Spiking a Cannon
Del Stanley
How was a cannon disabled by spiking? Was it a literal spiking
such as driving a rail spike into the vent hole, which
caused a crack in the barrel? In many battles, when a battery
was overruned, the victorious unit would turn the captured guns
on its enemies. Sometimes the captured guns were coveted as
trophies in the way a battle flag may be captured. Occasionaly
the unit's "victory" was rather tenous, and their enemies would
recapture the guns (to be used again).
(1) Again, how do you spike a cannon, and what makes it non
functional after it has been spiked? Ruptured bore?
(2) How long does it take to spike a cannon? It would seem that
if your battery was going to be overrunned, wouldn't it be
advisable (in most cases) to spike the cannon before abandoning
the battery; rather than letting your enemy take possession of it?
Or, if many men of the battery were injured such that they could
no longer function as a battery, wouldn't it be better to retire
the guns, or spike them? Anything to avoid capture and have them
turned on you? It seems that the only time a gun was spiked was
when it was captured, and could not be transported. If spiking was
a time consuming process needing special tools then I can
understand.
Of course time in the heat of battle is very relative.
(3) Was spiking your own gun considered "cowardly" and such a morale
deflator, that no battery would it employ it? Yes weapons were
precious and expensive (especially for the confederates), but
a captured effective gun versus a captured worthless gun...
whae...@itol.com
wrote:
>(1) Again, how do you spike a cannon, and what makes it non
> functional after it has been spiked? Ruptured bore?
Generally, spiking was one by driving a spike into the touch hole.
This kept the cannon from firing as the flame from the fuse couldn't
reach the powder.
>(2) How long does it take to spike a cannon?
It didn't take long. However, if you're about to be overrun, panic
will get your moving out of the area and you won't necessarily think
about spiking your guns.
>
>(3) Was spiking your own gun considered "cowardly" and such a morale
> deflator, that no battery would it employ it? Yes weapons were
> precious and expensive (especially for the confederates), but
> a captured effective gun versus a captured worthless gun...
I don't know about this but I haven't seen any references to spiking
being a cowardly act.
Charles Ten Brink
Del Stanley <dgs...@earthlink.net> wrote:
>
>How was a cannon disabled by spiking? Was it a literal spiking
>such as driving a rail spike into the vent hole, which
>caused a crack in the barrel?
>
>(1) Again, how do you spike a cannon, and what makes it non
> functional after it has been spiked? Ruptured bore?
>
into the vent hole, but it does not rupture the barrel. Spiking is
intended to only temporarily disable the cannon.
The spike would be inserted into the vent hole and the rammer jammed down
the bore, bending it over. The portion protruding from the vent hole
might be bent over or broken off, using a handspike or pickaxe. (The
caissons were furnished with pickaxes.)
>(2) How long does it take to spike a cannon? It would seem that
> if your battery was going to be overrunned, wouldn't it be
> advisable (in most cases) to spike the cannon before abandoning
> the battery; rather than letting your enemy take possession of it?
> Or, if many men of the battery were injured such that they could
> no longer function as a battery, wouldn't it be better to retire
> the guns, or spike them? Anything to avoid capture and have them
> turned on you?
>
>
Yes, it would be advisable - *if* you were reasonably certain that you
had only these two alternatives.
> It seems that the only time a gun was spiked was
> when it was captured, and could not be transported. If spiking was
> a time consuming process needing special tools then I can
>understand.
> Of course time in the heat of battle is very relative.
>
I think these last element is the key. No, spiking the gun was not
especially time consuming, and it *was* done by the artillerymen about to
lose their guns. However, the tendency is to keep the guns firing as long
as possible. Once you've spiked your guns, they are useless to you as
well, and what could be more embarrassing than discovering that you have
made the decision prematurely?
>(3) Was spiking your own gun considered "cowardly" and such a morale
> deflator, that no battery would it employ it?
>
It wasn't considered cowardly (at least I'm not aware of any contemporary
account which characterizes it thus). Instructions for spiking were
included in all the artillery manuals of the day, and are presented
without any particular animus. But it would certainly deflate morale, and
possibly lose a battle, to spike one's guns at a time when they could
still be useful. I suspect that in the heat of battle most artillery
captains were too optimistic about judging that time. The calculus of
risk is also in favor of delaying the decision to disable the gun: if you
can keep your battery in action, you may be able to turn the tide in your
direction. If you are going to lose your guns, your army is probably in
such disarray that the enemies use of them will not be the dispositive
issue.
> Yes weapons were
> precious and expensive (especially for the confederates), but
> a captured effective gun versus a captured worthless gun...
>
Finally, I should add a note on the long-term effects of spiking a gun.
There are none. Field tools could be used to drill out the spike, and it
could easily be in use by the next day. Spiking only removes the gun from
action for the rest of the battle.
Regards,
Chuck Ten Brink
www.cwartillery.org
--
Associate Law Librarian < He did not catch babies with a spearhead as
D'Angelo Law Library, UC * was the practice of other Vikings; for this
c-ten...@uchicago.edu > reason he was called "child-friend".
Thomas Duvernay
>
>How was a cannon disabled by spiking? Was it a literal spiking
>such as driving a rail spike into the vent hole, which
>caused a crack in the barrel?
I can't answer it for you (I hope someone else can, as I'm interested, too),
but it was something in the records that the US did in 1871 during their
first invasion of Korea. The orders were, dump the small guns into the
water and spike the larger ones.
Thomas
Dennis J. Francis
> How was a cannon disabled by spiking?...How long does it take...?
--------------------
A spike with a soft point or nail is driven into the vent, broken off
flush at the top, and clinched using the rammer. A few good whacks
would do the job, so it would not take much time at all.
Basically, all that you're doing is plugging up the vent and rendering
the gun useless for the time being. The spike can later be extracted,
or a new vent drilled, but that's something that would have to be done
later, and it's a task beyond the capabilities and resources of troops
in battle.
Dennis
GlennShiv
> and what makes it non functional after it
> has been spiked? Ruptured bore?
Basically, there were two ways to "spike" a cannon. (1) With a brass nail
(or other soft metal) using a hammer, and (2) with a bayonet. As I understand
it, the idea was to jam the vent so the cannon could no longer be used in
battle, not to rupture the bore. In practice, method (1) was rarely used, and
method (2) was the more common practice. At the end of the ACW, discarded
cannon were spiked to prevent their capture. The damage caused by spiking
could probably be reversed with the proper tools, however, a spiked cannon
would be essentially useless during the remainder of the battle.
> (2) How long does it take to spike a cannon?
> It would seem that if your battery was going
> to be overrunned, wouldn't it be advisable
> (in most cases) to spike the cannon before
> abandoning the battery; rather than letting
> your enemy take possession of it? Or, if
> many men of the battery were injured such
> that they could no longer function as a
> battery, wouldn't it be better to retire the
> guns, or spike them? Anything to avoid
> capture and have them turned on you?
> It seems that the only time a gun was spiked
> was when it was captured, and could not be
> transported. If spiking was a time
> consuming process needing special tools
> then I can understand. Of course time in
> the heat of battle is very relative.
By method (1), probably just a few minutes, providing someone brought along a
hammer and some brass nails. Otherwise, somebody has to search for these in
the supply train. By method (2), probably just a minute, providing some has
the presense of mind to think about spiking the cannon with their bayonet
during the heat of battle. Spiking the cannons is easier than transporting
them to a safe location, which would almost certainly require horses. If
there was enough time to transport cannon to another location, then spiking
becomes unnecessary.
> (3) Was spiking your own gun considered
> "cowardly" and such a morale deflator, that
> no battery would it employ it? Yes weapons
> were precious and expensive (especially
> for the confederates), but a captured
> effective gun versus a captured worthless
> gun...
Spiking cannon might be a last step before the surrender of a fortress. No
point to spike a cannon still being used for defensive purposes. Also,
cannons being discarded (after battle or after the ACW) would be disabled so
they could no longer be used, before being shipped to the foundry for scrap.
Best wishes,
Glenn Shiveler
Thomas Yaglowski
While I'm no expert on civil war artillery, I believe a cannon was spiked
when you took the long pick used to puncture the powder bag, placed it
into the vent hole as you normally would, and break off the part that was
in the vent hole.
I think a gun could be spiked in only a few seconds (just long enough to
twist and break the pick.)
There was no greater shame to an artilleryman than to abandon his guns to
the enemy. Of course, I think there are exceptions to this rule (Bigelow's
guns at Gettysburg). Years after the war, Gulian Weir, commander of a
battery at Gettysburg, committed suicide over the loss of his guns at
Gettysburg.
NFry umbc
To spike a cannon:
1. Roll some solid round shot into barrel without a charge behind it.
-or-
2. Wedge something inside the barrel and tamp it home.
Basically you're blocking the venthole from the inside of the barrel. Thus
your gunpowder cannot ignite and you have a very useless brass, or iron tube.
-Nick =|:-)>
Ernie Fisch
On Wed, 4 Nov 1998 14:05:04, Del Stanley <dgs...@earthlink.net> wrote:
>
> How was a cannon disabled by spiking? Was it a literal spiking
> such as driving a rail spike into the vent hole, which
> caused a crack in the barrel? In many battles, when a battery
A spike was driven into the vent hole. It didn't need to rupture the
bore. With the vent hole blocked the gun was out of action.
It could eventually be cleared but not in timely fashion.
>
> (1) Again, how do you spike a cannon, and what makes it non
> functional after it has been spiked? Ruptured bore?
see above
>
> (2) How long does it take to spike a cannon? It would seem that
> if your battery was going to be overrunned, wouldn't it be
> advisable (in most cases) to spike the cannon before abandoning
If the spike is handy not very long. You just need the spike and a
heavy object to druve it home. By the time of the ACW where you had a
separate ignition device it was probable sufficient to drive the
priming tube into the vent so that it could not be pulled out easily.
>
> (3) Was spiking your own gun considered "cowardly" and such a morale
> deflator, that no battery would it employ it? Yes weapons were
No, it was merely a recognition of the facts of life. It was fairly
common.
Sometimes it was dangerous to capture guns. When the French cavalry
captured some British guns at Waterloo they were shot down by nearby
British infantry. The cavalry was milling around trying to secure the
guns and became easy targets.
There was one battery at Waterloo that did not spike their guns but
just abandoned them and sheltered behind the infantry squares. As
soon as the French cavalry was driven back the artillerymen reserved
their weapons and helped defeat the cavalry.
ernie fisch
Don Plezia
>
>To spike a cannon:
>1. Roll some solid round shot into barrel without a charge behind it.
If it is stuck, this would seem irremediable? Unless a means of tapping the
shot and extracting it could be devised. Answers?
Don Plezia
Bev Clark/Steve Gallacci
My impression of the various techniques for spiking a cannon was for the
temporary disabling of it. jamming a ball down the bore or a spike in the
touch hole means it can't be used for the moment or easily repaired in
the field, making it useless for anything except to be dragged back to an
armory or machinist's to have it worked on. Yes, it could be fixed, but
much more expeidiant to abandon it altogether.
Don Plezia
Bev Clark/Steve Gallacci wrote in message
<36425c76...@news.agoron.com>...
Not my question!
I assume that the shot would be somewhat larger than the bore of the cannon
causing an interference fit. If this is so, ramming the shot into the
cannon bore without a charge behind it, finishes the cannon forever.
Unless a means of tapping the shot in the bore and allowing a screw to be
run into the shot and extracting it by a come-along or someother device.
Does anyone know if this is the case?
Bev Clark/Steve Gallacci
>Not my question!
>
>I assume that the shot would be somewhat larger than the bore of the cannon
>causing an interference fit. If this is so, ramming the shot into the
>cannon bore without a charge behind it, finishes the cannon forever.
>
>Unless a means of tapping the shot in the bore and allowing a screw to be
>run into the shot and extracting it by a come-along or someother device.
>
>Does anyone know if this is the case?
>
>
normal cannonball would not jam into the gun on its own. packing in some
other debris would temporarily jam the ball down the bore, and perhaps,
in a worse case, beyond the point it was practical to deal with.
To tap the ball would need an armory's resources, not ususally availalbe
in the field. These balls were cast iron, making a tapped removeal a major
task.
Bill Wright
> (snip)
> Unless a means of tapping the shot in the bore and allowing a screw to be
> run into the shot and extracting it by a come-along or someother device.
>
> Does anyone know if this is the case?
I know that one of the cannons beside he Confederate statue on the lawn in front
of the Charlottesville, VA court house has a ball (or a shell) stuck in it.
Nobody knows whether its charge is there or not. As a result it was not given
the hot wax treatment when the statue was refurbished this year.
Bill Wright
Don Plezia
whae...@itol.com
>
>I assume that the shot would be somewhat larger than the bore of the cannon
>causing an interference fit. If this is so, ramming the shot into the
>cannon bore without a charge behind it, finishes the cannon forever.
>
>Unless a means of tapping the shot in the bore and allowing a screw to be
>run into the shot and extracting it by a come-along or someother device.
>
>Does anyone know if this is the case?
Since there is a ball extractor for muzzle loading rifles that will
pull a ball out in event of a misfire, I would assume that a similar
device was available for cannons. It would be some sort of self
tapping screw that would twist into the barrel. Several men would be
needed to pull it out.
William H. Roberts
writes:
>Does anyone know if this is the case?
No, it is not.
>>I assume that the shot would be somewhat larger than the bore of the cannon
>>causing an interference fit.
Projectiles in muzzle loading cannon have "windage," or clearance, to
facilitate loading -- in the USN 32-pounder of 57 cwt, for example, the shot
was 6.25 inches in diameter and the bore 6.40 inches in diameter. Muzzle
loading rifles tended to use elongated projectiles with some sort of gas check
device, but said gas check was normally actuated by the force of the powder
burning behind it. (See Spencer Tucker's _Arming the Fleet_ , table 27, for
windage figures and Warren Ripley's _Artillery and Ammunition of the Civil
War_, chapter 13, for rifle projectiles.)
Trying to disable a muzzle-loading cannon by ramming a shot down the bore
would not be productive.
<snip>
>It would be some sort of self
>tapping screw that would twist into the barrel.
The "worm," a metal corkscrew sort of thing, was used to extract wads and
cartridges if necessary -- it might have been used for extracting shot.
Ernie Fisch
>
> Since there is a ball extractor for muzzle loading rifles that will
> pull a ball out in event of a misfire, I would assume that a similar
> device was available for cannons. It would be some sort of self
> tapping screw that would twist into the barrel. Several men would be
> needed to pull it out.
A musket ball was lead and therefore easy to penetrate. The screw is
also guided by a rod and tip that is close to bore size .
Round shot is usually iron. A simple screw is not going to do it.
ernie fisch
a...@dustdevil.com
>
>The "worm," a metal corkscrew sort of thing, was used to extract wads and
>cartridges if necessary -- it might have been used for extracting shot.
>
>
into it. I don't believe it would be of any use, except case or grape
shot.>
a...@dustdevil.com
Gallacci) wrote:
>In article <3649407...@news.agoron.com>,
>Don Plezia <d...@southernet.net> wrote:
>>NFry umbc wrote in message <71sb61$5...@s10.math.uah.edu>...
>>>
>>>To spike a cannon:
>>>1. Roll some solid round shot into barrel without a charge behind it.
>>
>>
>>If it is stuck, this would seem irremediable? Unless a means of tapping the
>>shot and extracting it could be devised. Answers?
>
>My impression of the various techniques for spiking a cannon was for the
>temporary disabling of it. jamming a ball down the bore or a spike in the
>touch hole means it can't be used for the moment or easily repaired in
>the field, making it useless for anything except to be dragged back to an
>armory or machinist's to have it worked on. Yes, it could be fixed, but
>much more expeidiant to abandon it altogether.
>
Civil war era cannon were extremely valuable. The last of the bronze
guns, many of them. Great amounts of labor would be used to save
them, and if not they were a treasure for salvage. Mass production of
steel changed all this at the end of the Civil War.
a...@dustdevil.com
>
>To spike a cannon:
>1. Roll some solid round shot into barrel without a charge behind it.
>-or-
>2. Wedge something inside the barrel and tamp it home.
>
>Basically you're blocking the venthole from the inside of the barrel. Thus
>your gunpowder cannot ignite and you have a very useless brass, or iron tube.
>-Nick =|:-)>
>
Round shot would not block the vent. Cannister "might", and it would
not roll back out. I would use a paper funnel at the vent and a
flask of fff pistol powder in the field to try to dislodge it if
tipping the whole carrage on its muzzle didn't.
a...@dustdevil.com
wrote:
>Smart!
>
>Don Plezia
>
>
>Bill Wright wrote in message <3646b1d1...@news.agoron.com>...
>>Don Plezia wrote:
>>> (snip)
>>> Unless a means of tapping the shot in the bore and allowing a screw to be
>>> run into the shot and extracting it by a come-along or someother device.
>>>
>>> Does anyone know if this is the case?
>>
>>I know that one of the cannons beside he Confederate statue on the lawn in
>front
>>of the Charlottesville, VA court house has a ball (or a shell) stuck in it.
>>Nobody knows whether its charge is there or not. As a result it was not
>given
>>the hot wax treatment when the statue was refurbished this year.
I don't think they could ever get enough heat throught the barrel
waxing to set even fresh powder off.
>>Bill Wright
>>
The charge is certainly dead by now. The shell could possibly be
live. It will be rusted very tight by now. If it is a bronze gun I
would want it out. Remove the barrel, point it straight up and pour a
quart of Kriol (a very good penetrating oil) in the muzzle and
forget it for a week. Then apply air pressure through the vent. You
can hold an airgun tight with a small o-ring. 90lb.s will give about
1200lbs thrust. If that doesn't work, an X-ray would tell if it is
solid shot. Take it to the guys who x-ray aviation parts. solid shot
can be tapped, insert threaded rod, put a washer over muzzle and crank
away with air through the vent as well.
Nathan Mitchell
A "worm" was standard to the kit issued for each artillery tube. It was an iron
"screw" that looked like a large, fat bedspring on the end of a pole. It was
used to extract rounds (projectiles) from the bore. There were frequent
misfires which required the round to be removed, as well as the "bad" charge, to
be removed so the gun could be reloaded. Needless to say, this was a hazardous
procedure. Most gunners were loath to stand in front of the muzzle of a gun
which contained even a suspected bad charge.
whae...@itol.com wrote:
> On 6 Nov 1998 16:17:14 -0600, "Don Plezia" <d...@southernet.net> wrote:
>
> >
> >I assume that the shot would be somewhat larger than the bore of the cannon
> >causing an interference fit. If this is so, ramming the shot into the
> >cannon bore without a charge behind it, finishes the cannon forever.
> >
> >Unless a means of tapping the shot in the bore and allowing a screw to be
> >run into the shot and extracting it by a come-along or someother device.
> >
> >Does anyone know if this is the case?
>
Charles Ten Brink
In article <72uv5u$p...@s10.math.uah.edu>,
Nathan Mitchell <mnem...@earthlink.net> wrote:
>
>A "worm" was standard to the kit issued for each artillery tube.
>
> It was an iron
>"screw" that looked like a large, fat bedspring on the end of a pole.
>
It is actually a double helix, terminating in two tines. Most bedsprings
I have seen are only a single spiral.
> It was
>used to extract rounds (projectiles) from the bore.
>
No. It was used to extract debris from the bore, like remnants of the
powder bag. The worm was not designed to grip the projectile.
>There were frequent
>misfires
>
Not really, but I suppose that "frequent" is subjective.
>which required the round to be removed, as well as the "bad" charge, to
>be removed so the gun could be reloaded.
>
A misfire typically was the result of a bad primer. The remedy was to
reprime. I'm not sure what a "bad" charge would be, except one too wet to
burn. This would require the combination of a lot of moisture and an
exceptionally oblivious gun crew. Or simply the latter, if a round of
fixed ammunition was loaded backwards. (In fact, this is the one
circumstance under which I can imagine the worm being useful for undoing
the gaffe, because it could easily pierce and grip the woolen powder bag.)
I am sure that guns were occasionally unusable from having an unfireable
round lodged in the bore, but it was certainly not common.
SMckay1234
Spiking a canon was done by artillerymen when their weapon(s) were subject to
capture, and they wanted it(them) to be deemed useless to their enemy.
The deed was quite simply done as it sounded; by hammering a spike into the
vent of the cannon, then breaking it off.
Scott McKay
Richard B Wright
Del Stanley <dgs...@earthlink.net> asked
>
>
> (1) Again, how do you spike a cannon, and what makes it non
> functional after it has been spiked? Ruptured bore?
slow-match is held over to ignite the powder charge in the interior of the
piece. Once that hole is obstructed, you cann't "fire" the cannon.
> (2) How long does it take to spike a cannon? It would seem that
> if your battery was going to be overrunned, wouldn't it be
> advisable (in most cases) to spike the cannon before abandoning
> the battery; rather than letting your enemy take possession of it?
> Or, if many men of the battery were injured such that they could
> no longer function as a battery, wouldn't it be better to retire
> the guns, or spike them? Anything to avoid capture and have them
> turned on you? It seems that the only time a gun was spiked was
> when it was captured, and could not be transported. If spiking was
> a time consuming process needing special tools then I can
> understand.
> Of course time in the heat of battle is very relative.
Doesn't take long...seconds, not minutes. Problem is that it WAS done
under duress since it's the only piece of equipment you have to defend
yourself from the mass of Infantry approaching. Additionally, the enemy is
taking pot-shots at you while you are executing your task.
Sometimes you were given the chore of defending to the last...not being
allow to retire...sometimes you were caught by surprise...sometimes you
were in the wrong place at the right time...etc It was just as distasteful
to loose a piece as it was as glorious to capture a piece. Lots of battle
flags had 'crossed-cannons' on them as a symbol of pride of capture.
Piece of wood, rock anything would do, but the battery forge and other
battery tools could be stuck in the vent to obscure use.
> (3) Was spiking your own gun considered "cowardly" and such a morale
> deflator, that no battery would it employ it? Yes weapons were
> precious and expensive (especially for the confederates), but
> a captured effective gun versus a captured worthless gun...
Often folks believe the guns were turned around by the infantry and used
against the fleeing enemy. This happened less frequently than purported.
The pieces are NOT that easy to use and would be used at very slow rate. I
doubt that the rifled guns would have been utilized in this manner at all.
I have not read any at least.
Rich
STL, Mo
EdBelledin
According to the CONFEDERATE ORDNANCE MANUAL, "spiking" was don as follows:
"drive into the vent a jagged and hardened steel spike with a soft point or a
nail without a head; break it off flush with the outer surface and clinch the
point inside by means of the rammer. Or, wedge a shot in the bottom of the bote
by wrapping it in felt or by means of iron wedges, using the rammer or an iron
bar to drive them in."
Ernie Fisch
>
> According to the CONFEDERATE ORDNANCE MANUAL, "spiking" was don as > > > follows:
Much snipped to conform to the rules.
This sounds like an instruction from a desk soldier. Spiking was
normally a last minute thing to prevent the gun from being turned on
your own troops. When spiked as described above it would normally
take some time to do so although bending the spike over with the
rammer might not be too bad.
If the gun was actually captured or recaptured and removed from the
field the spike could be removed by an arsenal. I am not sure about
the firmly wedged cannon ball.
ernie fisch
Walter Kaufman
loader? Both sides used a few British made Armstrong & Whitworth rifled
breech loaders.
George Avery
breech loader. Modern techniques of disabling one generally involve using
explosives to disable the breech block. I imagine one might have beat the
block on a Whitworth to ruin the fit, but I can't recall a case where it
actually occurred. I can't think of many cases where opposing infantry was
ever allowed close enough to even threaten it. DH Hill, for example, used
his as a stand off weapon against shipping in the Carolinas.
Walter Kaufman <froga...@webtv.net> wrote in article
<14817-36...@newsd-122.bryant.webtv.net>...
EdBelledin
Ernie,
I don't propose to be an "expert" in the use of artillery, and am only
quoting information that I've read, supposedly provided by an authority on
artillery and obtained in conversations with artillery reinactors. But it
seems, people proficient in loading/firing cannon, as artillerymen were
supposed to be, could spike a cannon quite rapidly via either method.
To me, the primary purpose of spiking the cannon would be to make it
useless at that immediat moment, unable to be used against you or your troops
by the enemy..... I'd not worry about later, nor particularly care if the
weapon could be rendered useful in a few days/weeks by anyone, and if it had to
be hauled to an armory for repair, had not the immediate objective been
acheived?
I do know that driving a hardened, tapered steel spike into cast iron or
bronze would cause minute fractures in the surrounding material, and that could
possibly cause severe damage or rupture at that point when again fired. The
size of charge and weight of the round(s) cause stress on the barrel and
chamber when the cannon is fired. The more a cannon was fired, the more brittle
the barrel and chamber would become, and the the greater the chance of rupture.
This was partly eliminated with the Parrotts, via a steel re-
inforcing band around the chamber. But, I'm not sure of the purity of the steel
nor the formula of manafacture (the amounts of magnesium, aluminum, copper,
zink, lime, etc. mixed with the cast iron to produce the steel). I do believe
that the steel produced then was considerably more brittle than now.
Any comments ?
Ed Belledin
Charles Ten Brink
EdBelledin <edbel...@aol.com> wrote:
> To me, the primary purpose of spiking the cannon would be to make it
>useless at that immediat moment, unable to be used against you or your troops
>by the enemy..... I'd not worry about later, nor particularly care if the
>weapon could be rendered useful in a few days/weeks by anyone, and if it had to
>be hauled to an armory for repair, had not the immediate objective been
>acheived?
>
serviceable with a few hours of work that could be performed in the field.
> I do know that driving a hardened, tapered steel spike into cast iron or
>bronze would cause minute fractures in the surrounding material, and that could
>possibly cause severe damage or rupture at that point when again fired. The
>size of charge and weight of the round(s) cause stress on the barrel and
>chamber when the cannon is fired. The more a cannon was fired, the more brittle
>the barrel and chamber would become, and the the greater the chance of rupture.
>
This confuses, I think, concepts of metal fatigue and stress fracture with
the question of how materials failure actually occurs. It is true that a
cannon, particularly a rifled cannon, is for many purposes of analysis a
pressure vessel like a boiler, subject to repeated changes in stress which
can cause failure. However, it is not true that the barrel, or reinforce
to be more specific, simply becomes more and more brittle until failure is
inevitable; under service loads, a gun that could fire a thousand rounds
could be safely relied upon to go on doing so functionally forever,
because its reaction to stress fluctuations approaches a limit. (This is
vastly oversimplified, but the closing observation is nonetheless
correct.)
Except in cases of spectacularly bad casting, material failure will not
occur through gradual propagation of a crack like one created by
scratching the interior of the vent, and in any case it would have been
common practice to prevent such a thing by drilling out the spike and
smoothing the vent surface to prepare it for further use. Best practice
would have been to insert a new vent piece and avoid this. Critical crack
length is basically a function of the resilience of a material, and
although cast iron has a notoriously low resilience, the critical Griffith
crack length will still be more than a scratch. See _Structures_, by J.
E. Gordon for a good discussion of this.
> This was partly eliminated with the Parrotts, via a steel re-
>inforcing band around the chamber. But, I'm not sure of the purity of the steel
>nor the formula of manafacture (the amounts of magnesium, aluminum, copper,
>zink, lime, etc. mixed with the cast iron to produce the steel). I do believe
>that the steel produced then was considerably more brittle than now.
> Any comments ?
>
A small correction; you seem to be using "chamber" to mean the base of the
bore, whereas the term actually means a narrower portion of the bore at
its base; most typically found in howitzers, it allows a projectile to be
fired using less powder than a gun of the same caliber. The Parrott
rifles did not have chambers.
The reinforcing band on the Parrotts was made of wrought iron, not steel,
and no one was really sure of the purity of its manufacture at the time
because modern methods of chemical analysis were only in their infancy.
Modern high-tensile steel was all but unknown, the nearest equivalent
being Damascus steel, which could not be produced by casting.
Wiards were produced of "semi-steel", which was not actually a true steel,
but puddled wrought iron. So far as is known only four guns (3-inch
ordnance rifles) made of steel were produced during the Civil War.
In any case, the wrought iron reinforcing band was indeed intended,
through the use of a material with greater resilience, to withstand the
stress produced by firing, a concept that was applied to the entire body
of the gun with the design of the 3-inch ordnance rifle.