Delaware, Lackawanna &Western 4-8-4 "Northern" Type Locomotives

Class Q1 (Locobase 259)

Data from DL&W 3 - 1938 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive collection. See also Robert A LeMassena, "The USRA HEAVY 4-8-2 and its Illustrious Ascendants", Railway & Locomotive Historical Society Newsletter (Vol 23, #2 - Spring 2003).

In his study of the USRA Heavy Mountain (see Locobase 232) and the locomotives it inspired, LeMassena notes that the DL&W had procured five 4-8-2s based on the USRA design but equipped with larger fireboxes ( Locobase 5731). Soon the railroad came back for still bigger descendants of the basic design that needed another axle under the firebox. Thus were erected the first DL&W 4-8-4s (Alco works #67526-67530). Called Poconos, this group of five engines led the way for 50 more. They had 88 sq ft of thermic syphons and 28 sq ft of arch tubes as part of their firebox heating surface. Also, they had the tallest drivers of any of the DL&W 4-8-4s.

Class Q2 (Locobase 260)

Data from DL&W 3 - 1938 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive collection. Alco works # ran in a batch: 67799-67818.

The next step in the DL&W's Pocono parade belonged to this dual-traffic design. Simliar in most respects to the Brooks-built Q1 (Locobase 259), the new class had smaller drivers and were expected to haul fast freights as well as passenger trains. Firebox had 110.5 sq ft of thermic syphons and 27.5 sq ft of arch tubes contributing to the heating surface.

Class Q3/Q3a (Locobase 9246)

Data from DL&W 3 - 1938 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive collection. See also Robert A LeMassena, "The USRA HEAVY 4-8-2 and its Illustrious Ascendants", Railway & Locomotive Historical Society Newsletter (Vol 23, #2 - Spring 2003).

This class (Alco works #68623-68632) represented a big boiler redesign compared to the Q2s that had preceded it only a few years earlier (see Locobase 260). Superpower dimensions had arrived: the number of firetubes shrank dramatically while scores of new, smaller-diameter flues for the Type E superheated resulted in an 69% increase in supeheater area (or more than 900 sq ft). The firebox saw little change and had 110 sq ft of thermic syphons and 27 sq ft of arch tubes contributing to the heating surface.

Also, LeMassena notes, the Q3s pioneered roller bearings on the Lackawanna with the first 8 (Q3) sporting roller bearings on the lead trucks and the last two (Q3a) fitted with roller bearings on all engine axles.

Class Q4 (Locobase 9247)

Data from DL&W 3 - 1938 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive collection. See also Robert A LeMassena, "The USRA HEAVY 4-8-2 and its Illustrious Ascendants", Railway & Locomotive Historical Society Newsletter (Vol 23, #2 - Spring 2003).

The last variant of the DL&W's sizable 4-8-4 stud, the Q4 also sported a superpower boiler on a slightly smaller scale than the Q3 (Locobase 9246), but pressed to a higher degree. The firebox, too, was a bit smaller with 95 sq ft of thermic syphons and 27 sq ft of arch tubes contributing to the heating surface. Driver diameter increased by 4" and the Q4s also traveled on roller bearings on all engine axles.

LeMassena says: "Although intended for fast freight trains between Buffalo and Binghamton, New York, these locomotives handled perishables eastward to Hoboken, New Jersey, returning westward on mainline passenger trains."

Specifications
ClassQ1Q2Q3/Q3aQ4
Locobase ID25926092469247
RailroadDelaware, Lackawanna &WesternDelaware, Lackawanna &WesternDelaware, Lackawanna &WesternDelaware, Lackawanna &Western
Whyte4-8-44-8-44-8-44-8-4
Road Numbers1501-15051600-16201621-16301631-1650
GaugeStdStdStdStd
BuilderAlco-BrooksAlco-SchenectadyAlco-SchenectadyAlco-Schenectady
Year1927192919321934
Valve GearBakerWalschaertWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase20'19'19'19.50'
Engine Wheelbase46.67'45.50'45.50'46.08'
Ratio of driving wheelbase to overall engine wheebase 0.43 0.42 0.42 0.42
Overall Wheelbase (engine & tender)82.21'84.62'84.62'86.54'
Axle Loading (Maximum Weight per Axle)
Weight on Drivers269000 lbs262000 lbs270000 lbs274000 lbs
Engine Weight421000 lbs418000 lbs432000 lbs447000 lbs
Tender Light Weight221500 lbs289000 lbs287200 lbs313000 lbs
Total Engine and Tender Weight642500 lbs707000 lbs719200 lbs760000 lbs
Tender Water Capacity12000 gals15000 gals15000 gals16000 gals
Tender Fuel Capacity (oil/coal)16 tons22 tons22 tons26 tons
Minimum weight per yard of rail on which locomotive could run112.08 lb rail109.17 lb rail112.50 lb rail114.17 lb rail
Geometry Relating to Tractive Effort
Driver Diameter77"70"70"74"
Boiler Pressure250 psi230 psi235 psi250 psi
Cylinders (dia x stroke)27" x 32"28" x 32"28" x 32"28" x 32"
Tractive Effort64379 lbs70067 lbs71590 lbs72043 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.18 3.74 3.77 3.80
Heating Ability
Firebox Area493 sq. ft515 sq. ft513 sq. ft493 sq. ft
Grate Area88.20 sq. ft88.20 sq. ft88.20 sq. ft88.20 sq. ft
Evaporative Heating Surface5193513654455488
Superheating Surface1324132422432180
Combined Heating Surface6517646076887668
Evaporative Heating Surface/Cylinder Volume244.89225.21238.76240.64
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation22050202862072722050
Same as above plus superheater percentage26529.7024443.6926774.1728318.78
Same as above but substitute firebox area for grate area148289.59142726.75155727.33158289.78
Power L129614.5723093.3233898.1037278.83
Power MT970.84777.281107.151199.79

Photos

Reference

Credits

Introduction and specifications provided by Steve Llanso of Sweat House Media.

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