> Yes ray is right most of the time he is. I
> found the info on the UP 9000. In the 1930
> loco cylp. pg. 260-262 look it up for your
> self. Why is it we are so lazy we can't take
> the time to look up the real deal. And we
> just say what we think it must be. Hint read
> a good book to night. regards bb

Sorry Guys, I got in on this a little late. During WW-2 I rode some 8 trips behind engines of the 9000 class between Topeka and North Platte
delivering new cabooses from the Mt Vernon Car Plant to the UP at North Platte.
It has been awhile but I'm sure I remembered a
"Waltz Time" exhaust which would indicate three
simple cylinders.
I also remember when on one trip we were jogging along about 25 mhp and the engineer went to sleep and ran past a flag a gravel train had out. When
he hit the torpedoes he wiped the slate and in
the cabooses at the rear end we went from 25 mph to a dead stop in one deafening crash. I was all
cleaned uo ready to get off at NPlatte and out there some were is a 3700 series UP caboose with
the heel prints of my new shoes in the cupola end wall.

Jim

rrfanjim@mvn.net

One thing that may be easily confused with the UP 9000 class was the Baldwin demonstrator #90,000 which was a 3 cylinder compound.
Roger Mitchell

n0mcr@netzero.net

> One thing that may be easily confused with
> the UP 9000 class was the Baldwin
> demonstrator #90,000 which was a 3 cylinder
> compound.
> Roger Mitchell
Yes thats right. Was the 60000 the only large 3 cy l. compound?. btw you can see it in phli. pa.regards bb

staybolt2@netscape.net

Sorry, been out of town. Humble apologies given, Bruce.

Matt.

To: mjanssen@sunvalley.net
Subject: UP 4-12-2

Matt:

Humble apologies requested, because, actually, Matt, you are wrong.

My copy of Alfred W. Bruce's The Steam Locomotive in America

shows 27" x 31" & 32" for cylinder sizes (i.e. same 27" bore on all three cylinders), with 96,000 lbs. tractive effort at 220 psi with 67" wheels.for U.P. 9000, and his text makes no mention of compounding.

For comparison, to get to 96,000 lbs. T.E. with 80 percent cutoff, PRR's Class I1sa used 30-1/2" x 32" cylinders at 250 psi with 62" wheels.

Do the arithmetic. Compare the working cylinder volumes, driver diameters and boiler pressures. At only 220 psi boiler pressure, and because of the problem of back pressure in a high pressure cylinder feeding a receiver to the low pressure cylinders, 96,000 lbs. of tractive effort with 67" drivers would be impossible on the UP 9000 unless all three cylinders operated simple only. If it were to have run compound it would have needed much bigger cylinders because maximum net working pressure in the high pressure cylinder would be 220 psi minus the working pressure in the low pressure cylinders.

Alfred W. Bruce was Chief Engineer at ALCO. Since he designed the U.P. 9000, I trust his numbers. Krattville Publishing is well-known for inaccuracy.

Note that, since I'm not a flamer, I am e-mailing you directly.

But I am a licensed Mechanical Engineer, and I do request that you post an apology on the RyPN Interchange.

Bruce Manwiller

___________________________________________________________


mjanssen@sunvalley.net

Sorry, been out of town. Humble apologies given, Bruce.
Matt.

mjanssen@sunvalley.net