Cannon Alignment

[JohnB40]

Greetings to all,

 

I've finally finished the 32 cannons for my Unicorn and I am ready to attach and rig 24 of them to the gun deck. I have decided to display them in the run out/firing position,with the carriages hard up against the bulwarks. I have been mulling this over and I would appreciate opinions on the following........

 

On a frigate,should all the guns be perpendicular to the keel/center line,or follow the curvature of the bulwarks? This dosen't really make much of a difference except at the foremost and two rearmost gun ports. Once the fore and quarter decks are fitted it is too late to change.  

 

John

[Stockholm tar]

John,

 

I think each gun would have been perpendicular to its own gunport, which means it would actually follow the curve of the bulwarks overall, depending on how much or little that was. The gun tackles would have induced that. Any horizontal aim required on a target would have been achieved by a crew during a battle, levering it's own particular gun round with the use of hand spikes.

 

The gun would also probably not literally have been right up against the side of the ship, as there would have been a gap caused by the by the foremost trucks coming up against the waterway.

Edited October 31, 2014 by Stockholm tar

[mtaylor]

I think the answer is "it depends".  Typically, we modelers show our guns all with the same elevation and aligned to the ports.  

 

I'm sure when the ship was headed into battle it would have been similar.  But once the shooting started (or even before) elevations would have changed based on the gunner's experience and also the training tackle would have come into play. 

[wq3296]

Greetings JohnB,
 
One guess is as good as another, but I expect that the guns were trained on the enemy ship as soon as she (they) came into range. Accordingly, this would have resulted in practically any gun orientation as appropriate from a forward bias to and aft bias and all points in between. As someone pointed out, the gun positions probably changed incrementally as the relative locations of the ships changed. The battle scenes in Master and Commander seem to give a pretty good representation of what goes on before the order to fire is given. Of course, after the first shot, it was probable ever gun crew for itself. The upshot is, you can't be wrong regardless of how you set your guns up.

 

wq3296

[robnbill]

I agree that the guns would be trained on the target. I also think that this might look at bit strange on a model. However, I could imagine where the guns would be loaded and run out and they would all be perpendicular to their gunport. Then as their target came into line, the crews would use the tackle to adjust the aim. All that said, I would play with it until you like it and go with that.

 

One thing that was pointed out to me (by Chuck) was since my guns were also pointed out and ready for firing was the lines coming from he blocks were  bundled neatly and laying to the side. This would have caused them to knot terribly once the cannon was fired. So I ended up just coiling them (not using the flemish flake), but just coiled since they were ready to fire.

 

I also placed the canon both before and after rigging and took lots of photos. I felt that allowed me to see the ship better and study what I liked or didn't before actually attaching and gluing the cannon to the deck.

 

Here are some photos of both the canons how I had them originally bundled and how I ended up with them installed.

 

 

[jud]

I have read that the tackles were flaked down so they could run. We used to flake down mooring lines for the same reason, no coils, bundles or drums.

jud

[robnbill]

I read somewhere where it described the sailors flaking the line back and forth over the deck in a somewhat zig-zag pattern. This could be done quickly and would allow for the line to run freely when the cannon recoiled. Unfortunately, I think it would make for a weird looking model. The flemish flake would certainly allow the line to run freely, but I question if they could or would do this under battle conditions firing the cannon as quickly as they could. That is why I settled on the coil. I know it is still problematic fort knotting, but having the flemish flakes makes it look like they are ready for inspection rather than battle. 

 

So if the cannon were not in firing position, I think the flemish flake would look great.

 

Anyway, that is my two cents.

[dafi]

A bit earlier than the Unicorn:

Van der Velde and others show plenty of diversity in elevation and how much run out on the single ships in their sketches and even paintings. Also sometimes they show a random pattern of tompions being in place and taken out ...

 

Cheers, DAniel

[JerseyCity Frankie]

Am I wrong in saying the conventional wisdom is that the guns are fired with the training tackle drawn up tight? The Breaching Rope is intended to take the shock load when the gun jumps backward, but is the training tackle expected to help in damping the recoil of the gun? I find this a bit hard to believe, I don't think a gun tackle can be used as a shock absorber.

In the instant after the gun is fired, perhaps eight feet of line would have to race through the blocks in fractions of seconds or part instantly, which I think is more likely. Also a lot of force would be trying to snap the pins within the sheaves and tear out the ringbolts in the few milliseconds the gun was flying inboard. If you have ever used a Handy Billy, a block and tackle tool very much like the Training Tackle of a great gun, you know it will not "ease" very fast, certainly not instantaneously. And if it WERE possible for the Training Tackle to run that fast, the coils or flakes on deck would instantly fly inboard with the gun, presenting an angry whipping danger to all those clustered around the gun when it went off, six or eight crewmembers with their handspikes and rammers would have to get their limbs out of the way and their bodies inboard to avoid the line or risk having some part of their anatomy wrenched or taken into the swallow of the blocks.

What makes a lot more sense to me is that the training tackle would be unhooked from the gun and run out on deck in the moments before firing, allowing the crew with handspikes to hold the gun in position and the breaching rope alone to take the shock load of the recoil. The blocks would be overhauled slightly so the tackle would be in the correct position to be hooked on again to prepare for the next shot. I admit this scenario stretches credulity too in that the guys with handspikes would need superhuman situational awareness and the danger of a semi-loose cannon would be faced every time the guns were used.

[wq3296]

Greetings Frankie,

 

Your comments make perfect sense to me. I suspect the lines would fetch up in the blocks when the guns were fired creating an even more dangerous situation. Recoil is way too fast and much too violent to think the tackles would used to help arrest it.

 

wq3296

[jud]

You guys need to check out the. 'HMS Victory Knowledge and Resource Forum'. You will find some horse's mouth Gun Drill writings. It's a good site to explore anyway, it's not restricted to Victory knowledge only.

jud

[Lieste]

On 11/4/2014 at 2:06 PM, JerseyCity Frankie said:

Am I wrong in saying the conventional wisdom is that the guns are fired with the training tackle drawn up tight? The Breaching Rope is intended to take the shock load when the gun jumps backward, but is the training tackle expected to help in damping the recoil of the gun? I find this a bit hard to believe, I don't think a gun tackle can be used as a shock absorber.

In the instant after the gun is fired, perhaps eight feet of line would have to race through the blocks in fractions of seconds or part instantly, which I think is more likely. Also a lot of force would be trying to snap the pins within the sheaves and tear out the ringbolts in the few milliseconds the gun was flying inboard. If you have ever used a Handy Billy, a block and tackle tool very much like the Training Tackle of a great gun, you know it will not "ease" very fast, certainly not instantaneously. And if it WERE possible for the Training Tackle to run that fast, the coils or flakes on deck would instantly fly inboard with the gun, presenting an angry whipping danger to all those clustered around the gun when it went off, six or eight crewmembers with their handspikes and rammers would have to get their limbs out of the way and their bodies inboard to avoid the line or risk having some part of their anatomy wrenched or taken into the swallow of the blocks.

What makes a lot more sense to me is that the training tackle would be unhooked from the gun and run out on deck in the moments before firing, allowing the crew with handspikes to hold the gun in position and the breaching rope alone to take the shock load of the recoil. The blocks would be overhauled slightly so the tackle would be in the correct position to be hooked on again to prepare for the next shot. I admit this scenario stretches credulity too in that the guys with handspikes would need superhuman situational awareness and the danger of a semi-loose cannon would be faced every time the guns were used.

While making no comment on gunnery practice, I note only that the recoil velocity of a gun firing single shot with maximum charge is *initially* less than 14ft per second (42lb gun of 65cwt, at 1463 fps, with a recoil augmented by windage losses and powder by around 40% - calculations according to the French "Aide Memoire d'Artillerie Navale"). This is immediately moderated by 'picking up' the carriage by a few ft/s (a reason that light carriages and heavy guns were preferred for naval use - the same momentum causes lower gun motion, and less stress on the carriage). Smaller bore guns are more heavily built, sometimes considerably so (6lb 8.5ft recoils at around 6 ft/s under the same loading condition).

Friction, both of the trucks and of the tackle running out can stop a heavily built light gun before it is fully brought inboard, and takes out some of the 'oomph' from even the lighter built large calibre guns. The breeching is more to assist with the final limitation of recoil length, and to aid firing to windward (when the deck is 'downhill') than a 'first recourse' for recoil moderation... (0.1 is a quoted value for friction forces for 'outhauling' and is likely to be slightly higher when running tackle.

With the exception of carronades, which are a little 'fiercer' and have a short recoil length on their slides. With the later pattern carronades of longer bore (7.5 cal) type, the recoil is likely to initially be 20fps. with a heavier carriage (but only a small part of that acting in recoil), and a shorter travel, albeit with a sliding rather than rolling friction. The length of recoil is limited, and is less than that needed for almost all carriage guns. Double breeching was called for in gunnery manuals, for carronades (the breeching and a preventer), and carronades were still noted as disabling themselves by breaking carriages or breechings rather more often than guns.

Reduced charges for medium guns were more about keeping recoils 'acceptable' than the strength of the gun metal, as were prohibitions or restrictions on using double shot.
 

[jud]

Remember that the gun does not move until after the projectile has left the bore so we are not talking about an engine delivering long term and steady force. When the projectile leaves the bore, it's all over folks, no more force attempting to overcome inertia of a stationary mass, what remains is working against the buffer action of the training tackles and whatever constraints the carriage and it's mass bring to bare, all energy absorbing masses and friction devices acting as restraints while absorbing diminishing energy. Bothers me not letting the tackle act as a brake. Recoil up to today is absorbed without harm just as it was done then, more energy today, yep. but time, distance and mass are still the controlling elements used to absorb energy delivered a blow. 6ft/sec means little when dealing with milliseconds absorbed over time and distance.

 

Edited April 2, 2021 by jud

[Lieste]

The gun *starts* immediately, increasing it's velocity as the ball is driven along the bore... the maximum doesn't develop until some time after the muzzle exit because of the influence of the powder solids and gasses ejected with the shot and for some time after, but recoil is on the order of an inch during the travel for a 32lb gun of 9.5ft

For almost all purposes this can be neglected - but it is incorrect to apply the recoil as an impulse applied all at once after the shot is expelled - the acceleration is high - around 32g average during the shot travel, but this is not of a high duration, and the 12fps recoil speed is reduced to ~10 fps when 'pulling the carriage' already by conservation of momentum, and the rope would only need to run at ~20fps, even if tightly drawn, after the first inch, part of which would be taking up tolerances in the carriage. and setting the trunnions against their socket in the cheeks and the caps.