[modeleng] Re: Slide valves

Peter et al,

The high pressure of superheated engines caused problems with the slide 
valves abrading their seats and wearing rapidly as well as making them hard 
to move which wore the valve linkage excessivly.  Possibly the Pom poms, had 
balanced slide valves?  If so that would have enabled the engines to operate 
with superheated steam - - - - I think.  Well, it sounds like a good idea to 
me anyway!

Jesse the Redneck machinist in Troy, TN


----- Original Message ----- 
From: <peter.chadwick@xxxxxxxxxxx>
To: <modeleng@xxxxxxxxxxxxx>
Sent: Wednesday, April 08, 2009 4:14 AM
Subject: [modeleng] Slide valves


> In 12 inch to the foot gauge, it appears from the various writings that
> slide valves were not too good with superheated steam. Why?
> Just to complicate matters, a lot of the GC Pom poms had slide valves and
> superheated steam,and they were not an unsuccesful design, especially
> considering the longevity of the class.
>
> In the late 1950's, it was usually a Pom pom on the 4.50 from Retford to
> Sheffield; not a very well patronised service from Retford to Worksop, and
> so it was good for clandestine meetings with the girls from the High
> School. Strange how age gets you: I remember more of what the Pom pom s
> looked like than the individual girls!
>
> Peter Chadwick, Swindon
>
>
> ----------
> Zarlink Semiconductor Limited is a Company registered in England and Wales
> under number 00705031 with its registered office at Cheney Manor, Swindon,
> Wilts SN2 2QW, England.
>
> This email is confidential and may contain information that is privileged 
> and
> exempt from disclosure by law.  If you have received it in error, please 
> contact
> the sender immediately by return email and then delete it from your 
> system; you
> should not copy it or disclose its contents to anyone.  Emails are not 
> secure
> and cannot be guaranteed to be error free as they can be intercepted, 
> amended,
> lost or destroyed, or contain viruses.  Anyone who communicates with us by 
> email
> is taken to accept these risks.
>
>
> MODEL ENGINEERING DISCUSSION LIST.
>
> To UNSUBSCRIBE from this list, send a blank email to,
> modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject 
> line.


--------------------------------------------------------------------------------



No virus found in this incoming message.
Checked by AVG - www.avg.com
Version: 8.0.238 / Virus Database: 270.11.47/2047 - Release Date: 04/08/09 
05:53:00

MODEL ENGINEERING DISCUSSION LIST.

To UNSUBSCRIBE from this list, send a blank email to, 
modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject line.

Other related posts: