Chicago, Burlington & Quincy 2-10-4 "Texas" Locomotives in the USA

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 of Sweat House Media

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 Rail Data Exchange. See also DeGolyer, Volume 81, pp. 386+. (Thanks to Chris Hohl for his 9 September 2016 email reporting the tender's original coal capacity and for his 22 September 2017 email reporting unlikely boiler pressure values for 177 entries. A Locobase macro caused the error .) 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.

Boiler had a feed water 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 (6.3 mm) lead, 3/8-in (9.5 mm) lap opening relatively generous 15" (381 mm) 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 (3.99 sq m) of arch tubes and 107 sq ft (9.94 sq m) 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 Rail Data Exchange.

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 of Sweat House Media
ClassM-4M-4A
Locobase ID96 5475
RailroadChicago, Burlington & Quincy (CB&Q)Chicago, Burlington & Quincy (CB&Q)
CountryUSAUSA
Whyte2-10-42-10-4
Number in Class1810
Road Numbers6310-63276311-13, 6315-20, 6322
GaugeStdStd
Number Built18
BuilderBaldwinCB&Q
Year19271935
Valve GearBakerBaker
Locomotive Length and Weight
Driver Wheelbase (ft / m)22.33 / 6.8122.33 / 6.81
Engine Wheelbase (ft / m)45 / 13.7245 / 13.72
Ratio of driving wheelbase to overall engine wheebase 0.50 0.50
Overall Wheelbase (engine & tender) (ft / m)95.96 / 29.2595.96 / 29.25
Axle Loading (Maximum Weight per Axle) (lbs / kg)72,800 / 33,022
Weight on Drivers (lbs / kg)353,000 / 160,118333,430 / 151,241
Engine Weight (lbs / kg)512,440 / 232,439504,570 / 228,869
Tender Loaded Weight (lbs / kg)385,700 / 174,951385,700 / 174,951
Total Engine and Tender Weight (lbs / kg)898,140 / 407,390890,270 / 403,820
Tender Water Capacity (gals / ML)21,500 / 81.4421,500 / 81.44
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)24 / 21.8020 / 18.20
Minimum weight of rail (calculated) (lb/yd / kg/m)118 / 59111 / 55.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)64 / 162664 / 1626
Boiler Pressure (psi / kPa)250 / 17.20250 / 17.20
High Pressure Cylinders (dia x stroke) (in / mm)31" x 32" / 787x81328" x 32" / 711x813
Tractive Effort (lbs / kg)102,106 / 46314.5683,300 / 37784.29
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.46 4.00
Heating Ability
Firebox Area (sq ft / m2)492 / 45.71492 / 45.72
Grate Area (sq ft / m2)106.50 / 9.89106.50 / 9.90
Evaporative Heating Surface (sq ft / m2)5914 / 549.425907 / 549.63
Superheating Surface (sq ft / m2)2487 / 231.052487 / 231.13
Combined Heating Surface (sq ft / m2)8401 / 780.478394 / 780.76
Evaporative Heating Surface/Cylinder Volume211.56259.01
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation26,62526,625
Same as above plus superheater percentage34,61334,613
Same as above but substitute firebox area for grate area159,900159,900
Power L129,34035,956
Power MT916.201188.70

Photos

Reference