Turntable question....

[TomDiehl]

You'd be wrong. I've visited places like Tindharia on the DHR, El Maiten on the Esquel branch, Cadem on the Hedjaz, and a shed on a Chinese forestry line I can't even spell the name of...Third-world sort of places.

Well there you go. I was talking about the first world.

I've seen an astonishing variety of steam-powered kit in sheds and workshops. Cranes, coal grabs, ash plants, traversers, pumps, fans, machines and stationary engines of all sorts. I never once saw a steam-powered t/t.

Well why would all these things be steamed powered BUT turntables not be so powered as well?

Nor, as I mentioned before, have I ever seen a printed reference to one.

If steam power was the only or the standard way of powering something why would they feel the need to mention it. Dog bites man is not newsworthy.

When I consider that every other type of machine, plant or steam loco specialty was advertised prominently in the trade press, I think that's significant. And the earliest reference I've seen to an electrically-powered t/t was in 1897.

Electric power turntable in 1897. Man bites dog. That IS significant.

Air power was obviously the intermediary between steam and electric

Really? Where, and in what context?.

I believe that compressed air can be used in a system originally designed to use steam with far less problems than steam can in an air system.

Personal experience tells me that steam-powered t/t's were very rare, if they existed at all, and the reasons why that was the case.

Well, existing ones would be rare if they had been converted to compressed air and/or later electricity. There would be no personal experience to be gained if the conversion had been done decades before you were born.

Regarding Westinghouse, being in production doesn't mean it was in wide use. From what I understand, Westinghouse had a problem selling the system until the ICC became their best salesman.

The figures I quoted contradict that. They indicate that airbrake compressors were in widespread use during the last quarter of the 19th century, and came from the ICC itself.

If they were in widespread use then why would the government feel the need to enact regulations to mandate their use? There would be little point.  A bunch of large railroads with 100% compliance can skew the statistics.

The act went into effect in 1900, after a seven year grace period. The act does not specifically mention air brakes. In 1903, the act was amended to require at least 50% of the cars in a train to be so equipped and in use.

Interesting, but irrelevant. The figures I quoted refer specifically to locomotives fitted with air brake compressors - not freight cars.

If the railroads weren't using freight cars with air brake system then the capacity of the air compression systen would only have to service the locomotive. So the compressors could be significantly smaller nd not able to supply a converted steam motor. 

 

Why would you run belts and shafts when you can just run an insulated steam line? All you need is a line running into the pit and up through the pivot.


If you've ever dealt with piping steam over a distance to actually work a machine, as opposed to piping process steam, you'd know it isn't that simple as providing an insulated pipe. And the state of the art being what it was in the period under discussion, a steam-tight, 360 degree rotating joint would have been a really big ask. Much easier to either turn engines by other means - manual, air, or electric.

Obviously manual is the easiest. If you require power, it depends on what's available. If you're starting from scratch and electricity is available. That's the next easiest.
But if you're building the facility prior to electricity then you're left with steam, air or a mechanical drive. The question becomes why would you opt for air and have to obtain, maintain two generation systems when you can go with steam and have to deal with just one?

Or worse still, mechanical drive. Running steam lines would have been preferred to running power shafts and gear boxes under the turntable, even if they leaked.

Even if you were using locomotive steam, the hose would logically be installed on the turntable not the locomotive. You'd pull steam off the front end near the cylinders, which would be near the end of the turntable where the table engine would be.

Again, really? Where exactly would you advocate taking steam off the loco from?

See above. What you quoted. Where would you place a valve on a steam locomotive if you wanted to be able to pull off steam?


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I'd imagine that a stationary air source would be employed, probably using the same steam line that had been used.

And yet every example of an air-operated t/t mentioned, or that I've ever seen took air from the loco brake or main res pipe, as there were no "steam lines" to use

If you converted from steam to air and ran it off a locomotive's air supply why wouldn't you remove the former steam piping? Either for ease of maintenance or for the scrap value of the obsolete parts?

A locomotive compressor might not make enough pressure to operate the turntable engine.

Sorry, that's just nonsense. When even a single-stage Westinghouse "F" pum

Smile, it makes people wonder what you're up to. Chief of Sanitation; Clowntown

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