CLASS R-2 and R-3 4-8-2

R-2 3500 was the precursor of twenty additional high horsepower Mountain type engines of similar design.  All twenty-one were built by Schenectady starting with 3500 in 1924, 7 additional R-2's in 1926 distiguished by high boiler pressure (3501-07), three R-3's with three cylinders in 1926 (3550-52) and ten more in 1928 (3553-62).  All were equipped with water-tube fireboxes which were not successful and soon replaced.
R-2 Class
3500 is in Chicago in June 1925 to display her water-tube firebox at the convention of the Mechanical Division of the ARA.
3500 with a shelter for testing engineers.
The cabin housed an instrument which diagrammed steam pressure in the cylinders which was used to calculate horsepower.
3500 with a Vanderbuilt tender at Cedar Hill in May 1938.
R-2-a Class
3501 at Cedar Hill July 1938.
 3504 with air compressors on the pilot deck at Southampton Street in July 1939.
3502 has received Baker valve gear and a new front-end throttle location eliminating the need for the slanting steam admission pipes.
 3503 at Sharon Summit with BO-1 in 1940.  Air tank has been removed to accomodate the new Walschaert valve gear.
R-2-a 3507 at Cedar Hill.
R-3 and R-3-a were built in 1926 and 1928 respectively.
R-3 3550 and R-3-a 3556
The front-end throttle on 3556 is below the superheater instead of in front of the stack and allows a straight steam admission pipe.
3550 is westbound near Danbury August 28, 1937.
R-3 3552 with an R-1-b at Readville on the way to Southampton Street November 1937.  Photo by Charles Brown.
3553 when new.
R-3-a 3554 with relocated air compressors
3554 at Cedar Hill
R-3-a 3556 at Cedar Hill April 1938
R-3-a 3559 being washed at Southampton Street in June 1938.
R-3 3551 at Cedar Hill  May 1920.
R-3-a 3553 has air compressors behind the shield mounted sideways to accomodate the Gresley valve gear.  Boston August 1940.
 R-3-a 3554 has no air compressor shield.
 R-3-a 3555 westbound near Branford February 1939
 R-3 3551 eastbound near Northford March 1941.
3558 at Maybrook powering a fan trip in September 1937.  An R-3-a with a passenger train was rare.
 3561 at Worcester in 1945 by H. W. Pontin.
Subpages (1): CLASS S FORNEY