two questions about steam

nw-mailing-list at nw-mailing-list at
Fri Mar 3 20:59:26 EST 2006

The design and use of the N&W's tenders were just as exemplary as its steam

Bud Jeffries

----- Original Message -----
From: <nw-mailing-list at>
To: <nw-mailing-list at>
Sent: Thursday, March 02, 2006 1:21 PM
Subject: Re: two questions about steam

Thanks to Dave Stephenson, Bud Jeffries, and Bill Sellers for their superb
answers to this newbie's questions. Bud, here I thought the empty tender
weight was heavy, but it turns out it was light relative to other railroads.
Bill, thanks for the great explanation of automatic stokers. With Dave
turning up the 1947 N&W study on the steaming efficiency of sized coal, both
questions seem to have pointed out just how well N&W had their act together.

Tom Leuthner


Message: 4
Date: Wed, 01 Mar 2006 23:00:31 -0500
From: nw-mailing-list at
Subject: Coal Size
To: nw-mailing-list at
Message-ID: < at>
Content-Type: text/plain; charset="us-ascii"

To the gentleman asking about the size of coal in a tender. As a former
locomotive fireman, the size of coal lumps was of no consequence. They
varied from egg-sized up to nearly the size of a football. Using a
HT Type stoker, a lump of coal falls into the coal trough in the floor of
the tender where it comes into contact with a screw or auger powered by a
cylinder steam engine to begin it's 12 to 14 foot journey to the jet plate
located in the firebox just below the butterfly door. As the coal is forced
through the round chute by the auger, it is crushed into smaller pieces much
;like meat going through a meatgrinder. When it reaches the entrance to the
firebox all of it is reduced to about the size of marbles as it falls on the
jet plate where air pressure blows or distributes these pieces of coal to
various locations in the firebox determined by vertical "wings" on the jet
plate. The fireman determines how strong the pressure is on each section of
the jet plate
with the use of 6 valve handles positioned in a "V" shape just below
main stoker valve that controls the speed at which the stoker engine
The biggest headache in using a Standard HT Type stoker is wet coal, that
falls on the jet plate as so much mud. This tends to build up a hard crust
on the jet plate which is loosened by a tool on the engine known as a jet
It is curved similar to a fish hook, and the fireman opens the fire door and
pulls the point back toward him to loosen this residue buildup. In the
case of a shovel fired locomotive, a tender full of egg -sized coal is
perfect to fire a locomotive. Again, to answer your question, on a stoker
locomotive coal size is of no consequence. Bill Sellers.

NW-Mailing-List at
To change your subscription go to

More information about the NW-Mailing-List mailing list