Norfolk & Western 4-8-2 "Mountain" Locomotives in the USA

The Norfolk & Western Railway built its first eight "Mountains" in its shops in Roanoke, VA during 1916. These locomotives (Class K-1, road numbers 100 through 107) had 29 x 28 cylinders, 70" drivers, a boiler pressure of 220 psi, exerted 69,920 lbs of traction effort and weighed 347,000 pounds. The following year another eight (road numbers 108 through 115) duplicates of the first Class K-1s, were built. All of these 4-8-2s entered passenger service.

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".

Roster

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

Class Details by Steve Llanso of Sweat House Media

Class K1 (Locobase 4395)

Data from table in July 1916 issue of Railway Mechanical Engineer (RME) with corrections from the N&W 12-1929 and 3-1955 Locomotive Diagram books supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange.

EW King, Jr. (in Drury, 1993) says these passenger Mountains had "over-square" cylinders in an effort to reduce piston speed at a given road speed. The arrangement, says King, "resulted in the K1s being hard starters".

The RME article and the N&W 12-1929 diagram book gave a tube count of 233 which contributed to an overall heating surface area of 3,984 sq ft. A later N&W book showed the 220 tubes and total area given in the specs. The first tender carried 9,000 US gallons (34,065 litres) of water and 14 tons (12.7 metric tons) of coal; total weight was 146,700 lb (66,542 kg). Over time, of course, the tender's capacity and weight more than doubled as is documented in the specs.

Class K2 (USRA) (Locobase 219)

Data from N&W 12-1929 Locomotive Diagrams supplied in March 2004 by Allen Stanley from his extensive Rail Data Exchange and DeGolyer, Vol 68, pp. 55+. Heavy USRA 4-8-2s built by Alco's Brooks works in 1919 (K-2, 116-125) and Baldwin (K-2a, 126-137) in 1923. Baldwin's works numbers were 56138 in January 1923, 56279-56289 in March.

Because they came four years later, the railway had some modifications to make to the original USRA design (Locobase 232). Firebox heating surface includes 34 sq ft (3.16 sq m) 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.

Class K3 (Locobase 1423)

Data from N&W 3-1955 Locomotive Diagram book supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. (Thanks to Chris Hohl for his 27 August 2018 email giving the details for this class's post-N&W service.) Roanoke works numbers were 235-238 in August 1926, 239-242 in September, 243-244 in October.

Firebox heating surface includes 34 sq ft (3.16 sq m) of arch tubes

Dropping the driver diameter size of the K-2s (Locobase 219) 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 [56 kph]."

In contrast to the K-2s, which never left the N&W, the K-3s were sold off in 1944-1945. 200-205 went to the Richmond, Fredericksburg & Potomac as their 515-520. 206-209 were sent to the Denver & Rio Grande Western as that railroad's 1550-1553.

In 1948, both railroads sold their ex-K3s to the Wheeling & Lake Erie, where they were placed in their own J-1 class and renumbered 6801-6810. Although all ten were accepted and renumbered, only four-6804-6806 and 6808--entered service on the W&LE. These were renumbered 844-846 and 848 by the New York, Chicago & St Louis (Nickel Plate) when that road merged with the W&LE in 1950. Regardless of their operating status, the rush of dieselization sent every engine to the scrapyard between 1952 and 1954.

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.