Chicago, Burlington & Quincy 2-10-4 "Texas" Type Locomotives

Introduction

The Chicago, Burlington & Quincy Railroad received twelve Texas" type locomotives from the Baldwin Locomotive Works in 1927 and another six Baldwin-built 2-10-4s arrived in 1929. On the CB&Q the 2-10-4s were called "Colorados"

The "Colorados" were designated Class M-4 and were assigned road numbers 6310 through 6327. They were built with 64" diameter drivers, 31" x 32" cylinders, a 250 psi boiler pressure, they had a rated with a tractive effort of 90,000 pounds and each weighed 512,110 pounds.

The boiler had feedwater heater, the valve gear had limited cutoff with 1/4-in lead, 3/8-in lap opening relatively and a 15" piston valves. The firebox heating surface included 43 sq ft of arch tubes and 107 square feet of combustion chamber. The firebox area was 492 square feet. The evaporative heating surface was 5914 square feet and with the superheater the combined heating surface was 8,401 square feet.

All eighteen of the Class M-4 locomotives were rebuilt by the CB&Q in the late 1930s and early 1940s. The cylinder diameter was reduced to 28" with a resultant change in tractive effort to 83,300 pounds and the piston valve was changed to 14". Several other changes were made including substitution of lighter materials, which reduced the total weight of each locomotive to 504,570 pounds. These changes allowed the rebuilt Class M-4a "Colorados" to achieve higher speeds.

There are no surviving CB&Q 2-10-4 "Colorado" type locomotives.

Roster by Richard Duley

ClassQty.Road NumberYear Built Builder Notes
M-4126310-63211927Baldwin1
M-4 66322-63271929Baldwin2
Notes:
  1. Numbers 6310-6321 scrapped in the early 1950s.
  2. Numbers 6322-6327 scrapped in the early 1950s.

Class Details by Steve Llanso

Class M-4 (Locobase 96)

Data from tables and diagram in 1930 Locomotive Cyclopedia and from CB&Q 3 - 1953 Locomotive Diagrams 2 supplied in May 2005 by Allen Stanley from his extensive collection. See also DeGolyer, Vol 81, pp. 386+. Baldwin works numbers were 60210-60211, 60252-60255 in October 1927; 60262, 60281-60283, 60291-60292 in November; 60767-60770 in April 1929; 60805-60806 in May; and 60898 in June.

Boiler had feedwater heater,; Elesco Type K-50 in the first six, Worthington Type BL in the last 12. Valve gear had limited cutoff with 1/4-in lead, 3/8-in lap opening relatively generous 15" piston valves. B4 Power reverse gear from Barco. Duplex stoker moved the coal.

Data for 1927 (6312); tractive effort is usually given as 90,000 lb because in the late 1930s the Burlington reduced the cylinder size to 28" in diameter when they rebuilt ten of the 18 as M-4A; see Locobase 5475.

Firebox heating surface included 43 sq ft of arch tubes and 107 sq ft of combustion chamber.

The Burlington called these Texas-type locomotives "Colorados".

Class M-4A (Locobase 5475)

Data from Corbin & Kerka (1960), p. 133 and from CB&Q 3 - 1953 Locomotive Diagrams 2 supplied in May 2005 by Allen Stanley from his extensive collection.

Boiler had feedwater heater, valve gear had limited cutoff with 1/4-in lead, 3/8-in lap. Firebox heating surface included 43 sq ft of arch tubes and 107 sq ft of combustion chamber.

These are the 10 M-4 Colorados (first described in Locobase 96) that were modified in the late 1930s-early 1940s to improve reliability. The big change was to drop the cylinder diameter to 28" (and the piston valve diameters to 14"), which lowered tractive effort to 83,000 lb and reduced all the demand factors commensurately while raising the factor of adhesion to 4.00. At the same time the railroad fitted disk drivers with better counterbalancing and installed Timken roller bearings on all driving axles, the main rod, and the leading truck bearings.

Boiler had feedwater heater, valve gear had limited cutoff with 1/4-in lead, 3/8-in lap. Firebox heating surface included 43 sq ft of arch tubes and 107 sq ft of combustion chamber.

These are the 10 M-4 Colorados (first described in Locobase 96) that were modified in the late 1930s-early 1940s to improve reliability. The big change was to drop the cylinder diameter to 28" (and the piston valve diameters to 14"), which lowered tractive effort to 83,000 lb and reduced all the demand factors commensurately while raising the factor of adhesion to 4.00. At the same time the railroad fitted disk drivers with better counterbalancing and installed Timken roller bearings on all driving axles, the main rod, and the leading truck bearings.


Specifications by Steve Llanso
ClassM-4M-4A
Locobase ID96 5475
RailroadChicago, Burlington & Quincy (CB&Q)Chicago, Burlington & Quincy (CB&Q)
Whyte2-10-42-10-4
Road Numbers6310-63276311-13, 6315-20, 6322
GaugeStdStd
BuilderBaldwinC B & Q
Year19271935
Valve GearBakerBaker
Locomotive Length and Weight
Driver Wheelbase22.33'22.33'
Engine Wheelbase45'45'
Ratio of driving wheelbase to overall engine wheebase 0.50 0.50
Overall Wheelbase (engine & tender)95.96'95.96'
Axle Loading (Maximum Weight per Axle)
Weight on Drivers353000 lbs333430 lbs
Engine Weight512440 lbs504570 lbs
Tender Light Weight385700 lbs385700 lbs
Total Engine and Tender Weight898140 lbs890270 lbs
Tender Water Capacity21500 gals21500 gals
Tender Fuel Capacity (oil/coal)20 tons20 tons
Minimum weight of rail (calculated) on which locomotive could run118 lb/yard111 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter64"64"
Boiler Pressure250 psi250 psi
Cylinders (dia x stroke)31" x 32"28" x 32"
Tractive Effort102106 lbs83300 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.46 4.00
Heating Ability
Firebox Area492 sq. ft492 sq. ft
Grate Area106.50 sq. ft106.50 sq. ft
Evaporative Heating Surface5914 sq. ft5907 sq. ft
Superheating Surface2487 sq. ft2487 sq. ft
Combined Heating Surface8401 sq. ft8394 sq. ft
Evaporative Heating Surface/Cylinder Volume211.56259.01
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation2662526625
Same as above plus superheater percentage3461334613
Same as above but substitute firebox area for grate area159900159900
Power L12934035956
Power MT916.201188.70

Photos

Reference

Credits

Introduction and roster provided by Richard Duley. Class details and specifications provided by Steve Llanso of Sweat House Media.