submarines one of the most recognizable
and well-known class of warships found
in modern fleets over the history of
modern naval warfare the submarine has
been one of the most technologically
advanced machines employed by worldwide
navies the ability to sneak past your
enemy without them having the slightest
idea of your presence has made these
vessels dominate the seas from as early
as the first world war as with any
weapon there have been countless
attempts to modify the design to make
them even more capable or to allow them
to conform to established doctrines many
of these attempts created vessels that
were unique complete failures or just
outright bizarre one particular design
that takes all these boxes is the
m-class submarine built for the royal
navy and today we will be looking at
this relatively unknown class of
underwater battleships from ancient
times mankind has yearned to master the
seas both for trade and for warfare as
centuries passed we learned and adapted
our seafaring vessels to be stronger and
more well-equipped to face off against
anything they could encounter from the
ships of the line during the age of sail
to modern nuclear submarines this is
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back to our earlier world war ii u-boat
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holding the title of the world's largest
navy for centuries prior to the cold war
the royal navy has seen its share of
naval projects that have resulted in
strange designs some were successful
such as the case of the hms dreadnaught
and some were
less than successful such as the hms
captain the m-class's development rose
out of the relative failure of the
k-class fleet submarines the k-class
also known as the calamity class by its
crews was designed as a class of subs
that would be capable of speeds equal to
fleets at the time primarily
dreadnoughts with this goal in mind
these ships were built with steam
engines yes you heard that right steam
engines in a submarine although the
class had supporters in the form of
inspector captain of submarines
commodore roger chaos and admiral john
jelico and david beatty it had one major
opponent in the form of admiral jackie
fisher who stated the most fatal error
imaginable would be to put steam engines
in submarines despite the potential
problems the k-class was greenlit these
boats were massive 103 meters in length
with a beam of 8.08 meters causing
significant control and depth keeping
problems two interesting problems with
the boats were that their internal
bulkheads were only capable of surviving
a pressure equal to 21 meters so if
there was a hull breach at anything
lower than this depth then the bulkheads
would collapse the second problem is
related to the length of the ship which
is 103 meters or 339 feet as we all know
submarines are intended to be
submersible the k-class however would
have a significant problem in that if it
descended at a 30 degree angle then the
bow would nearly reach maximum safe
depth while the stern would almost
breach the surface we'll likely
resurface to cover the k-class in more
depth in the future but for now i think
it's safe to say it's understandable by
only 17 of the planned 21 were built
the m class was ordered in place of the
remaining four k-class units with three
of them eventually being completed m1
was completed sometime in 1917 being
remodeled from k-18 m2 and m3 were
completed in 1920 with m4 being scrapped
prior to completion despite being built
from the previous class of submarine the
m-class had something quite unique when
looking at the m-class it's hard to miss
one feature that sets this design apart
from its peers what you are looking at
is an armstrong whitworth 12-inch naval
gun on a submarine these guns were
actually spares from the formidable
class pre-dreadnought battleship which
gave the m-class the distinction of
being the only submarines to have the
armament of a battleship the idea to
equip these submarines like this
originated from the royal navy expecting
that germany would create a class armed
with guns that would leave the british
ships in their wake although this did
happen with the arming of multiple
u-boats with 15 centimeter guns the
creation of the m-class easily gave the
royal navy the most powerful submarine
class in the world in terms of armament
with this armament in mind these
submarines originally were going to be
used as shore bombardment vessels
alongside merchant raiding but this was
changed this is understandable as one
large caliber gun would not be entirely
effective for shore bombardment this is
especially true of one which was
essentially fixed in mounting instead it
was decided that the subs would use the
gun to engage merchant vessels this does
beg the question of why would you use a
gun to do this when you could use the
torpedo armament most submarines are
known for normally you would be correct
in this question but this is not world
war ii submarine torpedoes were not as
reliable as those you may be familiar
with from classes such as the type 7
u-bolt or gato in world war 1 torpedoes
were known to be unreliable when
engaging a moving ship at more than 900
meters commodore sydney s hall once
stated no case is known of a ship of war
being torpedoed when underway at a range
outside 1 000 yards on the other hand a
12-inch gun once on target would almost
guarantee that a merchant ship would not
survive assuming the shell hit the one
problem with this plan is that the shot
had to neutralize the target in the
first shot as the gun could only be
loaded when the sub surfaced with this
you may be wondering why future
submarines were not built with such
massive armament that's quite simple as
the m-class had its fair share of issues
in the field the hms m1 lead ship of the
class acted as the trial run of the
concept showing multiple problems with
the overall design the first major
problem was that the effectiveness of a
single 12-inch shell from a submarine
and reliably sinking a merchant ship was
not actually trialled so there was no
guarantee that this would actually
happen as expected by her designers in
addition as mentioned before the gun
could only reload when the ship surfaced
and took three or more minutes to
complete the reload if the m1 had fired
and missed the target then she would
have to expose herself to reload or
would be forced to attempt a torpedo
attack on the target another problem
with the gun was that the breach
mechanism was exposed to the sea which
caused leaks and such leaking caused
severe damage to the muzzle of the gun
when it was fired as mentioned though
these subs did still contain torpedoes
with m1 and m2 having 18 inch tubes and
m3 and m4 having 21 inch tubes causing
the overall length to increase by 3
meters despite these problems the
m-class was not entirely a class with as
many ailments as their predecessors
ditching the steam engines for diesels
alone already put them ahead in terms of
technology these ships were reported to
handle well underway and could dive in a
respectable 90 seconds in addition they
perfected a firing pattern called the
dip check procedure the sub would
approach the surface until the muzzle
reached near six feet out of the water
then the muzzle would be opened and the
gun would be fired then the ship would
submerge again with this procedure the
ship was only exposed from 35 to 75
seconds for a submarine of her size and
time this is quite respectable the ships
were also well liked by the crews who
praised the diving ability as well as
how easy to handle they were however the
novel m class was not to have a
significant legacy in 1925 on routine
exercises in the english channel hms m1
collided with the swedish ship vidar and
sank with all 69 hands in the collision
the gun and its entire housing were
ripped off the submarine and caused the
interior to be flooded apparently the
impact was so slight that the captain of
the vidar was unaware of the impact when
it occurred the m1's wreck was
discovered in 1999 at a depth of 73
meters ironically despite being built
for the sole purpose of one-upping the
german u-boats in terms of armament this
same factor would prevent m1 from ever
seeing combat despite being ready during
the war fears of the germans building a
submarine with an even bigger gun
although definitely possible knowing
germany essentially dry docked the
m-class hms m2 and m3 had their guns
removed in response to the washington
naval treaty which restricted the size
of the guns on a submarine to under 8
inches m2 would be converted to a
seaplane carrier with her gun turret
becoming a watertight hangar in 1925.
she was lost in 1932 off the chessel
beach in dorset and it is believed that
the hangar door was opened prematurely
and caused flooding of the ship m3 would
be the only ship of the class to not
sink and it was converted to a mine
layer in 1927. unfortunately for m3 she
was only to be used as a test ship to
assess the equipment for the grandpa's
class of mine laying submarines after
trials had been completed she was
scrapped in 1932 despite being liked by
their crews two of the three submarines
would end up taking their crews with
them to a watery grave the m class of
submarines was an exceptionally unique
take on the doctrine of submarine
warfare arming the ships with a gun
caliber only found on the mightiest
class of warship of the day the
dreadnought battleship she was a product
of some of the royal navy's most
experienced commanders of the time and a
result of a combination of multiple
different ideas on what a submarine
should be able to do at sea while the
m-class was theoretically the most
powerful submarine ever built in terms
of armament until the cold war they
would not be the designs to inspire
future submarines as such we can only
look back and imagine what could have
been had these ships been successful
still these submersible battleships live
on in the pages of history as a strange
solution to technological limitations
as this video has been very focused on
vessels prowling above and below the
waves of our oceans it seems only right
that i add on a small mention to the
current team seas fundraiser i'm sure
you've heard of it from one of the
countless youtubers who have joined in
to raise awareness of this effort but if
not i'll quickly explain it similar to
the team trees effort every dollar
donated will mean one pound of trash is
removed from our oceans their goal is 30
million dollars to remove 30 million
pounds with each pound being verified
before payment is given you can read
more on their site which i'll link below
i'll personally be donating 305
or the millimeter equivalent of the
12-inch guns mounted to the m-class
submarines regardless of if you choose
to donate or not i hope you did enjoy
today's video thanks as always to my
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next video