Philadelphia & Reading 2-8-2 "Mikado" Locomotives in the USA

Class M-1 (Locobase 11023)

Data from Record of Recent Construction #98 (Baldwin Locomotive Works, 1920), p. 31 and Proceedings of the Annual Convention of the International Railway Fuel Association (Published by The Association, 1914), p. 346. See also DeGolyer, Volume 49, pp. 318+ and Volume 51, p. 186. Baldwin works numbers were

1913

December 41029-41030, 41052

1914

January 41089, 41094, 41106

1915

November 42673-42686, December 42728-42733

Known as "Big Dutch Mikes", these had the enormous Wooten boiler in a conventional-cab arrangement. The first of the class was built in the Reading shops and had a saturated boiler with a heating surface area of 5,508 sq ft, of which 298 sq ft came from the firebox and combustion chamber. The remaining 2-8-2 were produced in two versions: this one, with the 61 1/2" drivers and the M1sb with smaller drivers and a lower boiler pressure (see Locobase 9548).

The M1s had a 36"(914 mm) high wall separating the firebox proper from the 81 sq ft (7.53 sq m) combustion chamber and 14" (356 mm) piston valves. They burned a mixture of hard (fine anthracite) and soft coal.

In the mid-1920s, the Reading reworked the boilers considerably while increasing the cylinder volume; see Locobase 9547.

Class M1-sa (Locobase 9547)

Data from Reading 11 - 1926 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange.

In the mid-1920s, the Reading rebuilt its stud of Mikados delivered with 61 1/2" drivers (Locobase 11023), principally by removing 39 of the boiler tubes from the original layout. At the same time, the railroad increased cylinder volume by boring out the cylinder by 1". It's possible that the Reading determined that the original design had too much heating surface in the relatively underperforming tube bundle. Another flaw may have been lack of steaming space, which the deletion of three or four rows of tubes may have alleviated.

Connelly's Baldwin list shows that all of the M1s were rebuilt in 1924 and again (?) in 1943. The M1-sb that had 55 1/2" drivers were converted to M1-sa in two batches: the last 10 delivered were rebuillt by 1929, the first 20 were rebuilt in 1941-1943.

All of the M1s were scrapped in the late 1940s.

Class M1-sb (Locobase 9548)

Data from Reading 11 - 1926 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also DeGolyer, Vol 58, pp. 366+. Baldwin works were

1916

January 42799-42801, 42823-42825; February 42906-42908, 42939; October 44329-44330; November 44443-44445, 44474-44475; December 44577-44581, 44619-44621, 44674

1917

January 44814-44816, 44870

After the first 26 Baldwin Big Dutch Mikes were delivered to the Reading (Locobase 9547), the railroad changed the specification by reducing the driver diameter by 6 1/2" and dropping the boiler pressure. Firebox heating surface area included 82 sq ft (7.6 sq m) in the combustion chamber; the latter was separated from the firebox by a brick half wall. Piston valves measured 14" (356 mm) in diameter. Apparently the Reading found the exhaust nozzle diameter a touch too large at 7" (178 mm); a handwritten "Hereafter" note states that exhaust nozzles were to measure 6 1/2" (165 mm).

Although the tractive effort remained about the same, the M1sb alosmst certainly proved sluggish. In any event, the last 10 were converted to M1sa (Locobase 9547) by 1929. The other 20 were converted to the M1sa standard in 1941-1943.