Class E (Locobase 140)

Data from C & NW 10 - 1952 locomotive diagram book supplied in May 2005 by Allen Stanley from his extensive collection.

This class of Omaha Road Pacifics delivered in May & June 1913, April 1914, and January & November 1916 was essentially identical to the E class engines of the C & North Western (Locobase 4856), although they did have a few more fire tubes in their boilers.

Class E (early) (Locobase 4856)

Data from C & NW 1 - 1927 locomotive diagram book supplied in May 2005 by Allen Stanley from his extensive collection.

The E class totalled 168 locomotives built at Schenectady from 1909 to 1923. Firebox heating surface included 27 sq ft of arch tubes. The first batches used Walschaert gear, but beginning with 1580 (delivered in May 1913), the design operated Baker valve gear.

The data shown here applied to all in the class but those produced for the North Western after World War One. For those, see Locobase 9383.

Class E - late (Locobase 9383)

Data from C & NW 10 - 1952 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive collection.

Earlier E-class Pacifics are shown in Locobase 140. After World War I, the North Western completed this large class of engines with a purchases of 19 from Schenectady (62695-62713 in April 1921) and 20 from Dunkirk, New York's Brooks works. (Works #63497-63506 in October 1922, 63883-63892 in March 1923). The basic dimensions remained the same in the firebox and the power segment (i.e., cylinder volume remained unchanged as did piston valve diameter, which still came in at 12").

But there were some tweaks, particularly on the the Brooks engines, which used Young valve gear in preference to the earlier batches' Baker equipment. These saw their wheelbases grow by 1 1/2 ft and weight rise by several tons. In both batches, some tubes were exchanged for two more superheater flues, and boiler pressure now reached 200 psi. Still, very little notice of the USRA designs seems to have been taken.

Retirements began in 1937, but the last engines didn't leave service until 1956.

Class E-1 (Locobase 4364)

Data from reproduction of 1913 Alco Bulletin 1016 on Richard Leonard's http://www.railarchive.net/alcopacifics/index.html (accessed 16 June 2006) and from the 1927 C & NW locomotive diagram book supplied in May 2005 by Allen Stanley from his extensive collection.

This batch operated on secondary passenger service. According to the diagram book, the class was delivered in two batches in two years. The first 15 came in 1910 and had consecutive works numbers: 49020-49034; their road numbers, on the other hand, ranged from 56 to 941-944. The others -- road numbers 2201-2220 -- were delivered in 1913-1915 with work numbers 53025, 53029-31 (April 1913), 54852-61 (Sept 1914), and 55544-55549 (November 1915).

NB: The Alco table shows the heating surface area and tube count as recorded in the specs (2,623 sq ft and 168 small tubes). The 1927 book shows 147 tubes and a 2,405 sq ft measurement. Locobase isn't sure whether the tube count would have dropped because that many were removed to simplify maintenance or because data in the 1927 book is somehow incomplete or incorrect. Other classes of locomotives showed a similar decrease, which suggests a railroad policy.

Class E-2 (Locobase 1184)

Firebox surface area included 14 sq ft of arch tubes, 74 sq ft of thermic syphons, and a combustion chamber. Drury (1993) notes that their dimensions place them about halfway between the two USRA classes.

Four of this class (2902-2903, 2907-2908) were substantially rebuilt in 1934, converting to oil burning, mounting cast-steel cylinders and 225-psi boilers and riding on 79" drivers. Tractive effort increased to 45,800 lb in the E-2A. The other eight followed, but remained coal burners (E-2B). When the oil-burners were converted back to coal burning in 1939, the whole class became E-2s once again.

The data are taken from a C&NW 1 - 1927 locomotive diagram (supplied in May 2005 by Allen Stanley from his extensive collection) showing the details of the 8-locomotive coal-burning variant of the upgrade.

They left service in 1954-1957.

Class E-3 (Locobase 5154)

Operated by subsidiary Chicago, St. Paul, Minneapolis, and Omaha. These were the heaviest Pacifics to be built for any railroad. Firebox heating surface included 14.2 sq ft of arch tubes and 72 sq ft of thermic syphons. Note too the superpower-like distribution of tubes and flues characteristic of the Type E superheater layout.

http://www.ironhorse129.com/Projects/Engines/CNW_Pacific/Graphics/CNW/Pacific_E3_Largest_Draw.jpg

Class I-2 - superheated (Locobase 4365)

Data from Larry Bohn, author of the website members.lsol.net/mollyandmic/c385.htm and reflects this batch of Pacifics after they were superheated; see Locobase 9485 for the original, saturated configuration of this class.

By then, they had 12" piston valves and Walschaerts gear. Firebox heating surface included 23 sq ft of arch tubes.

Bohn offers the following comments about a typical I-2: "The "Noon Train" (northbound) at Shell Lake generally indicated to everyone in town that it was time for lunch. This low angle shot taken at about driving axle height shows details that most locomotive photos don't. first, the "laceyness" of the quill spoked driving wheels, second, the springs mounted directly above the drivers, and third, the fact that the driving wheels were quartered with the right side drivers leading the left side by 90 degrees thus spreading out the 4 power strokes per revolution evenly ....All of the Omaha passenger engines had bigger driving wheels (75", or 81") than the 69" drivers of the Iron range passenger engines, and were capable of much higher speeds although the Spooner-Baronett hill made #364 work for a living. speeds in excess of 70 mph. were common on many parts of the run."

Class L (Locobase 8386)

Data from C & NW 1 - 1927 locomotive diagram book supplied in May 2005 by Allen Stanley from his extensive collection.

These were small Pacifics that almost certainly were delivered as saturated-steam locomotives; their fireboxes favored the lignite they were designed to burn. One arrived in October 1908 (works #45236), and one in September 1909 (45933). The rest came in bigger batches of 9 in September 1910 (47891-47899) and 10 in October 1910 (49010-49019).

At some point, the class received superheaters and the data show that upgrade. As modified, this design was one of the lightest 4-6-2s on the North American standard gauge

The last was retired in 1935.