Class K1 (Locobase 4395)

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".

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.

Class K2 (Locobase 219)

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. Firebox heating surface includes 34 sq ft in 5 arch tubes. The final set of heating surface areas are shown in the specs.

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 retired in 1957-1959.

Class K3 (Locobase 1423)

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. 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 N&W 3-1955 Locomotive Diagram book supplied in May 2005 by Allen Stanley from his extensive collection 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.