Illinois Central 4-6-4 "Hudson" Locomotives in the USA

The Illinois Central rebuilt one of its 2-8-4 "Berkshires" (number 7038) to be a 4-6-4 "Hudson" in its own shops and gave it road number 2499.

When first rebuilt this new "Hudson" had 27 x 30 cylinders, 73.5 drivers, a 270 psi boiler pressure, and a tractive effort of 68,350 pounds. The tractive effort was too great for the weight on the drivers, so this locomotive was very slippery. After extensive tests in 1937, it was decided that the cylinder diameter would be reduced by three inches. After this modification number 2499 was assigned to passenger service.

Class Details by Steve Llanso of Sweat House Media

Class 1/2499 (Locobase 1357)

Data from IC 12 - 1937 Locomotive Diagrams and Illinois Central RR 1 - 1947 Locomotive List supplied in August 2013 by Allen Stanley from his extensive Rail Data Exchange. See also a letter in the November 1997 issue of the "Green Diamond",the Illinois Central Historical Society Magazine as reproduced on [], last accessed 15 November 2015, for full details of the origins of this single Hudson. (Many thanks to Chris Hohl for his 29 April 2015 email pointing out the error in valve gear and his 26 November 2015 email and spreadsheet supplying more details and his 2 February 2016 email correcting a typo in the cylinder diameter.)

Perhaps the only freight Hudson built. An unsuccessful rebuild in May 1937 using the Berkshire 7038's boiler (Locobase 48) and placing it on a one-piece cast-steel bed. While the 1947 Locomotive List states that the shops used the 2038's boiler, the data suggest that only the firebox was retained and a new boiler adopting the Type A superheater was built. Moreover, piston valve diameters decreased from 14" to 12" (356 to 305 mm).

According to the Green Diamond article, a freight-drivered 4-6-4 was an attempt to provide "right-sized" power for fast freight trains. The first set of modifications produced a slippery and top-heavy locomotive that was susceptible to derailing. Because the railroad retained the original 27" cylinders, the 1 generated far too much tractive effort for the weight the engine put on much taller drivers. A photograph shows some odd features, including an outside-equalized front truck,

The account says that it fell to John McIntyre, road foreman of engines at Clinton (Ia), to try to solve some of 1's problems. His rebalancing of the equalizing system to reapportion the weight on the drivers seemed to help. Still, as John S Ingles, writing in Drury (1993) observed, the engine was too powerful for its limited adhesion.

Chris Hohl's research suggests that it was in the late 1930s that the Clinton shops fitted new 24 1/2" cylinders to the 1. Its tractive effort dropped to 55,200 lb and its FofA rose to a more manageable 3.8. In 1947, adhesion weight was given as 198,287 lb (89,942 kg).

A review of the 1937 and 1955 diagram books suggests that the IC originally planned to convert the entire class of 2-8-4s, a supposition prompted by the presentation of the Hudson data on 1937 diagrams showing all 50 engines as converted.

After the 1 revealed how slippery three-axle adhesion could be, it seems that the railroad used the new boiler in its 1939 Berkshire rebuild; see Locobase 15624.

The Green Diamond letter described some of the 1's duties after the 1939 modifications: "From Cimic to Clinton, No. 1 was rated at 4,600 tons while the 2500 series 4-8-2's were rated al 6000 tons. No.1 handled coal trains as well as dispatch trains from Clinton to Markham." It never returned to the Springfield Division.

The IC changed the 1's number to 2499 in July 1945.

he IC also renumbered the 1 to 2499. It was retired in 1950.

Class 1434 (Locobase 6983)

Data from IC 1911 locomotive data supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also E E R Tratman, "Tank Locomotives", Official Proceedings of the Western Railway Club (Chicago: W F Hall Printing Company, 1905), pp. 368.

This set of locomotives were rebuilt from Ten-wheelers that had entered service in the 1880s as Chesapeake, Ohio & Southwestern 37-38 and 42; see Locobase 6995. Like most IC rebuilds, the principal change seems to have swapping the tender for a fixed extension of the frame to hold water and coal while simplifying bi-directional operation.

Tratman quoted Superintendent of Machinery W Renshaw on the operating environment of these engines: ";I]t may be noted that express trains make the run from Randolph St. to Hyde Park (6.57 miles) in 13 minutes, including one stop at Van Buren St. and one at the combination switch just north of 12th St. The rate of speed, including these two stops, is 30.2 miles per hour, while the rate between Van Buren St. and Hyde Park (5.74 miles), including the stop at the switch, is 31.4 miles per hour. This means that the train must attain a speed of 55 to 57 miles per hour for a large part of the distance in order to maintain the schedule time. This speed is frequently exceeded when an engineman wishes to make up time."

Thus detailing particular demands for high acceleration and high average speed, Renshaw described average train weights: "[E]xpress and local trains on all the five runs have from four to six cars and weigh 84 to 126 tons, except that on the Woodlawn run the local trains have three to four cars and weigh 84 to 150 tons."

As a result of the system-wide electrification project begun after passage of the Lake Front Ordinance in 1919, all of this class was sold for scrap in March 1928 when steam service ended.

Class 1437 (Locobase 6984)

Data from IC 1911 locomotive data and 1913 locomotive diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also E E R Tratman, "Tank Locomotives", Official Proceedings of the Western Railway Club (Chicago: W F Hall Printing Company, 1903), pp. 342 et seq.

The railroad built up its suburban tank roster with rebuilds. This quartet began their careers as Chesapeake, Ohio & Southwestern Ten-wheelers 66, 70-71, 73 produced by Schenectady as their works numbers 2042, 2046-2047 in February 1886 and 2049 in March. The design put down more adhesive weight at the expense of a longer wheelbase.

As a result of the system-wide electrification project begun after the IC's acceptance of the Lake Front Ordinance passed on 21 July 1919, all of this class was sold for scrap in March 1928 when steam service ended.

Principal Dimensions by Steve Llanso of Sweat House Media
Locobase ID1357 6983 6984
RailroadIllinois Central (IC)Illinois Central (IC)Illinois Central (IC)
Number in Class134
Road Numbers1/24991434-14361437-1440
Number Built4
Valve GearWalschaertStephensonStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m)12.75 / 3.8911 / 3.3510.50 / 3.20
Engine Wheelbase (ft / m)39.71 / 12.1034.25 / 10.4433.92 / 10.34
Ratio of driving wheelbase to overall engine wheebase 0.32 0.32 0.31
Overall Wheelbase (engine & tender) (ft / m)82.29 / 25.0834.25 / 10.4433.92 / 10.34
Axle Loading (Maximum Weight per Axle) (lbs / kg)70,000 / 31,752
Weight on Drivers (lbs / kg)209,918 / 95,21771,400 / 32,38772,275 / 32,783
Engine Weight (lbs / kg)398,126 / 180,587148,300 / 67,268155,133 / 70,367
Tender Loaded Weight (lbs / kg)286,000 / 129,728
Total Engine and Tender Weight (lbs / kg)684,126 / 310,315148,300155,133
Tender Water Capacity (gals / ML)15,000 / 56.822760 / 10.452760 / 10.45
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)20 / 18.204 / 3.604 / 3.60
Minimum weight of rail (calculated) (lb/yd / kg/m)117 / 58.5040 / 2040 / 20
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)73.50 / 186756.50 / 143556.50 / 1435
Boiler Pressure (psi / kPa)265 / 18.30150 / 10.30150 / 10.30
High Pressure Cylinders (dia x stroke) (in / mm)27" x 30" / 622x76218" x 24" / 457x61018" x 24" / 457x610
Tractive Effort (lbs / kg)67,023 / 30401.1617,548 / 7959.6517,548 / 7959.65
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.13 4.07 4.12
Heating Ability
Firebox Area (sq ft / m2)414 / 38.46122 / 11.3496.20 / 8.94
Grate Area (sq ft / m2)100 / 9.2917.36 / 1.6123.50 / 2.18
Evaporative Heating Surface (sq ft / m2)4773 / 443.421115 / 103.621270 / 118.03
Superheating Surface (sq ft / m2)1355 / 125.88
Combined Heating Surface (sq ft / m2)6128 / 569.301115 / 103.621270 / 118.03
Evaporative Heating Surface/Cylinder Volume240.09157.74179.67
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation26,50026043525
Same as above plus superheater percentage32,33026043525
Same as above but substitute firebox area for grate area133,84618,30014,430
Power L131,08734473499
Power MT979.45319.30320.19

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