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Forged
Guns
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Making Guns from Wrought-Iron.
The
earliest guns found on shipwrecks were made from wrought-iron,
although even earlier a form of gun was produced on land using
bronze “vase-shaped” chambers (see Artillery
101).
Wrought-iron guns were made from long iron strips, hammered
to form flat rods. These
were curved slightly by hammering them into shape on a forge, then
they were grouped together to create a hollow circle, a bit like
the staves of a wooden barrel. The founders probably used a wooden former to wrap the staves
around, although we know almost nothing about how these guns were
made, apart from what we can learn by looking at examples which
survive today.
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Where
are these guns today?
Well,
several museums have examples, most of which come from
shipwrecks. The
Mel Fisher Maritime Museum has several examples, recovered
from The
St. John’s Wreck
and also smaller ones from the two wrecks of The
1622 Treasure Fleet.
Others
can be found in Texas, Florida and in several museums in
Europe. Some of
the most spectacular guns of this type never went to sea as
they were far too heavy. These were the huge guns known as “bombards”, a 15th
century gun type which could measure up to 16 feet long, and
fire a 36 inch wide ball!
One of the best known “bombards” is “Mons
Meg”, which can be seen in Edinburgh Castle in Scotland.
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Once
the gunmakers had finished their circle of wrought-iron staves,
which were often six feet long or so, the next stage was to fit on
the rings which held the gun together. A series of wrought-iron cylinders or rings (also called
“hoops and bands”) were made with their inner hole the same
size as the diameter of the bundle of staves.
These were then heated up, then slipped over the end of the
bundle of staves. They
were hammered down one after to other, forming an outer tube of
cylinders and rings. As
these cooled they shrunk, forming a tight seal over the staves
beneath them, forming a sort of protective jacket or outer tube.
When the gunmakers had finished, they had produced a long,
thin wrought-iron tube, open at both ends.
The
next stage was to make a “powder chamber” to hold the main
charge of the gun. This
was often built the same way, although very crude cast-iron
examples have also been found.
The main feature of these was that unlike the main barrel,
the end was closed off, creating a flat face.
A “touch-hole” was drilled through the metal at the
bottom of the side of the chamber, so that the gunpowder charge
inside could be fired off. Often
these powder chambers were constructed with an inner lip at the
mouth which was a little smaller than the end of the main
wrought-iron tube. This was so that when the chamber was set up against the main
barrel, it would form a tight seal.
It was also common to fit these powder chambers with lugs
and rings, so they could be easily lifted in and out of the
carriage when the gun was being reloaded.
The same type of chamber was used in swivel guns, although
the whole thing was designed on a smaller scale.
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Swivel
Guns?
They
named these after the way they were mounted, the guns
sitting on a swiveling bracket or “yoke, looking exactly
like the rowlock on a rowing boat. Small “trunnions” on
the gun fitted through loops at the top of the swivel
mounting, and the whole thing was mounded on the ship’s
rail. The guns
themselves were small, and the barrels were rarely longer
than three feet, although unlike larger wrought-iron guns,
they also incorporated a sort of holder for the chamber
itself. Another
feature was a tail (sometimes called a “monkey-tail”),
which stuck out the back of this holder, allowing the gun to
be aimed easily and quickly.
The Spanish called their swivel guns versos”, or
even “verso dobles” for larger pieces.
Although the earliest swivel guns were made from
wrought-iron, bronze and later cast-iron versions became
common, although shipborne wrought-iron swivel guns survived
into the early 18th century.
One variant was the method of sealing the outer bands
around the gun itself.
As they were so small, many wrought-iron swivel guns
were enclosed in a single sheet of metal rather than by a
series of cylinders and rings, creating a smoother, more
finished look to the gun.
These
guns were designed to be fired at point-blank range at an
enemy trying to board your ship.
They were essentially anti-personnel guns, and fired
just about anything; bags full of musket balls, scrap iron,
solid shot and even nails! If the gunner had a supply of spare chambers and bags of shot
handy, the guns could be reloaded again in seconds,
guaranteeing a fast rate of fire.
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The
next stage was to mount these wrought-iron forged guns on a
carriage. Unlike cast
guns, the barrel was more fragile, and needed a greater deal of
support. The
gunmakers of the 15th and 16th centuries who
made these weapons came up with the idea of sinking the barrel
into the carriage itself, creating a kind of reinforced wooden
cradle that became an integral part of the gun itself.
A large tree trunk or slab of wood was used (favored
timbers were oak, elm and even mahogany), cut into the shape
needed for the carriage. The
carpenter would then carve out a slot or trough to take the gun,
mirroring the shape of the cylinders and rings of the outer
barrel. Once it was finished, the wrought-iron barrel would be
half-sunk in the carriage, which also contained a recess for the
powder chamber, plus an extra space behind it.
The
barrel was then strapped into place.
Sometimes the gunmakers used rope, but more commonly
wrought-iron bands were hammered around the gun and carriage, then
pinned into place using iron fasteners.
The carriage could then be mounted on wheels, and it was
ready for use. The wreck of the Mary Rose (1545) contained a
mixture of wrought-iron guns and cast bronze guns, all mounted on
carriages. The
carriages of the wrought-iron guns were all similar, but some had
two small, solid “truck” wheels while others had two wheels
similar to those used on land guns.
When
the whole contraption was to be fired, a wooden or wrought-iron
wedge was hammered into place between the back end of the powder
chamber and the carriage itself, ensuring that there would be a
tight seal between the barrel and the powder chamber.
The
gun would then be ready to fire.
The range was not very great with these guns, and although
no statistics survive, experiments with replica guns have shown
that the shot from these guns could be not be expected to reach
more than 2-300 yards, or less than a third of the effective range
of cast guns. The
problem with these wrought-iron breech-loading guns was that they
were inefficient, and due to leaks they lacked the pressure and
velocity of cast guns. They did retain one big advantage, which
was that the powder chamber could be removed and replaced with a
fresh, loaded one fairly quickly, ensuring a reasonably fast rte
of fire. The guns
were therefore used at close range, and could fire either solid
roundshot, or scraps of metal, like a larger version of the swivel
gun.
These
long wrought-iron guns were known as “bombardettas” by the
Spanish, and as “murderers” or “port-pieces” by the
English. As this type
of gun was considered obsolete from the late 16th
century on, and is rarely (if ever) found on shipwrecks after
1600, most examples found in American or Caribbean waters are from
Spanish shipwrecks.
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