PRR S1

PRR S1

Industrial designer Raymond Loewy stands on the front of the S1
Power type	Steam
Builder	Pennsylvania Railroad
Serial number	Altoona 4341
Build date	1939
Total production	1
Configuration	6-4-4-6
Gauge	4 ft 8½ in (1435 mm)
Driver size	84 in (2.13 m) diameter
Total weight	608,170 lb.
Boiler pressure	300 lbf/in² (2.07 MPa)
Fire grate area	132 ft² (12.3 m²)
Cylinders	4
Cylinder size	22×26 in (559×660 mm)
Valve gear	Walschaerts
Tractive effort	71,900 lb.
Career	Pennsylvania Railroad
Number in class	1
Number	6100
Retired	1945

The PRR S1 class steam locomotive (nicknamed "The Big Engine") was an experimental locomotive that was the largest rigid frame passenger locomotive ever built.^[1] In 1937, Pennsylvania Railroad officials decided to build a new passenger locomotive to replace its aging K4s locomotive. In a collaborative effort, the Pennsylvania Railroad, Baldwin Locomotive Works, the Lima Locomotive Works and the American Locomotive Company contributed to the experimental S1 design.^[2] The streamlined Art Deco styled shell of the locomotive was designed by Raymond Loewy.^[1][3] The S1 was the only locomotive ever built to use a 6-4-4-6 wheel arrangement. Also, the S1 class was a duplex locomotive, meaning that it had two pairs of cylinders, each driving two pairs of driving wheels. Unlike similar-looking articulated locomotive designs, the driven wheelbase of the S1 was rigid. The S1 was completed January 31, 1939 and was assigned locomotive number 6100.^[4] The S1 was displayed at the New York World's Fair of 1939 with the lettering American Railroads rather than Pennsylvania Railroad. After the World's Fair, the S1 was relettered and numbered. It was assigned to passenger service on the main line between Chicago, Illinois and Crestline, Ohio. The S1 was used by the PRR for publicity purposes as well. Its image was featured in calenders and brochures. It was hoped that the locomotive could haul 1,000 tons at 100 miles per hour, but this goal was not reached. There are many apocryphal stories of the S1 reaching or exceeding 140 miles per hour.^[5] Furthermore, the locomotive's extreme length (140 feet 2 1/2 inches) limited its usefulness as it was incapable of negotiating curves on most of the PRR track system. Wheel slippage was another problem with the S1. No further S1 models were built and the last run for the S1 was in December 1945.^[6] and the engine was scrapped in 1949.^[2]

Profile view of the S1

Construction history

The S1 under construction at Altoona. The smaller boiler in the photo is for a B6 switcher giving a sense of scale.

In 1937, Pennsylvania Railroad officials decided to build a new passenger locomotive to replace its aging K4s locomotive. The PRR officials also hoped that the new S1 steam locomotive would have performance equal to their GG1 electric locomotive.^[2] In a collaborative effort, the Pennsylvania Railroad, Baldwin Locomotive Works, the Lima Locomotive Works and the American Locomotive Company contributed to the experimental S1 design.^[2] The S1 was the largest express passenger locomotive ever constructed with an overall length was 140 feet 2 1/2 inches. At 77 feet long, the cast steel locomotive bed made by General Steel Castings was the largest single piece casting ever made for a locomotive application.^[2] The boiler unit for the S1 was the largest built by the Pennsylvania Railroad. The six-wheel leading and trailing trucks were added as the locomotive's design became too heavy for four-wheel units. However, the locomotive was still overweight by a significant margin. The streamlined Art Deco styled shell of the locomotive was designed by Raymond Loewy.^[1][3] The final construction cost for the S1 was $669,780.00.^[2]

World's fair display

The S1 at the New York World's Fair of 1939

Detail view of the driving wheels and cylinders; note the rollers upon which the wheels rested while on display

The S1 was displayed at the New York World's Fair of 1939 with the lettering "American Railroads" rather than "Pennsylvania Railroad". To reach the New York World's Fair, the S1 took a circuitous route over the Long Island Rail Road. Many obstacles had to be temporarily removed and other obstacles were passed at a slow crawl to reach the fairgrounds. At the World's Fair the S1 was a dynamic display; the drive wheels operated under the locomotive's own steam power.^[2] This was done by placing the S1 on a platform that had rollers under the drive wheels. By using this type of display, visitors could see the duplex drive in use. After the World's Fair, the S1 was relettered and numbered for use in the Pennsylvania Railroad fleet.

Service History

The S1 class locomotive was so large that it could not fit on most of the track lines of the PRR system. In its brief service life it was restricted to the main line between Chicago, Illinois and Crestline, Ohio. It was assigned to the Fort Wayne Division and based at the Crestline enginehouse. The S1 hauled passenger trains such as the The General and The Trailblazer on this route.^[2] Crews liked the S1, partly because of its very smooth ride. The great mass and inertia of the locomotive soaked up the bumps and the surging often experienced with duplex locomotives. No further S1 models were built and the last run for the S1 was in December 1945,^[6] and the engine was scrapped in 1949.^[2] The PRR continued developing the T1 class of 4-4-4-4 duplex locomotives, but they also met with limited success. Its high speed capability was such that some have claimed the S1 may have even exceeded the 126 mph record steam locomotive speed set in 1938 by the LNER locomotive Mallard However, it appears that no verifiable records are available to authenticate the claim.^[5]

Modern culture

The design of the S1 has proved to be very popular:

• The S1 appears in the Sandman comic series, book IX.
• A locomotive resembling the PRR S1 pulls the train in the "Billion Dollar Limited" episode of the 1940s "Superman" cartoon series.
• The S1 is was also represented in a (c)1939 painting by railroad artist Griff Teller that appeared in the Pennsylvania Railroad's picture calendar.
• The PC Game Grim Fandango's "Number Nine" train resembles the S1 very strongly.
• Scale model railroad versions of the S1 are available
• Prints, paintings and lithographs are also available

See also

• PRR locomotive classification

References

1. ^ ^{a b c} Raymond Loewy-Locomotives. The Avanti. Retrieved on 2007-09-02.
2. ^ ^{a b c d e f g h i} Actual Production Models Shown. Brochures. www.lionel.com (2003). Retrieved on 2007-09-03.
3. ^ ^{a b} It's a bird! It's a plane! No, it's - an office tool. The Home Forum > Essays. The Christian Science Monitor (September 23, 2004 edition). Retrieved on 2007-09-04.
4. ^ PRR Chronology 1939. PRR Chronology. Pennsylvania Technical and Historical Society (September 2004 Edition). Retrieved on 2007-09-02.
5. ^ ^{a b} Milwaukee A class Atlantics cont.. Was German 05 002 The World's Fastest Steam Loco?. www.germansteam.co.uk (Page Added 21st April 2005). Retrieved on 2007-09-03.
6. ^ ^{a b} PRR Chronology 1945. PRR Chronology. Pennsylvania Technical and Historical Society (September 2004 Edition). Retrieved on 2007-09-02.