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machines which I have made, am making, or intend to make, and some other stuff. If you find this site interesting, please leave a comment.

Tag: naval cannon

CARRONADE VS LONG GUN

 

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Models 24lb long gun and 32 lb carronade.  1:10 scale.

In a shoot out, which would win?

Doubtless, at this range, there would be no winner.

But there were quite a few battles between ships equipped with these weapons in the Napoleonic wars, the first American civil war (the War of Independence), the 1812 war between Great Britain and the US, and many others.

The long gun, manned by 9-11 highly trained gun crew, fired a ball of 24lbs weight, up to 2000 yards, with some accuracy.  The largest long guns mounted on the biggest battleships (like “Victory”) fired  balls up to 42 lbs.

The carronade was operated by 4-6 men, and fired a ball in this case of 32 lbs, at three times the rate of a long gun, but with dismal accuracy beyond 500 yards.  They were much less expensive to buy and operate, and very popular with the bean counters.  Carronades fired balls up to 68 lbs.

Since most sea battles were fought at ranges much less than 500 yards, carronades were credited with many spectacular victories.  The British were so impressed that they installed carronades in addition to the usual long gun armament, to increase the overall firepower of their ships, but later they replaced the long guns with carronades in some ships.

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In the war of 1812 between the Brits and the US, while the Brits were simultaneously engaged in a life and death struggle with the Napoleon, they were often beaten by the newer and more powerful frigates of the small US navy.  One factor cited is that the British ships had fewer and less powerful long guns, and partly because they had changed over to carronades.   The US ships remained out of effective range of the British carronades while causing huge damage with their long guns.

 

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Short squat and ugly vs long and elegant and expensive.  Note: no SWMBO comments.

 

The carronade was used by the British navy for only half a century, vs 3 centuries for long guns.

They were both replaced by guns which were rifled, fired explosive shells, and were breech loaded.

For a very detailed analysis of these weapons, including original results of British Admiralty trials and summaries of many sea battles, see Adrian Caruana’s book, “The History of English Sea Ordnance” Vol 2, 1997.  If you can locate a copy.  I found one at the State Library of Victoria.

 

CARRONADE 1

It has been a while since I posted, but I have been busy.

Some of that has been in the workshop making a scale model carronade.

A carronade, in case you are wondering, was a muzzle loading cannon, made 1776-1852 in the Scottish town of Carron, by the Carron company.  And subsequently much copied elsewhere.

It is a cannon which is short, squat and ugly.

Weighs about 1/3 as much as an equivalent bore long gun, (see previous posts), requires only 3 men to operate (compared to 9-11 for a long gun), and can fire balls or other nasties at 3 times the rate as long guns.

2 carronades, 68 pounders,  were on the foredeck of Nelson’s “Victory”, and they caused huge damage  at Trafalgar.   Can you imagine loading a 68 pound cannon ball into the muzzle of a hot cannon?   Many actions proved the killing power of carronades, and the British Admiralty were so impressed that they replaced long guns with carronades on many of their ships.

The French, and Americans were less rapid to  access this new technology, although Napoleon, who was an artillery officer, was adamant that the French navy should have the carronades installed as quickly as possible.

The British equipped some of their ships almost exclusively with carronades, and at close quarters they were devastating and they won some notable victories.

Unfortunately, although they were devastating at close quarters, they did not have the accuracy or range of long guns beyond about 500 meters.

So in the war between the Brits and the Yanks in 1812, the Americans found that all they had to do to win at sea and on the Great Lakes, was for their frigates to remain beyond the carronade range, and shoot their long guns, with many victories, and great frustration of the Brits, who were not used to losing naval battles.

Carronades were commonly installed on merchant ships, privateers, pirate ships, and small naval vessels, due to their relatively light weight, and small gun crew. But the Royal Navy stopped using them from 1852, when breech loaders were the latest new technology being installed wherever possible.

I decided to make another 1:10 scale model cannon.  A 32 pounder carronade, the same scale as the previously blogged 24 pounder long gun, to put them side by side for comparison.

It is almost finished.  I will post some photos soon.  Look forward to squat and ugly.

 

 

Turning a cannon barrel

Today the exterior surface of the model 1779 naval cannon barrel was turned.

The piece of brass material weighed 5.1kg, was 300mm long and 50.8mm diameter.

I had used Loctite to glue a spigott in the bore, to provide a center and a driving diameter which the small CNC lathe would accept.

Although the lathe was nominally 300m between centres, the toolpost would move only about 200mm.  So the turning had to be accomplished by turning the cannon mouth end first, and then reversing the workpiece to turn the breech end.

The CNC lathe, owned by Bob Julian,  is about 30 years old, and it came out of a school.  In the course of this  job, it seemed to progressively free up, making us suspect that this is possibly the first time it has ever been seriously used.

The lathe electronics had been replaced by Stuart Tankard to use Mach3.  The G codes were generated by Stuart’s program “Ezilathe”, which is available as a free download on “CNC Zone”.   It is an excellent CNC lathe program, and I thoroughly recommend it.

I will eventually post some videos of the turning progress, but my Oz internet connection is so slow, that for the moment I will post photos only.

I started by turning a piece of rubbishy pine as a test.

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That’s me, watching carefully.  Later we installed the swarf cover.

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The metal turning lathe does not miss a beat chomping through wood.  These are the roughing cuts.  F300mm/min, S800/min.

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The Mach3 picture of progress.

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The finished distal half of the cannon barrel in pine.  If I stuff up the brass version at least I can have a wooden barrel. 

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Roughing the barrel in brass.  1mm cuts, feed 100mm/min.  It took almost 50 minutes for this section, and about 15 minutes for the breech section.

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The barrel mouth.  No gouging resulting from the 22 degree HSS cutter.

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Finish was quite good.  Will require minimal polishing with ScotchBrite.

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The workpiece was reversed in the lathe, the Z zero carefully set, the X unchanged, and the breech end turned.

The starting weight was 5.1kg.  The end weight, including the spigott was 2.9kg.  So at least 2kg of brass swarf, most of which I swept up and saved for possible future use.

Next to machine the trunions and some silver soldering.

 

Making a Cannon Barrel is boring

The bore in my 1779 naval cannon is 14mm diameter, 270mm deep.

I made a D bit from silver steel, as per the Jerry Howell plans.  I tried it without heat treating, but it blunted after  boring a couple of centimeters  so I heated it red hot and quenched it in water, then annealed it  and resharpened it. There were  no further issues with edge holding.

I then tried it without, then with, a preliminary drilled hole in some scrap.   I have decided that it is better to give it a starting hole of the correct diameter.

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This is the setup.  The 50mm brass rod is held in a 3 jaw chuck, and the tailstock end held in a centre while the chuck jaws are tightened.  The bore is then started with a drill which is accurately sharpened.    Then the D bit is fitted, and the deep boring job starts.  I used an accurate 3 jaw chuck in the tailstock to hold the D bit.  The headstock does not accept 50mm stock, but the 3 jaw chuck does, albeit with some stick out.  Once the D bit enters the workpiece, it acts to stabilise the workpiece.  The whole process was easier than I had anticipated.

 

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Each peck of the  bit advances 2-2.5mm.   The D bit is withdrawn and the chips are cleared.  Initially I used  a small brush, but as the hole deepened, the brush was replaced with a compressed air blast, delivered through a small bore copper pipe.

The 270mm bore took 2 hours to complete.  It was not a boring job.  I was anxious not to muck up the hefty lump of brass.

Next to drill the trunion holes in the barrel stock.  That will be straight through all layers of the barrel.  (retrospective note added later…  The trunnion holes were stopped short of the bore, and I was just very careful to keep the holes at 180 degrees and in line)

Then to turn the exterior of the barrel.  There will be a video if that is successful.

Then to silver solder the trunnions to the barrel in one piece.  Then to use the D bit to rebore the barrel, removing the trunnion rod which is obstructing the bore.  Some readers will not agree with this method, and it is not according to the Jerry Howell plans, but it does ensure that the trunnions are exactly in line with each other.  Silver solder, if properly used, is said to be as strong as the parent metal, so I believe that I will not be compromising the integrity of the barrel.   The main disadvantage is that the finished exterior of the barrel will need to be held in the 3 jaw chuck during that final D bit reboring.  I have not quite worked out how to do that, while avoiding marking the finished brass surface.

 

More Naval Cannon

Some temporary bolts inserted until I get around to making the permanent brass fixtures.  And the quoin and bed finished.  And the wheel halves joined with brass pins.

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The quoin is the wedge which is used to set the elevation of the barrel.  It has a dovetail connection to the bed underneath.    The brass pins which connect the wheel halves are also seen here.

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The dovetail groove was smaller than any commercially available router cutter.  That top opening is only 3mm (1/8″) across.  After considering options I elected to cut the bed in half and then machine a 60 degree groove into each half, then superglue the halves together.   The tongue in the quoin was similarly machined, but in one piece.   That handle hole in the quoin is not centered, despite careful positioning.  The wood grain must have pushed the drill bit laterally.  I will use an end mill to get a bigger, centered hole and glue in a patch.

 

The barrel is 300mm-12″ long.  It has straight sections, a taper section and several curved sections.  Plus several types of bands called astrogals.  It would be ideally suited to turning on a CNC lathe, but is much too long for my Boxford.  So I am asking around, to locate a larger CNC lathe for hire/loan.  If all else fails I will use my manual lathe, but I expect that the finish would be better on a CNC.

I will drill the bore first, and after considering the options, will use the Jerry Howell recommended method, which is to use a D-bit.

DESERT IRONWOOD

Some decades ago I made a table for our kitchen.  (cannot find  photo just now, will add one later)

I bought the wood from a wood recycler.  He removed trees from Melbourne suburban gardens, then cut them into slabs and air dried them.

I recall that I paid about $AUD 1000 for the 6-8 planks.  They were about 40mm thick and 300mm wide and about 2.5m long.  They were so heavy that I could barely lift them.

I have since learned that they weigh 1.1 to 1.4 tonnes per cubic metre, which is at the high limit of wood densities.

The tree must have been 400mm diameter, because some slabs still had the bark attached to both sides.

The wood has a beautiful dark brown colour, with almost white sapwood solidly attached. It is unbelievably hard, and I struggled to machine it with my thicknesser/buzzer.  Also, it was the most reactive wood I have ever worked.  When planed or thicknessed it would bend and react totally unpredictably.   My 40-45mm thick planks ended up 25-28mm thick and even then they were not totally flat.

But SWMBO liked the table, and it still is the main meal table in out house.  One of my daughters requested a similar table, which I made from Gippsland Blue gum, another spectacular dense hard Australian wood.

The ironwood has survived kids dancing on it, steam engine demonstrations, being used as a work bench, not to mention many meals with never a table cloth.   And the wood itself is unmarked!  The polish has disappeared in places, but the wood itself seems impervious to damage.

To get to the point of this post, I am currently making a 1779, 24 pounder, 1:10 scale naval cannon.  Jerry Howell design.  About 300mm (one foot) long.

When I was looking in my shed I considered various woods for the carriage-base.  I considered some black walnut, which was recommended, but it seemed a bit light in weight and colour.  I considered some Australian redgum, which polishes beautifully, and is dense and tough, but it is a bit too red.  Some African Odum looked possible, but the figuring is a bit plain.  Then I found some ironwood offcuts from the table job, and the decision was made.  Ironwood it is.

So here are the initial photos of the carriage parts.  They were machined on my metalworking mill, using HSS cutters.   I CNC’d where possible.

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Ironwood after conventional thicknessing.  Tearouts are a problem.

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Ironwood after surfacing with a 1″ endmill.  Here I am CNCing the profile of the carriage.  3000rpm, 500mm/minute.

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After milling, I am tempted to just oil the surface.  The edges are sharp, like milled metal.

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CNCing the wheels.

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A little deburring or with wood is it called defuzzing? required

Watch this space for progress on the cannon.

There are some technical challenges, including deep boring 14mm diameter 275mm deep, making a tiny dovetail in the ironwood,  and turning the barrel from 50mm diameter brass.

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