Baltimore & Ohio / Buffalo, Rochester, & Pittsburgh 2-6-6-2 Type Locomotives

Class KK-1 (Locobase 3099)

Like the T-1/T-2 4-8-2 comparison, the KKs were built in single copies to compare the Emerson watertube firebox to a conventional locomotive. This was the EWT entry.

These are the only 2-6-6-2 articulateds the B&O operated other than the BR&P KK-1s (see record #295) and are almost unknown today. This engine was converted briefly to a 4-4-6-2 arrangement for passenger service, but soon was restored as a Prairie Mallet and lasted until 1953.

Class KK-2 (Locobase 296)

Data from B&O to 1954 Assorted Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive collection. Note that the number of superheater flues is estimated because the figure on the two available diagrams is not clear -- Locobase is 95% certain the number is 53 as shown in the specs.

The 7450 with the conventional stayed firebox was built to compare to the 7400 with an Emerson watertube firebox. In addition to 110 sq ft of heating surface in the combustion chamber, this engine's firebox heating surface at first included 46 sq ft of arch tubes in a total of 436 sq ft, but the appliance contribution was later revamped with 18 sq ft of arch tubes and 95 sq ft of thermic syphons for a total of 403 sq ft.

Class LL (Locobase 295)

Alvin F Staufer & Lawrence W Sagle, B & O Power (1964).

Data confirmed by table in May 1916 RME.

These 55 locomotives were built at Alco's Schenectady and Brooks works from 1914 to 1923.

Several batches delivered as follows, as classified by the B&O and renumbered in 1932:

KK-4 7500-7504 Schenectady 1914

KK-4a 7505-7509 Brooks 1917

KK-4b 7510-7525 Brooks 1918

KK-4c 7526-7540 Brooks 1918

KK-4d 7541-7554 Brooks 1923

One was rebuilt as KK-5 in 1949 with chassis lubrication, bed casting

Retired by 1951.

Specifications
Class	KK-1	KK-2	LL
Locobase ID	3099	296	295
Railroad	Baltimore & Ohio (B&O)	Baltimore & Ohio (B&O)	Buffalo, Rochester, & Pittsburgh (B & O)
Whyte	2-6-6-2	2-6-6-2	2-6-6-2
Road Numbers	7400	7450	700-754
Gauge	Std	Std	Std
Builder	Baldwin	Baldwin	Alco-Schenectady
Year	1930	1930	1923
Valve Gear	Walschaert	Walschaert
	Locomotive Length and Weight
Driver Wheelbase	34.92'	12.17'	10.33'
Engine Wheelbase	56'	55.67'	49.66'
Ratio of driving wheelbase to overall engine wheebase	0.62	0.22	0.21
Overall Wheelbase (engine & tender)		104.41'	86.48'
Axle Loading (Maximum Weight per Axle)		68000 lbs
Weight on Drivers	372000 lbs	373000 lbs	367500 lbs
Engine Weight	465000 lbs	466000 lbs	445000 lbs
Tender Light Weight	273000 lbs	273000 lbs	205600 lbs
Total Engine and Tender Weight	738000 lbs	739000 lbs	650600 lbs
Tender Water Capacity	18000 gals	18000 gals	12000 gals
Tender Fuel Capacity (oil/coal)	20 tons	20 tons	14 tons
Minimum weight per yard of rail on which locomotive could run	103.33 lb rail	103.61 lb rail	102.08 lb rail
	Geometry Relating to Tractive Effort
Driver Diameter	70"	70"	57"
Boiler Pressure	250 psi	250 psi	200 psi
Cylinders (dia x stroke)	23" x 30" (4)	23" x 30" (4)	23.5" x 32"
Tractive Effort	96354 lbs	96354 lbs	75112 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort)	3.86	3.87	4.89
	Heating Ability
Firebox Area	866 sq. ft	436 sq. ft	388 sq. ft
Grate Area	92 sq. ft	92.30 sq. ft	72.20 sq. ft
Evaporative Heating Surface	6543	5471	4935
Superheating Surface	1666	1698	1046
Combined Heating Surface	8209	7169	5981
Evaporative Heating Surface/Cylinder Volume	226.77	189.62	307.20
	Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation	23000	23075	14440
Same as above plus superheater percentage	27667.80	28540.39	16965.37
Same as above but substitute firebox area for grate area	260438.24	134816.99	91171.24
Power L1	26148.68	23182.73	7771.74
Power MT	929.80	822.13	279.73