The A-1 and A-(Locobase 6798) had very similar specifications except that the A-1s rolled on 63" drivers.

The North Western's shops built this batch of Eight-wheelers.

The North Western's shops built this batch of Eight-wheelers. They seem to have formed part of a larger group that included A-3s with a slightly larger boiler. See Locobase 6799.

Omaha-road predecessor West Wisconsin actually bought this petite Eight-wheeler from a small, but well-regarded Massachusetts builder.

Most of this class was produced by Schenectady with a few coming from the North Western's own shops. The Schenectady engines arrived mostly in 1883 with a few more coming in 1884. The design had the same cylinder volume and boiler pressure as the A-2s, but slightly more heating surface and taller drivers.

RG's report credits the design of this "standard" locomotive to the C & NW's Superintendent of Motive Power GW Tilton. The engine was "...strongly proportioned throughout." Standard it may have been, but there were no other locomotives placed in the A-4 class.

Its dimensions, power, and weight were very similar to Schenectady-built E-6 locomotives supplied in 1886 to the Chicago, St Paul, Minneapolis & Omaha (Locobase 9326), which was controlled by the North Western.

The diagram book's table of engines shows that the locomotives in this class were originally delivered in 1881-1882 as class A-1, but rebuilt in 1898-1904.

McShane (1899) data for total heating surface varies slightly from Railway Age 11 Oct 1895. The latter noted that these engines were serving the Chicago-Council Bluffs run and pulling up to 11 cars per train. Sometime after delivery the railroad reduced the boiler's tube count to the figure given in the specs and added 13.3 sq ft of arch tubes to the firebox heating surface.

See Locobase 3151 for the modified Class As of 1899.

The RG account notes the C-class mail-train engines with their 80" drivers (Locobase 454) and this sextet of fast passenger engines with smaller drivers but a larger boiler. The report credits W H Marshall, the B&A's Assistant Superintendent of Motive Power, with the design. "Each detail was considered with a view of reducing its weight without a sacrifice of strength, and so cast and pressed steel have been largely used." RG also observed that the journals of the driving and truck axles were larger than usual, "being respectively 9 inches in diameter by 11 1/2 long, and 6 by 12 inches."

The North Western later removed 19 of the tubes from the boiler (most likely from the bottom), reducing the tube count to 323. At the same time, the firebox heating surface increased to 204.1 sq ft (19 sq m). The combined effect of these changes was to reduce the evaporative heating surface area to 2,408.8 sq ft (223.8 sq m).

The North Western's shops built this batch of Eight-wheelers. As with many railroads, class IDs often follow no real chronological orders. These locomotives were considerably earlier than the Class B shown in the 1908 book and even earlier than the A-2s.

Locobase 3490 describes the large class of N-1 class 4-4-0s that both Hinkley and Baldwin delivered in 1864-1867. This locomotive was that class's Mississippi and had road number 144. In 1890, the North Western sold it to the SSM&SW as their #6. Two years later the railroad was reorganized as the Chicago, St Paul, Minneapolis & Omaha at which point this engine fell into class B-1 and renumbered 184. Locobase notes that the grate was now smaller.

In 1909, the Omaha Route sold the 184 to the Fairchild & Northeastern as their #6.

Given the date when these were built and their specifications, Locobase suspects that these were replacements for earlier engines.

When delivered their boilers contained 320 fire tubes that contributed to a total evaporative heating surface of 2,353 sq ft. The 26 May 1899 Railroad Gazette credited the quintet with 80" drivers and said that these engines were ticketed for the fast west-bound mail trains and fast passenger trains eastbound. According to the report, mail trains would usually consist of four cars weighing a total of 160 tons. At the time of writing, there had been "no opportunity to make a thorough test of the running qualities," said the RG, "but, at speeds of 70 and 80 miles an hour, they are known to be remarkably easy riding engines."

By 1905, the railroad had removed 19 of the tubes. Also later came the 13.9 sq ft (1.3 sq m) of arch tubes as additions to the firebox heating surface, which resulted in an evaporative heating surface area decrease to 2,236.9 sq ft (207.8 sq m) as well as a reduction in driver diameter from 80".

NB: The direct heating surface (including the firebox heating surface) is an estimate calculated by subtracting the calculated tube heating surface from the reported total evaporative heating surface.

Schenectady completed these twelve in April & May 1885. Notice the very deep and narrow firebox, which resulted in a small grate that likely didn't adequately heat all of that firebox area. Later on they had tenders with 10 tons (9.1 metric tons) of coal and either 4,500 US gallons (17,033 litres) or 5,200 gallons (19,682 litres) of water.

Schenectady went into volume production with this design after delivering the 12 C-2s. The principal differences were an 2" increase in the stroke and the addition of 15 boiler tubes. The very deep and narrow firebox, which seems restrictive, was not changed.

More of the same in the C-2/C-3 (Locobase 6803-6804) vein from Schenectady: Same small grate, still more boiler tubes All were produced in April-May 1888 except 887-888.

Beginning in May 1916, the C & NW began rebuilding their large class of 1880s-era Eight-wheelers with a smaller boiler. Obviously, the modest tractive effort level was more thatn outweighed by the light axle loading and general usefulness of this mixed-traffic engine.

The program continued for seven years with the last locomotive emerging from the shops in November 1923. The profile showed the tapered stack, a rounded-thimble sandbox just behind, a taller steam dome on the second course of boiler and ahead of the first drivine axle.

When the C-6s were delivered by Schenectady in 1893, they had the same narrow fireboxes as earlier North Western Eight-wheelers (see, e.g., Locobase 6803-6805). Only a few years later, the railway itself rebuilt the locomotives by enlarging the boilers, expanding the grate area by increasing both width and length and raising it above the axles, and fitting piston valves. The first locomotive, 309, appeared in July 1899. 191 followed in December. Three -- 251, 253, 250 -- were rebuilt in April, August, and December 1900 respectively. 190 (August) and 421 (October) were the 1901 pair while 427 (April) and 99 (October) came in 1902 and 252 finished the program in February 1903.

The 1927 diagram showed a reduction of 23 tubes in the boiler and the addition of 11.8 sq ft of arch tubes to the firebox heating surface; altogether, total evaporative heating surface shrank to 1,665 sq ft.

Small, lightweight Eight-wheelers from a small Massachusetts builder.

Two years after Taunton supplied the Omaha Road with some mixed-traffic 4-4-0s (Locobase 9303), the small Massachusetts builder added this pair of freighters with slightly larger fireboxes and a little more boiler area.

Baldwin's supply of Eight-wheelers to the Omaha Road was part of series of orders from this road in that period.

The only difference between this pair of engines and the 123 shown in Locobase 9318 is the driver diameter, which was smaller by 5" than the lower-numbered locomotive. Otherwise, they were identical, right down to the curiously heavy tenders.

As noted in Locobase 12039, the C & NW bought 2 locomotives to try out different sizes of Vauclain compounds. This entry shows a surprisingly low-drivered Eight-wheeler. Locobase wonders if the expectation was to gain tractive effort by taking advantage of the smoother action of a 4-cylinder compound. The piston valve on each side measured 9 3/4" in diameter.

In any event, the North Western didn't adopt the Vauclain compound and this 4-4-0, like the 4-6-0, was converted to simple expansion. Indeed, the 821 was first to jettison the compound arrangement in September 1899, fitting 18" x 24" cylinders and 69" drivers. In this setup, the engine ran for more than 20 years before being scrapped in May 1922.

More than 20 years after their introduction, the Baldwins had apparently remained unaltered. Five -- 415, 421, 428, 429, 443 -- had been sold to the Winona & St Peter in the 1890s as that railway's 31, 11, 14, 21, and 52. The W & St P, a subsidiary of the Chicago & Northwestern returned the locomotives in 1900, at which point these locomotives were reunited with the rest of the class.

As the C & NW was scrapping the class in the first decade of the 20th Century, the 426 went to the Wyoming & Missouri River in July 1905 while the 425 was sold to the Hillsboro & Northeastern in July 1907 as their #3.

Baldwin's production of Eight-wheelers for the Omaha Road during this period (1879-1880) tended to be classed in ones and twos. This D-3 class, however, was a relatively homogenous decade of engines supplied in drips and drabs. Five -- 37 , 39, 41-43 -- had "weighted decks" to increase adhesion by 400 lb.

Baldwin's production of Eight-wheelers for the Omaha Road during this period (1878-1880) tended to be classed in ones and twos, but all of the D series from this time had the same boiler and grate and very slight differences in firebox heating surface. Differences between classes related primarily to driver diameter.

In the series of D-class locomotives supplied to the Omaha Road in 1877-1881, the D-5s stand out as unusual. Although they had virtually the same dimensions and weights as all of the others, they were missing a boiler tube. All of the others had 153 tubes, the D-5s, for some obscure reason probably having to do with aesthetics, made do with 152. Otherwise - peas in a pod.

As the Omaha Road added to its roster of Eight-wheelers, it bought this batch of engines that were at least middle-sized for the time.

This locomotive had its own class in the 1900 diagram book, presumably because it retained the 60" drivers of the original class. It also had two fewer tubes than the D-8s delivered in the same year (Locobase 9316) and consequently slightly less heating surface area. But the firebox was identical. It was retired in July 1912, 30 years after its introduction.

The first six locomotives (works #998-1003) were named GREEN ISLE 101, ARLINGTON 102, WINTHROP 103, REDWOOD 104, FRANKLIN 105, GREENFIELD 106. The Lambert-Rumary list shows all of these as delivered with 60" drivers, but the 1900 books shows the 63" drivers in the specifications. Most of these were retired in the first decade of the 20th Century with the higher numbers being scrapped in 1913. See Locobase 9317 for the single D-7 from this builder.

Although similar to many of the Eight-wheelers coming into service on the Omaha Road, this one had taller drivers than most. Produced in January 1883, it accompanied two others of similar dimensions but smaller drivers.

The F E & MV was a Nebraska road that was acquired by the Chicago & North Western in 1886, although the name of the subsidiary didn't change in 1901. These light freight Eight-wheelers gave 3 decades and more of service before being scrapped between February 1915 (1234) and January 1923 (1243).

The Baldwins shown in Locobase 7555 had the passenger drivers, but these Schenectadies probably accounted for most of the freight traffic on the FE & MV.

A sextet of passenger engines to flesh out the motive power profile of the Omaha Road. The E class consisted of locomotives with 18" diameter cylinders.

75 was retired first in August 1914 and 70 followed in December 1915. It was 11 years before the next withdrawal, but 1926 saw disposal of the rest: 71 (May), 73 (June), 74 (August), and 72 (December).

Passenger Eight-wheeler that appears to have been the only locomotive in the class. It was scrapped in October 1926.

The Ashland Route was part of the Milwaukee, Lake Shore and Western Railway, which operated independently in northeast Wisconsin from 1872 to 1893. These small Eight-wheelers came in two batches in the early 1880s.

By 1890, the MLS&W had accumulated 850 miles (1,369 km) of line.

The Chicago & North Western acquired the MLS&W in September 1893. The C&NW began scrapping this class in November 1901 (Engine 939) and completed the dissolution in August 1808 with road #926.

Adding to the 6 Baldwin 18" passenger engines (Locobase 9322), this sextet came from a rival builder 3 years later. They had the same power dimensions, but a slightly larger grate and substantially increased heating surface areas. Thus, they may be thought to have had more steam stamina under similar conditions.

As the Omaha Road settled on the 18" diameter cylinder, its locomotive purchases increased in number per class. This decade of mixed-traffic engines were produced in December 1882 and January 1883 (1 locomotive).

This class has to be seen as one of the standard classes for the Omaha Road in the mid-1880s. The number of engines, the size of the drivers, the capacity of the boiler and grate all mark the design as a mixed-traffic locomotive that operated all over the series.

As the decade wore on, the Omaha Road's Eight-wheelers grew in size and capacity. At the same time, they were still constrained by a firebox that was deeply set between the driving axles and consequently limiting the grate area. Delivered in July 1888, these were immediately followed by a larger class of very similar locomotives; see Locobase 9328.

Who knows why these differences arise? When this Hudson-River builder continued its building program for the Omaha Road in July 1888, it produced a set of engines that were lacking just one tube, had drivers measuring 1" less, and had boilers pressed to 5 psi less than the E-7s that immediately preceded them. (Locobase 9327). Schenectady produced the first 7 in July 1888, 4 more in August, and the last 3 in September.

Passenger power on the Omaha Road in the late 1890s included this class of Eight-wheelers supplied in April 1896 (275-277), June 1898 (278), December 1898 (255-260), and January 1900.

They were somewhat more modestly scaled than their B-class (Locobase 6800) and C-class (Locobase 454) Eight-wheeler contemporaries on the parent Chicago & North Western, but still represented adequate mainline power.

Although several, very similar engines were built in the next few years, then-current practice meant that "standardization" could only be loosely defined. Gushing noted that both Hinkley & Williams (of Boston) and Baldwin supplied engines in a 50-locomotive purchase in 1866-1867. Hinkley records compiled by Gene Connelly show that Hinkley & Williams works numbers for this class were 714-715, 726-732 in 1864; (741), (742), 743-746, and 751 in 1865; and 780-782, 789, 791-794, (796), 808 in 1866. Baldwin's works numbers were 1560-1568, 1570, 1575 in January 1867; 1576, 1579-1580, 1586-1587 in February; 1589-1591, 1593-1598, 1602-1605 in March; 1606-1608, 1610, 1613, 1615, 1617-1618, 1620-1622 in April.

Gushing's report provided a tour through some of this design's good features: "The pressure of 130 pounds indicates an increase in steam, at that time, in engines of this class; and the tank was also a large one. The ample heating surface given made a good steamer, and this was assisted by the use, at that time, of a Hunter pattern of stack, which gave excellent freedom to the waste products of combustion, and retained the sparks in circulation until made harmless, to be passed out through the proper openings. The front end was fitted with a pipe dropping below the base of the stack, of suitable diameter, much the same as are fitted to very good steamers now. It was also fitted with a petticoat pipe, skirted to attract proper circulation of gases and cinders through the upper or lower tubes as desired."

In September 1900, George B Snow described some "Old-Time Chicago Locomotives" for the RMM beginning on page 479. He noted that nearly every locomotive of the time burned wood, a low-calorie combustible that cramped locomotive speed and range: "Then, the concomitant of every water tank on the line of a railway was a large pile of cordwood, the sticks being sawed once in two; and while the tender was filling with water, all the available help belonging to the station and train were occupied in throwing wood and heaping it on the tender. This load would last an engine, if working hard, about an hour. Passenger engines usually ran about thirty miles, and freight engines about ten miles, with one tender full of wood."

Snow described the operational implications: "The fire door was placed as near the crown sheet as it could be, and, when running, the firebox was kept full of wood, or up to the level of the door at any rate. If the engine was working hard, the wood would burn about as fast as it could be handled; and, if running against a strong head wind, a passenger engine would sometimes consume the wood so fast that the fire door would be open for mile after mile, the fireman throwing in wood as fast as he could handle it."

Almost all were scrapped by 1900.

Specifications by Steve Llanso | ||||||||||||||||||||||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|

Class | 99 | A-1 | A-2 | A-2 | A-3 | A-4 | A-5 | A-modified | A-modified | B | B-1 | B-1 | B-2 | B-3 | C | C-1 | C-2 | C-3 | C-5 | C-5 - 1916 rebuild | C-6 | C-7 | C-9 | D-1 | D-10 | D-14 | D-3 | D-3 | D-4 | D-5 | D-6 | D-7 | D-8 | D-9 | E / E-6 | E-10 | E-2 | E-3 | E-3 / J-3 | E-4 | E-5 | E-6 | E-7 | E-7 | E-8 | F-1 | F-8 | N-1 |

Locobase ID | 11113 | 15897 | 6798 | 9293 | 6799 | 13301 | 7553 | 3151 | 15896 | 6800 | 6801 | 9297 | 15898 | 15899 | 454 | 6802 | 6803 | 6804 | 6805 | 8381 | 6806 | 9303 | 9305 | 9306 | 9319 | 12040 | 7554 | 9307 | 9308 | 9309 | 9310 | 9317 | 9316 | 9318 | 7555 | 7556 | 9322 | 9323 | 7558 | 9324 | 9325 | 9326 | 9327 | 7560 | 9328 | 7557 | 9336 | 3490 |

Railroad | Chicago & North Western (C&NW) | Chicago & North Western (C&NW) | Chicago & North Western (C&NW) | Chicago, St Paul, Minneapolis & Omaha (C&NW) | Chicago & North Western (C&NW) | Chicago & North Western (C&NW) | Chicago & North Western (C&NW) | Chicago & North Western (C&NW) | Chicago & North Western (C&NW) | Chicago & North Western (C&NW) | Chicago & North Western (C&NW) | Sault Sainte Marie & Southwestern (C&NW) | Chicago & North Western (C&NW) | Chicago & North Western (C&NW) | Chicago & North Western (C&NW) | Sioux City & Pacific (C&NW) | Chicago & North Western (C&NW) | Chicago & North Western (C&NW) | Chicago & North Western (C&NW) | Chicago & North Western (C&NW) | Chicago & North Western (C&NW) | Chicago, St Paul, Minneapolis & Omaha (C&NW) | Chicago, St Paul, Minneapolis & Omaha (C&NW) | Chicago, St Paul, Minneapolis & Omaha (C&NW) | Chicago, St Paul, Minneapolis & Omaha (C&NW) | Chicago & North Western (C&NW) | Chicago & North Western (C&NW) | Chicago, St Paul, Minneapolis & Omaha (C&NW) | Chicago, St. Paul & Minneapolis (C & NW) | Chicago, St Paul, Minneapolis & Omaha (C&NW) | Chicago, St Paul, Minneapolis & Omaha (C&NW) | Chicago, St Paul, Minneapolis & Omaha (C&NW) | Chicago, St Paul, Minneapolis & Omaha (C&NW) | Chicago, St Paul, Minneapolis & Omaha (C&NW) | Fremont, Elkhorn & Missouri Valley (C&NW) | Fremont, Elkhorn & Missouri Valley (C&NW) | Chicago, St Paul, Minneapolis & Omaha (C&NW) | Chicago, St Paul, Minneapolis & Omaha (C&NW) | Milwaukee, Lake Shore & Western (C&NW) | Chicago, St Paul, Minneapolis & Omaha (C&NW) | Chicago, St Paul, Minneapolis & Omaha (C&NW) | Chicago, St Paul, Minneapolis & Omaha (C&NW) | Chicago, St Paul, Minneapolis & Omaha (C&NW) | Fremont, Elkhorn & Missouri Valley (C&NW) | Chicago, St Paul, Minneapolis & Omaha (C&NW) | Chicago & North Western (C&NW) | Chicago, St Paul, Minneapolis & Omaha (C&NW) | Chicago & North Western (C&NW) |

Country | USA | USA | USA | USA | USA | USA | USA | USA | USA | USA | USA | USA | USA | USA | USA | USA | USA | USA | USA | USA | USA | USA | USA | USA | USA | USA | USA | USA | USA | USA | USA | USA | USA | USA | USA | USA | USA | USA | USA | USA | USA | USA | USA | USA | USA | USA | USA | USA |

Whyte | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 |

Road Numbers | 99, 191-192, 250-253, 309, 421, 427 | 19, 133, 405 | 156, 497-506 | 229 | 500 series | 274 | 908 | 908 | 196, 198, 200, 203, 208, 211 | 350-400 + | 184 | 4, 15, 35 | 258-259 | 215-216, 218-220 | 5-6 / 1004, 1065 | 597-608 | 686-704, 887-88 | 686-704, 887-88 | various | 216-217, 230 | 261-262 | 2-7, 9 | 124-125 | 821 | 410-429, 440-449 | 34-43 | 32-33 | 54-63 | 76-89 | 110 | 101-106, 109, 111-112 | 123 | 32-46 / 1232-1246 | 1247-1287 | 70-75 | 94 | 23-24, 20-22, 34-39/925-927,923-924, 934-939 | 95-99 | 113-122 | 100, 126-147 | 154-159 | 1223-1227 | 160-173 | 251-260, 275-278 | ||||

Gauge | Std | Std | Std | Std | Std | Std | Std | Std | Std | Std | Std | Std | Std | Std | Std | Std | Std | Std | Std | Std | Std | Std | Std | Std | Std | Std | Std | Std | Std | Std | Std | Std | Std | Std | Std | Std | Std | Std | Std | Std | Std | Std | Std | Std | Std | Std | Std | Std |

Builder | Schenectady | C&NW | C&NW | Taunton | Schenectady | C&NW | C&NW | Schenectady | Schenectady | Schenectady | C & NW | Hinkley | C&NW | C&NW | Schenectady | Schenectady | Schenectady | Schenectady | Schenectady | C & NW | C&NW | Taunton | Taunton | Burnham, Parry, Williams & Co | Schenectady | Burnham, Williams & Co | Burnham, Parry, Williams & Co | Burnham, Parry, Williams & Co | Burnham, Parry, Williams & Co | Burnham, Parry, Williams & Co | Burnham, Parry, Williams & Co | Manchester | Manchester | Schenectady | Burnham, Parry, Williams & Co | Schenectady | Burnham, Parry, Williams & Co | Burnham, Parry, Williams & Co | Rhode Island | Schenectady | Rhode Island | Schenectady | Schenectady | Schenectady | Schenectady | Taunton | Schenectady | several |

Year | 1893 | 1881 | 1883 | 1871 | 1883 | 1884 | 1898 | 1895 | 1895 | 1899 | 1878 | 1890 | 1875 | 1891 | 1899 | 1899 | 1885 | 1885 | 1888 | 1916 | 1899 | 1878 | 1880 | 1879 | 1883 | 1892 | 1881 | 1879 | 1878 | 1881 | 1882 | 1882 | 1882 | 1883 | 1885 | 1886 | 1882 | 1883 | 1880 | 1885 | 1882 | 1886 | 1888 | 1891 | 1888 | 1881 | 1896 | 1865 |

Valve Gear | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson |

Locomotive Length and Weight | ||||||||||||||||||||||||||||||||||||||||||||||||

Driver Wheelbase | 8.83' | 8.33' | 8.33' | 7' | 8.33' | 8.83' | 8.83' | 8.50' | 8.50' | 8.50' | 8.33' | 7' | 8.33' | 8.67' | 8.50' | 8.50' | 8.83' | 8.83' | 8.83' | 8.83' | 8.83' | 7.50' | 7.50' | 8' | 8.50' | 7.50' | 8.25' | 8' | 8' | 8' | 8.50' | 8' | 8' | 8.50' | 8.83' | 8.83' | 8.50' | 8.50' | 7.25' | 8.50' | 8.50' | 8.83' | 8.83' | 13.10' | 8.83' | 8.50' | 8.50' | |

Engine Wheelbase | 23.83' | 22.98' | 23.10' | 20.75' | 23.10' | 23.62' | 23.48' | 23.08' | 23.08' | 24.67' | 22.98' | 20.67' | 22.98' | 23.08' | 24.67' | 23' | 23.62' | 23.62' | 23.62' | 23.62' | 23.79' | 21.42' | 21.50' | 22.50' | 22.67' | 21.69' | 22.06' | 22.67' | 22.50' | 22.50' | 22.50' | 22.50' | 22.50' | 22.67' | 23.67' | 23.67' | 22.50' | 22.50' | 21.33' | 24.08' | 23.25' | 23.60' | 23.60' | 24' | 23.60' | 22.46' | 23.08' | |

Ratio of driving wheelbase to overall engine wheebase | 0.37 | 0.36 | 0.36 | 0.34 | 0.36 | 0.37 | 0.38 | 0.37 | 0.37 | 0.34 | 0.36 | 0.34 | 0.36 | 0.38 | 0.34 | 0.37 | 0.37 | 0.37 | 0.37 | 0.37 | 0.37 | 0.35 | 0.35 | 0.36 | 0.37 | 0.35 | 0.37 | 0.35 | 0.36 | 0.36 | 0.38 | 0.36 | 0.36 | 0.37 | 0.37 | 0.37 | 0.38 | 0.38 | 0.34 | 0.35 | 0.37 | 0.37 | 0.37 | 0.55 | 0.37 | 0.38 | 0.37 | |

Overall Wheelbase (engine & tender) | 46.46' | 43.19' | 43.28' | 40.08' | 43.28' | 45.17' | 49.37' | 49.37' | 52.52' | 44.62' | 39.08' | 43.19' | 45.17' | 52.54' | 47.17' | 45.25' | 45.25' | 45.25' | 45.79' | 47.02' | 40.42' | 42.58' | 42.17' | 43.17' | 43.37' | 43.67' | 44.17' | 44.17' | 44.17' | 43' | 43' | 43.17' | 44.83' | 44.33' | 48.35' | 48.35' | 41.67' | 45.37' | 45' | 45.58' | 45.46' | 44.33' | 45.46' | 43.61' | 47.75' | |||

Axle Loading (Maximum Weight per Axle) | ||||||||||||||||||||||||||||||||||||||||||||||||

Weight on Drivers | 67500 lbs | 53900 lbs | 54300 lbs | 42800 lbs | 54300 lbs | 57800 lbs | 66710 lbs | 83300 lbs | 76000 lbs | 87000 lbs | 51400 lbs | 35450 lbs | 50000 lbs | 50000 lbs | 85700 lbs | 71000 lbs | 56750 lbs | 57650 lbs | 61870 lbs | 61600 lbs | 76000 lbs | 40500 lbs | 43300 lbs | 48600 lbs | 48200 lbs | 64000 lbs | 50500 lbs | 48600 lbs | 48600 lbs | 48600 lbs | 49400 lbs | 44800 lbs | 46300 lbs | 51200 lbs | 54400 lbs | 56200 lbs | 53300 lbs | 57800 lbs | 43000 lbs | 74600 lbs | 58200 lbs | 57300 lbs | 61000 lbs | 81700 lbs | 61000 lbs | 50000 lbs | 82700 lbs | |

Engine Weight | 107500 lbs | 84800 lbs | 84400 lbs | 67400 lbs | 84400 lbs | 90000 lbs | 108180 lbs | 131100 lbs | 125600 lbs | 137000 lbs | 81000 lbs | 63000 lbs | 79700 lbs | 78000 lbs | 133800 lbs | 111500 lbs | 88550 lbs | 90000 lbs | 95300 lbs | 102800 lbs | 118500 lbs | 62200 lbs | 66000 lbs | 75000 lbs | 74600 lbs | 98000 lbs | 80400 lbs | 75000 lbs | 75000 lbs | 75000 lbs | 77000 lbs | 70400 lbs | 71900 lbs | 77600 lbs | 87000 lbs | 89700 lbs | 81000 lbs | 87500 lbs | 68000 lbs | 98000 lbs | 90500 lbs | 90600 lbs | 62500 lbs | 105900 lbs | 92500 lbs | 80500 lbs | 130700 lbs | 60000 lbs |

Tender Light Weight | 61500 lbs | 58000 lbs | 48200 lbs | 58000 lbs | 82000 lbs | 109500 lbs | 97500 lbs | 109500 lbs | 82000 lbs | 43000 lbs | 61500 lbs | 65300 lbs | 110800 lbs | 79500 lbs | 82000 lbs | 82000 lbs | 82000 lbs | 82000 lbs | 82000 lbs | 49300 lbs | 53800 lbs | 56400 lbs | 63700 lbs | 61500 lbs | 56400 lbs | 56400 lbs | 56400 lbs | 57200 lbs | 52300 lbs | 52300 lbs | 63500 lbs | 63150 lbs | 61200 lbs | 63400 lbs | 59100 lbs | 61500 lbs | 80600 lbs | 72000 lbs | 73500 lbs | 73600 lbs | 70000 lbs | 73600 lbs | 61500 lbs | 107500 lbs | ||||

Total Engine and Tender Weight | 146300 lbs | 142400 lbs | 115600 lbs | 142400 lbs | 190180 lbs | 240600 lbs | 223100 lbs | 246500 lbs | 163000 lbs | 106000 lbs | 141200 lbs | 143300 lbs | 244600 lbs | 191000 lbs | 170550 lbs | 172000 lbs | 177300 lbs | 184800 lbs | 200500 lbs | 111500 lbs | 119800 lbs | 131400 lbs | 138300 lbs | 141900 lbs | 131400 lbs | 131400 lbs | 131400 lbs | 134200 lbs | 122700 lbs | 124200 lbs | 141100 lbs | 150150 lbs | 150900 lbs | 144400 lbs | 146600 lbs | 129500 lbs | 178600 lbs | 162500 lbs | 164100 lbs | 136100 lbs | 175900 lbs | 166100 lbs | 142000 lbs | 238200 lbs | ||||

Tender Water Capacity | 3600 gals | 2800 gals | 2800 gals | 2000 gals | 2800 gals | 3800 gals | 5200 gals | 4500 gals | 5200 gals | 3800 gals | 1900 gals | 2800 gals | 3200 gals | 5200 gals | 3500 gals | 3800 gals | 3800 gals | 3800 gals | 3800 gals | 3800 gals | 2200 gals | 2283 gals | 2770 gals | 2750 gals | 3600 gals | 2800 gals | 2400 gals | 2400 gals | 2400 gals | 3000 gals | 2805 gals | 2805 gals | 2800 gals | 2800 gals | 2750 gals | 3000 gals | 3000 gals | 2000 gals | 3300 gals | 3400 gals | 3000 gals | 3000 gals | 3200 gals | 5000 gals | 2800 gals | 4500 gals | 1800 gals | |

Tender Fuel Capacity (oil/coal) | 7 tons | 7 tons | 5 tons | 7 tons | tons | 8 tons | 8 tons | 10 tons | 8 tons | 8 tons | 3.5 tons | 7 tons | 8 tons | 10 tons | 7 tons | 8 tons | 8 tons | 8 tons | 8 tons | 8 tons | 6 tons | 6 tons | 6.5 tons | 6.5 tons | tons | 7 tons | 6.5 tons | 6.5 tons | 6.5 tons | 6.5 tons | 6.5 tons | 6.5 tons | 6.5 tons | 6 tons | 6 tons | 6 tons | 6 tons | 5 tons | 6 tons | 6.5 tons | 6 tons | 8.5 tons | 7 tons | 6.5 tons | 7 tons | 10.5 tons | 5 tons | |

Minimum weight of rail (calculated) on which locomotive could run | 56 lb/yard | 45 lb/yard | 45 lb/yard | 36 lb/yard | 45 lb/yard | 48 lb/yard | 56 lb/yard | 69 lb/yard | 63 lb/yard | 73 lb/yard | 43 lb/yard | 30 lb/yard | 42 lb/yard | 42 lb/yard | 71 lb/yard | 59 lb/yard | 47 lb/yard | 48 lb/yard | 52 lb/yard | 51 lb/yard | 63 lb/yard | 34 lb/yard | 36 lb/yard | 41 lb/yard | 40 lb/yard | 53 lb/yard | 42 lb/yard | 41 lb/yard | 41 lb/yard | 41 lb/yard | 41 lb/yard | 37 lb/yard | 39 lb/yard | 43 lb/yard | 45 lb/yard | 47 lb/yard | 44 lb/yard | 48 lb/yard | 36 lb/yard | 62 lb/yard | 49 lb/yard | 48 lb/yard | 51 lb/yard | 68 lb/yard | 51 lb/yard | 42 lb/yard | 69 lb/yard | 0 |

Geometry Relating to Tractive Effort | ||||||||||||||||||||||||||||||||||||||||||||||||

Driver Diameter | 69" | 63" | 56" | 57" | 63" | 70" | 69" | 75" | 75" | 75" | 63" | 63" | 62" | 62" | 80" | 62" | 63" | 63" | 63" | 63" | 69" | 63" | 57" | 59" | 63" | 63" | 63" | 59" | 63" | 59" | 57" | 60" | 63" | 69" | 63" | 59" | 69" | 69" | 63" | 69" | 63" | 63" | 64" | 63" | 63" | 63" | 73" | 54" |

Boiler Pressure | 180 psi | 140 psi | 140 psi | 140 psi | 140 psi | 135 psi | 180 psi | 190 psi | 190 psi | 190 psi | 140 psi | 135 psi | 140 psi | 140 psi | 190 psi | 185 psi | 150 psi | 150 psi | 150 psi | 150 psi | 180 psi | 140 psi | 140 psi | 140 psi | 140 psi | 180 psi | 135 psi | 140 psi | 140 psi | 140 psi | 140 psi | 140 psi | 140 psi | 140 psi | 140 psi | 145 psi | 140 psi | 140 psi | 135 psi | 140 psi | 140 psi | 140 psi | 145 psi | 165 psi | 140 psi | 140 psi | 190 psi | 130 psi |

High Pressure Cylinders (dia x stroke) | 18" x 24" (2) | 17" x 24" (2) | 17" x 24" (2) | 14" x 22" (2) | 17" x 24" (2) | 18" x 24" (2) | 17" x 24" (2) | 19" x 24" (2) | 19" x 24" (2) | 19.5" x 26" (2) | 17" x 24" (2) | 15" x 24" (2) | 17" x 24" (2) | 17" x 24" (2) | 19" x 26" (2) | 18" x 24" (2) | 18" x 22" (2) | 18" x 24" (2) | 18" x 24" (2) | 18" x 24" (2) | 18" x 24" (2) | 16" x 24" (2) | 16" x 24" (2) | 17" x 24" (2) | 17" x 24" (2) | 12" x 24" (2) | 17" x 24" (2) | 17" x 24" (2) | 17" x 24" (2) | 17" x 24" (2) | 17" x 24" (2) | 17" x 24" (2) | 17" x 24" (2) | 17" x 24" (2) | 17" x 24" (2) | 17" x 24" (2) | 18" x 24" (2) | 18" x 24" (2) | 16" x 24" (2) | 18" x 24" (2) | 18" x 24" (2) | 18" x 24" (2) | 18" x 24" (2) | 18" x 24" (2) | 18" x 24" (2) | 17" x 24" (2) | 19" x 24" (2) | 15" x 24" (2) |

Low Pressure Cylinders (dia x stroke) | 20" x 24" (2) | |||||||||||||||||||||||||||||||||||||||||||||||

Tractive Effort | 17242 lbs | 13101 lbs | 14739 lbs | 9002 lbs | 13101 lbs | 12747 lbs | 15380 lbs | 18656 lbs | 18656 lbs | 21289 lbs | 13101 lbs | 9836 lbs | 13313 lbs | 13313 lbs | 18948 lbs | 19722 lbs | 14426 lbs | 15737 lbs | 15737 lbs | 15737 lbs | 17242 lbs | 11605 lbs | 12827 lbs | 13990 lbs | 13101 lbs | 12343 lbs | 12633 lbs | 13990 lbs | 13101 lbs | 13990 lbs | 14480 lbs | 13756 lbs | 13101 lbs | 11962 lbs | 13101 lbs | 14489 lbs | 13411 lbs | 13411 lbs | 11191 lbs | 13411 lbs | 14688 lbs | 14688 lbs | 14975 lbs | 17311 lbs | 14688 lbs | 13101 lbs | 19168 lbs | 11050 lbs |

Factor of Adhesion (Weight on Drivers/Tractive Effort) | 3.91 | 4.11 | 3.68 | 4.75 | 4.14 | 4.53 | 4.34 | 4.47 | 4.07 | 4.09 | 3.92 | 3.60 | 3.76 | 3.76 | 4.52 | 3.60 | 3.93 | 3.66 | 3.93 | 3.91 | 4.41 | 3.49 | 3.38 | 3.47 | 3.68 | 5.19 | 4.00 | 3.47 | 3.71 | 3.47 | 3.41 | 3.26 | 3.53 | 4.28 | 4.15 | 3.88 | 3.97 | 4.31 | 3.84 | 5.56 | 3.96 | 3.90 | 4.07 | 4.72 | 4.15 | 3.82 | 4.31 | |

Heating Ability | ||||||||||||||||||||||||||||||||||||||||||||||||

Firebox Area | 137.96 sq. ft | 115 sq. ft | 115 sq. ft | 83 sq. ft | 124.30 sq. ft | 119 sq. ft | 171.77 sq. ft | 186.10 sq. ft | 172.75 sq. ft | 190.17 sq. ft | 115.90 sq. ft | 74 sq. ft | 187 sq. ft | 143 sq. ft | 128.37 sq. ft | 135 sq. ft | 137.61 sq. ft | 146.30 sq. ft | 149.30 sq. ft | 88.20 sq. ft | 92 sq. ft | 104.50 sq. ft | 108.60 sq. ft | 132.20 sq. ft | 114.36 sq. ft | 106.30 sq. ft | 107.20 sq. ft | 106.50 sq. ft | 117 sq. ft | 109.60 sq. ft | 109.60 sq. ft | 108.60 sq. ft | 120 sq. ft | 115 sq. ft | 124.80 sq. ft | 115.90 sq. ft | 134.70 sq. ft | 121.70 sq. ft | 125.20 sq. ft | 135 sq. ft | 126 sq. ft | 135 sq. ft | 119.87 sq. ft | 171 sq. ft | ||||

Grate Area | 16.70 sq. ft | 16 sq. ft | 16 sq. ft | 13.60 sq. ft | 17.50 sq. ft | 17.50 sq. ft | 17.75 sq. ft | 27 sq. ft | 27 sq. ft | 30.22 sq. ft | 16.20 sq. ft | 11.50 sq. ft | 16.20 sq. ft | 17.75 sq. ft | 30.22 sq. ft | 25.20 sq. ft | 15 sq. ft | 15 sq. ft | 15 sq. ft | 16.26 sq. ft | 25 sq. ft | 14.30 sq. ft | 14.50 sq. ft | 15.30 sq. ft | 17.10 sq. ft | 26.70 sq. ft | 16.40 sq. ft | 15.30 sq. ft | 15.30 sq. ft | 15.30 sq. ft | 17 sq. ft | 16 sq. ft | 16 sq. ft | 17.10 sq. ft | 17.50 sq. ft | 17.50 sq. ft | 16.80 sq. ft | 16.80 sq. ft | 14.85 sq. ft | 17.20 sq. ft | 17 sq. ft | 17.50 sq. ft | 17.30 sq. ft | 16.63 sq. ft | 17.30 sq. ft | 17.75 sq. ft | 26.50 sq. ft | 13.50 sq. ft |

Evaporative Heating Surface | 1692 sq. ft | 1090 sq. ft | 1090 sq. ft | 737 sq. ft | 1048 sq. ft | 1378 sq. ft | 1632 sq. ft | 1878 sq. ft | 1937 sq. ft | 2506 sq. ft | 996 sq. ft | 811 sq. ft | 2353 sq. ft | 1700 sq. ft | 1286 sq. ft | 1338 sq. ft | 1567 sq. ft | 1238 sq. ft | 1797 sq. ft | 780 sq. ft | 798 sq. ft | 1030 sq. ft | 1049 sq. ft | 1525 sq. ft | 943 sq. ft | 1031 sq. ft | 1032 sq. ft | 1026 sq. ft | 1154 sq. ft | 1089 sq. ft | 1201 sq. ft | 1049 sq. ft | 1212 sq. ft | 1282 sq. ft | 1173 sq. ft | 1254 sq. ft | 1406 sq. ft | 1171 sq. ft | 1375 sq. ft | 1566 sq. ft | 1549 sq. ft | 1548 sq. ft | 1078 sq. ft | 1854 sq. ft | ||||

Superheating Surface | ||||||||||||||||||||||||||||||||||||||||||||||||

Combined Heating Surface | 1692 sq. ft | 1090 sq. ft | 1090 sq. ft | 737 sq. ft | 1048 sq. ft | 1378 sq. ft | 1632 sq. ft | 1878 sq. ft | 1937 sq. ft | 2506 sq. ft | 996 sq. ft | 811 sq. ft | 0 | 0 | 2353 sq. ft | 1700 sq. ft | 1286 sq. ft | 1338 sq. ft | 1567 sq. ft | 1238 sq. ft | 1797 sq. ft | 780 sq. ft | 798 sq. ft | 1030 sq. ft | 1049 sq. ft | 1525 sq. ft | 943 sq. ft | 1031 sq. ft | 1032 sq. ft | 1026 sq. ft | 1154 sq. ft | 1089 sq. ft | 1201 sq. ft | 1049 sq. ft | 1212 sq. ft | 1282 sq. ft | 1173 sq. ft | 1254 sq. ft | 0 | 1406 sq. ft | 1171 sq. ft | 1375 sq. ft | 1566 sq. ft | 1549 sq. ft | 1548 sq. ft | 1078 sq. ft | 1854 sq. ft | 0 |

Evaporative Heating Surface/Cylinder Volume | 239.37 | 172.88 | 172.88 | 188.02 | 166.22 | 194.95 | 258.84 | 238.45 | 245.94 | 278.84 | 157.97 | 165.22 | 275.78 | 240.50 | 198.47 | 189.29 | 221.69 | 175.14 | 254.22 | 139.66 | 142.88 | 163.36 | 166.38 | 485.42 | 149.56 | 163.52 | 163.68 | 162.73 | 183.03 | 172.72 | 190.48 | 166.38 | 192.23 | 203.33 | 165.95 | 177.40 | 198.91 | 165.66 | 194.52 | 221.54 | 219.14 | 219.00 | 170.98 | 235.40 | ||||

Computations Relating to Power Output (More Information) | ||||||||||||||||||||||||||||||||||||||||||||||||

Robert LeMassena's Power Computation | 3006 | 2240 | 2240 | 1904 | 2450 | 2363 | 3195 | 5130 | 5130 | 5742 | 2268 | 1553 | 2268 | 2485 | 5742 | 4662 | 2250 | 2250 | 2250 | 2439 | 4500 | 2002 | 2030 | 2142 | 2394 | 4806 | 2214 | 2142 | 2142 | 2142 | 2380 | 2240 | 2240 | 2394 | 2450 | 2538 | 2352 | 2352 | 2005 | 2408 | 2380 | 2450 | 2509 | 2744 | 2422 | 2485 | 5035 | 1755 |

Same as above plus superheater percentage | 3006 | 2240 | 2240 | 1904 | 2450 | 2363 | 3195 | 5130 | 5130 | 5742 | 2268 | 1553 | 2268 | 2485 | 5742 | 4662 | 2250 | 2250 | 2250 | 2439 | 4500 | 2002 | 2030 | 2142 | 2394 | 4806 | 2214 | 2142 | 2142 | 2142 | 2380 | 2240 | 2240 | 2394 | 2450 | 2538 | 2352 | 2352 | 2005 | 2408 | 2380 | 2450 | 2509 | 2744 | 2422 | 2485 | 5035 | 1755 |

Same as above but substitute firebox area for grate area | 24833 | 16100 | 16100 | 11620 | 17402 | 16065 | 30919 | 35359 | 32823 | 36132 | 16226 | 9990 | 0 | 0 | 35530 | 26455 | 19256 | 20250 | 20642 | 21945 | 26874 | 12348 | 12880 | 14630 | 15204 | 23796 | 15439 | 14882 | 15008 | 14910 | 16380 | 15344 | 15344 | 15204 | 16800 | 16675 | 17472 | 16226 | 0 | 18858 | 17038 | 17528 | 19575 | 20790 | 18900 | 16782 | 32490 | 0 |

Power L1 | 6975 | 3882 | 3451 | 3909 | 3892 | 4396 | 8178 | 8469 | 8446 | 9135 | 3673 | 3410 | 0 | 0 | 9763 | 6531 | 4686 | 4485 | 5025 | 4388 | 7449 | 3214 | 2996 | 3390 | 3712 | 4734 | 3406 | 3412 | 3656 | 3403 | 3668 | 3635 | 4078 | 4065 | 4225 | 4199 | 4093 | 4176 | 0 | 4736 | 3701 | 4161 | 4904 | 5341 | 4623 | 3911 | 7951 | 0 |

Power MT | 455.62 | 317.56 | 280.23 | 402.70 | 316.04 | 335.35 | 540.53 | 448.28 | 490.01 | 462.97 | 315.08 | 424.13 | 0 | 0 | 502.30 | 405.59 | 364.08 | 343.03 | 358.11 | 314.09 | 432.16 | 349.91 | 305.08 | 307.56 | 339.57 | 326.15 | 297.38 | 309.55 | 331.69 | 308.74 | 327.39 | 357.76 | 388.36 | 350.07 | 342.45 | 329.44 | 338.59 | 318.56 | 0 | 279.92 | 280.39 | 320.19 | 354.47 | 288.25 | 334.16 | 344.89 | 423.92 |

*Chicago and Northwestern 1941-1953*by Lloyd Keyser*Chicago and North Western Power - Modern Steam and Diesel 1900 to 1971*by Patrick C. Dorin (Superior Publishing Co.)*Chicago and North Western Steam Power - 1848 - 1956 - Classes A - Z*by Charles T. Knudsen (Knudsen Publications)*Zeppelins They Were Called, But Zeppelins They Were Not*by Wallace W. Abbey in "Trains" October, 1970 page 20-33- Chicago & North Western Historical Society