This type of valve gear is usually exclusively associated with stationary engines. But, Franco-Belge built a Garrett 4-6-2+2-6-4 for PLM
of Algeria that had Corliss valve gear.

You can see them on top of the cylinders in the linked picture of 231-132BT1 below. The picture is from Gavin Hamilton's excellant website on Garrett locomotives.

One type of steam engine that did use Young valve gear almost exclusively was the humble duplex steam pump. It had no need for a reverser gear; so it was the ultimate in simplicity.

-James Hefner
Hebrews 10:20a

The Garrett Locomotive

james@survivingworldsteam.com

James,

These engines actually had Cossart valves, which were similar to poppet valves. Several classes of French steam locomotives used them. This arrangement had two vertically-oriented piston valves at each end of the cylinder, 1 for exhaust and 1 for admission at each end of the cylinder, and they were actuated by cams. The odd-ball looking rod connected to the eccentric on each side of the engine actually turns a crank on the end of a camshaft which runs above the cylinders. The valve rods are large so that they provide partial balancing for the weight of the reciprocating parts (pistons, crossheads, etc.). There's a French name for these rods but I have no idea what it is (this was discussed on the steam_tech list in the last few months).

These Algerian engines were even more unique in that an electric servo motor was used to change the valve cutoff setting. Unfortunately, they were delivered just before WWII, and suffered greatly from neglect during the war.

Corliss valves IIRC are rotary valves and while they could look externally similar to Cossarts, are actually very different internally.

Best Regards,
Hugh Odom

> This type of valve gear is usually
> exclusively associated with stationary
> engines. But, Franco-Belge built a Garrett
> 4-6-2+2-6-4 for PLM
> of Algeria that had Corliss valve gear.



The Ultimate Steam Page
whodom2001@yahoo.com

> James,

> These engines actually had Cossart valves,
> which were similar to poppet valves. Several
> classes of French steam locomotives used
> them. This arrangement had two
> vertically-oriented piston valves at each
> end of the cylinder, 1 for exhaust and 1 for
> admission at each end of the cylinder, and
> they were actuated by cams. The odd-ball
> looking rod connected to the eccentric on
> each side of the engine actually turns a
> crank on the end of a camshaft which runs
> above the cylinders. The valve rods are
> large so that they provide partial balancing
> for the weight of the reciprocating parts
> (pistons, crossheads, etc.). There's a
> French name for these rods but I have no
> idea what it is (this was discussed on the
> steam_tech list in the last few months).

> These Algerian engines were even more unique
> in that an electric servo motor was used to
> change the valve cutoff setting.
> Unfortunately, they were delivered just
> before WWII, and suffered greatly from
> neglect during the war.

> Corliss valves IIRC are rotary valves and
> while they could look externally similar to
> Cossarts, are actually very different
> internally.

> Best Regards,
> Hugh Odom

Yes you are correct about this loco. However there were a few locs built with corless valves. See old loco cylpdes. I have seen a pix of a CPR g2 4-6-2 with corless valves of about 1912 to 1916 or so. I think it lasted about 1 year. That type of valve does not like superheat. bb

I'm not sure if it will help, but you might look for a copy of Fred Jukes' book "One Hundred One Valve Motions," published by the R&LHS. It has no date, but the contents are reprints of articles originally found in R&LHS Bulletins 88, 89, 90, & 91. It has diagrams and discussion of 101 different varieties of valve motion, as the title suggests.

rdgoldfede@aol.com