Skip to main content

Replies sorted oldest to newest

Perhaps the greater difficulty with the 9000's was their ridgid wheelbase. I recall a long ago picture of UP crews trying to get the #9000 through the tight curves of Cajon Pass, while heading to Los Angeles for display in 1956. It eventually made it after much greasing of rail and a number of fellows on the ground watching for driver "chatter". She is on display at the LA Fairgrounds in Pomona. A 9000 was clearly a mainline locomotive! Interestingly, if memory serves, they ran regularly up to 60 mph, so track damage pretty clearly was not a problem.

       Howard Fogg produced some steam locomotive recordings in the 1960's, one of which was "the big steam......UNION PACIFIC". One cut on this record has the #9009 easing around a freight derailment in 1954, then, later, paced side by side, where it sounded like she was doing around 50 mph. Fogg commented, "those 9000's did a lot of clanking and banging"!

Originally Posted by DominicMazoch:

Now SP and UP did have 4-10-2's.  I remember reading this book called THREE BARRELS OF STEAM.  If I remember correctly, one rebuilt their 4-10-2's into a more conventional locomotives.  which one was it?

It was UP which rebuilt its ten 8800 class three cylinder 4-10-2's into two cylinder 5090 class locos.  As designed, the 8000 (later 8800) class 4-10-2's were almost identical in specifications (driver diameter, boiler size and pressure, grate, etc.) to their 5000 class 2-10-2 in order to compare as closely as possible the difference in performance of two versus three cylinder arrangements.  Because of this it wasn't tpp difficult to convert the 4-10-2's to two cylinder operation.

 

Stuart

  By the late 1930's, the UP had 10 3-cylinder 4-10-2's that were showing their ages. The Los Angeles & Salt Lake needed fast heavy freight locomotives to meet ever-increasing speeds by the competition. But the "Overlands" couldn't deliver. Otto Jabelmann had become head of the Research and Mechanical Standards Department that he had created in 1937. Around March, 1939, the federal government requested railroads to assess their motive power in light of an anticipated surge in hot/fast/higher-speed freight traffic.

  In the 1920's, with exclusive rights to Gresley valve gear in America, ALCo had trumpeted advantages of 3-cylinder power - more tractive effort at speed with little increase in axle loadings. The UP acquired the 4-10-2's in preparation for the 4-12-2's. To meet demands of surging traffic, the 4-10-2's looked good; the 4-12-2's, even better. A total of 88 4-12-2's were delivered between 1926 and 1930. Then the Great Depression began, and maintenance costs for 3-cylinder power began to mount. In brief, piston thrusts wore bearings on the center rods, but they were difficult and time-consuming to repair. Scroll up to the photo of No. 9000 and imagine getting down beneath the frame and working on the crosshead and crank on the second driving axle. As wear increased, out-of-balance forces made things worse. But apparently there was no damage to the track, probably because the UP had installed 100-pound rails.

  Only the last 25 (UP-5) had cast frames, and no 4-12-2 ever had roller bearings on axles. It took 18 years for roller bearings to be installed on pivot points on Gresley valve gear. But 88 heavy freight locomotives could not be written off the roster and replaced, especially with the Pacific theater in World War II looming on the horizon.

  Otto Jablemann disliked 3-cylinder power. The need for faster, reliable locomotives for the desert district gave him the opportunity to do something with the 10 Overlands, preferably tilting the scales in favor of new power. His original proposal specified conversion to 2 cylinders, cast steel frames with integral cylinders, roller bearings on all engine axles, an increase to 235 lbs. boiler pressure, and other refinements, at a cost of $128,456 each. Jabelmann thought that would put the UP's New York office off, and he was right. Eventually the NY office approved bolting new cast cylinders to the original frames, upgrading the running gear, and increasing the boiler pressure to 230 lbs.

   Jabelmann wrote motive power history with 4-cylinder Challengers and Big Boys and the final FEF-3's, concluding with No. 844. These locomotives delivered what 3-cylinder locomotives had promised, but with everything outside and accessible. They had cast frrames and roller bearings, too.

 

Last edited by ReadingFan
Post
×
×
×
×
Link copied to your clipboard.
×
×