Recreating a Cannon, Part Two

brass furnace

Revolutionary-era cannon tell the story of the evolution of war technology. Director of Historic Trades Jay Gaynor and Master Blacksmith Ken Schwarz continue their overview of recreating a light infantry three-pounder.


Lloyd Dobyns: Hi. Welcome to Colonial Williamsburg: Past & Present on This is “Behind the Scenes” where you meet the people who work here. That’s my job. I’m Lloyd Dobyns and mostly I ask questions.

This week, we resume our talk with Jay Gaynor and Ken Schwarz, as they discuss the process of recreating an 18th-century infantry cannon.

What are the mechanics of it?

Ken Schwarz: Well, this was our interest in reproducing the cannon, as we have most of the technical components in place. We have a brass foundry, we have a blacksmith shop, we have a wheelwright, we have bricklayers. The idea was, we could all contribute to this project and kind of stretch our technical abilities, because the casting of the barrel is much larger than any casting that we’ve done before.

The construction of the furnace was larger and more complex than most of the construction work that the brickmakers had done. Wheelwrights have made gun carriages before, but we had good patterns, good illustrations from the time period that show us the design, the construction, and so our thought was, we can further the historic trades mission by stretching our technical abilities and producing this cannon.

Lloyd: It sounds as if you have almost everybody working on a piece of this project.

Jay Gaynor: Close to it.

Lloyd: How long will it take?

Ken: That is yet to be determined. With so many of these technologies, we’re, as I say, we’re pushing the cutting edge of our knowledge. We know how to cast little things, we’ve never cast anything this large. So as we scale up the technology, we find that it doesn’t always work exactly the same way at a larger scale. So we have to re-learn the process, or learn more about the process.

So there’s probably a list of 15 or 20 different things that we’ve never done on this scale. With each one, it’s a new test to see if we can accomplish that. Sometimes when we try a new technique, it won’t work out on the first try. We have to figure out how to modify the technology to make it work as it did in the 18th century. So I anticipate the first one is going to take a long time. We’ve been working on this for probably six or eight months now.

Jay: Off and on, with bits and pieces.

Ken: We probably will have another six or eight months before the whole thing is put together. Part of that is the trial and error of learning the new techniques or larger scale techniques.

Jay: We’re taking stuff that was written 210, 250 years ago. So, we’re trying to figure out what they said, and probably more importantly, what they didn’t say, because everybody took this aspect of it for granted. So you know, we take our experience, and we try to dovetail it with what they’re telling us how to do. Sometimes, if we’re lucky, we’re very successful right off, other times, we’re not.

But that’s what historic trades is all about. Part of what we’re here to do is to preserve what we know, but just as importantly, we really have a pretty passionate group of folks that are trying to figure out, you know, not just how to make something that looks like the old one, but to get there exactly the same way. By doing that, you get inside the heads of the people that were doing it, you get to figure out what their motives are, how they’re dividing up the work, how they’re choreographing the stuff.

Going back to your candlestick, one reason that they cast the thing in two halves and soldered it together is, as you’ve both said, to save material. But it’s a heck of a lot more work. It’d be a lot faster just to cast it as a solid piece. It reflects this very important reality of the 18th century, that materials are almost always worth significantly more than the labor. There’s all these little glitches that come into it like that. So, yeah, you can get frustrated if you want to, or you can say, “Wow, never thought about it like that, let’s try this.”

Ken: The other thing is, we look at original documents that describe these techniques. It’s very, very difficult to put in writing the nuances of the process. There’s so much of this technology that relies on the judgment of the workmen. The only way that you can learn appropriate judgment is through experience. You really can’t communicate that in writing.

That’s why these trades were passed on in an oral tradition, and not through classroom learning. So, when we look at this document, we’ve got a framework to work from that describes the basic process. When we operate the furnace, we’ll be looking for other clues: the color of the flame, whether it’s producing smoke a certain way, the color of the material, the texture of the material, and all of these things give us a clue as to what’s happening in the furnace and when we’re ready to pour.

Lloyd: You’ve got to be able to read the flame to see when it’s ready.

Ken: To me, that’s the importance of historic trades and the program that we have here. The goal is to keep a body of skilled workmen involved in these kind of trades, and again, learning new things, pushing the envelope, and passing that information on to the next generation, so that it’s not lost.

Jay: I don’t know so much about making cannon, but I think a lot of what we do may be saving alternative technologies, or at least keeping people’s minds open to alternative ways of doing things. And it’s interesting that the main book written about the whole gunfounding operations in the 18th century, is “The Art of Gunfounding.” It’s not “The Skill of Gunfounding,” it’s not “The Process of Gunfounding,” it’s not “The Technology of Gunfounding,” it’s “The Art of Gunfounding.”

So much of what we do is in that gray area between very methodical, very rational, very straightforward approaches to things. That gut feeling that this is the time it’s ready, or this is how I’ve got to hit it, or this is how it’s going to move. Without both of those, it isn’t going to work.

Lloyd: Why bronze? Why not lead or steel, or something else?

Jay: Bronze is defined as the kind of gunmetal that we’re using. It’s 90 percent copper and 10 percent tin. What that does is, it gives you the right combination of strength and flexibility. It gives you a tube that you can fire that will withstand the stresses that that entails without fatiguing to the point that it ends up self-destructing or exploding.

Ken: Some of those other metals you mentioned are either too soft to withstand the pressure, or they’re too brittle to hold together under that much pressure. Or, they work harden with time. That is, they may work the first dozen times, but every time you fire it, the stress makes the metal a little bit harder. Eventually it begins to develop cracks, and it will fail.

Jay: They’re making guns out of iron as well, and Ken can probably talk better about that, about the advantages of iron versus bronze guns – or disadvantages. They’re cheaper, a lot cheaper.

Ken: Right. They also have to be heavier to overcome the brittleness of cast iron. That’s one of those materials that works efficiently, but if there’s any flaw in it, you don’t want to be around it when it’s being shot.

Lloyd: How long will it last?

Jay: We hope a long time. But everybody keeps asking, “Are you going to fire this thing?” I have to say that, unless somebody says, “No, you can’t,” yes, you can’t make a cannon without testing it. But I also think we’re going to find a big, big open field somewhere and put a very long fuse in it and run like the dickens in the other direction when we light it. And hope that it, you know, cause we’ll do it with a proof load, which is going to be more than a, you know, a standard load would be.

Our expectation is, that unless there’s a hidden flaw in the casting or something like that, that it will be as good as an 18th-century one. If that’s the case, and we use it for, I mean, the frequency with which we would use it for live fire is very small. We’ll probably test it, we’ll probably shoot a few rounds just to see what’s involved in doing it, but I think most of the times it’s going to live in the Historic Area and be used for programming. If it’s fired there, it will be fired with blanks like we do our other artillery pieces.

Lloyd: Are you going to make another? I mean, once you learn how …

Jay: Well, we are going to do two. We’re going to cast this smaller gun, which is a mortar, designed to sit fairly upright and lob shells at a high altitude. That’s our test pour. Assuming that works, we’ll have one, if there’s some glitches we’ll have two or three or four before it’s all over before we get the process down. We’re talking about casting one light three at this point. But if it’s successful, and our guests get involved in it, and our museum and military history and technology folks seem to get involved in it, then I’d like to do more than one. It’s a big project to do as a one-time only and that’d be it.

Ken: Well, the other thing is, we’re developing the infrastructure that if we wanted to do larger castings of other objects, we’ll have the furnace, we’ll have the knowledge, so this furnace can be used for a lot more than just artillery pieces, potentially.

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