Baltimore & Ohio 0-2-2 Locomotives in the USA

Class Atlantic (Grasshopper) (Locobase 3311)

Data from Angus Sinclair, Early Motive Power of the Baltimore & Ohio RR (New York: Angus Sinclair Co, 1912) , p. 18. See also Comstock (1971) and John H White, Jr, A History of the American Locomotive: Its Development: 1830-1880 (New York: Dover Publications, 1979 - original publication in 1968); and Henry Latrobe, "Phineas Davis and the 'Grasshopper' Engine', letter dated 4 February 1873, Railroad Gazette, Volume 5 (8 March 1873), pp. 91-94. (NB: Sinclair used data published in the B&O's Eight Annual Report from 1834.) (Thanks to Chris Hohl for his 3 December 2018 email questioning the wheel arrangement usually credited to the Atlantic.)

These were the "Grasshoppers" which enjoyed sufficient success to have stayed in yard service for up to 60 years. One of the deepest dives into the particulars of this remarkable design came from Henry Latrobe in a February 1873 illustrated letter to the Railroad Gazette.

Steam came from a vertical boiler mounted on a platform over two axles.These were driven off cranks turned by vertical rods moved by walking beams, the up-and-down rocking motion giving the type its nickname. (According to the Eighth Annual Report, the Atlantic used a 28 x 14 inch (711 x 356 mm) gearing linked to one pair of drivers only.)

The Atlantic was reported by the B&O's chief engineer Jonathan Knight (on 16 August 1832) to have pulled 90 passengers on six cars at the rate of 13 mph (21 km/h) for a total of 82 miles (132 km). This was calculated to be the equivalent of 43 horses whose daily expense was estimated to be $33.

Total consumption of anthracite coal came to one ton. Total cost of the trip was $16, of which half was spend on the coal. The three crew were paid a total of $3.50 and $3 went to estimated wear and tear and interest. Water station expenses came to another dollar and oil and packing amounted to 50 cents.

Her sister Arabian managed 113 tons at 12 mph.

Reder (1974) says the boiler had 400 1" tubes measuring 3' 2" long..

Class Tom Thumb (Locobase 1015)

Data from J Snowden Bell, Early Motive Power of the Baltimore & Ohio (New York: August Sinclair, 1912), pp. 6-8. See also William H Brown, History of the First Locomotives in America (Philadelphia: Barclay & Co, 1877), pp. 22-23; Alvin F Staufer's Baltimore & Ohio Steam and Electric Locomotives (Medina, Ohio) supplied by Allen Stanley from his extensive Rail Data Exchange May 2005. Kinert 1962, Sagle 1964, Comstock 1971. (Thanks to Chris Hohl for his 19 April 2018 email commenting on wheel arrangement and wheel diameter.)

This tiny engine was built by Peter Cooper to show that automotive power was possible for the new B&O. Inside a five-foot tall vertical boiler were a firebox burning anthracite coal and boiler flues cobbled together from musket barrels. A fan created an artificial draft over the grate.

In size a powered handcar, Tom Thumb was gear-driven, the cylinder rod turning a flywheel through a crank as the flywheel teeth engaged the front wheels. Cooper estimated the engine generated 1.43 horsepower, three times that of the Rainhill Trials' Rocket. Originally designed to cope with the sharp curves in the B&O's first few miles, the Tom Thumb demonstrated its tight turning radius in a test at Mount Clare. H B Latrobe, of the B&O and brother of the railroad's Chief Engineer John Latrobe, wrote a description of the outcome in a letter to Howard in 1877.

Cooper, "with his own hand, opened the throttle, admitted steam into the cylinder, when the crank substitute operated successfully with a clacking nois, and the machine moved slowly forward, with some of the bystanders, who had stepped upon it."

Kinert perhaps overstates Cooper's ingenuity when he claims that Cooper preceded Stephenson in the use of a multi-tube boiler and forced draft. (Stephenson's layout would be widely used; Cooper's not at all.) On the other hand, Latrobe's summary of the fateful first movement doesn't understate the import of the moment: "And this was the first locomotive ever built in America, and this was the first transportation of persons by steam that had ever taken place on this side of the Atlantic on an American locomotive."

Latrobe's description of the famous first trip to Ellicott City on 28 August 1830 is worth seeking out (see Howard's book online at Google Books). After demonstrating its ability over 13 miles outbound and several miles return, the Tom Thumb was met by a horse and car set at the Relay House by stage proprietors Stockton & Stockton. In the race that followed, the Tom Thumb had established a good lead until its fan-blower drive belt slipped off and the engine lost steam. The horse won the race, but steam power had been proved practical.

The 1926 replica built by the B&O, whose data is given in Staufer's diagram, differed considerably from the original. To allow it to draw any reasonable carriage, its single cylinder measured 5" (127 mm) x 27" (685 mm). 38 two-inch (50.2 mm) tubes, each 27" long, yielded 28.42 sq ft (2.64 sq m) of heating surface area. Together with the firebox's 11.5 sq ft (1.07 sq m), the total came to 39.92 sq ft (3.71 sq m). Boiler pressure was set at 90 psi, which generated a calculated tractive effort of 820 lb (371.95 kg or 3.65 kN). Adhesion weight on the geared driver was 5,800 lb (2,631 kg) and engine weight was 10,800 lb.(4,899 kg).

Photos and films show this version to bave placed the geared wheels at the rear and thus it operated as a 2-2-0.