Steam & Excursion > NYC RR Steam Engine Question - *Follow Up

I've seen photos taken in the 1880's such as this (NYC&HR RR 472) of NYC steam power and wondering what that extended smokebox is all about.
Anyone have any details or information ?
It didn't seem to last long, at least from photos I can find.
Thanks

George M. Sitting photo from Steam Locomotives of the New York Central Lines by Edson and Vail; Vol. 1



Edited 2 time(s). Last edit at 02/08/23 13:02 by train1275.

---

As a 'base' for that immense, acetylene headlight?
Without that extension, what would the headlight supports look like ?
There seems to be 'deck braces',  too?

W.

 

Built as a wood burner with a diamond stack.  Converted to burn coal fuel and extended smokebox was added for the netting to replace the diamond stack.

-LD

LarryDoyle Wrote:
-------------------------------------------------------
> Built as a wood burner with a diamond stack. 
> Converted to burn coal fuel and extended smokebox
> was added for the netting to replace the diamond
> stack.
>
> -LD

Thanks

As usual, Larry has the answer.

Victor Baird


LarryDoyle Wrote:
-------------------------------------------------------
> Built as a wood burner with a diamond stack. 
> Converted to burn coal fuel and extended smokebox
> was added for the netting to replace the diamond
> stack.
>
> -LD

At first glance Wes' answer makes more sense.

Out 

Well I was figuring that Larry was correct, BUT looking at more history of the locomotive, it was built in 1883 by Schenectady c/n 1714. Doubtful the NYC would have been ordering wood burners at that time. Also there is a reference to Richardson Balanced Valves. That is a new one on me. Anybody know anything about Richardson Valves ? 
NYC 472 was originally numbered 533, renumbered to 472 in 1890. 

 



Edited 1 time(s). Last edit at 02/08/23 13:03 by train1275.

train1275 Wrote:
-------------------------------------------------------
> Well I was figuring that Larry was correct, BUT
> looking at more history of the locomotive, it was
> built in 1883 by Schenectady c/n 1714. Doubtful
> the NYC would have been ordering wood burners at
> that time. Also there is a reference to Richardson
> Balanced Valves. That is a new one on me. Anybody
> know anything about Richardson Valves ? 

The Richardson Balanced Slide Valve is the standard plain vanilla slide valve widely used on locomotives after about 1880 until superheating came into use..

The rectange of balancing strips and wearing plate on the top of the valve reduced the amount of the friction on the wearing surfaces.

-LD

---

I'll take a stab at 'balanced' slide valves.

Originally, steam was directed to the pistons, and then exhausted
up tha stack at the end of a power stroke.

So the directing of the steam for useful purposes, meant using 
a timing scheme to open the steam ports at the proper stages and piston position.

At the ends of the loco cylinders there is a port ( passage) between the cylinder and the 
valve housing, above the cylinder.  The directing of the steam flow is controlled by a box-like
cast iron, sliding valve the covers the steam ports --- leading to the pistons.

The 'slide valve' rides on a fiat 'valve seat'...the flat seat has rectangular ports
that direct the steam TO and FROM the face of the piston.

The box is hollow on it's bottom... closed in by 4 sides, and a flat top. 
The bottom of the box rides over-top of a central, rectangular, exhsust port 
that is the entrance to the passage that goes to the base of the smoke stack..
There is only very slight pressure in the exhaust passages, under the slide valve,
and up the stack. 

The slide valve is moved by cams on a drive axle, and it slides back and
forth over the central exhaust port.  At the end of piston stroke,
the open, inverted, valve-box connects the port leading from the cylinder
to the central, exhaust, port in the 'port-plate'... The ports alternate communication
with piston ports and the centeral ' exhsust passage' leading to the base of
the engine's 'stack.

At the opposite end of the cylinder, the box valve has opened the port to that
piston face to the flow of live steam supplied by the boiler..

The box-like valve always has pressure on its back, whenever the throttle is opened.
With low pressure under the bottom, and boiler pressure on top of the box,
the pressure forces the slide valve, forcefully, onto the flat port face, that the
slide valve moves on. 

As boiler pressures increased, the drag forces between the flat valve 'box' 
became immense ,,, like a boiler running at 200 psi, could have a very high 
figure of square-inches exposed to boiler pressure. Tons of pressure!

With such great drag-forces, it became very dangerous to unlatch the 
engineer's 'reverese' lever ( which also allows him to shorten the admission
timing ) ... so, engineers left the valve gear in full-forward, for most of a trip.

A solution was to design a box valve with more equal pressures on its 
steam supply-side and the lower side --- always connected to the central port 
that leads to the exhaust stack & base.

The general approach was to surround the back side of tte slide valve with
a fixed wall that covered most of the back of tne box-valve.  That space inside the
'walls' was also connected to the exhaust passage.  Many various schemes 
were developed and patented, that covered these 'balanced' slide valve schemes.

So, you'll find the names of the designers of the varoius, patented, solutions attached 
to their design variants..

Part of the success of the slide valves was the percentage of heat-saturated steam 
that condensed into water on the way to the pistons and at the pistons , as they moved
down the cylinders...continual expansion lowers the temperature...and more steam
condenses into water , .. the presence of water aided the movement of the slide valves 
on the port plates.

When superheating was tired .... no steam condensed into water,  until out
the smoke stack.... thus, the days if the high-friction slide valves was OVER!

What came next started an explosion in higher powered engines of the 20th
century.  Dawn of the dramatic benefits and the challenging design problems 
of superheating.

Remember: Saturated Steam is a term relating to the temperature of the steam
in the boiler & is the same as the temperature of the boiling water, in that boiler.
The steam is "heat-saturated".... it can be very dry, and have no water
vapor; but, it's still the same temperature as the water that's boiling..

Adding more fuel does NOT raise the steam temperature --- it boils 
at a faster rate; but, not at a higher temperature.

There will be a final exam...with essay questions...

​W.
 
 



Edited 1 time(s). Last edit at 02/08/23 14:15 by wcamp1472.

Thanks guys !

A key part of the drawing ( the side view of the slide valve) above,
is not very discernible...   At the very top of the curve of the slide-valve
is a barely visible 'hole' connecting the two spaces --- above & below.  

Thus, the pressure inside the 4 ' packing strips' ( on the back of the slide valve)
is about the same as the pressure in the exhaust passages to the base
of the 'stack..

Thus, the slide valve is partially 'balanced' ( low pressure on both sides);
but, there's enough live-steam exposed area to keep the slide valve firmly
forced onto the port-plate, that it rides on.

W.

( The '4-strips' are not steam-tight, so the hole at the top of the
   sliding valve vents any steam that leaks around the 4 "packing strips") .



Edited 7 time(s). Last edit at 02/08/23 17:56 by wcamp1472.

You got me on that. Yes, it would be a little late for NYC to have a new woodburner. And often the extended smokeboxes were longer than that in the photo.

Victor Baird

train1275 Wrote:
-------------------------------------------------------
> Well I was figuring that Larry was correct, BUT
> looking at more history of the locomotive, it was
> built in 1883 by Schenectady c/n 1714. Doubtful
> the NYC would have been ordering wood burners at
> that time. Also there is a reference to Richardson
> Balanced Valves. That is a new one on me. Anybody
> know anything about Richardson Valves ? 
> NYC 472 was originally numbered 533, renumbered to
> 472 in 1890. 
>
>  



Edited 1 time(s). Last edit at 02/08/23 19:16 by wabash2800.