Norfolk & Western 2-8-8-2 "Chesapeake" Locomotives in the USA


Class Details by Steve Llanso of Sweat House Media

Class Y-1 (Locobase 10991)

Data from Record of Recent Construction #67 (Baldwin Locomotive Works, 1910), p.28-29. See also DeGolyer, Volume 34, pp. 124+. (Thanks to Greg Mills for his series of March 2018 emails commenting on the N&W's series of 2-8-8-2 and providing the publishing cite for William E Warden, Norfolk & Western's Magnificent Mallets (Lynchburg, VA:TLC Publishing, 1996), see especially page 10.). Works numbers were 34671-34672 and 34696-34698 in May 1910.

Baldwin was experimenting with all kinds of moderate-superheat systems, claiming to believe that such designs were kinder to the locomotive than the higher-temperature kinds. Thus, the heating surface number in the first class of Mallets for the N & W include some uncommon devices that did not contribute anything like the supplemental power that the Schmidt superheater made available.

Between the Baldwin smokebox reheater (which was credited with 586 sq ft/54.44 sq m) and the firetubes themselves was Baldwin's feed water heater in a "separable" boiler. This was a bundle of 450 2 1/4" (57 mm) tubes that filled the boiler's cross-section; water surrounded the tubes and thus was pre-heated before being admitted to the rear boiler to be turned to steam. The reheater in the smokebox intercepted the steam as it left the HP cylinders, dried it out to some degree, and admitted to the LP cylinders.

All four cylinders were fed by large 15" (381 mm) diameter piston valves. The N&W calculated compound tractive effort as 66,892 lb (30,383 kg or 297.55 kN) and starting tractive effort with all cylinders fed live steam 83,615 lb (37,927 kg or 371.94 kN).

See Locobase 13802 for an extended look at the Y-1s' rival, the Alco-Schenectady-built X1 0-8-8-0s. Locobase lifts a paragraph from that entry as a summary in this one:

Which design better suited the purpose of moving freight over the road? Well, according to Drury (1993), "Tests showed the X1 was the better performer, but the leading and trailing trucks of the Y1 gave it better riding stability." He also points out that the Y1s were retired in 1924 because of their complicated separable boilers, while the N&W superheated the X1s and raised their boiler pressures to 230 psi..


Class Y2/Y2a (Locobase 3560)

Data from N&W 3-1955 Locomotive Diagram book supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also "N&W 267-ton Mallet Locomotive", Railway Mechanical Engineer, Vol 92, No 8 (August 1918), pp. 445-450 and "Results of Road Tests of N&W Mallet Locomotive," Vol 92, No 9 (September 1918), pp. 502-503. (Thanks to Chris Hohl for his 21 November 2013 email that noted the sale of fifteen Y-2/Y-2as to the Denver & Rio Grande Railway in 1943; see below. Thanks also to Greg Mills for his series of March 2018 emails commenting on the N&W's series of 2-8-8-2 and providing the publishing cite for William E Warden, Norfolk & Western's Magnificent Mallets (Lynchburg, VA:TLC Publishing, 1996), see especially page 10.).

The first of a long line of compound Mallet Consolidations, Y2s appeared in several batches. Roanoke built five (works numbers 224-258 in 1918, 226 in 1919, and 227-228 in 1921). These were delivered with 24 1/2" (635 mm) diameter HP cylinders. All cylinders used piston valves, the HP diameter taking 14" (356 mm) and the LP cylinders 17" (432 mm). The N&W calculated compound tractive effort as 104,300 lb (47,310 kg or 463.95 kN) and starting tractive effort with all cylinders fed live steam 123,960 lb (56,227 kg or 551.40 kN).

Baldwin supplied twenty in 1918-1919 to USRA standards as shown in the spec above. They had works numbers 51036 in January 1919; 51341 in February; 51514, 51557 in March; 51678,51699-51700 in April; 51813 in May; 51866-51880, 51936-51937 in June; 52298, 52317-52319, 52351 in September; and 52469 in November; and 52676, 52707 in December.

Heating surface area in the electrically welded firebox included 45 sq ft (4.2 sq m) in five arch tubes and 134 sq ft (12.45 sq m) in the combustion chamber. All cylinders used 14" (356 mm) piston valves. The fireman must welcomed the Duplex mechanical stoker that came standard.

RME notes that many of the components and other aspects of the design were sized to deliver the most power within a limited set of clearances. For example, using a thinner plate (13/16"/20.6 mm) in the fourth boiler ring over the combustion chamber saved over 3,000 lb (1,361 kg). RME also notes the use of a Sentinel low-water alarm, which was intended to reduce the tendency to carry too high a water level in the boiler (as a conservative measure to avoid boiler explosions) and thus compromise the efficiency of the superheater.

Roanoke followed with six more in 1924; works numbers were 229-234. The earlier engines were all upgraded to the Y2a configuration and all eventually used 25" (635 mm) diameter HP cylinders. Other than that, the Y2as were not much changed throughout their careers.

One of the class--1702--was fitted in 1927 with Franklin reversible boosters in its two tender trucks. Starting tractive effort was calculated at 33,900 lb (15,377 kg or 138.48 kN).

As the N&W added more modern articulateds, the railway sold half of its Y-2/Y-2as in 1943 to the Denver & Rio Grande Western to boost their power in the face of wartime demands. Classed by the D&RGW as L-109s, the engines were numbered 3550-3594 as follows:

Road numbers D&RGW former N&W Month transferred

3550 1701 April

3551 1722 April

3552 1724 April

3553 1728 April

3554 1729 June

3555 1730 June

3556 1710 August

3557 1727 June

3558 1706 May

3559 1709 May

3560 1713 May

3561 1714 May

3562 1719 May

3563 1725 May

3564 1726 May

Data from Richard Prince, Norfolk & Western Railway, Pocahontas Coal Carrier (Millard, NE: Richard E Prince, 1980).

Prince also reports that the Utah Copper Company bought 1721 and 1723 for the Bingham & Garfield in June 1943. The B&G did not renumber the pair.

The remaining thirteen locomotives were scrapped in 1948-1945


Class Y3/Y3a (Locobase 1421)

Data from N&W 3-1955 Locomotive Diagram book supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also "N& W Applies Power Tender Trucks for Hump Yard Service", Railway Age, Volume 85, (14 July 1928), pp. 59-60. (Thanks to Greg Mills for his series of March 2018 emails commenting on the N&W's series of 2-8-8-2 and providing the publishing cite for William E Warden, Norfolk & Western's Magnificent Mallets (Lynchburg, VA:TLC Publishing, 1996), see especially page 10.). Alco-Schenectady works numbers were 61073-61088 in April 1919, 61089-61112 in May. Alco-Richmond's works numbers were 64070-64079 in March 1923, 64080-64089 in April, 64090-64091 in May, 64092-64099 in June. Baldwin's works numbers were 52157, 52189, 52226, 52250-52251 in August 1919.

This design first came to the N&W as an example of the USRA heavy articulated design (Locobase 330), which itself was based on Norfolk & Western's Y2. Firebox heating surface then included 134 sq ft (12.45 sq m) of arch pipes and syphons, boiler pressure was set at 240 psi (16.5 bar), and the piston valves measured 14" (356 mm) in diameter. The N&W calculated compound tractive effort as 114,154 lb (51,779 kg or 507.78 kN) and starting tractive effort with all cylinders fed live steam 136,985 lb (62,135 kg or 609.34 kN).

2006 received a tender with Bethlehem side-rod-driven tender boosters on each of the two trucks in 1927.

Alco-Schenectady built 45, Baldwin added 5. In 1923, Alco-Richmond delivered 30 more Y3a, which were similar except for a larger tender. Over time the Y3s received a Worthington feed water heater and a different boiler with thirty fewer tubes, but higher boiler pressure, more superheat and a firebox with 65 sq ft (6.04 sq m) of arch tubes. That version is the one shown in the specifications.

Most of both classes that remained with the Norfolk & Western served until 1957-1959.

During World War Two, the N&W sold several Y-3s to other railroads who needed big freight locomotives, but couldn't build them because of wartime production constraints. The Santa Fe bought eight in 1943-- N&W road numbers 2021-2022, 2015, 2026, 2014, 2029, 2035, 2042--which they renumbered 1790-1797 and put to work as helpers on the Raton Pass that crossed the Colorado-New Mexico border.

After the war, the Santa Fe scrapped the 1797 (ex-2042), and sold the other seven to the Virginian as their class USE, road numbers 736-742. The Virginian operated all seven for another seven-eight years before retiring them in 1954-1955.

The Pennsylvania bought class leader 2000 as well as 2008, 2027, 2034, 2036, and 2046 in 1943. (The 2046 was the only Baldwin-built Y-3 sold; the others all came from Alco.) Redesignating them HH1 and numbering 373-378, the Pennsy operated the sextet on drag freights between Hagerstown, Md and Harrisburg, Pa. After World War Two ended, the HH1s were reassigned to the Columbus, Ohio area until they were retired in 1947-1949.

Union Pacific bought five in June 1945--N&W 2030, 2020, 2025, 2041, 2013--which they redesignated MC-57 and numbered 3670-3674. After they operated for two years in Wyoming, the UP scrapped the class.


Class Y3b/Y4 (Locobase 323)

Data from N&W 12-1929 Locomotive Diagram book supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. (Thanks to Chris Hohl for the valve gear ID. Thanks also to Greg Mills for his series of March 2018 emails commenting on the N&W's series of 2-8-8-2 and providing the publishing cite for William E Warden, Norfolk & Western's Magnificent Mallets (Lynchburg, VA:TLC Publishing, 1996), see especially page 10.). Works numbers were 67130-67139 in January 1927.

Firebox had combustion chamber. All four piston valves measured 10" (254 mm) each. Mallet compounds built in a total of eight batches. The ten Y-4s were originally classed as Y-3bs. The large LP cylinders posed some problems in steam exhausting due to the internal design of steam lines, ports, and valves. The N&W calculated compound tractive effort as 114,154 lb (51,779 kg or 507.78 kN) and starting tractive effort with all cylinders fed live steam 136,985 lb (62,135 kg or 609.34 kN).

Updates later in their careers included a Worthington 4 1/2 BL feed water heater, and an increase in boiler pressure to 270 psi (18.6 bar). Tender capacity increased considerably to 24,000 US gallons (90,480 litres) and 27 tons (24.5 of coal

Later N&W engines were built to a larger design; see the Y-6 record.


Class Y4a/Y5 (Locobase 4396)

Data from N&W 3-1955 Locomotive Diagram book supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. (Thanks to Greg Mills for his series of March 2018 emails commenting on the N&W's series of 2-8-8-2 and providing the publishing cite for William E Warden, Norfolk & Western's Magnificent Mallets (Lynchburg, VA:TLC Publishing, 1996), see especially page 10.). Works numbers 246-254 were delivered as Y-4a in 1930, 255-264 arrived as Y-5 in 1931.

Continuation of the N&W series of large Mallet compounds, the Y-5s were first introduced in 1930 as the first "modern" 2-8-8-2s, according to EL King in Drury (1993). In addition to the 300-psi boiler, these engines had the "waffle-iron" nozzles for the low-pressure cylinder exhaust that reduced back pressure. They also had a prominent external steam bridge pipe that formed a shallow, inverted V between the two fron cylinders. Beginning with the Y5s, the railway's calculated compound tractive effort was 126,838 lb (57,533 kg or 564.2 kN) and 152,206 lb (69,040 kg or 677.0 kN) working simple.

The Y4s' outdated fabricated frames couldn't handle the immense power generated by the boiler and cylinder combination and at first they ate up maintenance time. In 1940-1941, however, ten of the remaining Y-4as--2094, 2090, 2098, 2096, 2095, 2100, 2091, 2097, 2099, and 2093--were rebuilt with cast-steel frames and cylinders. They also received Worthington BL feed water heaters.

This fixed the wracking problem and the Y-5s, now virtually identical to the later Y-6s, served out steam on the Norfolk & Western.


Class Y6, Y6a (Locobase 324)

Data from N&W 3-1955 Locomotive Diagram book supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. (Thanks to Greg Mills for his series of March 2018 emails commenting on the N&W's series of 2-8-8-2 and providing the publishing cite for William E Warden, Norfolk & Western's Magnificent Mallets (Lynchburg, VA:TLC Publishing, 1996), see especially page 10.)..Y-6 works numbers were 268-272, 281-310 in 1973-1940. Y-6a continued with 316-331 in 1942.

Continuation of the N&W series of large Mallet compound with the final signficant change in the basic design Y-6 series engines had integrally cast cylinders in cast-steel frames, Beginning with the Y5s, the railway's calculated compound tractive effort was 126,838 lb (57,533 kg or 564.2 kN) and 152,206 lb (69,040 kg or 677.0 kN) working simple. Timken roller bearings on all axles, Worthington feed water heater, and piston valves as large as 18" (457 mm) in diameter. 2154-2170 engines' Baker valve gear used McGill multirol bearings. All engines soon received 58" drivers (1,473 mm).


Class Y6b (Locobase 1422)

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 3 January 2018 email pointing out the Y-6b's 58" diameter drivers. Thanks also to Greg Mills for his series of March 2018 emails commenting on the N&W's series of 2-8-8-2 and providing the publishing cite for William E Warden, Norfolk & Western's Magnificent Mallets (Lynchburg, VA:TLC Publishing, 1996), see especially page 10.). Works numbers were 363-379 in 1948-1949, 391-396 in 1950, and 397, 414-415 in 1951, and 416-419 in 1952.

HP piston valves measured 14" (356 mm) in diameter while the LP valves had an 18" (457 mm) bore. Beginning with the N&W Y5s, the railway's calculated compound tractive effort was 126,838 lb (57,533 kg or 564.2 kN) and 152,206 lb (69,040 kg or 677.0 kN) working simple.

Greg Mills noted in his 30 March 2018 email that the Y6b used "variable valve plumbing" in the LP cylinders to allow simple-expansion steaming in all four cylinders at all speeds, "not just at startup." He adds that the railway "had to add some 26 tons of lead to the front engine frame to prevent slipping." Despite the extra weight, the engine's facto of adhesion operating simple dropped to 3.60.

Heating surface data from N&W diagram book in Allen Stanley's large Rail Data Exchange. Stanley also includes data on the extended combustion chamber variant. The tube and flue areas remained the same, but the superheater was reduced by 60 sq ft (5.57 sq m) and the arch tubes by 41 sq ft (3.81 sq m) while adding 100 sq ft (9.29 sq m) of circulators. The engine also used a Worthington 6 SA feed water heater.

Last in a series of compound articulated locomotives that ranked as the best. See earlier entries on the Y-3, Y-4, Y-5, and Y-6 (Locobases 1421, 323, 4396, and 324). All axles had Timken roller bearings and the valve gear used McGill multirol bearings.

The Y-6bs could divert live, high-pressure steam to the LP cylinders while working compound expansion.

Pulling a load of 13,500 tons (12,273 tonnes) on the level at 25 mph, the Y-6b developed 5,500 indicated horsepower (cut-off of the HP cylinders of 60% and in the LP cylinders 55%). In his 30 March 2018 email, Mills directly compares the Y6bs and the Union Pacific's Big Boys (Locobases 346 and 13026) and concludes: "Considering weight on the rails, power to weight ratios, overall length, practical speeds (which nearly doubled that of the earlier compound Y series), economy of operation, and quantity built, this appears to be the most successful articulated locomotive ever built."

E W King, Jr. (in Drury, 1993) summarizes the story: "In tinkering with the design over a period of 33 years, the road wound up with a locomotive capable of producing 5,600 drawbar horsepower at 25 mph (40 km/h) with a top speed of 50 mph (81 km/h) -- perfect matches for N&W's tonnage, grades, and curves ... while retaining the economies of compound operation and in a locomotive that weighed 100,000 lb less than either the [C&O's] 2-6-6-6 or [UP's] 4-8-8-4 [Big Boy]."

These engines were carefully maintained and well-designed, yielding to diesels only because the N&W could no longer afford to be the "odd man out" in the diesel parade. The last Y-6 was completed in 1952, and the last one ran in April 1960..

Principal Dimensions by Steve Llanso of Sweat House Media
ClassY-1Y2/Y2aY3/Y3aY3b/Y4Y4a/Y5
Locobase ID10,991 3560 1421 323 4396
RailroadNorfolk & Western (N&W)Norfolk & Western (N&W)Norfolk & Western (N&W)Norfolk & Western (N&W)Norfolk & Western (N&W)
CountryUSAUSAUSAUSAUSA
Whyte2-8-8-22-8-8-22-8-8-22-8-8-22-8-8-2
Number in Class531801010
Road Numbers995-9991700-17302000-20792080-20892101-2109, 2110-2119
GaugeStdStdStdStdStd
Number Built531801010
BuilderBaldwinseveralSeveralAlco-RichmondN&W
Year19101918191919271930
Valve GearWalschaertBakerBakerBakerBaker
Locomotive Length and Weight
Driver Wheelbase (ft / m)15.50 / 4.7215.50 / 4.7215.75 / 4.8015.75 / 4.8015.75 / 4.80
Engine Wheelbase (ft / m)55.50 / 16.9257.33 / 17.4758 / 17.6858 / 17.6858 / 17.68
Ratio of driving wheelbase to overall engine wheebase 0.28 0.27 0.27 0.27 0.27
Overall Wheelbase (engine & tender) (ft / m)83.28 / 25.38101.02 / 30.79102.02 / 31.1098.23 / 29.94102.75 / 31.32
Axle Loading (Maximum Weight per Axle) (lbs / kg)65,500 / 29,710
Weight on Drivers (lbs / kg)360,000 / 163,293472,000 / 214,096485,200 / 220,083508,500 / 230,652522,850 / 237,161
Engine Weight (lbs / kg)390,000 / 176,901526,000 / 238,590539,000 / 244,487567,000 / 257,187582,900 / 264,399
Tender Loaded Weight (lbs / kg)170,000 / 77,111312,700 / 141,839312,700 / 141,839271,200 / 123,014378,600 / 171,730
Total Engine and Tender Weight (lbs / kg)560,000 / 254,012838,700 / 380,429851,700 / 386,326838,200 / 380,201961,500 / 436,129
Tender Water Capacity (gals / ML)9000 / 34.0918,000 / 68.1820,000 / 75.7616,000 / 60.6122,000 / 83.33
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)14 / 12.7026 / 23.6026 / 23.6023 / 20.9030 / 27.30
Minimum weight of rail (calculated) (lb/yd / kg/m)75 / 37.5098 / 49101 / 50.50106 / 53109 / 54.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)56 / 142256 / 142257 / 144857 / 144857 / 1448
Boiler Pressure (psi / kPa)200 / 13.80265 / 18.30270 / 18.60240 / 16.50300 / 20.70
High Pressure Cylinders (dia x stroke) (in / mm)24.5" x 30" / 622x76225" x 32" / 635x81325" x 32" / 635x81325" x 32" / 635x81325" x 32" / 635x813
Low Pressure Cylinders (dia x stroke) (in / mm)39" x 30" / 991x76239" x 32" / 991x81339" x 32" / 991x81339" x 32" / 991x81339" x 32" / 991x813
Tractive Effort (lbs / kg)78,394 / 35558.96114,034 / 51725.01114,148 / 51776.72101,465 / 46023.80126,831 / 57529.64
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.59 4.14 4.25 5.01 4.12
Heating Ability
Firebox Area (sq ft / m2)210 / 19.51468 / 43.48453 / 42.10426 / 39.58430 / 39.96
Grate Area (sq ft / m2)75.20 / 6.9996.30 / 8.9596 / 8.9296 / 8.92106.20 / 9.87
Evaporative Heating Surface (sq ft / m2)5908 / 548.876308 / 586.035753 / 534.675932 / 551.105822 / 541.08
Superheating Surface (sq ft / m2)586 / 54.441567 / 145.581582 / 147.031582 / 146.971582 / 147.03
Combined Heating Surface (sq ft / m2)6494 / 603.317875 / 731.617335 / 681.707514 / 698.077404 / 688.11
Evaporative Heating Surface/Cylinder Volume360.92346.96316.44326.28320.23
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation15,04025,52025,92023,04031,860
Same as above plus superheater percentage16,39430,62331,62227,87838,551
Same as above but substitute firebox area for grate area45,780148,824149,218123,710156,090
Power L1550512,71812,90311,49214,307
Power MT269.70475.23469.02398.59482.61

Principal Dimensions by Steve Llanso of Sweat House Media
ClassY6, Y6aY6b
Locobase ID324 1422
RailroadNorfolk & Western (N&W)Norfolk & Western (N&W)
CountryUSAUSA
Whyte2-8-8-22-8-8-2
Number in Class5130
Road Numbers2120-21702171-2200
GaugeStdStd
Number Built5130
BuilderN&WN&W
Year19421948
Valve GearBakerBaker
Locomotive Length and Weight
Driver Wheelbase (ft / m)15.75 / 4.8015.75 / 4.80
Engine Wheelbase (ft / m)58 / 17.6858 / 17.68
Ratio of driving wheelbase to overall engine wheebase 0.27 0.27
Overall Wheelbase (engine & tender) (ft / m)103.85 / 31.65114.87 / 35.01
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)522,850 / 237,161548,500 / 248,796
Engine Weight (lbs / kg)582,900 / 264,399611,520 / 277,381
Tender Loaded Weight (lbs / kg)378,600 / 171,730378,600 / 171,730
Total Engine and Tender Weight (lbs / kg)961,500 / 436,129990,120 / 449,111
Tender Water Capacity (gals / ML)22,000 / 83.3322,000 / 83.33
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)30 / 27.3030 / 27.30
Minimum weight of rail (calculated) (lb/yd / kg/m)109 / 54.50114 / 57
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)57 / 144858 / 1473
Boiler Pressure (psi / kPa)300 / 20.70300 / 20.70
High Pressure Cylinders (dia x stroke) (in / mm)25" x 32" / 635x81325" x 32" / 635x813
Low Pressure Cylinders (dia x stroke) (in / mm)39" x 32" / 991x81339" x 32" / 991x813
Tractive Effort (lbs / kg)126,831 / 57529.64124,644 / 56537.63
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.12 4.40
Heating Ability
Firebox Area (sq ft / m2)430 / 39.96555 / 51.56
Grate Area (sq ft / m2)106.20 / 9.87106.20 / 9.87
Evaporative Heating Surface (sq ft / m2)5647 / 524.814915 / 456.61
Superheating Surface (sq ft / m2)1775 / 164.961478 / 137.31
Combined Heating Surface (sq ft / m2)7422 / 689.776393 / 593.92
Evaporative Heating Surface/Cylinder Volume310.61270.34
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation31,86031,860
Same as above plus superheater percentage39,50639,188
Same as above but substitute firebox area for grate area159,960204,795
Power L115,31313,759
Power MT516.54442.42

Photos