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Casey Karp
11-26-2014, 12:24 AM
I'm looking for validation here. Anybody with knowledge of metal arts, feel free to jump in and tell me if I'm within the bounds of plausibility.

I've written a bronze sculpture of a man riding a bull. For plot reasons, it's hollow, about six feet high from the bull's hooves to the top of the man's head, and weighs about 1500 pounds.

I've carefully avoided giving any specifics about the thickness of the metal or the exact composition.

So the question is, are these numbers realistic, or do I need to make some adjustments (i.e. make it heavier or smaller in order to make the metal thicker so it can actually stand without collapsing)?

Drachen Jager
11-26-2014, 12:35 AM
This is the only large bronze sculpture I could think of to compare.

http://en.wikipedia.org/wiki/Spirit_of_Haida_Gwaii

It's much bigger, but should give some idea. I suspect yours would be heavier than what you've guessed, based on the specs of the above (weight is at the bottom of the Wikipeida article).

mirandashell
11-26-2014, 01:09 AM
Sort of like this?

http://www.laurencebroderick.co.uk/news2.html

Ken
11-26-2014, 01:22 AM
... also this one, immortalized by Pushkin:

http://en.wikipedia.org/wiki/Bronze_Horseman

Casey Karp
11-26-2014, 05:07 AM
I'm definitely picturing something that looks more like Ken's horseman than either of the other two pieces. Pity I can't find a weight for that piece--knowing the boulder under it weighs some outrageous number of tons doesn't help much. ;) Rather smaller, though. 6 feet tall versus 20 would make a major difference, I'm sure.

Drachen, I suspect you're right, but I'm not sure by how much I'm off. If I simply scale down the Spirit piece by something between 66% and 75%, I come up with a weight around twice what I wrote. But I could certainly fudge things a bit by saying that my piece (a) is smaller, so it can have thinner walls because it doesn't need to support as much weight and (b) is shaped differently, so it has a smaller volume, even if scaled to the same height/length.

Anyone else want to weigh in? (Sorry) I'd especially love to hear from anyone who's actually worked with bronze.

Drachen Jager
11-26-2014, 06:00 AM
But I could certainly fudge things a bit by saying that my piece (a) is smaller, so it can have thinner walls because it doesn't need to support as much weight and (b) is shaped differently, so it has a smaller volume, even if scaled to the same height/length.

I'd buy that.

Also, things like the canoe paddles are going to be nearly solid, and there's lots of bits sticking out of the sculpture like that which will make it weigh more than a similarly-sized statue without all those details.

King Neptune
11-26-2014, 06:10 AM
Bronze has a density of 8.7 grams per cc; that's eight times that weight of water (there is a range, but 8.7 is the standard, and it's in the middle of the range). Can you estimate that volume of the bronze in the statue? I have no idea what it would weigh, or what the volume of metal would be, but I am certain that I couldn't budge the thing, and 1500 pounds would be enough for that.

After a little more thought: 1500 pounds might be a reasonable guess. It wouldn't weigh as much as a car, but it wouldn't be much less. If you feel uncertain, then tack on a few hundred more, but keep it under 3000 pounds.

That reminds me of a story I heard a few years ago. I believed the guy, but that's something else.

Bolero
11-26-2014, 06:18 PM
Don't want you to give away your plot, but just wondering exactly what you are doing with it as in

1. Moving it
2. Hiding inside it
3. Destroying it
4. Creating it

That will affect a bit what you need to think of and to mention. Obviously as well as a lot of bronze, you'd need a lot of wax and fuel. (In terms of logical consistency with your world.)

Casey Karp
11-26-2014, 10:37 PM
Don't want you to give away your plot, but just wondering exactly what you are doing with it as in

1. Moving it
2. Hiding inside it
3. Destroying it
4. Creating it

That will affect a bit what you need to think of and to mention. Obviously as well as a lot of bronze, you'd need a lot of wax and fuel. (In terms of logical consistency with your world.)

That's a good point, Bolero.

Briefly, I'm moving it.

In more detail: the sculpture actually comes apart into two pieces: the man and the bull. The bull weighs about twice as much as the man and for plot reasons needs to be right about at the upper limit of my character's strength (this is an urban fantasy, so having him lugging nearly half a ton is justifiable, but once the weight gets into the four-figure range, it starts to look ridiculous.)

I'm thinking I can probably fudge this a bit and have it work. I'll probably make the whole piece a little smaller and do a bit of hand-waving. I did say in several places that the piece is mostly hollow, so I've got that working for me.

Thanks all!

blacbird
11-27-2014, 10:22 AM
Your figures sound reasonable. Bronze is heavy, and large bronze pieces (e.g., bells) are made by molding, and that is tricky, but you might not need to get into all the technology for story purposes. And story is really what matters, no?

caw

frimble3
11-27-2014, 12:46 PM
This guy: Chris Navarro http://www.natureartists.com/chris_navarro.asp does that kind of stuff and might be willing to answer questions. If the police will answer questions from writers, why not a sculptor? I don't know this person, but I Googled looking for artists doing the kind of thing you're describing, and he was the first name I ran into that wasn't Frederic Remington, or doing little desk-top things.

Casey Karp
11-28-2014, 02:07 AM
Thanks, Frimble. I may drop him a note. Can't hurt, certainly.

One final point: Anyone know if the age and place the piece was created in is relevant? In-story, the piece in question dates from China around 1000 BC. My assumption is that it doesn't make much difference, since bronze doesn't oxidize much.

King Neptune
11-28-2014, 07:27 PM
Thanks, Frimble. I may drop him a note. Can't hurt, certainly.

One final point: Anyone know if the age and place the piece was created in is relevant? In-story, the piece in question dates from China around 1000 BC. My assumption is that it doesn't make much difference, since bronze doesn't oxidize much.

Bronze (and other metals and alloys) show their origin in the minor components. One location will have some arsenic, while another will have some nickel mixed in, ets. Those are not usually deliberate alloy addition but minor components in the ore. So it should be possible to determine that a piece was made in China. Dating can be more difficult, but carbon dating associated organic matter, in addition comparing to similar styles, will usually provide a good date.

King Neptune
11-28-2014, 07:49 PM
Having someone lift and carry 1000 pounds is not outrageous. That is what I was reminded of earlier. A retired well-drilled described picking up the end drill section for his rig after it fell off the truck. He explained that he got out and argued with his brother about picking it up. The bother didn't want to, but this guy said he took one end and put it back on the truck.

I complained, "But that would weigh 1000 pounds."
He said, "Well, not quite."
"Yeah, it might have been a hundred pounds under."
"But then there were the toggles, so, yeah it was about that."

He was in his 80's when I met him, but I got the impression that he wasn't stretching the truth. If you need that character to haul a heavy weight, then do it. It might seem like a stretch, but people can and do lift and carry 1000 pounds.

Casey Karp
11-28-2014, 09:30 PM
Thank you again, Your Majesty. I wasn't quite clear in my final point. I was wondering whether the time and place the piece was created would have any significant effect on its weight, due to the particular ratio of metals used in the alloy and the passage of time.

As I said, I'm guessing that the differences are most likely negligible. Unless I'm wrong to a significant number of pounds, I'll ignore that, shrink the sculpture a little and increase the weight a little and call it good.

King Neptune
11-29-2014, 12:30 AM
Thank you again, Your Majesty. I wasn't quite clear in my final point. I was wondering whether the time and place the piece was created would have any significant effect on its weight, due to the particular ratio of metals used in the alloy and the passage of time.

As I said, I'm guessing that the differences are most likely negligible. Unless I'm wrong to a significant number of pounds, I'll ignore that, shrink the sculpture a little and increase the weight a little and call it good.

Yes, there might be a little more ornate style is one time of place, but it wouldn't add more than a few pounds, and the difference in ratio of tin to copper might make a small difference, but not much. One thin that could make a large difference would the thickness. I think your idea is within the believable range, so go with it.