Louisville & Nashville 4-8-2 "Mountain" Locomotives in the USA

The Louisville & Nashville Railroad took delivery of 16 USRA design 4-8-2s in 1926. These locomotives had 27 x 30 cylinders, 70" drivers, a boiler pressure of 200 psi, exerted 53,900 lbs of tractive effort and each weighed 334,240 pounds. They were built by the Baldwin Locomotive Works, designated Class L-1, carried road numbers 400 through 415 and were assigned to passenger service.

In 1930, six more Class L-1s came from Baldwin and were assigned road numbers 416 through 421. These locomotives were similar to the ones delivered in 1922 except they weighed 3,490 lbs more. The "Mountains" were later transferred to freight service and later their boiler pressure was raised to 210 psi to increase tractive effort to 55,800 pounds.

To open up a block of numbers for newly arriving GP7s in the early 1950s, the 14 remaining L-1 "Mountains" were renumbered in 1953 and they then carried road numbers 470 through 483.

There are no surviving L&N "Mountains".


Roster

ClassQty.Road NumbersYear BuiltBuilder
L-116400-4151926Baldwin
L-16416-4211930Baldwin

Class Details by Steve Llanso of Sweat House Media

Class L-1 (Locobase 209)

Data from L & N 8-1927 locomotive diagram book supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange, supplemented by DeGolyer, Vol 76, pp. 63+. Works numbers were 58877-58878 in December 1925, 58910-58915 in January, 59523-59527 in September, 59550-59552 in October.

Firebox had combustion chamber surface area amounting to 104 sq ft (9.67 sqm) and 28 sq ft (2.6 sq m) of arch tubes contributed to firebox heating surface area. Based on the USRA light Mountain design (Locobase 231) that saw service throughout the L&N system except for the Gulf Coast west of Mobile. The last five of the class were delivered with significant modifications to the fireboxes; see Locobase 14353.

Charles B Castner in Drury (1993) tells us that the Mountains stepped right into heavy mainline passenger service between Cincinnati and Atlanta with some trains continuing on to Birmingham. Barred by bridge loading limits from operating further south, the 4-8-2s later added Louisville-East St Louis trains and even freights. They saw out steam on the L & N, retiring in the mid-1950s.


Class L-1 - 1930 (Locobase 14353)

Data from DeGolyer, Volume 82, pp. 147+ and L&N 8-1927 locomotive diagram book supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also Richard E Prince, Louisville & Nashville Steam Locomotives (1968, reprinted by Indiana University Press in 2000), p. 126. Works numbers were 61541-61542, 61549-61552 in October 1930

Locobase 209 describes the first sixteen L-1s from 1926, which were based on the USRA's Light Mountain (Locobase 231) design. In this later sextet, the L&N devoted even more space to direct heating surface area. The combustion chamber now added 113 sq ft (10.5 sq m) and thermic syphons contributed 72 sq ft (6.7 sq m); arch tube area was cut in hafl to 14 sq ft (1.3 sq m).

Prince says this group hauled Cincinnati to Atlanta expresses and the Southland and Flamingo expresses to Florida. Over the road times on the 489 miles (787 km) between the two major cities was as low as 11 hours and 20 minutes, averaging 43.3 mph; 70 km/h). The trains stopped for coal and water six times and the run included one change of engines at Corbin. According to Prince: "This performance would seem quite remarkable considering the mountainous terrain encountered on this route."

Principal Dimensions by Steve Llanso of Middle Run Media
ClassL-1L-1 - 1930
Locobase ID209 14353
RailroadLouisville & Nashville (L&N)Louisville & Nashville (L&N)
CountryUSAUSA
Whyte4-8-24-8-2
Number in Class165
Road Numbers400-415416-421
GaugeStdStd
Number Built166
BuilderBaldwinBaldwin
Year19261930
Valve GearWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)18.25 / 5.5618.25 / 5.56
Engine Wheelbase (ft / m)40 / 12.1940 / 12.19
Ratio of driving wheelbase to overall engine wheelbase 0.46 0.46
Overall Wheelbase (engine & tender) (ft / m)75.70 / 23.0775.70 / 23.07
Axle Loading (Maximum Weight per Axle) (lbs / kg)57,400 / 26,03657,100
Weight on Drivers (lbs / kg)223,950 / 101,582226,910 / 102,693
Engine Weight (lbs / kg)333,100 / 151,092337,730 / 151,609
Tender Loaded Weight (lbs / kg)194,000 / 87,997196,000 / 88,904
Total Engine and Tender Weight (lbs / kg)527,100 / 239,089533,730 / 240,513
Tender Water Capacity (gals / ML)10,000 / 37.8810,000 / 37.88
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)16 / 1519 / 17
Minimum weight of rail (calculated) (lb/yd / kg/m)93 / 46.5095 / 47.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)69 / 175369 / 1753
Boiler Pressure (psi / kPa)200 / 1380200 / 1380
High Pressure Cylinders (dia x stroke) (in / mm)27" x 30" / 686x76227" x 30" / 686x762
Tractive Effort (lbs / kg)53,883 / 24440.9553,883 / 24440.95
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.16 4.21
Heating Ability
Tubes (number - dia) (in / mm)190 - 2.25" / 57190 - 2.25" / 57
Flues (number - dia) (in / mm)45 - 5.5" / 14045 - 5.5" / 140
Flue/Tube length (ft / m)20.50 / 6.2520.50 / 6.25
Firebox Area (sq ft / m2)351 / 32.61415 / 38.55
Grate Area (sq ft / m2)70.30 / 6.5370.80 / 6.58
Evaporative Heating Surface (sq ft / m2)3959 / 367.804023 / 373.75
Superheating Surface (sq ft / m2)1078 / 100.151087 / 100.98
Combined Heating Surface (sq ft / m2)5037 / 467.955110 / 474.73
Evaporative Heating Surface/Cylinder Volume199.14202.36
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation14,06014,160
Same as above plus superheater percentage17,01317,134
Same as above but substitute firebox area for grate area84,942100,430
Power L117,83518,373
Power MT702.29714.04

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