WAS: THE ARROW and TAF now valve setting

Thu Feb 1 11:39:48 EST 2018

Greetings from the UK,

This task was undertaken even in the latter days of modern steam in the UK with fitters and valve specialists using oil or candle light to make the valve adjustments. I think the valve setting was one of the most precise items on a steam loco and could seriously influence power output and efficiency. 

The three cylinder locomotives (Mallard, Flying Scotsman) had a very syncopated beat when working hard but they had a complex derived motion for the inner cylinder which could, and did, work loose in the intervals between shopping. They then developed a very characteristic exhaust sound. Cranks were at 120 degrees. Some experimentation with crank angles did not seem to make a huge difference. The use of poppet valves with external shaft drives was advocated and supported by some but loathed by others. The re-activated Duke of Gloucester has this valve gear and is a superb performer.

Phil Mortimer  

From: NW-Mailing-List [mailto:nw-mailing-list-bounces at nwhs.org] On Behalf Of NW Mailing List via NW-Mailing-List
Sent: Thursday, February 1, 2018 2:34 PM
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Cc: NW Mailing List
Subject: Re: WAS: THE ARROW and TAF now valve setting

Was hoping Ed would make a comment - He probably either knew or helped some of N&Ws valve setters - Ron H

On Saturday, January 27, 2018 6:35 AM, NW Mailing List <nw-mailing-list at nwhs.org> wrote:

Not really sure what you mean by “top dead center” since I always thought there was a front and back dead centers (unless you have a vertical steam engine).  If you really need to get tight about it, you’ll find that the front and back dead centers are not 180 degrees apart unless the center line of the piston rod coincides with the center line of the driving wheels, a situation rarely seen.

EdKing

From: NW Mailing List 

Sent: Friday, January 26, 2018 4:48 PM

To: NW Mailing List 

Subject: WAS: THE ARROW and TAF now valve setting

Ron, et al

Cannot answer your very specific question about N&W shop practice.  It is unlikely that it was a job entrusted to a single individual. 

However, last year as my wife prowled the vendor stands at the Cabin Fever Model Engineering Expo, she found a small 104 page book entitled "Locomotive Valve Setting" by Frank Williams, Mechanical Designer for Canadian National Railways.  It is volume 505C of a series published by the International Text Book Company of Scranton, PA.   As I own several live steam locomotives in scales including 1:32, 1:20.3, 1 in/ft, and 1.5 in/ft; she felt this was an essential addition to my library.  

It has more than I really need to set the timing on my relatively small locomotives, but I gained much insight into various valve gears and how they actually work.  Of course, "Da' Boss" did not know I already had three other books on the subject.  It is worthwhile have more than one book on a subject like this as some explanations are more clear than others. 

I will freely admit that I rotate my drivers to achieve "top dead center" and other positions to set the valve events.   Even with marks on the ports and valves, I am not sure how I would accurately set everything on both sides without moving the valve motion. 

I am sure some "old head" has the real answer as to if it can be done.  

Sent from my digital telegraph key 

Jim Stapleton

On Jan 26, 2018, at 14:38, NW Mailing List via NW-Mailing-List <nw-mailing-list at nwhs.org> wrote:

Yeah Larry, probably "job security" too , Ron H

On Friday, January 26, 2018 10:25 AM, NW Mailing List <nw-mailing-list at nwhs.org> wrote:

Ron

       There’s a great mystic about valve setters, I have talked to old timers about this. I think in the trades and crafts knowledge was power.

Not down playing it in anyway but it was just good mechanical and machinist skills. Google Books have the books already mentioned .and a haft a dozen

others on valve setting more than you will ever want to know on the subject.

Larry Evans

Kenova ,WV

From: NW-Mailing-List [mailto:nw-mailing-list-bounces at nwhs.org] On Behalf Of NW Mailing List
Sent: Wednesday, January 24, 2018 12:03 PM
To: NW Mailing List <nw-mailing-list at nwhs.org>
Subject: Re: THE ARROW and TAF

Ron

Your question may well be one that no one is positive on an answer to is why you have not gotten a response.

Your question:

When steam locomotives had a complete overhaul, and was re assembled, did only one trained mechanic set the valve assembly without moving or rotating the wheels, and how did he do it ?

Those questions are for the folks who have restored steam today and how it is handled. My guess for steam era valve setting was handled with several folks, one lead person and some helpers. It is a science.

I remember "Pappy" Houseman with the 611 restoration in 1982, he knew all the details from all those years ago.

Best

Ken Miller

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