How Its made

[whughett]

Saw an episode recently on how cannons are made. Expected them to be cast same as bells, that is inner and outer molds, but these were cast solid then bored.

Would they have bored them in the Revolution and Civil War era.

Guess it is a good thing I am a city dweller, judging by how my hand gun, smokeless and black, collection has grown over the years don't think the wife would have been too happy with the same in cannons. Too bad I am a wood worker also and the carriages would have been a hoot to construct.

 

[Skinny 1950]

There must have been some cannon boring going on in the 1700's because the scientists of the day used the heat generated to calculate the (Work= Heat) equivalents that are still in use to this day. B.t.u./sec=1.41391 Horsepower
I don't know if they used a core in the moulds back in the day but it would save a lot of boring if they did.

 

[DaveP (UK)]

Interesting point - I too would have expected them to be cast hollow and then bored.
I found this: http://www.wrexham.gov.uk/english/heritage/bersham_ironworks/boring_for_britain.htm
Its aimed at a young audience, but its quite clear about a date and the reason for change.

 

[Kynoch]

There must have been some cannon boring going on in the 1700's because the scientists of the day used the heat generated to calculate the (Work= Heat) equivalents that are still in use to this day. B.t.u./sec=1.41391 Horsepower
I don't know if they used a core in the moulds back in the day but it would save a lot of boring if they did.

Gundrilling of anything that size back in the 18th Century would have been quite a challenge. Reaming and /or lapping of a cast bore would seem far more likely.

 

[WestKentucky]

A task of that magnitude most likely would have been driven by falling water or slave labor. Neither was too reliable when dealing with that much force requirement. I agree with the others...cast hollow then finished. I wish we had some photos or historical texts and drawings outlining some of the antiquated methods like this. Steam engines changed the world quickly and a lot of pre-installed revolution tech went to the grave of many of our ancestors.

 

[TheRodDoc]

They were cast solid. Then the casting (barrel) is turned while the non-revolving drill and or boring bar are feed in. The same way rifle barrels are bored.

If a tube is cast around a spindle core representing the bore, then the result is an undesirable texture in the metal surounding that spindle core when cast and it also frequently would shift in position when the metal was poured. Giving the cannon unequal wall thickness making boring the bore accuratly centered nearly imposable.

The trunnions were cut with a tool that much resembles a thread die. It was turned by hand.

 

[kBob]

Towards the end of the muzzle loading cannon era, during the ACW, some cannon were cast using a core for the bore that was cooled by water during the time the cannon sat cooling in the mold. This made the area of the bore denser than the surrounding area which both made for a more void free bore area and a softer outer shell that had some give and was less prone to burst rather than streatch.

Some if not most of the older cannon were indeed cast with core pins and then reamed to finish.

Like rifle barrels, boring from solid was an 1800's thing.

Some of the "Leather Guns" of the Swedes were actually built up from scaps hammer forged around a hard mandrill just like folks used to make musket and rifle barrels in small shops (or large ones for that matter at the time). They were thin bored and wrapped with tarred rope to add strength and then covered with Leather to protect the rope, making for a light weigh highly portable gun, though one with a very low round count life.......Note that they were soon given up, though wire wrapped guns have been seen since.

Pretty much if you can imagine a way of casting and making a cannon barrel it has been tried.

-kBob

 

[CANNONMAN]

Interesting. It was my love of woodworking that led me here as "cannonman". Furniture, backgammon and other game boards and jewelry boxes, but I always wanted to build a cannon carriage. So I took an adult hobby milling class at our local college and began making cannons. Then I made the molds for the shot and now the BP to shoot them. Other than not realizing how much space my already too full garage was, it has been immense fun. The insight and thought management from this sight has been priceless. And believe it or not, my Wife say's she is proud of me. Off to tend to a new batch of BP. In the meanwhile, a simple safe cannon can be produced in a myriad of ways. Or just buy one and build the carriage, Either way its a journey well worth taking.

 

[MagnumDweeb]

One day, if I have the space. I'd want to set up to build a 2 pounder muzzle loading cannon. http://www.lovettartillery.com/Woodruff_Gun_American_Civil_War.html

I'm thinking the Woodruff would be a good archetype to start with. It wouldn't be a huge cannon (it's still incredibly big but it's no eight pounder).

Mind you I'd want to use steel and that's what would make it incredibly expensive, not to mention the horizontal lathe I'd have to buy for it. But the difference between men and boys is the price of their toys.

 

[Kynoch]

A task of that magnitude most likely would have been driven by falling water or slave labor. Neither was too reliable when dealing with that much force requirement. I agree with the others...cast hollow then finished. I wish we had some photos or historical texts and drawings outlining some of the antiquated methods like this. Steam engines changed the world quickly and a lot of pre-installed revolution tech went to the grave of many of our ancestors.

Jan Verbruggen Foudary -- Horizontal Boring Machine: Exact drawing made with camera obscura
of horizontal boring machine by Jan Verbruggen in Woolwich Royal Brass Foundry circa 1778.​

 

[Kynoch]

I suspect the above machine is water-powdered. Watts' steam engine was still in the design stage. The guy in the brown coat appears to be standing in front of a steady that looks more like the carriage of a lathe.

The guy at the opposite end wearing the chapeau seems to be feeding the tool -- a reamer I suspect. While the barrel would be turning painfully slow, I serious doubt enough thrust could be generated to actually do some gundrilling.

 

[Field Tester]

I suspect the above machine is water-powdered. Watts' steam engine was still in the design stage. The guy in the brown coat appears to be standing in front of a steady that looks more like the carriage of a lathe.

The guy at the opposite end wearing the chapeau seems to be feeding the tool -- a reamer I suspect. While the barrel would be turning painfully slow, I serious doubt enough thrust could be generated to actually do some gundrilling.

To me it looks like he's pointing, not feeding. Could be wrong though. Probably guiding?

 

[WestKentucky]

Thanks, that's awesome.

 

[TheRodDoc]

That image was copied and colorized by someone. Here is the original on this page about gunfounding. The pic is explained.

http://www.riv.co.nz/rnza/hist/gun/found.htm

 

[Steel Horse Rider]

Great explanation! Thanks for posting here. This place is a wealth of information.

 

[whughett]

Some very smart people on this forum. Guess we are not all Small Town Red Necks clinging to our guns and religion. Well I am but that's only speaking for me. (Weak attempt to some jocularly) . As an aside the myth buster crew bored a cannon from a green tree trunk, made a nice boom and a pile of splinters, but not much else.

 

[Jim K]

Leather Cannon

One of the more interesting cannon was the "leather cannon", used by the Swedish king Gustavus Adolfus. The tube was not made of leather, but consisted of a thin copper or bronze liner wrapped with leather bands for strength. Extremely light for the day, it could be pulled by one horse and emplaced by only two men. Unfortunately, it was too light and didn't stand up to much firing before overheating.

Jim