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Bearings and maps

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  • James Mathews
    John; Well, following your flow of engineering juices, I dug into the book The Ancient Engineers (L. Sprague de Camp). Looking into the Oriental Engineers
    Message 1 of 1 , Sep 15, 2012
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      John;

      Well, following your "flow of engineering juices," I dug into the book "The Ancient Engineers" (L. Sprague de Camp).  Looking into the Oriental Engineers after the period 700 AD to 900 AD the Islamic engineers deal in carriage wheels and pivoting axles  as well as windmills of different kinds, water clocks, and a number of other items using wheels and axles.  However, there is no mention of bearings of any kind.   I will have to go and dig into my library and look into my encyclopedia, or go to the local library.  If I find anything about bearings of any kind I will let you know. 

      Meanwhile, in my spare time, I will be drawing maps for the coming reenactment event on Sept. 29.  The event host has asked me for a map copy and so I will accommodate him as best that I can.  I am also collecting maps of battles both in Roman period and the Byzantine period.  I try to draw the map and then give it some basic colors so that those who are not familiar with reading maps can easily make sense of them.

      Regards;

      Marcus Audens




      On Sep 15, 2012, at 6:44 PM, JOHN BRAY wrote:

      Hi Marcus
       
      Interestining isn't it.  Its got my engineering juices flowing.  So I think it is time for a bit of digging
       
      Regards
       
      John

      From: James Mathews <jlmtopog@...>
      To: JOHN BRAY <jbray405@...>; ByzantiumNovumCulture@yahoogroups.com; ByzantiumNovumMilitarium@yahoogroups.com; Sodalitas Militarium <SodalitasMilitarium@yahoogroups.com>; Res-Publica-Romana@yahoogroups.com; RPRMilitaria@yahoogroups.com; Nova-Roma@yahoogroups.com
      Sent: Saturday, 15 September 2012, 22:08
      Subject: Re: Roller / Ball Bearings, iron and steel rolling

      John;

      Well, I am not sure about this.  I know that on heavy loads such a large stone corn grinder no bearings were used since periodically the stones had to be replaced when the stones central axis wore out.  In regard to water wheels for various tasks also there is no mention of bearings.

      In your diagram, the roller brgs. would have to be shaped and polished to some degree and they would all need to conform to a given size in circumference as well as being as close to being true round as possible.  This could only be done with black-smithing since they had no way to shape the bearing to size and exact shape except by hand and eye.  Now if you made the brgs. from bronze or brass the bearings could be cast, cut, and polished more easily, and of course the holding rings could be cast as well, I think.  I have never worked with brass or bronze on a forge and I have no experience with casting except that I am aware that a rough casting must be worked to make a smooth path for the roller bearings.  I think there was a very basic casting industry, but I really don't know what size that capability could produce.  Lead was shipped in cast "pigs" so there was some knowledge in that area.  A hardwood bearing could probably have been made with a hardwood bearing ring, but it would still have to be greased periodically or oiled to smooth the operation.  The Landel's book talks about the ancient engineer's and their ideas, but also makes some comments about what these people seemed to have missed which is plainly obvious to us today, even without specific knowledge and training.

      There is also the idea of need.  We use brgs. to make things last longer and to reduce work, however, if you have slaves to do the work, you don't worry about that so much.  I agree that the Romans were "closer to the ground" than we are in our current century, but I am not sure that they either saw the need for brgs. as we do, nor were they worried about saving manpower since slavery was so wide spread.  I refer you to Hero's steam engine.  When he presented the invention to the Emperor and suggested that such be used to power a boat instead of slave rowers, he made hero destroy is invention, because such a new idea would completely upset a civilization based on slavery.

      You are certainly right in that there are many things that the Romans were capable of, but they weren't much on initial new ideas.  Rather they usually borrowed ideas from other people , improved upon them and made good use of them.  Then to, he level of technology and available materials, also depend upon new and needed ideas.  In looking over the Landel's Book on ancient engineering, there is a discussion on smelting and the temperature limit 1100 t0 1300 degrees F due to proper fuel, but there is no mention of bearings although there is a number of discussions about water wheels as pumps, and as food grinders.

      If anyone in the militariums, or the discussion forums who read this, and have any references to the use of ball or roller bearings or the use of anything of that nature, John Bray and I should very much appreciate the information.

      Thanks for the permission to share this information.

      All the best to you and yours;

      Respectfully;

      Marcus Audens


        
      On Sep 15, 2012, at 4:05 PM, JOHN BRAY wrote:

      Hi Marcus
       
      I am OK with you sharing things. 
       
      I think bearings could be an interesting area of research.  I have attached some images of a roller brg I have modeled on CAD.  It has simple in and outer race and rollers.  Given the metal working skills they had I don't think it would be beyond them.
       
      For the bearing installations I am thinking about where they would have heavy rotating loads.
       
      Regards
       
      John
       
       





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