They were designed to be the best…
they met enemies face to face,
endured tragedies and enjoyed victories…
they went down in history due to the bravery of their crews…
they are the ships that deserve to be called
“Naval Legends!”
Bofors
US battleship Alabama,
British cruiser Belfast,
and Polish destroyer Błyskawica—
these ships are very different, but they all have one thing in common.
The Bofors L60,
one of the best automatic antiaircraft guns of World War II.
It is estimated that this model of 40-mm
automatic cannon shot down more airplanes than
all other antiaircraft guns put together.
Caliber: 40 mm
Barrel weight: 103 kg
Barrel length: 56 calibers
2,250 mm
Loading principle: clips (4 shots each)
Rate of fire: 120 round/min
Shell type: primarily fragmentation
Shell weight: around 900 g
Maximum vertical range: 7,160 m
Guns were installed in single, coaxial,
quadruple, and six-barreled mounts.
It became a very efficient gun
for antiaircraft and surface targets.
As time progressed, the first of the Bofors that
came online with the Royal Navy were hand driven
in terms of elevation and training.
And they had a very basic sight system and again,
like a lot of early systems, they were reliant on
training, ability of the aimers, and the gun crew.
The specifics of World War II artillery
relies on the fact that the smaller the caliber is,
the more it depends on the gun crew,
on their cohesion in combat.
The performance characteristics of light guns,
antiaircraft guns,
and Bofors in particular,
are a combination of the artillery mount itself,
and the training and coordination of its crew.
Especially in battle, when tensions are running very high,
there’s no time to think and you need to move very fast,
turn around, load new shells, and start firing.
And all this happens automatically, without thinking.
After a battle, sailors often couldn't even remember
what they were doing.
That level of performance was achieved through constant training.
This weapon is operated by a crew of four.
Three on the mounting:
the Gun Layer, the Gun Trainer, the Loader.
The fourth member
carries the ammunition from the magazine,
and loads them into the clips on the side of the gun.
The L60 was developed in neutral Sweden.
Bofors, a metallurgy company,
started manufacturing cannons around the 1870s,
then it was owned by the famous Alfred Nobel for a while,
and after World War I, Bofors actively cooperated
with the German Krupp consortium.
In March 1932, the official trials of the automatic antiaircraft
cannon L60 were completed,
and it was put on the market.
In 1933, British and American military engineers
studied the gun
and were quite impressed—
the Swedish system
was more effective than the obsolete British Vickers "pom-poms"
and had more firepower than the "Chicago pianos" used by the US.
The maximum vertical range of Bofors
was almost twice that of the British gun and,
though the Swedish system had a slightly lower rate
of fire than its American counterpart,
the shells it used were twice as heavy.
Great Britain, the USA, and 10 other countries
purchased a license to produce the gun,
and by the beginning of World War II,
Bofors exported their L60 to 18 countries on different continents.
In particular,
Denmark, Greece, Egypt, Siam, Australia, and Argentina.
It wasn’t just the Allies that used the Bofors L60.
Japanese forces captured several British guns in Singapore
and only their underdeveloped industry
prevented them from mass-producing them.
The German Navy used L60s captured in Poland,
Norway, and France from 1939,
under the designation Flak 28.
They were installed on submarines,
and cruisers Admiral Hipper
and Prinz Eugen.
However, the Swedish gun wasn't ideal and required modernization.
After 300 rounds
it would be too hot and require
the barrel to be changed.
The barrel is air-cooled
and therefore the ambient temperature plays
a great part in how long it would actually require to cool down.
During an intense battle,
several hundreds or even thousands of shots are fired.
That's why the issue of barrel replacement is so vital.
This is why the gun crew
was trained to carry out this maintenance
under combat conditions.
They could complete this procedure in mere seconds.
The mechanical drive system on ship-based antiaircraft mounts
would break down due to its exposure to salt water,
and needed to be replaced with a hydraulic one,
the air-cooling of the barrel
also had to be replaced with water cooling.
Also, some design modifications were
required to mass-produce the gun.
One of the main problems of the Bofors L60’s application
was a high reliance on the training
and skills of the gun crew.
The job of the Loader
is to carry or load the gun by lifting the clip
and dropping it into the weapon so.
Once he’s done that
he then taps the Gun Layer
on his head to let him know that the gun is loaded.
Loading a gun like this wasn't easy.
Ammunition had to be taken
out of a box and carried to the gun.
As the gun constantly rotated,
the carrier had to run around it with a clip of shells in his hands,
to pass it to the Loader.
This position on the gun is known as the Trainer’s position.
And these handles are turned or reversed
to allow the gun to move backwards and forwards on the target
using the graticule sight in front of you.
Following the tracer being fired from the gun,
we can adjust for the aim of,
if we are too far in front or too far behind the target
to allow the other side of the gun,
which is the Layer’s side,
to then manufacture the elevation for the target.
As time went on,
the gun developed and
so that we could come away from the hand driven gun,
she was turned into a hydraulic driven gun.
So she had pressure tanks and oils and suchlike,
which sped up the training and the elevation of the gun,
so that they could lock onto targets quicker.
This is the Gun Layer’s position.
He was also the captain of the gun
and responsible for giving orders to the rest of the crew.
He would, for instance, initiate the loading sequence
by telling the loader to bring the gun to half-cock.
This means that the weapon can then be loaded
with rounds into the auto feeder.
He was also responsible for aiming the weapon
using the 300 Knot sight in front of him,
using the tracers from the rounds to adjust accordingly.
The sight arrangement was going away from
the spider web type of sight to a mirror type of sight,
which was basically what we call a head-up display today.
On small-displacement ships,
antiaircraft guns were aimed manually.
But on cruisers, battleships, and aircraft carriers,
the firing data was produced by directors—
special systems that controlled antiaircraft artillery by calculating
targeting parameters and sending them
centrally to the receiving devices on guns.
The information on target parameters
was supplied by antiaircraft rangefinders
and, later, by gun radars.
The command to engage or fire
comes directly from the Command.
And without further ado
the Gun Captain would press the firing push.
As long as he held his foot on
the firing push the gun would continue to fire as long as
it had enough ammunition in the hopper to keep feeding it.
The guns created a fire barrage,
which was almost impossible
for a single aircraft or entire squadrons to penetrate.
You can see it in old newsreels—
there's literally a wall of fire in the air
and some plane trying to get through it.
The probability of an aircraft breaking through to its target,
for example, an aircraft carrier or some other ship, is very very small.
The Bofors L60 proved its worth during World War II.
The antiaircraft gun Bofors L70 became its logical continuation.
The human factor is crucial in wars.
A man can become frightened,
may be poorly trained,
or something unexpected can happen to them...
As a result, the struggle to minimize
the influence of the human element
and to increase the gun's survivability and rate of fire,
led to development of the modernized Bofors L70,
which required minimal human input,
if compared to the very first Bofors guns, such as the L60.
However, the L60 remained in use on some ships.
In 1982, during the Falklands War,
which involved Great Britain and Argentina,
the British managed to shoot down a jet plane using this Bofors gun!
Even in the 1970s,
when artillery was gradually replaced by missile systems,
Bofors cannons remained in service.
Not only the upgraded L70s,
but also the veteran L60.
It can still be found on some German minesweepers
and the heavily armed US AC-130 gunships,
which provide fire support to ground units.