandinavian mythology, like Thor or Odin.
The first thing that catches the eye is the size of the mortar.
It's one of the largest
self-propelled artillery weapons by caliber.
Everything in it was unusual and unique,
which made it terrifyingly legendary:
a 540 mm (21.2 inches) and 600 mm (23.6 inches) gun,
projectiles weighing more than 2 tons...
Another remarkable fact was that the 600 mm (23.6 inches) barrel,
capable of launching huge projectiles,
was only 8.5 caliber-long.
The barrel was a solid unit, which had 112 grooves inside.
Together with a breech, it weighed over 28 tons.
Depending on its type,
a projectile weighing about 2 tons contained anywhere
from 280 to 348 kg (617 to 767 lbs) of explosives,
which can be compared to a sizeable air bomb.
And the impact points demonstrated
the corresponding damage caused by its shots:
10 meters-deep (33 feet) funnels
and a sand cloud reaching up to 170 meters (560 feet).
The self-propelled tracked chassis
was a distinguishing feature of Karl-Gerät.
It allowed the gun to move independently,
though its top speed was only 10 km/h (6.2 mph).
The front side contained a 580 hp engine.
To ensure its manoeuvrability, the mortar was placed
on a self-propelled carriage.
They even ensured the carriage was slightly armoured
to protect it against enemy fire.
But generally, Karl was transported by rail.
The mortar was placed on two platforms
and transported to its destination.
It was often almost completely disassembled
and then only reassembled at the front line.
Transporting Karl to a war zone was hardly a subtle task,
and the 16 crew members who operated the gun
were supplemented by people who protected
the mortar from the enemy.
The mortar was armoured mostly for the sake of reassurance.
This wonder-machine could be easily destroyed
by the World War II classical tank T-34.
It was suggested that while on the site,
the gun should be protected by Special Forces,
who otherwise did not play any part in battle.
One could say
that defense of the Karl mortar wasn’t effective enough,
if compared to its effect in combat.
There was a need for AA gunners,
communication support, and defense,
depending on the presence of enemy forces.
So, you can bet that several hundred people
were engaged in the mortar’s operation.
Using the mortar was rather demanding,
in terms of its operational conditions.
Karl’s horizontal aiming was performed
by turning the mortar’s mount only within a +/- 2.5 degree range.
If a wider aiming range was required,
they had to turn the whole chassis.
Vertical aiming was within a 0 to 70 degree range.
Aiming was performed manually.
The shell’s weight of over two tons
should also be taken into consideration.
The rate of fire was one round per 10 minutes
—its maximum rate.
So, why was that?
First, the mortar was quite difficult to reload after firing.
Gun overheating
was another major factor that should be considered.
Additionally, if the mortar was loaded in haste,
the shells became stuck in the gun,
which proved to be a problem to its operating personnel.
The mortar was able to launch
anti-concrete shells weighing 2,170 kg (4,784 lbs),
with a range of fire up to 4.5 km (2.8 miles).
It could also launch high-explosive shells
weighing “only” 1,700 kg (3,748 lbs) at a distance of up to 6.5 km (4 miles).
The shells reached the speed of 220 to 285 m/s (722 to 935 ft/s);
one could even see them “slowly” flying in the sky.
Karl’s gun was so large that it could, theoretically,
fire shells the size of T-34 tank turrets,
which weighed about three tons.
It's battle performance would probably be just as formidable.
On the one hand,
due to the huge destructive power of its high caliber shells,
they were able to severely damage a target.
On the other hand, however, Karl’s mortars
did not play a significant role in any of its battles.
The gun’s main purpose turned out to be psychological,
supporting German troops who felt more confident
being covered by such a tremendous gun.
In 1944, during the Warsaw Uprising,
these mortars were used to bombard the city.
Karl’s rounds were made purely for deterrence.
There are pictures that show its shell bursting
through a building, causing massive destruction,
with debris scattered everywhere —icons of the horrors of war.
In fact, this behemoth
with a huge gun and devastating shells
was never really battle-tested.
Its use was limited for a number of reasons.
Historians have pointed out only three battles
where Karl’s mortars were used more or less effectively:
the siege of Brest Fortress, the Battle of Sevastopol,
and the suppression of the Warsaw Uprising.
Despite the lack of any significant service in battle,
the Karl mortar is considered
one of the most bizarre combat machines.
In fact, the Karl mortar is a typical
German Wunderwaffe (wonder weapon) from a book:
huge, complicated, impressively designed,
completely extraordinary, but absolutely useless in practice.
However, in terms of implementing military engineering projects,
the Karl mortar deserves respect, because its designers
created a massive device, possible only at that time.
In other words, attempting to create
something even bigger would have been impossible.