Steam & Excursion > SP (T&NO) (H&TC) 553 mogul

Does the water tank extend the length of the tender, and the fuel oil contained above in the 
steel traingular shaped tank above the water tank?  If so, curious why this arrangement vs a
simpler rectangular tank arrangement with an oil tank above the water like the Katy and others used.

Note on back says 553 was former Houston & Texas Central 553, built by Brooks in 1908.

May 1941 photo taken at  LAFAYETTE, LA

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This is called a "Vanderbilt" design tender.  As the drawing below shows, the fuel space (that truncated triangle) has a sloped bottom just like every tender intended for use on a coal burning engine.  Adapting it for oil burning the "coal boards" (doors) facing the cab were simply uninstalled and an oil bunker shaped to fit the former coal space is dropped into place.  Converting back to coal would be simple, as well.

Some oil burning tenders did have a full length cylindrical tank with a divider to separate the oil and water spaces, and look more like regular tankcars.  These, of course, were not convertable. And many oil burning engines have the more common rectangular design, but with a drop-in oil bunker to fit the coal space.

-LD

 



Edited 1 time(s). Last edit at 01/27/25 11:28 by LarryDoyle.

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That's a really good-looking mogul.
Bob

That is a good looking little engine.
1522 was originally built as a coal burner. That didn't last long and she was converted to oil. The bunker is made to fit in the coal space and there is wood "Cushion" that the bunker sits on and is bolted down.  Changes in the firebox would include removing the grates and making a new solid floor lined in firebrick on the floor and extending up the side walls with a space below the front of the firebox for the burner to nest in.  Vent holes are in the sides and front (around the burner) and a damper admitting air at the firebox door.
All netting, etc removed from the smokebox and it's just the nozzle/exhaust stand below the stack.
This is a very simplistic explanation, but should give an idea of how it works.
In the late '40s, Frisco converted some 1500s and 4100s back to coal burners. 1503 and 1514 stick in my mind.

Great posting, thanks.

I believe that this is a Harold Vollrath photo.  If so, please attribute it accordingly.

elueck Wrote:
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> I believe that this is a Harold Vollrath photo. 
> If so, please attribute it accordingly.

I would have already if I knew.
There is no note about who took it.

In general, a round or spherical shape handles pressure better.  Consider this, how many square or rectangular air tanks do you see in railroad applications?  Since tenders aren't designed to be pressure vessels, it seems the transition to rectangular vessels traded more volumn (better) for a stronger seam.