Early use of cannon at sea

[Mark P]

I have just finished reading a very interesting article in Mariner's Mirror, volume 82 (1996) no.3 p301-324. This was written by NAM Rodger, and is titled 'The Development of Broadside Gunnery'. This discusses, amongst other points, the evidence for the development of broadside gunnery as opposed to the use of bow & stern chasers, which latter seemingly continued much longer than most of us might suppose. 

 

Several points arise which I will try to summarise here, as they will be of interest to fellow modellers: 

 

Firstly, in 16th & early 17th century ships, the heaviest guns were frequently mounted to fire forward over the bows, as tactics generally dictated that the bows were pointed at the enemy in an attack, and not the broadside. The broadside guns were angled forwards, or 'bowed', as much as possible, to allow them to participate in the action. 

 

Secondly, the guns were loaded and fired relatively infrequently, being re-loaded in progression by a team of gunners once the ship had wore (assuming she had the weather gage) and moved away from the enemy fleet.

 

Thirdly, the guns were fired from a fixed position, and were not allowed to recoil inboard, with re-loading carried out from outboard (this is a reasonable method if the ship is not engaged broadside to broadside with an enemy vessel) Rodger gives examples of early writings which support these arguments, and also dismantles some previously quoted texts which seem to support broadside firing from an early date, by showing that they have been mis-translated. 

 

One piece of evidence cited is Sir Henry Mainwayring's 'Seaman's Dictionary', written in the early 1630s, which specifically states that breechings are not used in a fight, but only at sea, chiefly in foul weather. An advantage to firing without allowing a recoil, not stated by Rodger, but which may well be a good reason for it, is that all the energy produced by the explosion of the powder is used to propel the shot from the barrel. By allowing recoil, the amount of energy necessary for this is thereby not used to propel the shot. The amount of energy necessary to move a 1-ton cannon backwards, especially if up a sloping deck, would be considerable, and would represent a noticeable reduction in the force of the cannon-shot, presumably. 

 

With the development of broadside firing (which Rodger shows was probably not fully developed until the mid 1620s) and a much more rapid rate of fire (early gun-crews were too small to allow individual running-in and out) it presumably became apparent that an increased rate of fire, brought about by allowing recoil and allocating much larger gun crews, outweighed the loss of projectile force. 

 

There is a lot more there, and I recommend the article to all with an interest in this era. 

 

All the best,

 

Mark P

 

[Baker]

Explained very well. And in line with what I have already read on this topic.

In the 16th century the so-called bow and stern chasers (usually heavy cannons) were very important in attack and defense.
Boarding was the primary method of capturing an enemy ship in the 16th century

[Jaager]

Mark,

I suspect that the reasoning behind fixed guns is specious. I remember all those pesky force vector lines from Physics.  I believe that the reverse direction force would be at the point of attachment of the gun to the ship.  Very little was probably redirected to the back of the projectile.  This does not mean that the time frame for the development of tactics for the use of guns at sea was any different.  What was believed to be true the determining factor.  The later method of allowing recoil and the dispersion of the reverse force over multiple points of attachment probably saved wear and tear on the body of the vessel.  

Another thought:  at the point of combustion, the force is spherical.  Would not some of the compression of the atoms of the breech be converted to heat?

[mtaylor]

To add a consideration also.   Possibly because of windage and also the "quality" and burn time of the powder, it's likely that much power went out the muzzle when firing.  Both around the ball and also still burning after the ball left the muzzle.   As these improved the need for breechings increased.  

[Mark P]

Good Evening Jaager;

 

Thank you for your thoughts. Although my study of physics was somewhat less thorough, and I remember very little of lines of force, I suspect that you are probably incorrect here, but certainly correct that some of the energy would be turned into heat, and therefore light also; but that would be a constant with or without recoil. My reasoning re the force would be that as the cannon is immovable, no energy can be used in moving it, although a much lesser amount may be used in attempting to move it. If the cannon cannot move backwards at the same time that the ball is starting to move forwards, then the only viable escape route for the expanding energy lies in pushing the ball down the barrel (disregarding windage around the ball, of course; but that would apply equally in either scenario) It could perhaps be contended that if the cannon cannot recoil, then the energy is in part dissipated by instead moving the ship's side to which it is attached; but as that is a considerably greater mass than a cannon-ball, I believe that the ball would move much more than the ship.

 

It would be interesting to know how much force was exerted on the ship's timbers by a non-recoiling cannon, as compared to a recoiling one being brought up short by its breeching, at which point considerable kinetic energy would need to be absorbed and dissipated over the structure. A corollary of this would perhaps be that a non-recoiling cannon would be more liable to explode.

 

All interesting stuff!

 

All the best,

 

Mark P

 

 

[Jaager]

29 minutes ago, Mark P said:

My reasoning re the force would be that as the cannon is immovable, no energy can be used in moving it, although a much lesser amount may be used in attempting to move it. If the cannon cannot move backwards at the same time that the ball is starting to move forwards, then the only viable escape route for the expanding energy lies in pushing the ball down the barrel

There is more movement than that in the visible range.  The atoms are what is actually being subjected to the force. 

I think that a segment about an F86 in Korea demonstrates some of the forces.  There was something like 6 or 8 50cal mounted in the nose.  A first generation pilot said that they had to be careful when chasing a MIG, not to fire too soon.  Firing the guns slowed the F86 down enough that the MIG could pull away.   The shipboard cannon would impart rearward force on the side of the ship.  If the structure held, that force would be transferred to the whole ship.  The ship would move backward.  It might be difficult to measure and it might not be significant, but I suspect that in a stern chase, a fixed gun firing would widen the gap between two ships enough to matter.

[Mark P]

Good Evening Jaager;

 

Thank you again for your further thoughts, which are very welcome, as they encourage further consideration. The comment re the nose gun is interesting, and may well be true, although it is perhaps (and I only say perhaps, not knowing any facts) subjective more than it is the result of careful analysis. I remember hearing a similar comment about the A10 Warthog, the tank-busting 'Flying Cross'. Remarkable machines, they were, and presumably the F86 was similar: an airborne Gatling gun with a high rate of fire and lethal projectiles.

 

However, a ship's cannon is only fired once, not many times a second, so the result would not be comparable, I suspect, as it is not cumulative, even if the relative masses of the two objects are in the same proportion in either case. I am not arguing that the discharge of the cannon has no effect on the motion of the ship, only that it is most likely to be a very small proportion of the total energy generated, if the cannon cannot recoil. 

 

All the best,

 

Mark P

 

 

[Jaager]

Mark,

 

I think this is a lot more involved.

If the projectile was frozen in place and the charge ignited, the gun would not move.  It would be a bomb and if it remained intact, a pressurized vessel.

The force of the recoil is equal to the mass of the projectile times the gas expansion velocity squared (while the projectile is in the system).

The rate of gas generation - the gas pressure - has a more significant effect on the projectile.  Recoil or no recoil, the gas pressure in the chamber does not change.

Flames coming out of the mouth of the cannon before the projectile = a poor fit and much loss of pressure pushing it.

Flames coming out long after the projectile has left = slow and inefficient generation of gas,  gas that is pushing against atmosphere instead of a solid.

[popeye2sea]

There were several other factors at play in early naval gunnery.  Inferior quality powder, breech loading cannon not creating a good seal, early carriages not always wheeled, stone shot, etc.

 

Regards,

[Baker]

Interesting pdf about the 16yh century (and free to download)

 

https://www.academia.edu/20120786/The_Arming_of_Late_16th_century_Merchantmen_A_Masters_Thesis_from_the_Maritime_Archaeology_Programme_University_of_Southern_Denmark

 

 

[Danstream]

I followed with much interest this conversation and I would like to bring some considerations about the physics involved.

 

I found that the argumentation of Mark P. are fundamentally correct from a 'first principles' approach point of view. Adding a lot of details about 'real effects' (as powder, distribution of forces, ...) do not help to shed light on the underlying concepts. One can consider two extreme 'ideal' pictures, i.e. a gun free to recoil and a gun rigidly bolted to a large (infinite for our considerations) mass. If you do correctly the math, applying the conservation of energy and the conservation of momentum principles (do not get involved into the details of forces), you find out that the velocity of the cannon ball (measured w.r.t. the ship) is higher in the second case.

 

Clearly these are 'idealizations' but they show in a simple way the trends of the phenomena. Of course, in a real case you have to consider practical implementation issues, like the forces that the gun transmits to its attachment points which might be a weak bottleneck or the strength any other structural link that connects the gun to the closest hard point of the ship structure. Increasing the energy and the efficiency of the guns, the reaction to these forces in the case of rigid connections and not recoiling guns might become prohibitive, especially considering a technology based on wood and nails. In addition, the need of having a gun that can be retracted for a quicker recharging, might have prevailed over the design of having a fixed gun at the cost of a small loss of velocity.

 

As far as the entity of the forces, for a given amount of energy delivered as useful energy for propelling the cannonball (i.e. net useful energy purged by the energy lost into heat, friction, noise, ...), this energy must be ultimately transformed into 'work' of the reaction points, being 'work' made of a force multiplied by a 'stroke' (i.e. Energy = force x displacement). Now, if the stroke is only the elastic deformation of a stiff supporting structure (case of a rigid connection of the gun to a structure), being this normally of the order of a fraction of a millimeter, it occurs that the forces are of huge entity. If, instead, a compliant structure is interposed (a kind of 'spring'), the stroke becomes much longer and consequently the forces to be reacted are much smaller.

 

I hope that the above is of help,

best regards,
Dan.

[Mark P]

Good Evening Dan;

 

Thank you for the explanations above, which all seem well grounded. You have summarised matters more clearly in technical terms than I could have done, which certainly helps. 

 

All the best,

 

Mark P

[Danstream]

Thank you Mark!

 

However, let me take the opportunity to add a numerical assessment. If I assume that I use a gun with a mass which is 50 times the mass of the cannonball (it is just a guess of mine to make a case, I do not know what could be a realistic mass ratio), then using the first principles mentioned above, I obtain that the velocity of the cannonball for the recoil case is about 99% of the velocity that I would obtain for the no-recoil case. Therefore, for a case with the masses of above, the reduction of velocity is probably insignificant. This can be explained by the fact that the mass of the gun is so larger than the mass of the cannonball.

 

Considerations about reaction forces are not affected and remain valid.

 

Kind regards,

Dan.

 

 

 

[Mark P]

Thank you for the further clarification, Dan;

 

In other words, the difference in projectile velocity is unlikely to have been noticeable, and cannot have been a factor in whether or not cannons were allowed/encouraged to recoil when fired. This will help when considering the process behind the changes outlined at the beginning of this thread.

 

All the best,

 

Mark P

 

 

[Matle]

I doubt these conclusions, except the one about bowed guns and chasers.

 

How would you arrange the gun to not let it recoil? Using tight breech ropes? The brackets holding them to the hull wouldn’t last long I suspect. Likewise bolting the carriage to the deck would be rather unhealthy to the gun and carriage. The force won’t be magically transferred to the ship: it would first cause immense strain on the barrel, connections and carriage. It could work for the smallest caliber guns, though. Also, the forward motion of the cannonball wouldn’t change in any significant way. There is no advantage other than not having to haul a breech-loaded gun out and in case of muzzle-loaders you’d have double work. Loading outboard sounds like a silly thing to do when actions were close-fought and the other fellows  armed with muskets and bows would be using you for target practice. edit: To clarify for heavy breechloaded guns this make  sense, but not muzzle-loaded.

 

Anyhow, researchers have recently been studying guns and their carriages from the Mars (1563, discovered some years ago): these had wheels and brackets for breeching lines.  There was no doubt that broadside firing was the chosen tactic there, based on written sources and ship design. In the beginning of Nordic 7-years war the allied Danes and Germans still employed boarding tactics, while the Swedes had started using artillery-only and designed their new ships for gunnery duels. Their tactic relied on trying to keep a distance and pounding the opposition with superior artillery. The broadside of Mars actually sank a Hanseatic (or Danish) ship in one of it’s first engagements. Even though the Mars was ironically lost during a boarding action, the Danes and Germans quickly adapted and started building artillery ships rather than boarders (getting rid of the high sterncastles for example). The Mars did seem to have had stern-chasers of grand proportions (5 m long 48-pounders), but they would not have wasted so much weight on broadside artillery as they did if it wasn’t meant to be used. Now, I guess the author focussed on English practice but I doubt the English were late to follow these developments.

 

 

—

As for the hypothetical case of fixed guns moving the ship sideways: no, it wouldn’t. Here’s a visual example. A few years ago a copy of a Vasa 24-pounder was casted and tested. They performed some 50 test shots, measuring a muzzle velocity of 350 m/s. The recoil is a balance of momentum: the ball’s  forward momentum should equal the backward momentum of the gun. 

Ball momentum: 11 kg * 350 m/s = 3850 kgm/s

The gun weights about 1400 kg, solving for the gun recoil velocity

v = 3850/1400 = 2.75 m/s

 

Check out this video and estimate the actual gun velocity (it is 2-3 m long):

 

Now imagine that the gun is instead a ship weighing a 1000 tons instead of a 1000 kilos: its velocity would be 1/1000 of that of the gun - and that only it were placed on wheels and free to roll, rather than having water and wind pushing back.

 

Incidently, in the end of the 18th century Chapman designed and built ”gun yawls”, which essentially were small floating gun carriages with a single fixed 20-something-pounder. Plenty of sources exists from this time so if there was some significant recoil moving the boat someone should have written it down - I’ll have a look if someone has bothered telling that story. That’s something entirely different of course.

[Mark P]

Good Evening Matle;

 

Thank you for your thoughts. I cannot help but feel that to some extent you are indulging in hindsight: you know what came later, and are inclined to dismiss other practices as unlikely or 'a silly idea'. Outboard loading of cannon is mentioned often in the sources, and is actually shown in a sketch by one of the Van de Veldes (elder or younger, don't remember which) who are widely regarded as the greatest marine artists of the 17th century, and very good authorities. 

 

I suggest that if possible you read the article I mentioned at the beginning of this thread, which is by a well-respected author; is much longer than my brief paragraphs (24 pages) deals with the the subject in depth; is well-researched (it does cover much more than purely Anglo-centric sources and has over 150 references to relevant works, most of them either contemporary, or nearly so) and is well-written. I am not saying that this will necessarily change your mind, but at least you will understand the debate, and the relevant factors and writings much more clearly.

 

For example, neither the author, NAM Rodger, nor I, made any claim that breechings did not exist, only that there is evidence that they were originally not used to restrain the gun during recoil; more specifically in the article, it mentions that they were used to secure the guns to the ship's side during stormy weather.

 

This article (and thousands of other interesting ones) can be found on the website of the Society for Nautical Research, although if you are not a member of the NRS, you will be unable to access this resource. 

 

All the best,

 

Mark P

[Matle]

As you said, I can not address the article as I have no access, only the short points you posted.

Since you did not address my main points, I feel you took the choice of word ”silly” a bit harsher than I intended: I did not mean to say that the author was silly to propose it, I merely meant that the idea of leaning out and trying to flip a 10-20 kg iron ball into a small hole, and powder too, seemed to me a rather impractical procedure to do, especially while simultaneously being shot at. I did not mean it in demeaning sort of way.

[Mark P]

Thanks for your reply Matle;

 

I do agree with you that it seems to be a rather daft idea to load outboard (in the Van de Velde sketch mentioned, a member of the gun's crew is sitting on the barrel outside the port) but according to the tactics of the period, the reloading was carried out away from the enemy, so while not being shot at. Nonetheless, it does seem rather inconceivable. 

 

Your mathematical workings are a welcome addition, and you are correct in that I did indeed ignore that, responding instead to the seeming intent of 'silly'. I will try to avoid such limited views henceforth. 🤐

 

The other points re broadside development had been discussed previously in the thread, and can only be settled in the mind of each reader, as there is no solid consensus either way. Rodger's article is interesting because it provides a lot of good reasons to believe in the development of full broadside fighting rather later than has been frequently stated in other works. I started this thread on the assumption that most modellers, and other readers on this site, will not be aware that there is much of a debate on this subject, lying as it does at a time in history before that which inspires the majority of models. If this thread succeeds in widening the debate slightly, that will be a beneficial outcome. 

 

The Vasa replica is a wonderful bit of film, which has been mentioned on here before, and I imagine that most people seeing it would be very glad not to be on the receiving end of cannon-fire. It obviously gives a solid and reliable basis for the mathematical calculations you show. 

 

All the best, and thanks for your contributions,

 

Mark P

[Matle]

I should really like to read it. Which time and space is he then refering to? None of the accounts of late 16th and early 17th century warfare indicates that the ships tried to disengage to load guns, rather the contrary. When Mary Rose sank, her newer guns had 4 wheel carriers while the older had only 2. Although this can be related to weight rather than age, adding wheels seems consistent with letting the gun recoil. One could argue that these were muzzle-loaded and wheels make hauling them back and forth easier, but it seems to me that someone would quickly realise that letting the guns do that job themselves seems like a rather tempting idea. And again, pinning the large guns would quickly damage them.

 

 

[Mark P]

Good Evening Matle;

 

It is well worth reading; as it is subject to copyright, I cannot post it or a link here. I can say that there are many accounts in the literature of the 16th-early 17th centuries which describe sea fights, all in the context of firing the bow guns, then the broadside guns, then the stern-chasers, then perhaps the other broadside also, and then moving away to reload. This was a common tactic for all nations, commencing with a 'charge' towards the enemy, before firing the bow guns. There are multiple references to this kind of tactic by many contemporaries. The ultimate aim originally was to soften up the enemy ready for boarding; which gradually developed into standing off and battering each other with broadsides.

 

Regarding the wheeled truck carriage, this is also discussed by Rodger in his article, with the view that the wheeled carriage was not developed as part of allowing for recoil, but more to allow the guns to be run out at the beginning of an engagement, and withdrawn inboard at the end of it. The idea of using the recoil was seemingly adopted much later than we might expect, part of the possible proof of this being noticeable increases in the sizes of gun crews in the first decades of the 17th century, with repeated running out being the main reason for this.

 

All the best,

 

Mark P

[popeye2sea]

Broadside naval gunnery tactics did not come into widespread practice until after the Spanish Armada (1588).  The English were considered to be early adopters of trucked carriages.  An entire class of ships (race built galleons) was developed to maximize forward firing artillery as that was the predominant gunnery tactic of the day.  Most reloading was accomplished while the ship wore away from the enemy to come back around for another assault.  Spanish naval tactics still relied heavily on boarding actions and so their gunners only were expected to get off one or two shots for an entire engagement.

 

Regards, 

[Matle]

Mark, 

I feel we might be talking past each other. The 16th century was a long period, full of experimentation and technological and tactical development. Even at the same time and place, different types of vessels were used with very different purpose and armament. For example, I focused my post on the pure-bred warship of the latter half of the 16th century in the Baltic - these were largely artillery ships. For the earlier type of breech-loaded heavy iron guns common during the end of the 15th and first half of the 16th centuries, having little recoil makes more sense. 

[Jaager]

3 hours ago, Matle said:

As for the hypothetical case of fixed guns moving the ship sideways: no, it wouldn’t.

I believe that the Physics involved would require sideways movement with both fixed guns and guns that recoil. The amount of movement and if it was enough to be observed is another factor altogether.  The greater mass of the ship and the resistance of the water suggest that when the equations are run, the number would be a small one.  Today, with our tech, a real number could be measured.  It might be  mm or cm  but the force has to go somewhere.  If it were localized at the points of attachment to the side of the ship, it would be just compression of a small volume of wood that absorbed these forces.  The body of the ship is a series of interlocking components that were built to transfer and diffuse these significant forces.

[Matle]

7 hours ago, Jaager said:

I believe that the Physics involved would require sideways movement with both fixed guns and guns that recoil. The amount of movement and if it was enough to be observed is another factor altogether.  The greater mass of the ship and the resistance of the water suggest that when the equations are run, the number would be a small one.  Today, with our tech, a real number could be measured.  It might be  mm or cm  but the force has to go somewhere.  If it were localized at the points of attachment to the side of the ship, it would be just compression of a small volume of wood that absorbed these forces.  The body of the ship is a series of interlocking components that were built to transfer and diffuse these significant forces.

You are, of course, correct. When I said it wouldn’t move, I meant that any sideways movement would be  insignificant, negligible - not that it would be absolutely 0. 

[AON]

OMG

Thank you for the video link Matle to the Vasa Gun Project.

The most dramatic part was the ball smashing through the ship's hull... and all the deadly splinters!

[Dr PR]

Alan,

 

There are other videos of the firing of this gun. In the video posted above you can see a vertical piece to the right of the hull siding. In other videos from a different angle this part was a flat sheet parallel to the hull siding. The splinters from the shot ripped the sheet to pieces, showing the effect of the splinters on anything inside the ship. The cannon ball was unlikely to strike a crewman because it was relatively small, but the spray of splinters was much larger and caused the most damage to the crew.

 

One thing to consider - and was briefly mentioned - is that whether or not the gun was fixed or recoiled on wheels, the energy of the recoil was transferred to the ship in both cases. It was transferred directly from the gun to the hull when the gun was solidly attached to the hull. When the gun was on wheels and recoiled the force of the recoil was transferred to the ship through the breeching. But much of the recoiling gun's momentum was lost through friction (heat) so the momentum transferred to the ship was smaller. You can see this in the video - the gun had slowed considerably before it was stopped by the breeching. In later ships the gun tackle absorbed much of the recoil energy.

[AON]

That energy has to go somewhere as no one has yet repealed Newton's third law:  for every action (force) in nature there is an equal and opposite reaction

[Matle]

8 minutes ago, AON said:

That energy has to go somewhere as no one has yet repealed Newton's third law:  for every action (force) in nature there is an equal and opposite reaction

Aye; it was applied in post #15  

[dafi]

On 9/10/2020 at 3:47 PM, Mark P said:

the heaviest guns were frequently mounted to fire forward over the bows, as tactics generally dictated that the bows were pointed at the enemy in an attack, and not the broadside.

Not a really early ship, but still to be seen in the Vasa. The two first guns on each deck only can fire forward seen the angle of the port, the two rearmost guns each deck only aftwards.

 

 

 

 

 

 

 

 

 

 

Also the big gun on the forecastle points very much forward, as its port shows. 

 

 

This also can be seen, as this gun is colliding with the cathead as result of the 90° position in the 1:10 reconstruction 😉

 

 

 

 

 

 

 

 

[dafi]

And sitting on the gun is not unusual to be seen on paintings. 

 

 

 

Also later on to be seen with the french ...

 

 

And a fresh picture of Hermione, giving a hint what it would mean 😉