[modeleng] Re: Rotary Throttle Questions

Hi Harry

This query deserves an answer but as no-one else has replied, I'll have a 
go.  The degree of movement on a regulator handle obviously varies from 
engine to engine, but 60 degrees sounds about right.  The direction of 
opening depends on whether the engine is left or right hand drive.

Up until the time of the grouping in 1923, about half of the railway 
companies in the UK used left hand drive, and the other half, right hand 
drive.  Shortly after the formation of the "big four", the LMS, LNER and 
Southern standardised on left hand drive, whilst the GWR stuck to right hand 
drive.  All of the locomotives built after nationalisation in 1948 were left 
hand drive.

When engines had small boilers, the regulator handle usually pointed upwards 
and the driver pushed it away from him to open, and pulled it towards him to 
close.  As the size of boilers increased, the regulator handle was turned 
downwards so that the driver lifted it up to open, and pushed it down to 
close.

Some engines, notably the LNER pacifics and the BR standards, had a 
fore-and-aft regulator handle which the driver pulled backward to open, and 
pushed forward to close.

Yer pays yer money and takes yer choice!

Regards
Ron

----- Original Message ----- 
From: "Harry Wade" <hww@xxxxxxxx>
To: <modeleng@xxxxxxxxxxxxx>
Sent: Monday, March 27, 2006 3:41 PM
Subject: [modeleng] Rotary Throttle Questions


> List,
>       I'm in the process of designing a Stroudley-type dome throttle
> mechanism for a 7+ga loco and I realized I've never come across mention of
> a typical range motion in degrees for British rotary throttles.  No doubt
> this varied from shed to shed and loco to loco but I'd like to know so as
> to be somewhere in the general vicinity.  Left to myself I probably would
> guess at 45 degrees to no more than 60.  What was typical?
>      Also was there a rotation convention?  CW open/CCW shut?  CCW open/CW
> shut?
>
>
> Regards,
> Harry Wade
> Nashville  Tennessee
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