Class 1/D (Locobase 11591)

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

The NYP & N was a Delmarva road that connected the Pennsylvania's end point at Delmar in the center of the peninsula with Norfolk. It was created by merging 9-mile Worcester & Newton with the Eastern Shore which linked Delmar to Salisbury and thence southwest to Annensic, later dubbed Crisfield, on Chesapeake Bay. The last and longest element was the 65-mile section built in the 1880s between Pocomoke, Md and the ferry at Cape Charles at the southern tip of the Delmarva Peninsula.

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.

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Class 10 (Locobase 11869)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University Volume 13. p 216. Works number was 8542 in May 1887.

This Eight-wheeler had a long, shallow firebox for burning anthracite coal. 30 years after it entered service, the 10 accompanied several other C&L engines as they merged with the Pennsylvania's stud in 1918.

Placed in the D odd class (along with a medley of other outliers), the 3689 remained on the roster for another five years until it was scrapped in October 1923.

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Class 1504 (Locobase 2834)

Data from diagram scanned in by Robert Schoenberg of [] . 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. (Thanks to Chris Hohl for his 27 August 2018 email supplying an Alco builder's card for this locomotive.) Works number was 3808 in May 1892.

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 (Locobase ). 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.

One interesting difference from prevailing PRR practice was a noticeably smaller grate area.

The later Alco card showed that at some point the Pennsylvania added 16 sq ft (1.49 sq m) to the firebox heating surface area, raising it to 160.3 sq ft (14.89 sq m). The Pennsy's own diagram noted that the tender was fitted with a water scoop.

This one was retired in 1911.

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Class 1510/D (Locobase 2835)

Data from diagram scanned in by Robert Schoenberg of [] . See also Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University Volume 18, p. 11. Works number was 12824 in July 1892.

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 (Locobase 2836).

Baldwin delivered the 1510 with the 22" LP cylinders shown in this spec, which generated an LP/HP ratio of 2.86, in keeping with many other Vauclain compounds. Each set of an LP and and HP cylinder was served by a single 10 1/2" (267 mm) balanced piston valve. Later diagrams show the class with 24" (610 mm) LP cylinders, which raised that ratio to 3.41. Very few compounds ever tried to make exhausted HP steam do so much work per square inch.

In 1903, the Pennsy converted the 1510 to a two-cylinder simple-expansion locomotive. In 1909, the railroad replaced its tall express drivers with 68" wheels. The engine was scrapped in 1911.

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Class 2 (Locobase 16351)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University Volume 16, p. 27 (by reference to Volume 15, p. 232). See also William Bender Wilson, History of the Pennsylvania Railroad Company: With Plan of ..., Volume 1 (Philadelphia: Henry T Coates, 1899), pp. 356-358. Works numbers were 10850-10851 in May 1890.

As an illustration of the hidden standardization of many Baldwin designs, the NB below provides certain proof. The two railroads (Tuckerton and the PS&S shown here) operated over similarly flat and relatively straight profiles in southern New Jersey and ordered pairs of Eight-wheeler passenger locomotives in October 1889 and end-December, respectively.

NB: Tuckerton Railroad's engines 4 and 5 (Locobase 11649) provided the heating surface data for the P&SS's 2-3 after a comparison of the two orders' showed them to have identical fireboxes and grates that burned "hard coal" as well as identical counts, diameters, and lengths of the tubes in the boiilers.

Unlike the Tuckerton, which remained independent for decades, the P&SS had entered receivership by November 1891. This followed some of the management's decision to acquire the Tuckahoe & Cape May, apparently sparking a liquidity crisis. The T&CM was declared insolvent in 1892. (Four later P&SS camelback Eight-wheelers produced in June 1890 were repossessed in February 1892 and sold to Philadelphia & Reading as their class D5-c.)

In August 1893, ownership of the 2 and 3 passed to the West Jersey as their 40-41. Bender's 1899 history notes that this line had a long history and an extensive network. In 1896, its system included "Camden to Cape May, Salem Branch, Woodbury to Salem, branch in Salem, branch, Elmer to Riddleton Junction, Bridgeton Branch, Glassboro to Bridgeton, branch in Bridgeton, Maurice River Branch, Manumuskin to Maurice River, Sea Isle and Ocean City Branch, Sea Isle Junction to Ocean City, Avalon Beach Branch, Sea Isle City to Stone Harbor, Anglesea Branch, Anglesea Junction to Holly Beach, total 184.84 miles, and operated the West Jersey and Atlantic Railroad, main line, Newfield to junction with Camden and Atlantic Railroad near Atlantic City Branch, Pleasantville to Somer's Point, Alloway and Quinton Railroad, Alloway Junction to Quinton, total miles, 43.96. Total owned and operated, 228.80 miles."

"To perfect its splendid system of catering to seashore traffic", Bender wrote, the Pennsylvania amalgamated several roads, including the West Jersey, as the West Jersey & Seashore in 1896. (By that time, the WJ included other railroads such as the Alloway and Quinton Railroad Company, the West Jersey and Atlantic Railroad Company, the Camden and Atlantic Railroad Company, the Chelsea Branch Railroad Company, and the Philadelphia, Marlton and Medford Railroad Company.)

The system was well worth the taking, Bender noted: "These railroads are peculiarly seashore lines, the West Jersey Railroad and its connections furnishing access to all portions of the New Jersey Coast from Atlantic City to Cape May, a distance of about thirty-six miles, and the Camden and Atlantic Railroad has comparatively little business outside of that pertaining to Atlantic City." This was principally passenger service and varied greatly with twice as many passengers taking the train in summer as in winter. Such disparity extended to the municipal electric lines in Atlantic City, which required "about fifty cars during the summer season and about eight during the winter."

Unlike many other such beachgoer lines, however, the WJ ran "considerable passenger and freight business over its lines to Salem, Bridgeton, Millville and some other smaller manufacturing towns, in all of which are glass works, of more or less extensive capacity, and manufactories of other kinds."

When the Pennsy incorporated the two Eight-wheelers into its main roster in 1903, the 41 received no new number and was scrapped in November 1905.

The 40 received #6040. but soon was sold to Senator Sproul in January 1905 to run on the Coal River Coal Company of Clothier, WVa as their #7. Taken over by the C&O in 1912, the 7 took no fewer than four numbers (904, 1005, 1305,and 53) before it went to the ferro-knacker in August 1915.

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Class A/D1 (Locobase 1132)

Data from "Pennsylvania Railroad; Standard Types of Locomotives - Table XII [13]", Engineering, Volume XXIV [24], No 4 (27 July 1877), pp. 65-67, Park Benjamin (Ed), Appleton's Cyclopedia of Applied Mechanics (New York: D Appleton & Company, 1884), p. 348. See also diagram scanned in by Robert Schoenberg of [] . 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.

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Class AAn/D7 (Locobase 1145)

Data from diagram scanned in by Robert Schoenberg of [] . Works numbers were 686-694 in August 1882, 780-799 in April 1883, 930-937 in September, 938-942 in October, 1021-1026 in June 1886, 1129-1130 April 1887, and 1229 in December, 1398-1399 in April 1889; 1400, 1410-1412 in May, 1536-1539 in May 1890. 1540 in September, 1662-1668 in 1891.

Based on Alexander Cassatt's K class (Locobase 2825) , but fitted with firebox suitable for burning anthracite coal and using a slightly greater tube length.

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Class AAn/D7A (Locobase 2825)

Data from diagram scanned in by Robert Schoenberg of [] . Works numbers were 1227 in December 1887, 1271-1276 in April 1888, 1277-1286 in May; 1287-1291, 1295-1297 in June, 1298-1308 in July, 1309-1312 in August, 1401-1409 in May 1889; 1539 in September 1890, and 1541 in October.

Differs from D7 (Locobase 1145) in having smaller drivers, more even weight distribution even as it weighed 1 1/2 tons more. Its firebox rode above the drivers' axles, which allowed the grate to be 41 3/4 (1,060 mm) wide.

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Class B/D2 (Locobase 1133)

Data from "Pennsylvania Railroad; Standard Types of Locomotives - Table XII [13]", Engineering, Volume XXIV [24], No 4 (27 July 1877), pp. 65-67, Park Benjamin (Ed), Appleton's Cyclopedia of Applied Mechanics (New York: D Appleton & Company, 1884), p. 348. See also diagram scanned in by Robert Schoenberg of [] . and PRR 3 - 1904 109-D Class and Description of Locomotives dated 1 March 1904 supplied in August 2013 by Allen Stanley from his extensive Rail Data Exchange.

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.

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Class Ba/D2a (Locobase 1143)

Data from diagram scanned in by Robert Schoenberg of [] and PRR 3 - 1904 109-D Class and Description of Locomotives dated 1 March 1904 supplied in August 2013 by Allen Stanley from his extensive Rail Data Exchange.

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.

NB: The direct heating surface (including the firebox heating surface) is an estimate calculated by subtracting the calculated tube heating surface from the reported total evaporative heating surface.

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Class C (Locobase 9945)

Data from C H Caruthers, "Early Baldwin Locomotives on the Pennsylvania Railroad", Locomotive Engineering, Vol XI, No 2 (February 1898), p. 110. Works 387, 389-390 in August 1850; 392, 394 in September 1850; 400 in October; 406 in November; 423 in April 1851; 431 in June; 459 in December; 462 in February 1852; 468 and 470 in March.

These engines were named when they first came into service: Venango, Centre, Clinton, Columbia, Elk, Erie, Bradford, Clearfield, Crawford, Fayette, Somerset, Greene, Lycoming, and Union.

As Caruthers describes the engines, he notes the big Bury firebox , safety valves on the dome and whistle, big cabbage stack, closely spaced truck, raked cylinder pitch (1 3/4" in 10").

The last of these was retired in 1870, although their obviously obsolescent design was recognized as early as 1857.

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Class C/D3 (Locobase 1134)

Data from "Pennsylvania Railroad; Standard Types of Locomotives - Table XII [13]", Engineering, Volume XXIV [24], No 4 (27 July 1877), pp. 65-67, Park Benjamin (Ed), Appleton's Cyclopedia of Applied Mechanics (New York: D Appleton & Company, 1884), p. 348. See also diagram scanned in by Robert Schoenberg of [] . and PRR 3 - 1904 109-D Class and Description of Locomotives dated 1 March 1904 supplied in August 2013 by Allen Stanley from his extensive Rail Data Exchange; and Charles E Fisher, "The Steam Locomotives of the Pennsylvania Railroad System: Part II", Railway and Locomotive Historical Bulletin No 90 (May 1954), pp. 133-146,

One of the classes established by Alexander J. Cassatt in 1867 when he became Master of Machinery. Duty was passenger and fast freight service and, Charles Fisher wrote, "Of the passenger locomotives, the Class C engines were the main 'work horses': The tenders for this class were fitted with water scoop for refilling their tanks while moving over sections that had water troughs between the rails.

Fisher provide a sample of their performance. On 1 June 1976, class C #573 took the Jarrett and Palmer Special theatrical train non-stop over the 438.5 miles (706 km) from Jersey City to Pittsburgh in 10 hours 5 minutes. Its relatively spritely average of 43.5 mph (70 kph) reflected good use of the water-scoop system and extra bags of coal.

By the end of the 1870s, the Cs had reached their limits and traffic demand kept growing. One successor came on line in 1883 as Class N; see Locobase 1147.

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Class C/D4A-68" (Locobase 2821)

Data from diagram scanned in by Robert Schoenberg of []; and Classification and Description of Locomotives, No 109-D, Pennsylvania Railroad, 1 March 1908.

These were fifteen D4s American anthracite burners delivered with 62" drivers (Locobase 1140) that were modified beginning in 1885 to roll on 68" wheels.

As the bigger and speedier Class Ks /D6 passenger Eight-wheelers (Locobase 1142) proliferated in the system, the Pennsy started sloughing off these updated engines in 1896. The last of the 68" D4a fell under the torch in March 1905.

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Class CAn/D4 (Locobase 1140)

Data from "Pennsylvania Railroad; Standard Types of Locomotives - Table XII [13]", Engineering, Volume XXIV [24], No 4 (27 July 1877), pp. 65-67, Park Benjamin (Ed), Appleton's Cyclopedia of Applied Mechanics (New York: D Appleton & Company, 1884), p. 348. See also diagram scanned in by Robert Schoenberg of [] . and PRR 3 - 1904 109-D Class and Description of Locomotives dated 1 March 1904 supplied in August 2013 by Allen Stanley from his extensive Rail Data Exchange.

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 longer, shallower firebox suitable for burning anthracite coal. The tenders later carried 6 tons (5.45 tonnes) of coal.

Fifteen of the class later received 68" drivers; see Locobase 2822. Most of the 22 62" locomotives went to the ferro-knacker in the late 1890s.

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Class D16a (Locobase 2833)

Data from diagram scanned in by Robert Schoenberg of [] . See also Charles B. Chaney's summary in Railway & Locomotive Historical Society Bulletin #59 (1942); and Alvin F Staufer (text by Bert Pennypacker, research by Martin Flattley), Steam and Electric Locomotives of the Pennsylvania Railroad 1900-1957 (Carrollton, Ohion: Standard Printing & Publishing Company, 1962), pp. 107-109. Works numbers were 346-348, 351-358, 363-367, 371-375 in 1895; 386, 393--397,399-402 in 1896; 426-430, 442, 445, 447, 449-452 in 1897, 476-484 in 1898; 2037-2050.

As with all Pennsy locomotives of this vintage or later, this design used a Belpaire firebox. The design represented the efforts of the Chief of Motive Power T N Ely, Mechanical Engineer Alex Vogt, and the Lines East's General Superintendent of Motive Power F D Casanave. See Locobase 1144 for more details on the design's origins.

Its chief difference from the original D16 was the mounting of 80" drivers, making it a true express engine. Even with such tall drivers, the L class's boiler and firebox were placed on top of the frame bars, rather than between them.

Pennypacker's commentary is plush with compliments: "superb mechanical perfection" over the Middle Division and offers the record of the 816, which "piled up more than three hundred thousand miles of service along that division in a period of three years and fouer months, without shopping or heavy repairs of any kind." On the dual "racetracks" between Jersey City and Atlantic City, engineer Martin Lee established "a legend of high-speed running." He is said to hit 102 mph (164 kph) over an 8-mile stretch ("fling", as Pennypacker calls it) and delivered PRR president AJ Cassatt's train to from Broad Street to Jersey City at an average of 70. 1 mph (113 kph).

These first Ls/

Many were later superheated as D16sb with 68" drivers; see Locobase 103.

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Class D16b (Locobase 13320)

Data from diagram scanned in by Robert Schoenberg of [] . The Pennsy didn't back away from long production runs once they were satisified with a design. After the Class L/D16 entered production in 1895 (Locobase 1144), its impact on PRR passenger trains led to subclasses of 80"-driver express locomotives: D16a (Locobase 2833) and D16c/D16d (Locobase 13221.)

But the biggest subclass was the 68" D16b produced from 1900 to 1908. In addition to the 262 for the Pennsy, Altoona turned 31 more in 1905-1906 for the Long Island Railroad.as their 200-230. Exactly half of these were later superheated beginning in 1914. (Locobase 103).

As with the other D16s, the D16bs presented a stylish profile in which the Belpaire firebox was visible, but not distracting. The long cab roof extension back to the edge of the tender established a "speed line".Even in its relatively low-driver diameter, the coupled wheels contributed to an impression of a locomotive in a hurry to be somewhere else.

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Class D16c/D16d (Locobase 13321)

Data from diagram scanned in by Robert Schoenberg of [] . See also Charles B. Chaney's summary in Railway & Locomotive Historical Society Bulletin #59 (1942).

As with all Pennsy locomotives of this vintage or later, this design used a Belpaire firebox. It's not clear why there were two different subclasses. The chief difference from the D16a (Locobase 2833) was slightly higher weights.

Those that were not later converted to D16 by being fitted with 68" drivers or left alone were upgraded with superheaters and other details very similar to the D16sb; see Locobase 103.

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Class D16sb (Locobase 103)

Data from Pennsylvania Railroad All-Time Steam Locomotive Diagrams supplied in May 2005 by Allen Stanley from his Rail Data Collection. (Many thanks to Chris Hohl for his 22 September 2017 email reporting unlikely boiler pressure values for 177 entries. A Locobase macro caused the error .)

Modernized from 1914 on with the 20 1/2"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." Fifteen of the updates were of Long Island Railroad D16b.

Among other changes applied in the 1920s, the sb variant used an electric headlight, the pilot was now made of horizontal bars. Some received air-powered sanders and bell-ringers.

All but three of the once-enormous D16 class had been retired by 1937 and only the 1223 was saved for display and later to run on the Straburg Railroad.

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Class D29 Inspection engine-long (Locobase 16397)

Data from D29 locomotive diagram found on Rob Schoenberg's prr.railfan.net website at [], last accessed 10 January 2019. Locomotive IDs based on William Edson and P Allen Copeland, "Steam Locomotives of the Pennsylvania Railroad--An All-Time Roster" (Potomac, MD: Edson Publications, 1994) p 87 , edited by Al Weber. (Many thanks to Chris Hohl for his extensive research and his 3 December 2018 email, spreadsheet, and article link. Chris particularly cites Ron Goldfeder for his article, "The Inspection Locomotive." Railroad History. Spring-Summer 2012. Number 206. pgs. 20 & 32, and further assistance.)

PFW&C shops at Allegheny and Fort Wayne each built an inspection engine in 1907.508, the Allegheny's product, shown here, took the more usual form of such rebuilds. (See Locobase 16398 for the 509; both were carried on the books of the Pennsylvania Company.)

The shops removed the cab from the Class PA 4-4-0 and replaced it with a long cabin (21 ft 1/4 in/6.4 m) resembling that of a passenger coach. Its top roof line was nearly level with the top of the straight stack. The dome's safety valve stand vented through a thinner stack poking up through the roof.

The front four were square. The rear two windows on each side stood taller, presumable to give the engine crew the best possible view. Boarding the vehicle through stairs built alongside the smokebox, inspectors and observers sat in chairs ahead of the dome.

It's not clear if the 508 (ultimately numbered 19404) remained an inspection engine. In any case, the engine was scrapped in July 1922.

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Class D29 Inspection engine-short (Locobase 16398)

Data from D29 Locomotive Diagram found on Rob Schoenberg's prr.railfan.net website at [], last accessed 10 January 2019. Locomotive IDs based on William Edson and P Allen Copeland, "Steam Locomotives of the Pennsylvania Railroad--An All-Time Roster" (Potomac, MD: Edson Publications, 1994) p 87 , edited by Al Weber. (Many thanks to Chris Hohl for his extensive research and his 3 December 2018 email, spreadsheet, and article link. Chris particularly cites Ron Goldfeder for his article, "The Inspection Locomotive." Railroad History. Spring-Summer 2012. Number 206. pgs. 20 & 32, and further assistance.)

Originally built in 1880 at the Fort Wayne shops as Class PA Eight-wheeler mixed-traffic locomotive (road numbers 167, later 1167), this engine was converted at Fort Wayne in the same year that 508 was converted at Allegheny (Locobase 16397) 7509 was carried on the books of the Pennsylvania Company

Unlike the full conversions usually performed during the conversion to inspection engine, the 509 showed an very odd partial adaptation. The original cab remained intact and the steam dome over the firebox was in full view. A short (10 ft 11 in/3.33 m), three-window cabin sat between the dome and the stack. Like the 408, a full set of stairs rose to the front of the cabin.

The 509 is often shown with 62" drivers, but the later Pennsy diagram N-273-2 clearly shows much taller 68" drivers.

Renumbered twice, the 19405 was scrapped in November 1920.

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Class G/D5 (Locobase 1138)

Data from "Pennsylvania Railroad; Standard Types of Locomotives - Table XII [13]", Engineering, Volume XXIV [24], No 4 (27 July 1877), pp. 65-67, Park Benjamin (Ed), Appleton's Cyclopedia of Applied Mechanics (New York: D Appleton & Company, 1884), p. 348. See also diagram scanned in by Robert Schoenberg of [] . and PRR 3 - 1904 109-D Class and Description of Locomotives dated 1 March 1904 supplied in August 2013 by Allen Stanley from his extensive Rail Data Exchange. Built by Pennsylvania shops from 1869 to 1874 and 1881 to 1884.

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.

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Class K/D6 (Locobase 1142)

Data from "Fast Passenger Locomotive for the Pennsylvania Railroad", Railroad Gazette, Volume 13 (4 November 1881), pp. 620; and "Express Locomotive for the Pennsylvania Railway [sic]", Engineer, Volume 53, (10 February 1882), pp. 96, 102 . See also diagram scanned in by Robert Schoenberg of []; and George L Fowler, "Recent Development of American Passenger Locomotives", Railroad Gazette, Volume XL [40], No 24 (15 June 1906), pp. 641-644.

One of the classes established by Alexander J. Cassatt in 1867 when he became Master of Machinery. This high-drivered design for express passenger service was devised by superintendent of motive power Theodore N Ely. Note that while the grate was larger than that of the earlier B & C classes in order to burn anthracite coal, the K-class designer chose to use more and 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. This came from placing the firebox above the engine's frame rails rather than between them; the location was one of the first such constructions in a locomotive.

K data in the later diagrams gave higher weights. Adhesion weight grew only slightly, but total engine weight increased to 96,700 lb (43,862 kg).

Fowler commented of the innovation: "Many and dire were the predictions as to the instability of the new design, because of the unprecedented height of 7 ft 5 1/4 in [2.271 m] at which the center of the shell was placed above the rails." This apprehension was not uncommon for the times, as Locobase has noted in many entries. But Fowler reported a different outcome: "[T]he not only did not upset, but ran with remarkable steadiness, and demonstrated from the outset the safety of the arrangement ...The advantages were so apparent that the wide firebox boiler at once became the vogue [on the Pennsylvania--narrow fireboxes with 33 3/4"(about 855 mm) wide grates would remain in widespread use for almost two more decades.

The Engineer (London) surveyed the design in its 10 February 1882 issue and sniffed at "certain features that will always appear objectionable to English eyes--such as the bar frames and the excessive use of cast iron." Somewhat more reasonably, the writer noted that Pennsylvania locomotive head Ely's choice of a wagon-top boiler had been "recently much criticised, and lastly condemned by United States railway men, and we cannot ourselves see much in it to recommend it." It was, Engineer noted, "of steel throughout."

[] (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 two-bar alligator crosshead, powered reversing gear, and sandboxes on the running board rather than sand in a top-mounted dome.

A dissent from this positive assessment is found closer to the time of their use in Railroad & Engineering Journal, Volume LXVI, No 11 (November 1892), p. 487.. The author comments that although they had tall drivers, "...owing to insufficient boiler capacity were not successful in the service for which they were intended - that is, heavy and fast passenger traffic."

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Class K/D6a (Locobase 2823)

Data from diagram scanned in by Robert Schoenberg of []; and PRR 5 - 1902 109C Class & Description of Locomotives supplied in August 2013 by Allen Stanley from his extensive Rail Data Exchange collection.

These eight engines were converted from Class K (later D6 )engines (Locobase 1142) with smaller drivers, which raised tractive effort. The factor of adhesion suggests, however, that this design still had some room for growth.

The entire octet was scrapped in 1906-1907.

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Class L/D16 (Locobase 1144)

Data from diagram scanned in by Robert Schoenberg of [] . See also Charles B. Chaney's summary in Railway & Locomotive Historical Society Bulletin #59 (1942) and J Parker Lamb, Perfecting the American Steam Locomotive (Bloomington, IN: Indiana University Press, 2003), pp. 25, 27; and Alvin F Staufer (text by Bert Pennypacker, research by Martin Flattley), Steam and Electric Locomotives of the Pennsylvania Railroad 1900-1957 (Carrollton, Ohion: Standard Printing & Publishing Company, 1962), pp. 107-109.

426 D-16 engines built in five sub-classes between 1895 and 1910. D-16 had 68" drivers; D-16a had 80" drivers (Locobase 2833). All had the characteristic (for the Pennsy) Belpaire firebox. According to J Parker Lamb, "An unlikely trio of international technical talent" were primarily responsible for designing this large, powerful passenger engine. They were the French-born general superintendent of motive power Frank D. Casanave, chief mechanical engineer Axel S. Vogt from Sweden, and American-born chief of motive power Theodore N. Ely. Lamb describes the division of labor: "Casanave supervised the design, whose details were refined by Vogt, while Ely ...used his artistic talents to provide the external contours, and to design the paint scheme and striping of the finished product."

They began with 18.5 x 26 cylinders, 185-psi boilers, yielding a 22,250 lb tractive effort; because of Vogt's "careful attention to details", the first of the class weighed in at a value only 68 pounds away from the estimate. All of the engines were fitted with the same number of tubes, each of which offered the unusual diameter of 1 7/8" inches.

A mark of the D16's reliability was the long production run (signifying satisfaction with the original design as well as a relatively conservative approach to innovation). Another was their longevity in service, with 143 remaining on the roster in 1929. Almost all rolled on 68" drivers by then, pulling a great variety of local passenger trains. Pennypacker noted that several were later sold to the Kishacoqullas Valley railroad of Lewistown, Pa.

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Class N/D8 (Locobase 1147)

Data from diagram scanned in by Robert Schoenberg of [] . PRR works numbers were 800-809 in June 1883, 905-912 in June 1884, 913-914 in July, 943 in November; 982, 984 in October 1885, 1027-1032 in June 1886, 1097-1099 in December., 1292-1294 in June 1888

The widely used C class passenger and fast freight locomotive had seen its best days, so the PRR began replacing it with larger, more powerful engines. Rolling on the same-size drivers, the Ns carried a larger boiler. Continuing preference for a firebox set low between the frames, the design found more direct heating surface area by widening the distance to 47".

Most of the class was withdrawn in the first few years of the 20th Century. PRR 8903 and 8933 survived until 1917.

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Class O/D10 (Locobase 2827)

Data from diagram scanned in by Robert Schoenberg of [],and PRR 5 - 1902 109C Class & Description of Locomotives supplied in August 2013 by Allen Stanley from his extensive Rail Data Exchange collection.

Altoona number 1528, one of the very first in the class in August 1890, was sold 16 years later to north central Pennsylvania road Coudersport & Port Allegheny, where it took road number #4. 1752 found a new career in April 1910 on the Central New York & Southern as their #5. 1632 wen to the Pittsburgh & Susquehanna in July 1914 as their #7.

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Class O/D10a (Locobase 3488)

Data from diagram scanned in by Robert Schoenberg of []; and PRR 5 - 1902 109C Class & Description of Locomotives supplied in August 2013 by Allen Stanley from his extensive Rail Data Exchange collection.

D10a had only 600 lb more total weight in working order than the D10 (Locobase 2827), but also had the taller drivers. Even so, the factor of adhesion rose to a more desirable ratio. Among the first Pennsylvania engines to have a Belpaire boiler. All of the class went into service on Lines West railroads (

In 1922 (3) and 1923 (5), the Pennsylvania sold eight D10a locomotives to the Norfolk & Western.

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Class O/D8a (Locobase 1148)

Data from diagram scanned in by Robert Schoenberg of []; and PRR 5 - 1902 109C Class & Description of Locomotives supplied in August 2013 by Allen Stanley from his extensive Rail Data Exchange collection, See also Paul T Warner, Motive Power Development of the Pennsylvania Railroad, 1831-1924 (Philadelphia: Baldwin Locomotives reprint, 1924) , p 28. By year, the Pennsylvania produced 66 at Altoona Machine Shops starting with 9 in 1883, followed by 11 in 1884, 2 ini 1885, 13 in 1886, 11 in 1887, 20 in 1888,

Similar to N, but with slightly larger cylinders. Warner wrote these replaced the Class B locomotives (later redesignated D2). While offering the same cylinder volume and driver diameter, the boiler's heating surface erea increased by 28 % and was pressed to a higher setting. Duty was passenger and fast freight service.

Warner characterized their profile as "plain", but a continuous splasher lay over the two driving axles on each side of the boiler and the tall, slender stack was capped.

In September 1897, the Pennsylvania redesignated all remaining Os as D8z. Among the second owners of these engines were the Pennylvania short line Ligonier Valley (#10), Quebec Southern, Pittsburgh, Summerville & Clarion (#3), Stewartstown (#3), two Susquehanna, Bloomsburg & Berwick (#2-3), three Western New York & Pennsylvania (#28, 13, and 10).

The class dwindled with these sales to other railroads and disposals for scrap in the first fifteen years of the 20th century.

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Class O/D9 (Locobase 2826)

Data from diagram scanned in by Robert Schoenberg of []; and PRR 5 - 1902 109C Class & Description of Locomotives supplied in August 2013 by Allen Stanley from his extensive Rail Data Exchange collection.

Had the earlier O class (Locobase 1148) 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 (Locobase 3489) had slightly more weight on the drivers..

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Class O/D9a (Locobase 3487)

Data from diagram scanned in by Robert Schoenberg of []; and PRR 5 - 1902 109C Class & Description of Locomotives supplied in August 2013 by Allen Stanley from his extensive Rail Data Exchange collection.

Locobase 2826 shows the data for the four O class locomotives (Locobase 1148) that would later be class D9. This entry describes the D9a, which put slightly more weight on its adhesion axles, but rolled on 6" (152 mm) taller drivers than did the D9s, but also had the Belpaire firebox.

Most of the class continued to run into the 19teens.

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Class P/D11 (Locobase 1149)

Data from diagram scanned in by Robert Schoenberg of [] . See also Charles B. Chaney, "The Famous Class P Passenger Engines - Pennsylvania Railroad" Railway & Locomotive Historical Society Bulletin #59 (1942), pp. 6-11.

Similar to O, but with slightly larger cylinders and higher boiler pressure and "toboggan-type" fireboxes with grates that sloped toward the front. Their service area included the Philadelphia, Wilmington & Baltimore and the Baltimore & Potomac pulling 20-car fast freight trains.

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Class P/D11a (Locobase 4152)

See also Charles B. Chaney, "The Famous Class P Passenger Engines - Pennsylvania Railroad" Railway & Locomotive Historical Society Bulletin #59 (1942), pp. 6-11. See also PRR 5 - 1902 109C Class and Desccription of Locomotives supplied in August 2013 by Allen Stanley from his extensive collection.

Like the D11s (Locobase 1149), which ran on 62" drivers, the D11as had radial-stay "toboggan-type" fireboxes with grates that sloped toward the front. Their 18 1/2" cylinder diameter was an unusual diameter in North American practice.

Chaney reported that a D11a ran two round trips daily between Philadelphia and Washington for one month in 1887 and accumulated 17,000 miles (27,370 km).

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Class P/D12 (Locobase 2828)

Data from diagram scanned in by Robert Schoenberg of [] . See also See also Charles B. Chaney, "The Famous Class P Passenger Engines - Pennsylvania Railroad" Railway & Locomotive Historical Society Bulletin #59 (1942), pp. 6-11.

These two engines were part of the landmark P class variant that introduced the Belpaire boiler, later to become a standard part of Pennsy practice. They were assigned to the Northern Central Railway.

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Class P/D12a (Locobase 2829)

Data from diagram scanned in by Robert Schoenberg of [] . See also See also Charles B. Chaney, "The Famous Class P Passenger Engines - Pennsylvania Railroad" Railway & Locomotive Historical Society Bulletin #59 (1942), pp. 6-11. Produced in 1889-1891.

This large class first used a Belpaire firebox on one of the few US railroads that would adopt the square-shouldered furnace in significant numbers. In this first version, the firebox had 90-degree corners. According to Chaney, "..this design developed a weakness at this point and the design was later modified."

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Class P/D13 (Locobase 2830)

Data from diagram scanned in by Robert Schoenberg of [] . See also Charles B. Chaney, "The Famous Class P Passenger Engines - Pennsylvania Railroad" Railway & Locomotive Historical Society Bulletin #59 (1942), pp. 6-11

This pair used the same boiler design as the much more numerous D13a, D13c classes shown in Locobase 3489, but rolled on smaller drivers that were better suited to the NCR's requirements.

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Class P/D13a, D13c (Locobase 3489)

Data from diagram scanned in by Robert Schoenberg of [] . See also See also Charles B. Chaney, "The Famous Class P Passenger Engines - Pennsylvania Railroad" Railway & Locomotive Historical Society Bulletin #59 (1942), pp. 6-11.

Still newer P class, now with more, but smaller tubes and more weight on the drivers. It introduced a new, stronger boiler mated with a flush joint to the Belpaire firebox. The D13a, with their taller drivers, were far more numerous than the duet of D13s (Locobase 2830). D13cs were virtually identical, the new designation representing a modest change in the boiler design introduced in 1893.

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Class P/D14 (Locobase 2831)

Data from diagram scanned in by Robert Schoenberg of [] . See also See also Charles B. Chaney, "The Famous Class P Passenger Engines - Pennsylvania Railroad" Railway & Locomotive Historical Society Bulletin #59 (1942), pp. 6-11

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.

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Class P/D14a (Locobase 2832)

Data from diagram scanned in by Robert Schoenberg of [] . See also Charles B. Chaney, "The Famous Class P Passenger Engines - Pennsylvania Railroad" Railway & Locomotive Historical Society Bulletin #59 (1942), pp. 6-11; and "Boiler for Class P Locomotive, Pennsylvania Railroad,"American Engineer and Railroad Journal, Volume LXIX, Number 7 (July 1895), pp. 310-312.

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.

Like most Pennsylvania engines, this class used the Belpaire firebox. The AERJ report explained that Belpaire boilers had caused "considerable trouble" by leaking at the joint between the barrel and the outer shell of the firebox. "This difficulty has been entirely overcome in the case of these boilers," the report continued, "by flanging the connecting sheet in line, thus making the boiler straight top. The strains of expansion and contraction are in this way brought fair against the riveting, and all working due to buckling is avoided."

As a result of replacing the 18" (457 mm) diameter stack with a tapered, 13 1/2" (343 mm) version, the engines now had exhausts that "sounded like the bark of a rifle," according to Charles Chaney.

NB: The evaporative heating surface area in the AERJ report was given as 1,551.84 sq ft because of a firebox heating surface calculation of 116.64 sq ft. Arch tubes added later probably accounted for the difference between that figure and the 148 sq ft shown in the diagram.

Later converted to D14b with 68" drivers.

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Class T/D15 (Locobase 1152)

Some data from "Compound Express Engine, Pennsylvania Railroad" The Locomotive & Railway Carriage & Wagon Review, Vol III (September 1898), p. 139

One of the Pennsy's rare excursions into compounding. Two-cylinder Lindner cross-compound for express passenger service designed by the Chief of Motive Power at the Altoona Shops Theodore N Ely.

Belpaire firebox was of typical Pennsy form, but the dome, the low running board with raised cups for the crankpins gave it a European look.

The author of the Locomotive article noted that the locomotive was a spirited performer, often making up time on the schedule while pulling 12 heavy Pullman cars. "With all this, however, in its favour" he is bound to report, "we doubt if 1515 has ever been really liked by the American drivers. There's something strange about it, with its boxed up wheels, rocking shaft, less valve year, &c, that the men have never taken to, the drivers of the States being very much attached to their American type of engine and its easily accessible parts."

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Class VD-6/D26 (Locobase 11107)

Data from Schenectady Locomotive Works, Illustrated Catalogue of Simple and Compound Locomotives (Philadelphia: J B Lippincott, 1897), pp. 8-9. Works number was 5002-5005 in February 1899.

Schenectady's catalogue of recent American-type engines includes this quartet, whose dimensions match those of the St Lawrence & Adirondack engine shown in Locobase 11106. The chief difference is the driving wheel diameter, which is 6" greater in these main-line express that hauled "...heavy fast trains ...between Indianapolis and St Louis."

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Class VD-6a/D26a (Locobase 9507)

Data from "Vandalia Express Engines" Railway and Locomotive Engineering, May 1899, page 225. Works numbers were 4372-4375 in September 1895.

Tall express Eight-wheeler quartet that went into service pulling the fast expresses that linked Indianapolis and St Louis "...and they are gaining," said the R&LE's correspondent, "a high reputation for the efficient way in which they do the required work ...we understand that they went into service with exceptionally small trouble from the annoyances common to the breaking-in process."

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Class unknown (Locobase 9519)

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 numbers 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."

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Class unknown (Locobase 11176)

Data from "Fuel for Railroads", William Tenney (ed.), The Mining Magazine and Journal, Vol Six, (January 1856) p. 64-66. See also Locobase 5570 for other early comments on the preference for coal as fuel.

According to the Mining Magazine, as of early 1856 "This is a subject of growing importance, and every investigation of it tends to show the value and importance of coal as an article of fuel." His discussion of the substitution of coal for wood included communications from several locomotive superintendents describing various tests by different railroads in 1855.

The P&C's J B Baker ran several trips measuring 82 miles (132 km) each and "elevation overcome" of 1,045 ft using equal parts of Hollidaysburg and Pittsburgh coal, Pittsburgh coal alone, and Broad Top coal. Broad Top burned the most economically with 6,432 lb (2,918 kg) consumed to evaporate 4,877 US gallons (18,459 litres) - this on a grate originally designed for wood burning. The reader will also be able to perform the back-of-the-envelope calculation that over an 82-mile trip pulling 50 cars in a train of 369 short tons total, and given the tender capacity of the day, the crew would have had to stop for water at least three times. No wonder the average speed was 10.9 mph (17.5 km/h).