Pennsylvania / Pittsburgh, Fort Wayne & Chicago / New York, Philadelphia & Norfolk 4-4-0 "American" Type Locomotives

Data from the Twelfth Annual Report of the American Railway Master Mechanics' Association, May 13th-May15th, 1879, page 83-84. NB: Boiler pressure is an estimate and the heating surface of the tubes is measured from the inside. Locobase believes this engine is one of the quartet produced by Baldwin in January 1867, works #1573-1574, 1577-1578.

James M. Boone of the P, Ft W & C described the boiler for which he gave the specifications as "a good steamer; will make steam freely with nut coal; does the best work with about 4" of coal on the grate."

Class 1 / D (Locobase 11591)

Data from Baldwin Locomotive Works Specification for Engines, 1888, as digitized by the DeGolyer Library of Southern Methodist University - their catalogue Vol 15, p. 36. Works numbers were 9901-9902 in March 1889.

These small Eight-wheelers eventually found their way onto the Pennsylvania's roster, but not for long. 12 left by 1906 and 1 was retired by 1913.

Class 1504 (Locobase 2834)

Data from diagram scanned in by Robert Schoenberg of http://prr.railfan.net . Calculated tube heating surface was 1,684 sq ft. Later data from Schenectady Locomotive Works, Illustrated Catalogue of Simple and Compound Locomotives (Philadelphia: J B Lippincott, 1897), pp. 14-15 gave tube heating surface as 1,672.2 sq ft.

One of three engines assessed at the end of the 19th century. The other two were the 1510, a Baldwin compound (Locobase 2835) , and 1320, a Webb compound. The New Yorker was a straightforward, orthodox simple-expansion locomotive that offered a good- sized boiler as well as a look at building techniques from a manufacturer other than Altoona or the PRR's natural bedmate, Baldwin.

This one was retired in 1911.

Class 1510 (Locobase 2835)

Data from diagram scanned in by Robert Schoenberg of http://prr.railfan.net . Calculated tube heating surface is 1,549 sq ft. Works number was 12824.

One of three engines assessed at the end of the 19th century. This was a Vauclain compound. The other two were the 1504, a Schenectady-built simple-expansion (Locobase 2834), and 1320, a Webb compound. This engine was later converted to a 2-cylinder simple-expansion and retired in 1911.

Class A / D1 (Locobase 1132)

Data from diagram scanned in by Robert Schoenberg of http://prr.railfan.net . Data confirmed and supplemented from Park Benjamin (Ed), Appleton's Cyclopedia of Applied Mechanics (New York: D Appleton & Company, 1884), p. 348.

One of the classes established by Alexander J. Cassatt in 1867 when he became Master of Machinery. His goal was to standardize to allow greater interchangeability of parts. Duty was light passenger service.

Class AAn/D7 (Locobase 1145)

Based on Cassatt's A class, but fitted with firebox suitable for buring coal. Very similar to K class, but with a slightly greater tube length.

Data from diagram scanned in by Robert Schoenberg of http://prr.railfan.net . Another D7 drawing shows a total heating surface of 1464 sq ft, but the number, length, and diameter of the boiler tubes is identical. Unless the firebox grew in height enough to add 160 sq ft to the heating surface, I don't see where the number comes from.

Class AAn/D7A (Locobase 2825)

Data from diagram scanned in by Robert Schoenberg of http://prr.railfan.net . Differs from D7 in having smaller drivers, more even weight distribution even as it weighed 1 1/2 tons more.

Class B/D2 (Locobase 1133)

Data from diagram scanned in by Robert Schoenberg of http://prr.railfan.net . One of the classes established by Alexander J. Cassatt in 1867 when he became Master of Machinery. Compared to As, Bs had larger pistons, smaller drivers, greater TE. Duty was as passenger-service helpers in the mountains.

Class Ba/D2A (Locobase 1143)

Data from diagram scanned in by Robert Schoenberg of http://prr.railfan.net . One of the classes established by Alexander J. Cassatt in 1867 when he became Master of Machinery. Passenger-service locomotive. Nine of these were later converted to D2s with 62" drivers.

Class C/D3 (Locobase 1134)

One of the classes established by Alexander J. Cassatt in 1867 when he became Master of Machinery. Duty was passenger and fast freight service.

Data from diagram scanned in by Robert Schoenberg of http://prr.railfan.net .

Class C/D4 (Locobase 2820)

Data from diagram scanned in by Robert Schoenberg of http://prr.railfan.net .

Class C/D4A (Locobase 2821)

These were 15 D4s that were converted to the 68" driver configuration.

Data from diagram scanned in by Robert Schoenberg of http://prr.railfan.net .

Class CAn/D4 (Locobase 1140)

One of the classes established by Alexander J. Cassatt in 1867 when he became Master of Machinery. Duty was passenger and fast freight service, had firebox suitable for burning anthracite coal.

Data from diagram scanned in by Robert Schoenberg of http://prr.railfan.net .

Class CAn/D4A (Locobase 2822)

This anthracite burner is identical to the other D4A except for a slightly larger firebox.

Data from diagram scanned in by Robert Schoenberg of http://prr.railfan.net .

Class D16sb (Locobase 103)

426 D-16 engines built in 5 sub-classes. D-16 had 68" drivers; D-16a had 80" drivers. All had the characteristic (for the Pennsy) Belpaire firebox. They began with 18.5 x 26 cylinders, 185-psi boilers, yielding a 22,250 lb tractive effort. A mark of their reliability was the performance of one engine (816) which went 3 years and 4 months without being shopped for repairs and traveled 300,000 miles.

Modernized from 1914 on with the 20.5-in diameter pistons and boilers limited to 175 psi, but superheated. According to Edson (Keystone Steam & Electric, 1974), the conversion created an "...excellent engine for suburban service and local trains." Used on many Pennsy branch lines; some later sent over to the Long Island RR.

Class G/D5 (Locobase 1138)

Data from diagram scanned in by Robert Schoenberg of http://prr.railfan.net . One of the classes established by Alexander J. Cassatt in 1867 when he became Master of Machinery. Duty was passenger branch-line service, which is shown by the low axle loading and tractive effort.

Class K/D6 (Locobase 1142)

Data from diagram scanned in by Robert Schoenberg of http://prr.railfan.net . One of the classes established by Alexander J. Cassatt in 1867 when he became Master of Machinery. High-drivered design for express passenger service. Note that while the grate was larger than that of the earlier B & C classes, the K-class designer chose to use more, smaller boiler tubes. One can also see closer spacing between the drivers, resulting in a shorter wheelbase even though the individual drivers are much taller.

http://www.mth-railking.com/search.asp?item=20-3156-1&page=cat (visited 11 Nov 2004), the MTH models site, confirms Locobase's analysis with the comment that the K represented "an elegant and successful step in the evolution of Pennsy motive power". Ks also featured a 2-bar alligator crosshead, powered reversing gear, and sandboxes on the running board rather than sand in a top-mounted dome.

Class K/D6A (Locobase 2823)

Data from diagram scanned in by Robert Schoenberg of http://prr.railfan.net . These 7 were converted from D6 engines with smaller drivers, which raised tractive effort. The factor of adhesion suggests, however, that this design still had some room for growth.

Class L/D16 (Locobase 1144)

Data from diagram scanned in by Robert Schoenberg of http://prr.railfan.net . See also Charles B. Chaney's summary in Railroad & Locomotive Historical Society Bulletin #59 (1942).

Class L/D16A (Locobase 2833)

Data from diagram scanned in by Robert Schoenberg of http://prr.railfan.net . See also Charles B. Chaney's summary in Railroad & Locomotive Historical Society Bulletin #59 (1942). As with all Pennsy locomotives of this vintage or later, this design used a Belpaire firebox.

Later converted to D16 with 68" drivers.

Class N/D8 (Locobase 1147)

Data from diagram scanned in by Robert Schoenberg of http://prr.railfan.net . Replaced C class. Had a larger boiler. Duty was passenger and fast freight service.

Class O/D10 (Locobase 2827)

Data from diagram scanned in by Robert Schoenberg of http://prr.railfan.net . Responded to the O class's low factor of adhesion by increasing the weight on the drivers. D10A had only 600 lb more total weight in working order. Among the first Pennsylvania engines to have a Belpaire boiler.

Class O/D10a (Locobase 3488)

Data from diagram scanned in by Robert Schoenberg of http://prr.railfan.net . D10A had only 600 lb more total weight in working order, but had the taller drivers. Among the first Pennsylvania engines to have a Belpaire boiler.

Class O/D8A (Locobase 1148)

Data from diagram scanned in by Robert Schoenberg of http://prr.railfan.net . Similar to N, but with slightly larger cylinders. Duty was passenger and fast freight service.

Class O/D9 & D9A (Locobase 2826)

Data from diagram scanned in by Robert Schoenberg of http://prr.railfan.net . Had the earlier O class cylinders, but saw a big jump in boiler pressure with commensurate jump in tractive effort. Also included a Belpaire firebox. Now, however, the factor of adhesion had dropped to the point of slipperiness. D9A had slightly more weight on the drivers.

Class O/D9a (Locobase 3487)

Data from diagram scanned in by Robert Schoenberg of http://prr.railfan.net . D9A put slightly more weight on taller drivers than did the D9s, but also had the Belpaire firebox.

Class P/D11 (Locobase 1149)

Data from diagram scanned in by Robert Schoenberg of http://prr.railfan.net . See also Charles B. Chaney's summary in Railroad & Locomotive Historical Society Bulletin #59 (1942).

Similar to O, but with slightly larger cylinders and higher boiler pressure and Belpaire boiler. Duty was general passenger service on heavier rail than before.

Class P/D11a (Locobase 4152)

Described in Charles B. Chaney's summary in Railroad & Locomotive Historical Society Bulletin #59 (1942). D11as had radial-stay fireboxes. The D11s ran on 62" drivers and had a different firebox..

Class P/D12 (Locobase 2828)

A newer P class, this with a smaller boiler, but higher boiler pressure. The Belpaire boiler, later to become a standard part of Pennsy practice, also made its first appearance on a passenger engine.

Data from diagram scanned in by Robert Schoenberg of http://prr.railfan.net . See also Charles B. Chaney's summary in Railroad & Locomotive Historical Society Bulletin #59 (1942), where he notes that these two low-drivered examples went to the Northern Central Railway subsidiary.

Class P/D12A (Locobase 2829)

D12 with 68" drivers. Also used a Belpaire boiler.

Data from diagram scanned in by Robert Schoenberg of http://prr.railfan.net . See also Charles B. Chaney's summary in Railroad & Locomotive Historical Society Bulletin #59 (1942).

Class P/D13 (Locobase 2830)

Still newer P class, now with more, but smaller tubes and more weight on the drivers. 77 D13c had a similar driver size. It's not clear how else they might have differed. Like most Pennsy locomotives, the design had a Belpaire firebox.

Data from diagram scanned in by Robert Schoenberg of http://prr.railfan.net . See also Charles B. Chaney's summary in Railroad & Locomotive Historical Society Bulletin #59 (1942).

Class P/D13a, D13c (Locobase 3489)

Still newer P class, now with more, but smaller tubes and more weight on the drivers. (But still using a Belpaire firebox.) The D13a, with their taller drivers, were far more numerous than the duet of D13s. D13cs were virtually identical, the new designation representing a modest change in the boiler design.

Data from diagram scanned in by Robert Schoenberg of http://prr.railfan.net .

Class P/D14 (Locobase 2831)

Now the P class stepped up in both boiler pressure and driver diameter for the higher speeds and train tonnages that marked the end of the 19th century. Belpaire firebox.

Later converted to D14c engines with 68" drivers.

Data from diagram scanned in by Robert Schoenberg of http://prr.railfan.net .

Class P/D14a (Locobase 2832)

Still taller drivers than on the D14 and 1/2" larger cylinders. Axel Vogt redesigned the crosshead, replacing the 2-bar Alligator type with a 3-bar crosshead. Also used the Belpaire firebox. As a result of replacing the 18" diameter stack with a tapered, 13 1/2" version, the engines now had exhausts that "sounded like the bark of a rifle," according to Charles Chaney.

Later converted to D14b with 68" drivers.

Data from diagram scanned in by Robert Schoenberg of http://prr.railfan.net . See also Charles B. Chaney's summary in Railroad & Locomotive Historical Society Bulletin #59 (1942).

Class T/D15 (Locobase 1152)

One of the Pennsy's rare excursions into compounding. Two-cylinder Lindner cross-compound for express passenger service. Belpaire firebox.

Specifications
Class		1 / D	1504	1510	A / D1	AAn/D7	AAn/D7A	B/D2	Ba/D2A	C/D3	C/D4	C/D4A	CAn/D4	CAn/D4A	D16sb	G/D5	K/D6	K/D6A	L/D16	L/D16A	N/D8	O/D10	O/D10a	O/D8A	O/D9 & D9A	O/D9a	P/D11	P/D11a	P/D12	P/D12A	P/D13	P/D13a, D13c	P/D14	P/D14a	T/D15
Locobase ID	9519	11591	2834	2835	1132	1145	2825	1133	1143	1134	2820	2821	1140	2822	103	1138	1142	2823	1144	2833	1147	2827	3488	1148	2826	3487	1149	4152	2828	2829	2830	3489	2831	2832	1152
Railroad	Pittsburgh, Fort Wayne & Chicago (PRR)	New York, Philadelphia & Norfolk (PRR)	Pennsylvania (PRR)	Pennsylvania (PRR)	Pennsylvania (PRR)	Pennsylvania (PRR)	Pennsylvania (PRR)	Pennsylvania (PRR)	Pennsylvania (PRR)	Pennsylvania (PRR)	Pennsylvania (PRR)	Pennsylvania (PRR)	Pennsylvania (PRR)	Pennsylvania (PRR)	Pennsylvania (PRR)	Pennsylvania (PRR)	Pennsylvania (PRR)	Pennsylvania (PRR)	Pennsylvania (PRR)	Pennsylvania (PRR)	Pennsylvania (PRR)	Pennsylvania (PRR)	Pennsylvania (PRR)	Pennsylvania (PRR)	Pennsylvania (PRR)	Pennsylvania (PRR)	Pennsylvania (PRR)	Pennsylvania (PRR)	Pennsylvania (PRR)	Pennsylvania (PRR)	Pennsylvania (PRR)	Pennsylvania (PRR)	Pennsylvania (PRR)	Pennsylvania (PRR)	Pennsylvania (PRR)
Whyte	4-4-0	4-4-0	4-4-0	4-4-0	4-4-0	4-4-0	4-4-0	4-4-0	4-4-0	4-4-0	4-4-0	4-4-0	4-4-0	4-4-0	4-4-0	4-4-0	4-4-0	4-4-0	4-4-0	4-4-0	4-4-0	4-4-0	4-4-0	4-4-0	4-4-0	4-4-0	4-4-0	4-4-0	4-4-0	4-4-0	4-4-0	4-4-0	4-4-0	4-4-0	4-4-0
Road Numbers	193-196	1, 12	1504	1510											299																				1515
Gauge	4' 9.2""	Std	Std	Std	Std	Std	Std	Std	Std	Std	Std	Std	Std	Std	Std	Std	Std	Std	Std	Std	Std	Std	Std	Std	Std	Std	Std	Std	Std	Std	Std	Std	Std	Std	Std
Builder	M. Baird & Co	Burnham, Parry, Williams & Co	Schenectady	Burnham, Williams & Co	Altoona	Altoona	Altoona	Altoona	Altoona	Altoona	Altoona	Altoona			Juniata				Altoona	Altoona	Juniata			Juniata		Altoona			Altoona	Altoona		Altoona	Altoona	Altoona	Altoona
Year	1867	1889	1892	1892	1867	1882	1883	1867	1881	1867	1873	1873	1873	1873	1895	1870	1880	1880	1896	1895	1883	1883	1890	1883	1883	1889	1883	1883	1890	1889	1892	1892	1892	1894	1892
Valve Gear	Stephenson	Stephenson	Stephenson	Stephenson	Stephenson	Stephenson	Stephenson	Stephenson	Stephenson	Stephenson	Stephenson	Stephenson	Stephenson	Stephenson	Stephenson	Stephenson	Stephenson	Stephenson	Stephenson	Stephenson	Stephenson	Stephenson	Stephenson	Stephenson	Stephenson	Stephenson	Stephenson	Stephenson	Stephenson	Stephenson	Stephenson	Stephenson	Stephenson	Stephenson	Stephenson
	Locomotive Length and Weight
Driver Wheelbase		8.50'	8'	7.50'	8'	7.75'	7.75'	8.50'	8.50'	8.50'	8.50'	8.50'	8.50'	8.50'	7.75'	7'	7.75'	7.75'	7.75'	7.75'	8.50'	8.50'	8.50'	8.50'	8.50'	8.50'	7.75'	7.75'	7.75'	7.75'	7.75'	7.75'	7.75'	7.75'	8'
Engine Wheelbase		23.17'	23.42'		19.60'	22.68'	22.68'	22.47'		22.47'	22.47'	22.47'	22.47'	22.47'	22.79'		22.72'	22.72'	22.79'	22.79'	23.46'	23.45'	23.45'		23.45'	23.45'	22.54'	22.70'	22.50'	22.70'	22.70'	22.70'	22.70'	22.79'	23.94'
Ratio of driving wheelbase to overall engine wheebase		0.37	0.34		0.41	0.34	0.34	0.38		0.38	0.38	0.38	0.38	0.38	0.34		0.34	0.34	0.34	0.34	0.36	0.36	0.36		0.36	0.36	0.34	0.34	0.34	0.34	0.34	0.34	0.34	0.34	0.33
Overall Wheelbase (engine & tender)			47.98'	47.85'	44.51'	48.50'	48.50'	44.52'	44.61'	44.97'	46.84'	46.84'	46.84'	46.84'	55.02'	40.51'	48.48'	48.48'	50.29'	50.29'	45.96'	47.37'	47.37'	45.51'	47.37'	47.37'	48.50'		48.10'	48.60'	48.60'	48.60'	48.60'	49.27'	48.09'
Axle Loading (Maximum Weight per Axle)		30670 lbs	41000 lbs	41800 lbs	24480 lbs	33100 lbs	32650 lbs	28000 lbs	28330 lbs	26880 lbs	29160 lbs	28410 lbs	29160 lbs	30188 lbs	52000 lbs	20500 lbs	32900 lbs	32900 lbs	48300 lbs	48400 lbs	30800 lbs	32700 lbs	32700 lbs	31300 lbs	31100 lbs	31100 lbs	38200 lbs	38200 lbs	36225 lbs	36850 lbs	37708 lbs	37708 lbs	42000 lbs	43500 lbs	48500 lbs
Weight on Drivers	46700 lbs	60730 lbs	81500 lbs	83900 lbs	42370 lbs	64000 lbs	65180 lbs	53200 lbs	53754 lbs	50950 lbs	56200 lbs	55520 lbs	56200 lbs	57456 lbs	98150 lbs	40700 lbs	65800 lbs	65800 lbs	93600 lbs	93100 lbs	57700 lbs	65350 lbs	65350 lbs	58300 lbs	59800 lbs	59800 lbs	74400 lbs	67800 lbs	72100 lbs	73350 lbs	74716 lbs	74716 lbs	82600 lbs	87300 lbs	95200 lbs
Engine Weight	73000 lbs	93570 lbs	126700 lbs	122400 lbs	71900 lbs	93350 lbs	96330 lbs	80500 lbs	82200 lbs	79100 lbs	81800 lbs	82060 lbs	81800 lbs	83500 lbs	142100 lbs	65200 lbs	96700 lbs	96700 lbs	135900 lbs	134500 lbs	91300 lbs	103000 lbs	103000 lbs	97900 lbs	96700 lbs	96700 lbs	108700 lbs	100600 lbs	105250 lbs	106500 lbs	109716 lbs	109716 lbs	122600 lbs	127650 lbs	145500 lbs
Tender Light Weight			88000 lbs	88000 lbs	54000 lbs			51400 lbs	51400 lbs	51400 lbs	51400 lbs	51400 lbs	51400 lbs	51400 lbs	138900 lbs	40800 lbs	56300 lbs	56300 lbs	82000 lbs	82000 lbs	50500 lbs	73350 lbs	73350 lbs	50500 lbs	73350 lbs	73350 lbs	56300 lbs	56300 lbs	56300 lbs	69700 lbs	69700 lbs	69700 lbs	69700 lbs	70000 lbs
Total Engine and Tender Weight	75000 lbs	0	214700 lbs	210400 lbs	125900 lbs	0	0	131900 lbs	133600 lbs	130500 lbs	133200 lbs	133460 lbs	133200 lbs	134900 lbs	281000 lbs	106000 lbs	153000 lbs	153000 lbs	217900 lbs	216500 lbs	141800 lbs	176350 lbs	176350 lbs	148400 lbs	170050 lbs	170050 lbs	165000 lbs	156900 lbs	161550 lbs	176200 lbs	179416 lbs	179416 lbs	192300 lbs	197650 lbs	0
Tender Water Capacity		2400 gals	3500 gals	3600 gals	2400 gals	2400 gals	2400 gals	2400 gals	2400 gals	2400 gals	2400 gals	2400 gals	2400 gals	2400 gals	5600 gals	1600 gals	2400 gals	2400 gals	3600 gals	3600 gals	2400 gals	3600 gals	3600 gals		3600 gals	3600 gals	2400 gals	2400 gals	3000 gals	3000 gals	3000 gals	3000 gals	3000 gals	3000 gals	3000 gals
Tender Fuel Capacity (oil/coal)			8 tons	7.5 tons	4 tons	6 tons	6 tons	4 tons	4 tons	4 tons	6 tons	6 tons	6 tons	6 tons	13 tons	3.3 tons	6 tons	6 tons	7.5 tons	7.5 tons	4 tons	7.5 tons	7.5 tons	tons	7.5 tons	7.5 tons	6 tons	6 tons	7.5 tons	7.5 tons	7.5 tons	7.5 tons	7.5 tons	7.5 tons	7.5 tons
Minimum weight per yard of rail on which locomotive could run	39 lb rail	51 lb rail	68 lb rail	70 lb rail	35 lb rail	53 lb rail	54 lb rail	44 lb rail	45 lb rail	42 lb rail	47 lb rail	46 lb rail	47 lb rail	48 lb rail	82 lb rail	34 lb rail	55 lb rail	55 lb rail	78 lb rail	78 lb rail	48 lb rail	54 lb rail	54 lb rail	49 lb rail	50 lb rail	50 lb rail	62 lb rail	57 lb rail	60 lb rail	61 lb rail	62 lb rail	62 lb rail	69 lb rail	73 lb rail	79 lb rail
	Geometry Relating to Tractive Effort
Driver Diameter	66"	62"	78"	78"	68"	68"	62"	62"	68"	62"	62"	68"	62"	68"	68"	56"	78"	72"	68"	80"	62"	62"	68"	62"	62"	68"	62"	68"	62"	68"	62"	68"	78"	80"	84"
Boiler Pressure	120 psi	130 psi	180 psi	180 psi	125 psi	140 psi	140 psi	125 psi	125 psi	125 psi	125 psi	125 psi	125 psi	125 psi	175 psi	125 psi	140 psi	140 psi	185 psi	185 psi	130 psi	160 psi	160 psi	130 psi	160 psi	160 psi	140 psi	140 psi	160 psi	160 psi	160 psi	160 psi	175 psi	175 psi	205 psi
Cylinders (dia x stroke)	16" x 24"	18" x 24"	18" x 24"	13" x 24"	17" x 24"	17" x 24"	17" x 24"	18" x 24"	18" x 24"	17" x 24"	17" x 24"	17" x 24"	17" x 24"	17" x 24"	20.5" x 26"	15" x 22"	18" x 24"	18" x 24"	18.5" x 26"	18.5" x 26"	17" x 24"	18" x 24"	18" x 24"	18" x 24"	18" x 24"	18" x 24"	18.5" x 24"	18.5" x 24"	18.5" x 24"	18.5" x 24"	18.5" x 24"	18.5" x 24"	18.5" x 24"	19" x 24"	19.5" x 28" (1)
Tractive Effort	9495 lbs	13859 lbs	15253 lbs	12302 lbs	10838 lbs	12138 lbs	13313 lbs	13326 lbs	12150 lbs	11886 lbs	11886 lbs	10838 lbs	11886 lbs	10838 lbs	23902 lbs	9392 lbs	11863 lbs	12852 lbs	20578 lbs	17491 lbs	12362 lbs	17057 lbs	15552 lbs	13859 lbs	17057 lbs	15552 lbs	15766 lbs	14375 lbs	18018 lbs	16428 lbs	18018 lbs	16428 lbs	15665 lbs	16110 lbs	15825 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort)	4.92	4.38	5.34	6.82	3.91	5.27	4.90	3.99	4.42	4.29	4.73	5.12	4.73	5.30	4.11	4.33	5.55	5.12	4.55	5.32	4.67	3.83	4.20	4.21	3.51	3.85	4.72	4.72	4.00	4.46	4.15	4.55	5.27	5.42	6.02
	Heating Ability
Firebox Area	86.10 sq. ft		144.30 sq. ft		181.72 sq. ft	155 sq. ft	155 sq. ft	115.11 sq. ft		115.11 sq. ft	155.56 sq. ft	155.56 sq. ft			181 sq. ft		155 sq. ft	155.60 sq. ft	171.40 sq. ft	171.40 sq. ft	142 sq. ft	93 sq. ft	93 sq. ft	142 sq. ft	127.60 sq. ft	127.60 sq. ft	164.40 sq. ft	164.40 sq. ft		138 sq. ft			148 sq. ft	148 sq. ft	163 sq. ft
Grate Area	15 sq. ft	17.60 sq. ft	26.20 sq. ft	38.50 sq. ft	16.10 sq. ft	34.80 sq. ft	34.80 sq. ft	17.60 sq. ft	17.60 sq. ft	17.60 sq. ft	28.54 sq. ft	28.54 sq. ft	24.30 sq. ft	29.13 sq. ft	33.20 sq. ft	13.30 sq. ft	34.80 sq. ft	34.80 sq. ft	33 sq. ft	33 sq. ft	17.65 sq. ft	17.34 sq. ft	17.34 sq. ft	17.60 sq. ft	17.60 sq. ft	17.60 sq. ft	34.76 sq. ft	34.76 sq. ft	33.25 sq. ft	33.25 sq. ft	33.25 sq. ft	33.25 sq. ft	33.25 sq. ft	33.25 sq. ft	30 sq. ft
Evaporative Heating Surface	831		1817		1052	1289	1289	1057	1172	1057	1158	1158	1314	1158	1400	721	1240	1240	1918	1918	1392	1256	1256	1392	1284	1284	1530	1530	1382	1382	1572	1572	1583	1583	1825
Superheating Surface															253
Combined Heating Surface	831	0	1817	0	1052	1289	1289	1057	1172	1057	1158	1158	1314	1158	1653	721	1240	1240	1918	1918	1392	1256	1256	1392	1284	1284	1530	1530	1382	1382	1572	1572	1583	1583	1825
Evaporative Heating Surface/Cylinder Volume	148.79		257.05		166.85	204.44	204.44	149.53	165.80	167.64	183.66	183.66	208.41	183.66	140.95	160.23	175.42	175.42	237.11	237.11	220.78	177.69	177.69	196.93	181.65	181.65	204.91	204.91	185.09	185.09	210.53	210.53	212.01	201.00	377.13
	Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation	1800	2288	4716	6930	2013	4872	4872	2200	2200	2200	3568	3568	3038	3641	5810	1663	4872	4872	6105	6105	2295	2774	2774	2288	2816	2816	4866	4866	5320	5320	5320	5320	5819	5819	6150
Same as above plus superheater percentage	1800	2288	4716	6930	2013	4872	4872	2200	2200	2200	3568	3568	3038	3641	6972	1663	4872	4872	6105	6105	2295	2774	2774	2288	2816	2816	4866	4866	5320	5320	5320	5320	5819	5819	6150
Same as above but substitute firebox area for grate area	10332	0	25974	0	22715	21700	21700	14389	0	14389	19445	19445	0	0	38010	0	21700	21784	31709	31709	18460	14880	14880	18460	20416	20416	23016	23016	0	22080	0	0	25900	25900	33415
Power L1	2981	0	8404	0	4405	5194	4736	2983	0	3345	3966	4350	0	0	9149	0	5188	4796	7193	8462	4478	4025	4415	3995	4496	4931	4557	4998	0	5032	0	0	7078	6882	6195
Power MT	281.45	0	454.67	0	458.41	357.84	320.38	247.23	0	289.48	311.16	345.46	0	0	411.00	0	347.65	321.38	338.84	400.76	342.19	271.57	297.89	302.14	331.50	363.58	270.07	325.04	0	302.49	0	0	377.83	347.59	286.92