Baltimore & Ohio / Baltimore & Ohio Southwestern / Buffalo & Susquehanna / Buffalo, Rochester, & Pittsburgh 4-4-2 "Atlantic" Locomotives of the USA


Class Details by Steve Llanso of Sweat House Media

Class A (Locobase 12459)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volume 23, p. 170. See also See also Alvin F Staufer, Baltimore & Ohio Railroad Diagrams, Steam and Electric Locomotives (Medina, Ohio: Alvin F Staufer, nd), page 69. (Many thanks to Chris Hohl for spotting the differences between the Baldwin specs and the railroad's weights. He also supplied the tender's coal capacity, found the proper road number range, and noted the class ID change.) Works numbers were 18334 in October 1900 and 18602-18604, 18616, 18626 in January 1901.

Big Atlantics with tall drivers, these Vauclain compounds had quite large 15"(381 mm)-diameter piston valves. Baldwin estimated the engines' adhesive weight to be 88,000 lb (39,916 kg) and engine weight to amount to 150,000 lb (68,039 kg).

Chris Hohl notes that the actual figures, taken from both Staufer's B&O book as well as the B&OSW diagram book and now given in the specs, were different. Locobase observes that overall engine weight was very close to the estimate, while the weight on the drivers was lower by more than two tons. The front truck seems very heavy, possibly because of the considerable weight of the four cylinders resting on those four wheels.

Not long after they were delivered, the Garrett County (Maryland) Republican News -- 01/31/1901-(Vol.24, No.47) -- reported that "Railroaders say these engines "run like a scared dog." They will haul the fast trains." . http://www.therepublicannews.com/archive/old%20archive/013101no9.html, accessed 26 September 2005.

They were soon converted (in 1903-1904) to the simple-expansion variety; see Locobase 6519.


Class A-1 (Locobase 6519)

Data from B&OSW 10 - 1901 Lococomotive Diagrams (dated July 1900) supplied in May 2005 by Allen Stanley from his extensive Raildata collection. See also Alvin F Staufer, Baltimore & Ohio Railroad Diagrams, Steam and Electric Locomotives (Medina, Ohio: Alvin F Staufer, nd), page 69. (Many thanks to Chris Hohl for his December 2014 email noting the change in class ID when the B&OSW was taken over by the B&O as well as suggesting another look at the driver and engine weights; see below for the ambiguous result of that investigation. He also called attention to the revised tender capacity.) See Locobase 2017 for the origins of the B & OSW.

Like almost all of the Vauclain compounds delivered in this period, the six Atlantics delivered to the B & O (Locobase 14259), soon had their compound-cylinder setup replaced with the simple-expansion setup shown in the specs.

Chris Hohl's pointer brought Locobase to contradictions among sources. On the B&OSW's table page, the weight on the drivers is shown as 83,400 lb (37,830 kg); the front truck was burdened with 37,940 lb while the trailing truck carried 28,260 lb. (The simple-expansion setup shown on that page was not applied until 1903-1904, according to Staufer.) But on the next page, which presents an axle-loading diagram of the same quintet dated "6-18-1908", the adhesion weight is just about 10 short tons heavier distributed relatively evenly over the two axles.

Staufer's own reproduction of a simpled class A-1 diagram records the front truck as carrying 25,850 lb, six tons lighter than the B&OSW table and less than a ton lighter than the Staufer diagram. The first driven axle weighed 52,650 lb while the second axle weighed 44,500 lb--unevenly distributed. The trailing axle took the remaining 22,000 lb and weighed 3 tons less than the B&OSW table and a ton less than the axle-loading diagram number. Total engine weight came to 97,150 lb.

So what gave? Who was right? Locobase doesn't have a good tie-breaker, but considers the growth in weight from the Staufer diagram, which was possibly prepared in 1904, as consistent with the usual results of modifications.

In this configuration, they operated into the 1920s with the last retiring in 1929.


Class A-2 (Locobase 6520)

Data from B & OSW diagram book dated July 1900 supplied by Allen Stanley from his extensive Raildata collection May 2005. (Thanks to Chris Hohl for noting the correct first-built date of 1903 and for his comments on locomotive weights and tender capacities.) Works numbers were 27014-27023 in January 1903, 27432-27441 in October.

See Locobase 2017 for the origins of the B & OSW.

Drury (1993) and Alvin F Staufer & Lawrence W Sagle, B & O Power (1964). note that these were some of the very few Schenectady engines on the B&O -- these duplicated the Pennsylvania's E-3a.

1474 received superheat and Walschaerts valve gear in 1926; see Locobase 15927.

The first retirements began in 1933 and were completed in 1947.


Class A-2A (Locobase 15927)

Data from B&O to 1954 Assorted Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection. (Thanks to Chris Hohl for his December 2014 recommendation that Locobase create a separate entry for this A-2 Atlantic, and for a March 2015 email noting the correct year for the upgrade. )

The B&O superheated only one of the A-2s supplied by Schenectady in 1903 (Locobase 6520). In addition to a good supply of superheater area, the railroad removed the inside Stephenson valve gear and substituted outside radial valve gear to operate 14" (356 mm) piston valves. Boiler pressure rose slightly as well.

Alone in its own class, the 1474 hauled trains for more than a decade longer than all of the other A-2s. It served throughout World War II before being retired in September 1947.


Class A-3 (Locobase 1246)

Data from DeGolyer, Volume 34, p. 71. (Thanks to Chris Hohl for his 18 January 2015 email pointing out the proper tender weight and capacity for this earlier form of the A-3.) Works numbers were 34278-34279, 34323-34327 in February 1910; 34355-34364, 34447-34448 in March; 34485-34491 in April.

The last B & O Atlantics, these were built with Walschaert gear and 14"-diameter piston valves. The specs helpfully tell us that these were modifications of the A-2 that consisted of "...substituting a radial type of firebox for the Belpaire, using flexible stay bolts in throat, sides and back head sheets, arranged similar to the Consolidation freight locos." That wasn't all. The design also used piston valves with the Walschaert valve gear, steel cab, and "a general redesign of spring rigging and frame cross bracing."

On the other hand, the details were to be interchangeable "as far as possible" with the Consolidation and the A-2s.

In 1927, the B&O refitted the class with superheaters and 74" drivers; see Locobase 8889.


Class A-3 - superheated (Locobase 8889)

Data from B & O to 1954 Assorted Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection.

Locobase 1246 describes the saturated-steam originals. In 1927, the B&O refitted the class with superheaters and 74" drivers, raising tractive effort to 29,360 lb. Weight reached 212,260 lb. All had retired by 1944. Sagle, 1964, comments: "The Atlantics were good, fast engines, and gave adequate service [on several divisions]. For a time they hauled the 'varnish', but as train loads increased ...they were forced off the main lines by Pacific-type locomotives ....They did not have a very glamorous existence on the B&O."


Class A-9/A-10 (Locobase 2082)

Data from Alvin F Staufer: Baltimore & Ohio Steam and Electric Locomotive Diagrams (Medina, Ohio; Alvin F Staufer, 1964), supplied by Allen Stanley in May 2005 from his extensive Raildata collection.

Atlantics with different driver sizes. The first had 73" drivers and came from Schenectady in 1904, the later two had 69" drivers and arrived from Brooks in 1906. Photographs of the engines in B&O service, show that the sand dome was much farther forward in the 1486 than in the earlier two.

In 1932, the Buffalo & Susquehanna came under B&O control. The three engines were renumbered 1484-1486. 1486 was retired in 1936. The other two endured until 1948 because flooding washed some of the line during the 1940s and isolated the rest of the B&S.


Class W (Locobase 12811)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University Volume 24, p. 20 and Volume 28, p. 64. See also David S Price, "The Fernwood, Columbia & Gulf Railroad: A Colorful Mississippi Short Line," Tap Lines, Number 26 (August 1998), p. 1, found at http://www.taplines.net/August/augindex.htm, last accessed 2 July 2011. (Thanks to Chris Hohl for his December 2014 , March 2015, and May2015 emails pointing out the disparities between the larger Brooks engines and this Baldwin qu artet.) Works numbers were 19045-19046 in May 1901 and 26144-26145 in August 1905.

These Atlantics were built in twos by Baldwin. See Locobase 2058 for the substantially larger Brooks pair that was delivered at the same time as the first pair of Philadelphians.

For some reason, the Baldwins were delivered with 19 1/2" (495 mm) diameter cylinders with the instruction to "Use 20" cylinder pattern". Unusually for Baldwin Atlantics at the time, these were delivered as simple-expansion locomotives. Unlike the Brooks locomotives, the Baldwins used slide valves.

160 was rebuilt after being damaged in a collision on Christmas Eve, 1906.

The Baldwin engines served the BR&P for less than twenty years. Locomotive rebuilder/reseller Southern Iron & Equipment bought one in 1919 (161) and September 1920 (160). Ex-161 went to the Fernwood, Columbia & Gulf in Mississippi as their #15, but it was out of place and not often used, one suspects. It was retired by 1936. 162 and 169 languished for a while in the SI&E stable before being sold to the Gulf Mobile & Northern in 1923 as their 40-41.

The first of this pair of Atlantics was scrapped in 1927 without being superheated.

169 was sold earlier (June 1920) to locomotive rebuilder/reseller Southern Iron & Equipment. SI & E sold the engine to the Gulf, Mobile & Northern in September of that year. It wound up on the Fernwood, Columbia & Gulf as their 15. Locobase thought this was an odd destination for an express engine, but thought maybe the FC & G had found some magic way to use the 15. But the TapLines site professes a similar mystification. It notes: "One wonders just how a high-drivered passenger locomotive could have been much use on a shortline with limited passenger traffic and necessarily slow speed operation. Number 15 was gone by 1936."


Class W-2 - Brooks/A-6 (Locobase 2058)

Data from "Brooks Chautaqua Type Passenger Locomotives, Buffalo Rochester & Pittsburgh, Railroad Gazette, Volume XXXIII, No 50 (13 December 1901), p. 853. Brooks's 162-163 were 3926-3927 in August 1901.

The Buffalo, Rochester, & Pittsburgh Railroad was a sizable regional railroad whose main line ran south from Rochester, NY through Bradford, Ridgway, Du Bois, Punxsutawney, and Butler, PA to the junction at Gallery where it shared track to Pittsburgh. The BR&P fell under B&O control on 1 January 1932. (Sagle 1964). Drury (1993) says that the BR&P "was a prosperous railroad, and the prosperity was reflected in their locomotives."

These Atlantics were built in twos -- two by Brooks, two by Baldwin -- and had inside piston valves. RG said that these were big, powerful engines with a relatively high boiler pressure, 11" (279 mm) piston valves, and generous heating surface. The Baldwin engines had smaller cylinders served by a smaller boiler and grate and a shorter wheelbase; see Locobase 15929.

The Brooks locomotives attracted the usual encomia in RG's report: "We are informed that these locomotives are doing very good work, sometimes hauling passenger trains of 14 cars on a quick schedule, with no difficulty in feeding the boiler sufficiently with one No. 9 injector. They have made a record for being 'smart' and economical."

Both engines were "remodeled" in December 1913 (163) and January 1914 (162). Ten years later 163 received a new boiler in July 1924 while 162 was similarly refitted in October of the same year.

The two Brooks engines were renumbered in 1932 to 1487-1488 and retired in 1937. The Baldwin engines were not carried over; locomotive rebuilder/reseller Southern Iron & Equipment bought both in 1919 (161) and September 1920. Ex-161 went to the Fernwood, Columbia & Gulf in Mississippi as their #15, but it was out of place and not often used, one suspects. It was retired by 1936. 162 languished for a while in the SI&E stable before being sold to the Gulf Mobile & Northern in 1923.


Class W-2 - superheated (Locobase 9637)

Data from "Comparative Service Tests of Locomotives," Railway Age Gazette (Vol. 53, No 11, 13 September 1912), pp.469-472. See also BR&P 11 - 1930 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection.

The RAG article describes the BR & P's test of the merits of installing a superheater in an otherwise unaltered Atlantic that used the same boiler as the superheated Consolidation shown in Locobase 2061. Among other results was a 22% decrease in water use per ton/mile and a 16% drop in coal use. Considering the relatively small superheater, these tests suggested that the railroad could derive a substantial benefit from adopting the new technology.

The two Brooks engines (162-163) were renumbered in 1932 to 1487-1488 after the BR&P was absorbed by the Baltimore & Ohio and retired in 1937.


Class W-3 (Locobase 2060)

Data from BR&P's 1930 Locomotive Diagram book supplied in May 2005 by Allen Stanley from his extensive Raildata collection. Works numbers were29391-29392 in December 1903 and 29389-29390 in April 1904.

Similar to W-2s, but mounting cylinders 1" smaller in diameter.

At some point, the class was rebuilt with a superheater; the specs reflect that upgrade. The superheater area is an estimate and based on the figure for the nearly identical Pittsburgh & Lake Erie engines shown in Locobase 6764.

The last 3 were renumbered in 1932 to 1489-1491; they were retired by 1936. Sagle 1964.


Class W-8/W-8a (Locobase 2059)

Data from 1930 BR & P Locomotive Diagram book supplied by Allen Stanley in May 2005 from his extensive Raildata collection. Works numbers were 40668-40671 in July 1906 and 46410 in October 1908.

These Atlantics had slide valves vs the piston valves of earlier engines; the 174 (W-8a) had Walschaerts valve gear and weighed 195,000 lb. The first four became B&O Class A-8, numbered 1492-1495. The last engine became A-8a, 1496. Sagle 1964.

Drury (1993) comments that an oddity of the BR&P Atlantics "was the driver spacing ...as though the builder intended to use 80" drivers, then changed his mind after the locomotive was under construction."

Specifications by Steve Llanso of Sweat House Media
ClassAA-1A-2A-2AA-3
Locobase ID12459 6519 6520 15927 1246
RailroadBaltimore & Ohio Southwestern (B&O)Baltimore & Ohio Southwestern (B&O)Baltimore & Ohio Southwestern (B&O)Baltimore & Ohio Southwestern (B&O)Baltimore & Ohio (B&O)
CountryUSAUSAUSAUSAUSA
Whyte4-4-24-4-24-4-24-4-24-4-2
Number in Class5620126
Road Numbers1450-14551450-14551456-147514741424-1449
GaugeStdStdStdStdStd
Number Built52026
BuilderBurnham, Williams & CoB&OAlco-SchenectadyB&OBaldwin
Year19001904190319271910
Valve GearStephensonStephensonStephensonWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase 6.75' 6.75' 7.42' 7.42' 7.42'
Engine Wheelbase25.58'25.58'30.79'30.79'30.80'
Ratio of driving wheelbase to overall engine wheebase 0.26 0.26 0.24 0.24 0.24
Overall Wheelbase (engine & tender)52.48'52.48'60.22'64.46'61'
Axle Loading (Maximum Weight per Axle)41940 lbs51650 lbs54750 lbs55400 lbs59080 lbs
Weight on Drivers83400 lbs103330 lbs109500 lbs109500 lbs116000 lbs
Engine Weight149600 lbs154700 lbs180000 lbs180000 lbs190000 lbs
Tender Light Weight100250 lbs100250 lbs154500 lbs154500 lbs154000 lbs
Total Engine and Tender Weight249850 lbs254950 lbs334500 lbs334500 lbs344000 lbs
Tender Water Capacity5000 gals5000 gals7000 gals10000 gals7000 gals
Tender Fuel Capacity (oil/coal)9 tons10.5 tons15 tons14 tons15 tons
Minimum weight of rail (calculated)70 lb/yard86 lb/yard91 lb/yard91 lb/yard97 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter78"78"80"80"80"
Boiler Pressure200 psi200 psi200 psi210 psi205 psi
High Pressure Cylinders (dia x stroke)15" x 28"19" x 28"22" x 26"22" x 26"22" x 26"
Low Pressure Cylinders (dia x stroke)25" x 28" (2)
Tractive Effort20192 lbs22030 lbs26741 lbs28078 lbs27410 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.13 4.69 4.09 3.90 4.23
Heating Ability
Firebox Area150 sq. ft150 sq. ft187.73 sq. ft187.77 sq. ft167.80 sq. ft
Grate Area42.50 sq. ft42.50 sq. ft55.50 sq. ft54.88 sq. ft55.50 sq. ft
Evaporative Heating Surface2663 sq. ft2663 sq. ft2676 sq. ft1857 sq. ft2350 sq. ft
Superheating Surface414 sq. ft
Combined Heating Surface2663 sq. ft2663 sq. ft2676 sq. ft2271 sq. ft2350 sq. ft
Evaporative Heating Surface/Cylinder Volume465.00289.82233.93162.34205.43
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation85008500111001152511378
Same as above plus superheater percentage85008500111001359911378
Same as above but substitute firebox area for grate area3000030000375464652934399
Power L1557896588426159647620
Power MT294.90412.12339.29642.82289.64

Specifications by Steve Llanso of Sweat House Media
ClassA-3 - superheatedA-9/A-10WW-2 - Brooks/A-6W-2 - superheated
Locobase ID8889 2082 12811 2058 9637
RailroadBaltimore & Ohio (B&O)Buffalo & Susquehanna (B&O)Buffalo, Rochester, & Pittsburgh (B&O)Buffalo, Rochester, & Pittsburgh (B&O)Buffalo, Rochester, & Pittsburgh (B&O)
CountryUSAUSAUSAUSAUSA
Whyte4-4-24-4-24-4-24-4-24-4-2
Number in Class263424
Road Numbers1424-1449272-274160-161, 168-169162-163/1487-1488160-163
GaugeStdStdStdStdStd
Number Built342
BuilderB & OAlco-SchenectadyBurnham, Williams & CoBrooksBR&P
Year19271904190119011912
Valve GearWalschaertStephensonStephensonStephensonStephenson
Locomotive Length and Weight
Driver Wheelbase 7.42' 6.67'7'8'8'
Engine Wheelbase31.21'27.33'25.08'29.17'20.17'
Ratio of driving wheelbase to overall engine wheebase 0.24 0.24 0.28 0.27 0.40
Overall Wheelbase (engine & tender)61'54.58'54.58'
Axle Loading (Maximum Weight per Axle)59080 lbs
Weight on Drivers117700 lbs89800 lbs90000 lbs99000 lbs113700 lbs
Engine Weight212260 lbs150800 lbs160000 lbs173000 lbs183000 lbs
Tender Light Weight159900 lbs114400 lbs120000 lbs120000 lbs120000 lbs
Total Engine and Tender Weight372160 lbs265200 lbs280000 lbs293000 lbs303000 lbs
Tender Water Capacity7000 gals5000 gals6000 gals6000 gals6000 gals
Tender Fuel Capacity (oil/coal)18 tons10 tons tons10 tons10 tons
Minimum weight of rail (calculated)98 lb/yard75 lb/yard75 lb/yard83 lb/yard95 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter74"69"72"72"72"
Boiler Pressure205 psi195 psi200 psi220 psi220 psi
Cylinders (dia x stroke)22" x 26"19" x 26"19.5" x 26"20.5" x 26"20.5" x 26"
Tractive Effort29632 lbs22547 lbs23343 lbs28379 lbs28379 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.97 3.98 3.86 3.49 4.01
Heating Ability
Firebox Area193.25 sq. ft153 sq. ft179 sq. ft202.30 sq. ft221.10 sq. ft
Grate Area54.80 sq. ft42.50 sq. ft46.89 sq. ft54.43 sq. ft54.43 sq. ft
Evaporative Heating Surface1890 sq. ft2022 sq. ft2950 sq. ft3008 sq. ft2379 sq. ft
Superheating Surface410 sq. ft480 sq. ft
Combined Heating Surface2300 sq. ft2022 sq. ft2950 sq. ft3008 sq. ft2859 sq. ft
Evaporative Heating Surface/Cylinder Volume165.22236.99328.25302.85239.52
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation11234828893781197511975
Same as above plus superheater percentage13256828893781197514010
Same as above but substitute firebox area for grate area4674729835358004450656911
Power L1144697325102681068420744
Power MT542.03359.66503.05475.84804.44

Specifications by Steve Llanso of Sweat House Media
ClassW-3W-8/W-8a
Locobase ID2060 2059
RailroadBuffalo, Rochester, & Pittsburgh (B&O)Buffalo, Rochester, & Pittsburgh (B&O)
CountryUSAUSA
Whyte4-4-24-4-2
Number in Class45
Road Numbers164-167170-174
GaugeStdStd
Number Built45
BuilderAlco-SchenectadyBrooks
Year19031906
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase7'8'
Engine Wheelbase27.92'29.17'
Ratio of driving wheelbase to overall engine wheebase 0.25 0.27
Overall Wheelbase (engine & tender)54.50'56.75'
Axle Loading (Maximum Weight per Axle)
Weight on Drivers102175 lbs115000 lbs
Engine Weight176680 lbs195000 lbs
Tender Light Weight120000 lbs
Total Engine and Tender Weight296680 lbs
Tender Water Capacity6000 gals6000 gals
Tender Fuel Capacity (oil/coal)9 tons12 tons
Minimum weight of rail (calculated)85 lb/yard96 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter72"73"
Boiler Pressure200 psi200 psi
Cylinders (dia x stroke)19.5" x 26"20.5" x 26"
Tractive Effort23343 lbs25445 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.38 4.52
Heating Ability
Firebox Area190.10 sq. ft203.70 sq. ft
Grate Area46 sq. ft54.40 sq. ft
Evaporative Heating Surface2318 sq. ft2263 sq. ft
Superheating Surface462 sq. ft
Combined Heating Surface2780 sq. ft2263 sq. ft
Evaporative Heating Surface/Cylinder Volume257.93227.84
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation920010880
Same as above plus superheater percentage1076410880
Same as above but substitute firebox area for grate area4448340740
Power L1198328039
Power MT855.83308.23

Reference


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