Atomic Awesome, Big Complicated Machines, Technostalgia

Mesta Memories #23: Rope Drives and Flywheels

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A large-ish rope drive wheel being turned on a pit lathe.

Following on to the last post about the giant frikkin’ gears that the Mesta Machine Co. used to make, this time we’ll take a quick look at their rope drives and flywheels which are also predictably huge.

As it states above, rope drives are used where quiet and smooth transmission of power is required and belts are either not strong enough or too cumbersome. A good example is the drive mechanisms used by most elevators used in buildings. Could you imagine riding a chain-driven elevator up to the 50th floor of a building? I can, unfortunately, and it makes me want to go outside and sit on the nice, safe gravel of my front yard.

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Mesta made several types of industrial flywheels of varying construction depending upon their application. For an idea of the forces placed on these huge pieces of spinning iron and steel, consider the rim speeds referenced in the plate below: 6,000 feet per minute = 68 MPH, 13,000 FPM = 148 MPH, 16,000 FPM = 182 MPH, and 20,000 FPM = 227 MPH. That’s quite a bit of kinetic energy in a massive metal wheel whizzing around, trying its best to fly apart, and must have been rather exciting for the men that had to work around them.

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Click to Largerizerize the image.

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Here is the black and white photo for the above image used in Mesta’s promotional pamphlet. You can really see how much the photo was retouched. Photo found on the Industrial Pittsburgh website.

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Lastly, here is a cool photo of a huge Mesta gear being transported, found on the Practical Machinist website, a great place to peruse old industrial machinery and, on occasion, stories by the men who used them.

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This photo missed the last Mesta Memories.

Except where noted, all images are from the 1919 edition of “Plant and product of the Mesta Machine Company, Pittsburgh, Pennsylvania“.

Other articles in this series:

Regarding the Images in “Mesta Memories”

Mesta memories #22: Gear Drives

  • I can't imagine a chain drive elevator, but I've often wondered if there ever were screw driven lifts. Like lead screws at each corner and some rotating nuts on the car. This would be impractical after about three floors, but talk about positive engagement!

    Anybody ever go skiing at a mountain with a rope-tow?

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    Longer ones had the insidious danger of the rope winding up as you went, and this would pull your mitten right off your hand! Worse, you'd get your fingers under your palm and not be able to release the rope at the top it was so wound up.

    • The Professor

      Some elevators use hydraulic rams, like the airplane elevators on an aircraft carrier, but I've never heard of a screw operated elevator.

      Many, many, many years ago I was at a ski run near Bend, Oregon, that had a rope tow. I didn't go near the sketchy thing.

      • OA5599

        A screw elevator would be a maintenance nightmare. Ding a thread and your passengers are stuck.

        I worked in a building with a hydraulic elevator. However much the elevator piston travels, you have at least that much cylinder underground. On ours, there was an electrolysis reaction that caused a number of tiny pinholes. After about a week, the fluid would leak down enough that the elevator couldn't reach the top floor.

        After the new part arrived, it took about a week to extract the old cylinder and replace it with the new. The piston was re-used. I had a chance to talk to the mechanics who were handling the replacement.

        They don't like to use hydraulic elevators for anything taller than around 6 stories. They said this wasn't a weight limitation, but the practical matter of working with parts that were that long. In our building, the faulty elevator was a freight elevator next to the loading dock, and only three stories tall, so there wan't a big problem maneuvering the parts, but I can see how it could be an issue elsewhere.

        • Oh, I don't know. Given a large enough diameter screw and a buttress thread (like an Acme thread with one angled side, for unidirectional loading) I'm sure you could avoid thread damage. Lead screws on lathes operate in terrible circumstances and still run true, the inside of an elevator shaft would be fairly safe.
          Taller and taller elevator shafts would demand stouter and stouter screws, until the whole thing became unfeasible. It could work for a forklift, though. It's like screw jack versus bottle jack, though. A heavy enough load will bind the threads and require much force to overcome. Then I guess you could use recirculating balls and tie an onion to your belt…

          What were we talking about?

          • <img src="http://farm5.staticflickr.com/4150/4982772070_897bcd01ca.jpg&quot; width="450">

            Ford used screw jacks to raise and lower the top on its 1957-59 retractable hardtops, but disguised them to superficially resemble hydraulic jacks. The paired jacks are driven by a central motor, thereby keeping them synchronized.

            Ford did use hydraulics on its soft-top convertibles during that same period, as these tops have more flexibility when responding to the slight "walking" motion of the hydraulics as they alternately go in and out of being the easy side to move. Such flexure was considered undesirable for the area surrounding the glass rear window of the retractables, nor did Ford want to make the hardtop stiff (and therefore heavy) enough to overcome the effects of hydraulics.

          • DustyB

            There is an old movable span railroad bridge over the Kansas River, in Kansas City's West Bottoms. It is where the old Kansas City Stock Yard was and Kemper Arena is located. This bridge has four large screws, one on each corner, and looks like they could raise it 20 feet or so. At least the two eastern spans are movable and the others may have also.

    • ptschett

      Yay, a Super C!
      (I used to spend many hours each summer driving one, towing a pair of New Holland bar rakes, to merge two windrows of hay into one… it had a wide front axle, but otherwise was just as much a non-fendered deathtrap as that one.)

  • cruisintime

    OSHA closed most of those old shops down. EPA just forced the last lead smelter in the country to close. We are killing industry in this country . All they do is move the pollution to another place on the planet.

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