Steam & Excursion > Steam novice questions

On a steam locomotive:

The unit the piston goes into and is connected to the drive wheels is called the engine, correct?

So the UP 4014 has 4 engines and UP 844 has 2 engines?

If a problem occurs in one engine is there a way to "isolate" it by shutting off any steam going to it?

Does the opposite engine (other side) then have to be shut off?

Is there a way to "regulate" the amount of steam going to each engine?

I would think it would be said the 4014 has two and the 844 has or is one. 

The "thing" that the piston goes into is called the cylinder. I've never heard of it referred to as an "engine".  The whole locomotive can be referred to as an engine, as in "steam engine".

jst3751 Wrote:
-------------------------------------------------------
> On a steam locomotive:
>
> The unit the piston goes into and is connected to
> the drive wheels is called the engine, correct?
>
So the UP 4014 has 4 engines and UP 844 has 2
> engines?
>
> If a problem occurs in one engine is there a way
> to "isolate" it by shutting off any steam going to
> it?
>
> Does the opposite engine (other side) then have
> to be shut off?
>
> Is there a way to "regulate" the amount of steam
> going to each engine?

I will let Wes or Hotwater answer this in detail. Look at the simplified diagram I attached. It might help.

---

This I'm sure will be lots of answers in the thread...so here are some:
- I've heard in an articulated locomotive, that it has 2 engines, the front and the back. The front one is articulated and the back one is solid to the boiler/firebox. 
- Each 'engine' in this case, would be the: cylinders, drivers, rods, that has steam applied to make it move the wheels. 
- The front 'engine' usually slips first, as there is a bit less weight on the drivers.
- You cannot control side to side amount of steam into an 'engine'.
- The throttle opens a value, that allows steam to enter the piping into the cylinders, but is not controllable or has another value to isolate one side of the cylinders.

Mike ONeill
Parker, CO

Generally the "engine" term is used on articulateds to denote the front and rear "engine", haven't heard
it used on non-articulated locomotives.

Out

No, there is no way to shut off steam to only one side of the cylinders.
Even if you could the imbalance of forces would probably over stress or crack the cylinder casting.

And you wouldn't want to for any length of time as the steam carries the lubricant into the valves and cytlinders
which allows normal operation as opposed to NO operation after an extended dry period ie you don't want to ask.

Out

PHall Wrote:
-------------------------------------------------------
> No, there is no way to shut off steam to only one
> side of the cylinders.
> Even if you could the imbalance of forces would
> probably over stress or crack the cylinder
> casting.
Then how do explain a J class locomotive running for repairs on one cylinder during the days of steam?
By definitions of physics a steam locomotive is an external combustion engine. The conversion from thermal to mechanical motion in the running gear would be a locomotive's engine.

Dreamer

Posted from Android



Edited 1 time(s). Last edit at 05/07/19 14:24 by Dreamer.

Dreamer Wrote:
-------------------------------------------------------
> PHall Wrote:
> --------------------------------------------------
> -----
> > No, there is no way to shut off steam to only
> one
> > side of the cylinders.
> > Even if you could the imbalance of forces would
> > probably over stress or crack the cylinder
> > casting.
> Then how do explain a J class locomotive running
> for repairs on one cylinder during the days of
> steam?
> By definitions of physics a steam locomotive is an
> external combustion engine. The conversion from
> thermal to mechanical motion in the running gear
> would be a locomotive's engine.
>
> Dreamer

To answer the question about the "J class locomotive running for repairs on one cylinder.....", the Engineer & Fireman could have very easily blocked the valve on the offending side, and then moved the locomotive on on cylinder, as a light move. That said, to answer the question directly about the throttle and steam distribution; there is NO WAY to shut off the steam to one side or the other, at the throttle or throttle header. PERIOD!

By blocking the valve in place you can stop steam flowing to either side of the piston if the valve is in the right position. How else do steam locomotives get the usage of the volumetric expansion of steam without closing the steam flow to both sides? By blocking the valve on this position you stop the steam flow to the piston. Read books on what to do in the event of a break down it's amazing what condition they ran in. The J story was recently replublished about running on one cylinder.

Dreamer


Posted from Android



Edited 1 time(s). Last edit at 05/07/19 15:32 by Dreamer.

Dreamer Wrote:
-------------------------------------------------------
> By blocking the valve in place you can stop steam
> flowing to either side of the piston if the valve
> is in the right position. How else do steam
> locomotives get the usage of the volumetric
> expansion of steam without closing the steam flow
> to both sides? By blocking the valve on this
> position you stop the steam flow to the piston.
> Read books on what to do in the event of a break
> down it's amazing what condition they ran in. The
> J story was recently replublished about running on
> one cylinder.
>
> Dreamer

Is it just me, or are you arguing with yourself?

Its you

Posted from Android

Wow...

Lots of partially-right answers...lots of misconceptions.
Tremendous interest in the subject.

Its great to see the interest.  This misconceptions are typical, weclme to the wonderful world of steam.
I had very similar experiences and questions that puzzled me.
We have wonderful communications today...newbies can learn so much in a very short time.

Lets not denigrate innocent questions and uncertainty about ‘terminology’.....
The terminology will come, but a lot of folks don’t know the basics, so they use the words they know.
Its a new world for our “new fans” to discover.

I will let the dust settle, a little bit.

Wes Camp...
 ( A typical example is that color drawing,  the incorrect component names and the awkwardly drawn, incorrect proportions of the relevant valve gear levers .... That simply generates more confusion.  That’s the opposite education path we want to go down.).

 



Edited 1 time(s). Last edit at 05/07/19 16:24 by wcamp1472.

      I believe it is a situation of "I have already made up my mind so DO NOT confuse me with any of your facts from experience."

      I ran into a lot of that in the oil and gas industry. Same people that could not tie their shoes because the process was confusing to them.

Ah c'mon Wes, just because the valve spool in the drawing won't shift far enough to double act
the cylinder?

Out

OUCH!!!

On the drawing, the driver cranks are on the same side as the counterweights...
WHY IS THAT INCORRECT?

WTF?

​W.

Ooh, engineer seat with built in vibro massage, nice feature.

Out

The way my father taught me (and he should know. He worked on them most of his railroad career.) was that each cylinder (With piston and valves) along with the attached valve gear is considered an engine. Therefore the 844 has 2 engines (one on each side) and the 4014 has 4 engines (2 on each side). The boiler is just that...The boiler... and is really not considered as an engine. However, the whole assembly is and has been called a steam engine. Probably dating back 175 years or so when the first locomotive had only ONE engine.

re: ‘vibro massage’

It took me a while...but, I finally GOT  IT!

W.



Edited 2 time(s). Last edit at 05/07/19 18:15 by wcamp1472.