Chesapeake & Ohio 4-6-2 "Pacific" Locomotives in the USA

The Chesapeake and Ohio was among the first railroads to test the 4-6-2 wheel arangement (around 1902) and had at least one 4-6-2 before the Missouri Pacific (from which the wheel arrangement gots its name). The C&O originaly called the 4-6-2s "Mountains", but the name did not stick. Their official name on the C&O was "Ten Wheeler with trailer".

The F-19 class of C&O Pacifics were the only Pacifics to be delivered new with Elesco feedwater heaters, flying (smokebox-mounted) airpumps, and deck-mounted headlights. They all were equiped with vanderbuilt tenders which carried the large C&O logo on the coal bunker sides.

These locomotives became the standard power for the George Washington (a night sleeper train) on most of the route between Washington and Newport News to Chicago. The F-19 class was considered to be the manifestation of the Georgian steam locomotive and was generally believd to be the prettiest locomotives the C&O ever owned.

In 1946 and 1947 they were rebuilt into streamlined class L-1 4-6-4 Hudsons (the road numbers remained the same). One, number 490 still survives at the B&O Railroad Museum.


Roster by Richard Duley

ClassQty.Road NumbersYear BuiltBuilder
F-195490 - 4941925 - 1926 

Class Details by Steve Llanso of Sweat House Media

Class F-15 - 1902 (Locobase 136)

Data from table in AERJ July 1903. See also C&O 9-1936 diagram books supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. Schenectady's works numbers were 26268-26269 in August 1902, 28450-28451 in August 1903. Richmond supplied works numbers 29788 in August 1904 and 29789 in September.

Firebox heating surface included 23 sq ft (2.14 sq m) of arch tubes.

First of a prolific line and designed "under the direction of Mr W S Morris when superintendent of motive power". These had saturated boiler, Stephenson link motion, 12" (305 mm) piston valves, and a classic late 19th-Century profile. Among the first "Pacifics" to be built in the US. See Locobase 7605 for the as-delivered superheated version.

Those saturated engines that were superheated varied in the number of tubes and flues installed . 430's boiler held 149 2 1/4" tubes and 26 5 1/2" flues while 431 had 168 tubes and 30 flues. Almost all of the rest had 166 2 1/4" tubes and 30 5 1/2" flues. New-built F-15s with superheaters installed had 183 2" tubes.


Class F-15 - 1906 (Locobase 11441)

Data from table in AERJ July 1903. Firebox heating surface included 23 sq ft of arch tubes.

First of a prolific line. These had no superheaters, Stephenson link motion, and a classic late 19th-Century profile. Among the first "Pacifics" to be built in the US. See Locobase

7605 for the as-delivered superheated version.

According to the C&O 9-1936 diagram books supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange, those saturated engines that were superheated varied in the number of tubes and flues installed . 430's boiler held 149 2 1/4" tubes and 26 5 1/2" flues while 431 had 168 tubes and 30 flues. Almost all of the rest had 166 2 1/4" tubes and 30 5 1/2" flues. New-built F-15s with superheaters installed had 183 2" tubes.


Class F-15 - 1911 (Locobase 7605)

Data from reproduction of 1913 Alco Bulletin 1016 on Richard Leonard's http://www.railarchive.net/alcopacifics/index.html (accessed 16 June 2006). Works numbers were 49842-49849

In Locobase 136, one of the earliest examples of this long line of C & O Pacifics appears in its saturated version. By the end of the run in 1911, Richmond was delivering the class with superheaters installed. An observer can note the tradeoffs between evaporative heating surface and superheater area. The builder took the unusual approach of reducing the diameter of the individual small tubes from 2 1/4" to 2", but adding 5 1/2" flues instead of the more usual (for the time) 5 3/8". As usual in that period, superheating meant a reduction of boiler pressure, too.

It was a design modification that changed little else. Inside Stephenson link motion still actuated the 12" (305 mm) piston valves, the firebox heating surface retained its 23 sq ft (2.14 sq m) of arch tubes, and the grate area remained unaltered as well.

F-15s were later (1915-1924) rebuilt with superheaters, mechanical stokers, Walschaerts valve gear, new cylinders, and sometimes new frames. Saw steam out on the Chessie.


Class F-16 (Locobase 6489)

Data from Eugene L Huddleston's article in the January 1999 C&O Historical Society Journal. See also Philip Shuster, Eugene Huddleston, and Alvin Staufer; C&O Power (Alvin Staufer, 1965), p. 231.Works numbers were 40070-40073 in June 1913; 40154-40157 in July.

Huddleston says that although these were Baldwin products, they duplicated Alco's #50,000 (see Locobase 128) in grate area, firebox size, heating surface, bore and stroke, and adhesion weight. (Locobase finds that data from C&O Locomotive Diagram book from 1936 (supplied by Allen Stanley in May 2005) shows some differences from the Alco design.) 16" diameter piston valves served the cylinders. Firebox heating surface included 30.8 sq ft (2.79 sq m) of arch tubes. As a concession to the C&O's hilly profile, driver diameter was decreased by 5" (127 mm).

Baldwin's specs reveal that the C&O expected the F-16s to pull a 692 ton train consisting of:

1 steel express and 1 steel postal car, each weighing 113,200 lb (51,347 kg)

1 steel combined car of 130,300 lb (59,103 kg)

1 steel coach of 135,200 lb (61,326 kg)

1 diner of 157,700 lb (71,532 kg)

5 steel sleepers weighing 147,000 lb (66,678 kg).

The ruling grade over which the trains were to keep time was 60 ft/mile (1.1%) over a 13 1/2 mile (21.7 km) stretch from milepost 291 to Allegheny, Va. Up this stretch, the trains were to average 24 mph (38.6 km/h). According to Huddleston, "From their construction in 1913 to their scrappings in 1951-1952, the F-16s served well." At first they hauled flatland expresses trains, later taking the Charlottesville-Newport News and Ashland-Louisville sections. Over the years, the locomotives were fitted with automatic stokers.

After World War II, the class entered what Huddleston describes as heavy-duty local service such as the daily Ashland-Elkhorn run and the Columbus-Toledo "accommodation train."


Class F-17 (Locobase 3075)

Data from "Two Pacific Type Locomotives of High Power", Railway Age Gazette, Volume 57, No 26 (25 December 1914), pp. 1185-.1189. See also Philip Shuster, Eugene Huddleston, and Alvin Staufer; C&O Power (Alvin Staufer, 1965), p. 231. Works numbers were 54621-54626 in August 1914.

These "Mountain Pacifics," if they can be so described, began their careers operating between Charlottesville, Va and Hinton, WVa over three mountain ranges. Their target was to pull ten-car trains (674 tons) at an average speed of 25 1/2 mph (44.3 kph).

In addition to the Schmidt superheater, these engines had a Ragonnet power reverse gear, Locomotive Stoker Company type C, Street mechanical stoker and Franklin pneumatic grate shaker. Firebox heating surface includes 27.4 sq ft (2.55 sq m) of arch tubes.

The boiler pressure seems low; all the dimensions -- including large 16" (406 mm) piston valves -- suggest a design capable of even more power. In the 1930s, their driver diameter was increased to 74" along with several other upgrades. See Locobase 9104.


Class F-17A (Locobase 9104)

Data from the C&O 9-1936 diagram books supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also Philip Shuster, Eugene Huddleston, and Alvin Staufer; C&O Power (Alvin Staufer, 1965), p. 231.

Locobase 3075 describes this Richmond-built sextet as they first saw service rolling on 69" drivers. In the mid-1930s, the C & O rebuilt the engines with 74" Boxpok drivers to enhance their usefulness on heavy passenger trains. Although the boiler layout remained essentially the same and still had the four arch tubes contributing 29 sq ft (2.69 sq m) to firebox heating surface area, boiler pressure increased to 200 psi and the vessel now contained a Worthington feedwater heater; steam was still admitted to the cylinders by large 16" (406 mm) piston valves.

Wheelbase grew by almost a foot, adhesion weight by almost 8 tons and engine weight by almost 11 tons. The loaded tender itself, which rolled on 6 axles, weighed 150 tons and would later grow to 347,000l lb as it held 18,000 gallons of water and 28 tons of coal.


Class F-18A (Locobase 7857)

Data from the C&O 9-1936 diagram books supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also Philip Shuster, Eugene Huddleston, and Alvin Staufer; C&O Power (Alvin Staufer, 1965), p. 234.

In the early 1930s, the class was rebuilt as F-18A and presented final form of the C & O Pacific that's better known from its slightly younger F-19s


Class F-19 (Locobase 137)

Data from 1930 Locomotive Cyclopedia table and from C&O 9-1936 and 12 - 1946 diagram books supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. Works numbers were 66555-66559 in February 1926.

Boiler had feedwater heater, piston valves measured 14"(356 mm) in diameter (less than those of the F-17). The omega of C & O Pacifics, they entered service with 12,000-gallon (45,420 litre), 15-ton (13.6 metric ton) coal tenders, but were later fitted with the enormous vessels shown in the specs. Also, the all in the class were fitted with roller bearings on the engine trucks; most used SKF, 494 rolled on Timkens.

All were converted to L-1s Hudsons in 1946; see Locobase 9382.

Specifications by Steve Llanso of Sweat House Media
ClassF-15 - 1902F-15 - 1906F-15 - 1911F-16F-17
Locobase ID136 11,441 7605 6489 3075
RailroadChesapeake & Ohio (C&O)Chesapeake & Ohio (C&O)Chesapeake & Ohio (C&O)Chesapeake & Ohio (C&O)Chesapeake & Ohio (C&O)
CountryUSAUSAUSAUSAUSA
Whyte4-6-24-6-24-6-24-6-24-6-2
Number in Class2710886
Road Numbers147-153/430-436154-165/437-448166-173/449-456174-181 / 460-467470-475
GaugeStdStdStdStdStd
Number Built2710886
BuilderAlcoAlco-RichmondAlco-RichmondBaldwinAlco-Richmond
Year19021907191119131914
Valve GearStephensonStephensonStephensonWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)12.67 / 3.8612.67 / 3.8612.67 / 3.8613 / 3.9613 / 3.96
Engine Wheelbase (ft / m)32.67 / 9.9632.67 / 9.9632.67 / 9.9634.08 / 10.3934.75 / 10.59
Ratio of driving wheelbase to overall engine wheebase 0.39 0.39 0.39 0.38 0.37
Overall Wheelbase (engine & tender) (ft / m)60 / 18.2960 / 18.2960.71 / 18.5075.19 / 22.9271.96 / 21.93
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)131,000 / 59,421158,000 / 71,668163,000 / 73,936190,000 / 86,183191,455 / 86,843
Engine Weight (lbs / kg)190,000 / 86,183211,000 / 95,708221,000 / 100,244290,000 / 131,542312,605 / 141,795
Tender Loaded Weight (lbs / kg)119,000 / 53,978119,000 / 53,978131,000 / 59,421245,000 / 111,130
Total Engine and Tender Weight (lbs / kg)309,000 / 140,161330,000 / 149,686352,000 / 159,665535,000 / 242,672
Tender Water Capacity (gals / ML)6000 / 22.736000 / 22.737000 / 26.5212,000 / 45.45
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)9 / 8.209 / 8.209 / 8.2015 / 13.60
Minimum weight of rail (calculated) (lb/yd)738891106106
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)72 / 182972 / 182972 / 182974 / 188069 / 1753
Boiler Pressure (psi / kPa)200 / 13.80200 / 13.80190 / 13.10185 / 12.80185 / 12.80
High Pressure Cylinders (dia x stroke) (in / mm)22" x 28" / 559x71122" x 28" / 559x71123" x 28" / 584x71127" x 28" / 686x71127" x 28" / 686x711
Tractive Effort (lbs / kg)31,998 / 14514.0731,998 / 14514.0733,224 / 15070.1743,376 / 19675.0546,519 / 21100.69
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.09 4.94 4.91 4.38 4.12
Heating Ability
Firebox Area (sq ft / m2)205 / 19.05202 / 18.77250.80 / 23.30282.80 / 26.28
Grate Area (sq ft / m2)47 / 4.3747.90 / 4.4546.80 / 4.3560.40 / 5.6180.33 / 7.47
Evaporative Heating Surface (sq ft / m2)3533 / 328.353755 / 348.982938 / 272.953782 / 351.364479 / 416.26
Superheating Surface (sq ft / m2)649 / 60.29879 / 81.66991 / 92.10
Combined Heating Surface (sq ft / m2)3533 / 328.353755 / 348.983587 / 333.244661 / 433.025470 / 508.36
Evaporative Heating Surface/Cylinder Volume286.79304.81218.20203.83241.39
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation94009580889211,17414,861
Same as above plus superheater percentage9400958010,49313,29717,536
Same as above but substitute firebox area for grate area41,00045,28855,21461,735
Power L1888016,57615,92116,983
Power MT448.33672.58554.21586.68

Specifications by Steve Llanso of Sweat House Media
ClassF-17AF-18AF-19
Locobase ID9104 7857 137
RailroadChesapeake & Ohio (C&O)Chesapeake & Ohio (C&O)Chesapeake & Ohio (C&O)
CountryUSAUSAUSA
Whyte4-6-24-6-24-6-2
Number in Class665
Road Numbers470-475188-193/480-485490-494
GaugeStdStdStd
Number Built65
BuilderC & OAlco-RichmondAlco-Richmond
Year193419231926
Valve GearWalschaertBakerBaker
Locomotive Length and Weight
Driver Wheelbase (ft / m)13 / 3.9613 / 3.9613 / 3.96
Engine Wheelbase (ft / m)35.42 / 10.8035.58 / 10.8436.58 / 11.15
Ratio of driving wheelbase to overall engine wheebase 0.37 0.37 0.36
Overall Wheelbase (engine & tender) (ft / m)83.42 / 25.4383.42 / 25.4376.48 / 23.31
Axle Loading (Maximum Weight per Axle) (lbs / kg)67,240 / 30,50067,240 / 30,50066,700 / 30,255
Weight on Drivers (lbs / kg)199,830 / 90,641199,830 / 90,641200,000 / 90,719
Engine Weight (lbs / kg)334,420 / 151,691334,420 / 151,691331,500 / 150,366
Tender Loaded Weight (lbs / kg)300,000 / 136,078305,000 / 138,346347,000 / 157,397
Total Engine and Tender Weight (lbs / kg)634,420 / 287,769639,420 / 290,037678,500 / 307,763
Tender Water Capacity (gals / ML)16,000 / 60.6116,000 / 60.6118,000 / 68.18
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)20 / 18.2020 / 18.2028 / 25.50
Minimum weight of rail (calculated) (lb/yd)111111111
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)74 / 188074 / 188074 / 1880
Boiler Pressure (psi / kPa)200 / 13.80200 / 13.80200 / 13.80
High Pressure Cylinders (dia x stroke) (in / mm)27" x 28" / 686x71127" x 28" / 686x71127" x 28" / 686x711
Tractive Effort (lbs / kg)46,892 / 21269.8846,892 / 21269.8846,892 / 21269.88
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.26 4.26 4.27
Heating Ability
Firebox Area (sq ft / m2)281 / 26.12281 / 26.12281 / 26.12
Grate Area (sq ft / m2)80.70 / 7.5080.70 / 7.5080.70 / 7.46
Evaporative Heating Surface (sq ft / m2)4470 / 415.434239 / 393.964239 / 393.96
Superheating Surface (sq ft / m2)1070 / 99.441213 / 112.731213 / 112.73
Combined Heating Surface (sq ft / m2)5540 / 514.875452 / 506.695452 / 506.69
Evaporative Heating Surface/Cylinder Volume240.91228.46228.46
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation16,14016,14016,140
Same as above plus superheater percentage19,20719,69119,691
Same as above but substitute firebox area for grate area66,87868,56468,564
Power L120,61222,01622,016
Power MT682.20728.67728.05

Reference