During World War I, the USRA took over the railroads and it supplied the N&W with ten "Heavy Mountains" (road numbers 116 through 125). They were built by the American Locomotive Company and were designated as Class K-2 . These locomotives had 28 x 30 cylinders, 69" drivers, a 200 psi boiler pressure, exerted 57,950 lbs of tractive effort and weighed 359,460 pounds. Another twelve (road numbers 126 through 137) were bought from the Baldwin Locomotive Works in 1923. This group of twelve, designated Class K-2a, were identical to the ten built by ALCO in 1919. Later, road numbers 116 through 137 were up-dated and received semi-streamlining, 70" drivers, an increased boiler pressure of 220 psi resulting in 62,832 lbs of tractive effort.
In 1926, the Roanoke Shops built ten "Mountains" (road numbers 200 through 209). These locomotives, designated Class K-3, had 28 x 30 cylinders, 63" drivers, a boiler pressure of 225 psi and exerted 68,880 lbs of tractive effort. They were built for through freight service, but because they could not provide the speed needed they were assigned to coal freight. This group was later sold to the D&RGW and the RF&P, during World War II, only to come back as W&LE numbers 6801 through 6810.
There are no surviving N&W "Mountains".
|Class||Road Numbers||Year Built||Builder|
|K-1||100 - 107||1916||N&W|
|K-1||108 - 115||1917||N&W|
|K-2||116 - 125||1919||ALCO|
|K-2a||126 - 137||1923||Baldwin|
|K-3||200 - 209||1926||N&W|
Data from table in July 1916 issue of Railway Mechanical Engineer (RME) with corrections from the N&W 3-1955 Locomotive Diagram book supplied in May 2005 by Allen Stanley from his extensive collection. The RME article gave a tube count of 233 which contributed to an overall heating surface area of 3,984 sq ft. Tthe N & W book showed the 220 and total area given in the specs. The first tender carried 9,000 US gallons of water and 14 tons of coal; total weight was 146,700 lb. Over time, of course, the tender's capacity and weight more than doubled as is documented in the specs.
Because they came four years later, the railway had some modifications to make to the original USRA design. Firebox heating surface includes 34 sq ft in five arch tubes and 115 sq ft (10.7 sq m) in the combustion chamber. Fourteen-inch (356 mm) piston valves supplied steam to the cylinders.
Some were streamlined in the style of the N&W's J-class 4-8-4s. In the late 1940s, in apparent defiance of the diesel revolution, N&W fitted the K-2s with roller bearings on all but the drivers, new fireboxes and stokers, and new cylinders. Given the road's great investment and skill in locomotive construction and, still more important, extensive maintenance, this virtual rebuild made sense. Even so, the class was retired and scrapped in 1957-1959.
Firebox heating surface includes 34 sq ft of arch tubes
Dropping the driver diameter size of the K-2s from 69" to 63" and driving the set from the third driver led to counterbalancing problems, according to EW King, Jr. (in Drury, 1993): "[They] rode hard, and they raised havoc with the track at speeds over 35 mph."
In contrast to the long-lived K-2s, the K-3s were sold off in 1944-1945 (6 to RF&P and 4 D&RGW -- all ten went to Wheeling & Lake Erie in 1948.).
An interesting sidelight in the 1955 diagram book was the "Proposal A" for a Class N 4-8-4. After some study of the diagram, the design proved to be a mating of the K3 boiler and running gear with a new, larger grate that would have measured 100.1 sq ft. Although the diagram shows a total direct heating surface equal to that of the K3, Locobase believes it would certainly have had more. With the boiler pressed to 225 psi, tractive effort was estimated at 68,880 lb.
|Specifications by Steve Llanso|
|Railroad||Norfolk & Western (N&W)||Norfolk & Western (N&W)||Norfolk & Western (N&W)|
|Locomotive Length and Weight|
|Ratio of driving wheelbase to overall engine wheebase||0.46||0.46||0.43|
|Overall Wheelbase (engine & tender)||72.92'||87.92'||83.40'|
|Axle Loading (Maximum Weight per Axle)||68917 lbs|
|Weight on Drivers||240700 lbs||248150 lbs||275400 lbs|
|Engine Weight||353900 lbs||359460 lbs||401900 lbs|
|Tender Light Weight||314340 lbs||378600 lbs||286530 lbs|
|Total Engine and Tender Weight||668240 lbs||738060 lbs||688430 lbs|
|Tender Water Capacity||18000 gals||22000 gals||16000 gals|
|Tender Fuel Capacity (oil/coal)||26 tons||30 tons||23 tons|
|Minimum weight of rail (calculated) on which locomotive could run||100 lb/yard||103 lb/yard||115 lb/yard|
|Geometry Relating to Tractive Effort|
|Boiler Pressure||200 psi||220 psi||220 psi|
|Cylinders (dia x stroke)||29" x 28"||28" x 30"||28" x 30"|
|Tractive Effort||57188 lbs||62832 lbs||69813 lbs|
|Factor of Adhesion (Weight on Drivers/Tractive Effort)||4.21||3.95||3.94|
|Firebox Area||374 sq. ft||369 sq. ft||410 sq. ft|
|Grate Area||80.30 sq. ft||76.30 sq. ft||84 sq. ft|
|Evaporative Heating Surface||3857 sq. ft||4470 sq. ft||4834 sq. ft|
|Superheating Surface||882 sq. ft||1085 sq. ft||1380 sq. ft|
|Combined Heating Surface||4739 sq. ft||5555 sq. ft||6214 sq. ft|
|Evaporative Heating Surface/Cylinder Volume||180.19||209.07||226.10|
|Computations Relating to Power Output (More Information)|
|Robert LeMassena's Power Computation||16060||16786||18480|
|Same as above plus superheater percentage||19111||20143||22546|
|Same as above but substitute firebox area for grate area||89012||97416||110044|