odd photo

[NW Mailing List]

I don't know why my fingers went to the "L", shoulda been the "Z"
I have an NKP model L1a, Confuscious say I'm Confusced...

yah, they're compounds, I relooked, I have a model of the Z1a, scoured 
the Prince pics, there are apparently 2 versions of a Z1a, one pic has 
just HUGE front cylinders vs the earlier Z1a, perhaps this was the remod 
back to the slide valve but not changing the front pistons as they were 
the one piece frame/cylinder body, maybe they shoulda called it the Z1A, 
(vs Z1a...see what I did there, huh huh)  when you say that its 
"Z1AAAaaaeeeeee"

They mention some clearance issues with the front cylinders like that.

The book also mentions since the Y's displaced the Z's in mainline 
running they got bumped to switching service and some mine runs, been 
trying to figure out how to use my model, now I know with along the 
M2c's I have.

-Lynn-

On 5/18/2015 8:23 AM, nw-mailing-list-request at nwhs.org wrote:
> Subject:
> Re: odd photo
> From:
> NW Mailing List <nw-mailing-list at nwhs.org>
> Date:
> 5/17/2015 8:58 AM
>
> To:
> nw-mailing-list at nwhs.org
>
>
> Lynn:
> Please re-read Prince's book.  The Z1s, a and b, (not "L") were ALL 
> compound engines.  The Z1 and Z1a were built with slide-valve low 
> pressure cylinders.  Those rebuilt to Z1b got piston valve low 
> pressure cylinders; there may have been other improvements, too, but 
> others more knowledgeable about such details can fill that in.
> There was one (1) fully simple Z, class Z2, No. 1399.
> This link http://www.steamlocomotive.com/2-6-6-2/?page=nw is helpful.
> Dave Phelps
> In a message dated 5/17/2015 8:08:42 A.M. Eastern Daylight Time, 
> nw-mailing-list at nwhs.org writes:
>
>     I can verify reading princes book 1331 is the lowest numbered
>     engine to get the treatment from an L1a to an L1b. N&W is no
>     stranger to reworking their engines, The point is about the L1b it
>     has low pressure front cylinders, while the L1a is basically a
>     full simple engine.
>     This is about grinding on the mountains to move that coal at low
>     speed. The simple engines could move faster. The reason why is the
>     larger cylinders at higher speed cause reverse pressures which
>     does not work well for higher speeds, but low speeds are fine, why
>     the Y class compound development, drag that freight over them
>     mountains.
>     N&W could probably pick and choose the best engines in condition
>     to take the modification and last many more years, and that they
>     did with all of their steam lineup, but again other lower end
>     steamers met the scrappers torch while steam technology advanced. 
>     The Roanoke shops were very talented keeping the steam fleet alive
>     why many of the older engines lasted to the end. M2c's built in
>     1917 still working in 1958? wotta run.
>

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