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Union Pacific's Super 800s

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This page was last updated on December 9, 2014.

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(excerpted from "Monarchs of the West," by William Kratville, published in Steam Glory, 2004, Kalmbach)

Super 800's, 1942 Version

In 1942, Otto Jabelmann, Union Pacific's Vice President of Research and Mechanical Design since mid-1939, directed his staff to began work on a better, dual-service steam design. As an aside, he also said, "We know we're going to the diesel after the war, but we have to lay out a steam proposal too."

First the existing locomotive fleet was reviewed and the decision to go with a 4-8-4 rather than an articulated was made, because an articulated would be costlier to maintain and total lengths would be difficult to accommodate systemwide without turntable and roundhouse expansions.

The emphasis was on keeping with the Jabelmann theory -- standardize to the fullest to achieve the lowest possible maintenance and operating costs. In line with this thinking was a thorough evaluation of all items then in use on the road's modern power.

The new power did not necessarily have to be bigger, but it did have to be better: However, the demands of freight consists were not the same as those of passenger trains. So to be a dual-service type as desired by Jeffers, boiler size and efficiency were critical to sufficient steam supply.

It was found that the most efficient boiler on the UP was that used on the FEF-2's and 3's. Although calculations were developed for larger boilers, the final conclusion was that the boiler would be sufficient if the firebox could be slightly increased in size and the combustion chamber given enough size to allow efficient gas travel.

A larger firebox meant use of the MB stoker to assure adequate coal delivery to all locations in the firebox. The Northwest and South Central districts were oil territory, so the use of new power there would require some of the engines to be equipped as oil burners. Instead, any new power would go only to the Nebraska and Wyoming divisions, with some Challengers released for oil conversion and reassignment. The smokebox size was not changed but there was many a debate over the exhaust system. For years the road had been experimenting with various frontend designs. Leonard Botteron's efforts to reduce back pressure by opening up the steam passages was taken a step further; and the 1942 preliminary design proposed four smokestacks.

As with the existing 800's, frames and cylinders were to be integrally cast and no changes in size envisioned. The 80-inch driving-wheel size was retained in the interests of standardization and because no increase in speeds was anticipated.

The new engines would have Walschaerts valve gear with Franklin reverse gear. The throttle was of the front-end type. The pilot, trailing, and tender truck wheels were all of 42-inch diameter, the largest possible. All these features matched big 800 specs.

Jabelmann had long wanted the full use of roller bearings, a desire influenced by his study of Norfolk & Western practices. However, others in the mechanical department had always thwarted his desire to fully utilize them. On the 1942 design, Jabelmann was at last able to specify roller bearings throughout. (ed. note: This date in 1942 is slightly misleading, as the concept of roller bearings on all axles was first delivered in 1937 with the FEF-1 class.)

The air-brake system would feature integral cast reservoirs and the compressors would be mounted on the pilot deck. Aftercooling would feature the Wilson sump design which eliminated the maze of piping common on most power. The team wanted to keep the general appearance clean.

The pilot was to be the latest version of the massive GSC retractable coupler model. It had been found that the GSC (with gate closed) gave the best possible deflective protection in grade-crossing collisions.

A unique feature was to be a revolving light mounted on a bracket above the standard Pyle-National headlight. This "safety" light idea was initiated by the success of the Streamliner lighting and was to be activated by a pressure switch incorporated in the air-brake line, the relay being activated when an emergency application was made. The light would be red in emergency situations and white during normal use.

Two tender designs were considered. One would utilize a four-axle truck at each end, while the other would retain the famous "centipede" design. UP's Transportation Department did not like the centipede because of derailments caused by its longer rigid wheelbase, but the load factor was better with this design, so the individual truck idea was discarded.

The use of a full vestibule cab was also discussed, but it was initially believed difficult to employ such a design because of clearance restrictions, so the idea was shelved.

The final design was a 4-8-4 with highly standardized parts, clean lines, and proven appliances and design. It would have developed approximately the same horsepower as the big 800's, but would operate more efficiently in both freight and passenger service.

When the calculations were finished, they were reviewed by Jabelmann and his staff and sent to Jeffers. By this time Jeffers was busy as the nation's wartime "Rubber Czar" and the plans went mostly unnoticed. They were finally filed away for "postwar projects." In the following year, 1943, UP lost its motive-power genius when Jabelmann died suddenly on a government trip to Britain.

Super 800's, 1945 Version

The super 4-8-4 project was revived in August 1945, as the war was almost over and the builders had begun directing their efforts toward diesel production. Jeffers was preparing to step down but still was very much in command, so the steam ideas were pushed to the top of the list as "designs for a new high-speed freight locomotive."

The initial step was to roll out the 1942 specs. A larger firebox was laid out with a larger boiler and the smokebox dimensions increased correspondingly. All this required a longer frame, increasing total engine length. Adjustments would have to be made in certain terminal and mainline curvature.

Boiler tube and flue quantities had been virtually reversed in the FEF-3's of 1944, resulting in a net loss of evaporating and superheat surfaces. The new power would again reverse the flue-tube quantity to allow greatest possible evaporative surface. The MB stoker was retained and additional arch capacity incorporated. The combustion chamber was redesigned for the larger boiler and firebox values.

Boiler efficiencies were to be aided by use of the Type A superheater, which had proven easier to maintain than the Type E. Water delivery was to be through a Worthington SA unit, found to be successful on the 835's.

The net effect of the changes would be to produce a locomotive with adequate steam supply for the service intended. The GSC pilot would be used with the same arrangement for air pumps and aftercooling.

On the new design, a Canadian National short-type smoke wing was planned, as were overfire jets.

Steam admission was discussed, and the road had watched with interest various attempts to employ poppet valves. UP's own poppet experience dated to 1929 and a stint with the Caprotti gear; the experiment ending in the usual problem of the gear not being able to withstand U.S. conditions.

There was much discussion over coal or oil firing, but with oil becoming more readily available at terminals, that fuel was preferred. This would eliminate the planned MB stoker and among other benefits would cut down on the annual prairie fire problem.

The full roller-bearing concept was retained because, besides the obvious maintenance factors, rollers would help reduce servicing times.

Another big improvement was to be a vastly extended network of lubrication for virtually all moving parts. The largest model force-feed lubricators were to be used along with steam heated lube lines wherever required.

During the war, new techniques had been employed in mechanical design and fabrication and the design team believed some should be utilized in railroad work. Among these was the expanded use of welding. The 1945 4-8-4's were to have welded flues.

The road had always experienced problems with cab comfort in winter storms, particularly in Wyoming, so an all-weather cab was designed. Because of the increased firebox size, the cab space was to be smaller, but it was felt that this would not be a problem because the latest cabs were more than generous, even for four men.

The already large sand box casing was to be increased slightly and provided with a pipe system to eliminate wet sand problems.

The headlight originally specified was the standard Pyle-National model, but sealed-beam designs were on the horizon and the UP held meetings with suppliers for possible furnishing of twin sealed-beam lighting, and twin units were shown on early sketches.

The centipede tender was used again, but with a "full top" design allowing 25,000-gallon capacity and 6000 gallons of oil.

In operation, no thought was given to eliminating helpers on severe grades, but the new power was proposed to handle trains then headed by 2-10-2's and 4-12-2's at much higher speeds and at greatly reduced costs.

Under the new power plan, the Sherman and Ogden grades would be handed over to Big Boys and Challengers, the new locomotives being assigned Green River-Laramie and east of Cheyenne. Driver size was to remain at 80 inches and other wheels at 42.

Two numbering schemes were suggested. The most popular was sticking with the 800 series because it was not felt that many locomotives would actually be built. The other was starting with 900, but this was ruled out and theseries assigned to new passenger diesels and older renumbered passenger units.

Even as the 1945 design was progressing, the builders came in with diesel proposals. Jeffers retired, and his successors did not share his faith in steam. After that, all steam efforts were pointed toward immediate, short-term economic improvements to existing designs, because it was thought that steam would vanish within a decade.

Super 800's, 1947 Version

(excerpted from Union Pacific Locomotives, Volume 1, by William Kratville and Harold Ranks, Barnhart Press, Omaha, 1960)

Proposed High Wheel Freight Locomotive -- Bigger and Better Power

Numbers 845-870

Union Pacific tests with a New York Central Hudson in the middle thirties showed the 5000 horsepower claimed by NYC was only on downgrade with twelve cars pushing the loco! The result was UP thought of bigger 4-8-2's but finally settled on the 800 series Northerns.

In the early post-war period, test engineers and motive power officials discussed various types of new steam power. Most talk centered around a high-wheeled freight locomotive which could also be used in passenger service.

The all-weather cab should have proven more adept at keeping the elements out than the UP's own weather-tight cab applied to earlier 4-8-4 and articulated locos. The bigger firebox would have given better firing, coupled with oil burners of the new types experimented with in the early 1950's. The bigger tender would have given longer runs and the larger drivers meant freight could really roll once the train was under way. Helpers were still planned for tough grades and the 4-8-4's would not be used in mountainous territory.

For better exhaust, four stacks were proposed and mention was made of experimentation with poppet valves although Caprotti gear had failed on UP in the late 1920's.

If the 800's would have remained in service longer, the oil cleaning sand box in the cab would have been remodeled, twin sealed-bam headlights installed, poppet valves probably tried, and four stacks standard practice. However, the size and power of future locos would have been limited by cylinder lube oil combustion. For practical, bigger power, better lube oil would have to have been brought out.

If steam power had been kept by the UP, the Challengers would have been fitted with larger steam passages to the rear cylinders, thus better equalizing the steam pressures of all cylinders.