Artillery cannon wheels

[AlanRoy]

Good afternoon,
New poster here.
Why did the wheels of the field carriages have 14 spokes? 360 degrees is not evenly divided by 14. Inquiring minds want to know .......

 

[Belfoured]

Good afternoon,
New poster here.
Why did the wheels of the field carriages have 14 spokes? 360 degrees is not evenly divided by 14. Inquiring minds want to know .......

I don't know why the specific number 14 was chosen but IIRC you need an even number to distribute the weight equally and the more spokes, the stronger.

 

[James Brenner]

I don't know the reason, either but I suspect Belfoured is correct. I think that the number of spokes is directly related to the Ordnance Department's development of the M1841 system of artillery: new carriages, new barrel designs, and new metals. A search through Ordnance reports and correspondence would likely explain why.

Question from a liberal arts major: why would the number of spokes have to evenly divide 360 degrees?

 

[RedRover]

Fourteen spokes were not uncommon. From 1845, London Cyclopedia, an explanation that the number of spokes was based on the size of the wheel.

Regarding carriages generally... from 1839:

From 1893, regarding cart wheels of fourteen spokes...

 

[Belfoured]

I don't know the reason, either but I suspect Belfoured is correct. I think that the number of spokes is directly related to the Ordnance Department's development of the M1841 system of artillery: new carriages, new barrel designs, and new metals. A search through Ordnance reports and correspondence would likely explain why.

Question from a liberal arts major: why would the number of spokes have to evenly divide 360 degrees?

I'd like to know as well - maybe with clarification of what "evenly divided" means. (I've also seen information in the past that an odd number of spokes distributes the weight "evenly", so who knows). Never actually cared enough to dive into it. Even for his unique carriage design, including wheels with his system for expedited changing of spokes, Norma Wiard used 14.

 

[AlanRoy]

I can understand 10, 12, and 16. 10 - the angle at the hub is 36 degrees. 12 - the angle is 30 degrees. 16 - the angle is 22.5 degrees. 14 - ????

 

[AlanRoy]

I don't know the reason, either but I suspect Belfoured is correct. I think that the number of spokes is directly related to the Ordnance Department's development of the M1841 system of artillery: new carriages, new barrel designs, and new metals. A search through Ordnance reports and correspondence would likely explain why.

Question from a liberal arts major: why would the number of spokes have to evenly divide 360 degrees?

Evenly for simplicity's sake.

 

[AlanRoy]

Not to worry, I have a liberal arts degree too. Worked with numbers my whole life, though. All 3 score and 13 years!

 

[James Brenner]

Not to worry, I have a liberal arts degree too. Worked with numbers my whole life, though. All 3 score and 13 years!

Three score and 13; that's what? 16?

 

[AlanRoy]

umm ... Yeah, that's it!

 

[drezac]

the 3rd Edition of the Ordnance manual simply has a table for all the wheel data, with no explanation. That leads me to believe that the dimensions, number of spokes, etc. was based on accepted engineering standards of the time. For other Items, the manual goes into more detail. Considering that the last chapters of the manual contain information regarding wood, iron, mathematical formulas and mathematical tables to me it looks like they considered the information on the wheels somewhat "Common Knowledge" and just used a table with dimensions as a reference.

 

[DixieRifles]

I don't know why the specific number 14 was chosen but IIRC you need an even number to distribute the weight equally and the more spokes, the stronger.

Well, even in those old days, balance would have been important. And I don't mean balanced as in an artistic view point but literally balance as in weight and center of mass. They didn't run at 60mph like our cars, which have balanced wheels. The other reason is stress. If you have gaps between some spokes then that rim will have to carry more load than the other parts of the wheel.

The strangest thing is how the spokes are not perpendicular to the wheel axle but they lean out. They form almost a cone. However, the spoke that is supporting the wheel is vertical to the ground.

 

[Dan Kohli]

I'm probably not adding much to the discussion, and I didn't look to much into this subject, but the wheels have to hold up to the forces involved in the traveling and firing of the artillery piece. Even the siege artillery have 14 spokes.

 

[BCS1973]

Here's my take. A wheel can be made with an even number of spokes, or an odd number of spokes, meet the requirement of "even spacing" which is essentially the distance between the tips of the spoke on the circle. The odd spoke count can still be balanced as well as an even spoke count wheel. In the case where spoke count is the limiting factor on the amount of load a wheel can carry, more spokes equals more load capacity for a given diameter. I.e. a 15 spoke wheel carries more load than a 14 spoke which carries more than a 13, and on down the line. However, if you look at the video linked below (start at the 9 minute mark), you'll notice something. The wheel has an even spoke count, and each of the 7 rim sections is basically identical. Same length, Same holes, same location, so a single cut fixture and drill fixture can be used to make the entire rim. In an odd spoke count wheel, the hole locations will stagger meaning there would be at least one odd piece and likely more. This would make it more efficient and less mistake prone to build wheels at an even spoke count.

 

[Rhea Cole]

The spokes are even numbered because the fellies had to be interchangeable.

The diameter of the hub had to be large enough to have the mass to set the spokes.

As Belfourd pointed out, Waird came up with an improved wheel design.

He substituted iron wedges for the solid block of wood.

A damaged spoke & fellie could easily be replaced in the field. A solid wooden wheel could only be repaired by a great deal of laborious effort.

 

[AlanRoy]

I was starting to feel that the determining factor could be equal sized fellies, the diameter of the wheel being nothing but a result of all of the fellies and spokes fitting. Does that make any sense?

 

[Rhea Cole]

The wheels of Chinese chariots are much greater in diameter & have many more than 14 spokes. The first link is to a history, the second is to a NOVA program where they build & drive a beautiful reproduction chariot. The detailed demonstration of the wheelwright's craft is illuminating.

Chariots in Ancient Chinese Warfare

The chariot was used in Chinese warfare from around 1250 BCE but enjoyed its heyday between the 8th and 5th century BCE when various states were constantly battling for control of China. Employed as...

www.worldhistory.org

Link to NOVA:

q=chinese+chariot+revealed&ie=UTF-8&oe=UTF-8&hl=en-us&client=safari#sbfbu=1&pi=chinese%20chariot%20revealed

On this NOVA program about building an Egyptian chariot the evolution in the number of spokes is covered. The number & spacing of the spokes was arrived at thousands of years ago. The small diameter wheel has 6 spokes.

Building Pharaoh's Chariot

A team uncovers the advanced engineering behind an ancient Egyptian war machine.

www.pbs.org

You just never know where a CWT inquiry is going to take you ¿no?

 

[Rhea Cole]

I was starting to feel that the determining factor could be equal sized fellies, the diameter of the wheel being nothing but a result of all of the fellies and spokes fitting. Does that make any sense?

Look at the NOVA programs linked in my post. Many answers will come for questions you haven't thought of yet.

 

[Belfoured]

I can understand 10, 12, and 16. 10 - the angle at the hub is 36 degrees. 12 - the angle is 30 degrees. 16 - the angle is 22.5 degrees. 14 - ????

25 and "almost .75" . I see I also called Wiard "Norma". Not going into what the angle is on that ...

 

[BCS1973]

The wheels of Chinese chariots are much greater in diameter & have many more than 14 spokes. The first link is to a history, the second is to a NOVA program where they build & drive a beautiful reproduction chariot. The detailed demonstration of the wheelwright's craft is illuminating.

Chariots in Ancient Chinese Warfare

The chariot was used in Chinese warfare from around 1250 BCE but enjoyed its heyday between the 8th and 5th century BCE when various states were constantly battling for control of China. Employed as...

www.worldhistory.org

Link to NOVA:

q=chinese+chariot+revealed&ie=UTF-8&oe=UTF-8&hl=en-us&client=safari#sbfbu=1&pi=chinese%20chariot%20revealed

On this NOVA program about building an Egyptian chariot the evolution in the number of spokes is covered. The number & spacing of the spokes was arrived at thousands of years ago. The small diameter wheel has 6 spokes.

Building Pharaoh's Chariot

A team uncovers the advanced engineering behind an ancient Egyptian war machine.

www.pbs.org

You just never know where a CWT inquiry is going to take you ¿no?

So, the PBS NOVA links don't work for me. Everything I find comes up behind a paywall, or non existent. It would be an interesting watch. In my post I wasn't giving credence for field repair-ability because the tires were a shrink fit on the wheel to keep everything in compression (exactly the opposite of today's modern spoked bicycle wheel). If they can't squeeze it all back together, the wheel would be considerably weaker. Did they have smith's and/or wheelwright's in the field close enough to do this type of work?