The United States Railroad Administration's Mountain design proved an excellent fit for the New Haven's fast freight requirements, so in addition to the ten supplied during the USRA's administration, the railroad bought 30 more in 1920. The boiler was little changed, although superheater area increased by 53 sq ft. The five-foot long combustion chamber added 106 sq ft (9.85 sq m).
These engines were among the first to be built with feed water heaters installed. They were type E-1s from Locomotive Feedwater Heater Company; the pump could move 7,500 gallons (28,388 litres) per hour.
The United States Railroad Administration's Mountain design proved an excellent fit for the New Haven's fast freight requirements, so in addition to the 10 supplied during the USRA's administration, the railroad bought 39 more - 30 in 1920 (Locobase 15995) and 9 in 1924. Over time, the class (R-1, R-1-a, R-1-b) was updated with 95 sq ft of syphons.
Maximum water evaporation rate was calculated at 56,555 lb/hour of which 22,825 lb/hour (40.4%) came from direct heating surfaces. As calculated by the New Haven, maximum steam consumption of 54,580 lb/hour yielded a 104% boiler factor.
To stave off the need to replace the class, the New Haven replaced the class's Southern valve gear with Baker gear in 1940 and fitted them with mechanical lubricators.
Thus equipped, all served the New Haven throughout World War II. Retirements occurred from the end of the war to the end of steam (1946-1951).
Although the specifications describe this locomotive after it was rebuilt as a conventional locomotive in 1929, it entered service as a test vehicle for a revised design of the McClellon watertube boiler. The Boiler Maker report says that the first two boilers built to this design were mounted on 2-8-2s in 1916, but "met with indifferent success." Troublesome weaknesses could be corrected and the design was "fundamentally sound", but McClellon died soon thereafter and it was only in 1920 that the New Haven's mechanical manager W L Bean could make the changes to the original boilers.
Bean doubled-down on this considerable variation of the conventional firebox by asking Schenectady to modify the 49th R-1 to a revised design. Numbered 3500 and designated R-2, the new locomotive appeared in 1924. Locobase recommends that those interested in all the details consult the long article cited above.
Here are the basic elements of the design, however. In place of side and back sheets in the firebox and side sheets in the combustion chamber, a picket line of vertical watertubes carried around all three sides. A photo shows that the backhead was framed in channel beams to provide a template for a heavy plate cross member that was bolted on pads on the two side channel beams. Two tubes on either side of the firedoor structure were significantly bowed--e.g. ()-- at the level of the firedoor. 43 tubes in the side sheets and 15 more in the combustion chamber had 4" diameters swaged to 3" at the ends; the back head tubes had constant 2" diameters.
As with other watertube boiler designs, the tubes conveyed water from the foundation ring at the bottom of the firebox to drums above the firebox proper. In the McClellon design, two 23" (584 mm) drums flanked the 30"' center drum as the three ran longitudinally from back head to the front sheet of the combustion chamber. The drums were open at the front.
Despite all the assurances that the problems with leaks in a watertube firebox had been addressed, the system proved leaky enough. Bean had already ordered seven more R-1a, which differed from the 3500 in having Type E superheaters; see Locobase 216. Three more were ordered as three-cylinder engines; see Locobase 217.
Like the others, the 3500's watertube firebox was replace in 1929 by a conventional furnace. In addition to the firebox itself, the direct heating surface area included 101 sq ft (9.4 sq m) in the combustion chamber and 95 sq ft (8.8 sq m) of thermic syphons in the firebox and combustion chamber. Feed water was heated through an Elesco installation. Steam entered the cylinders through 14" (356 mm) piston valves actuated by Baker gear, which replaced the original Southern gear installation.
This was a quirky mixture of new ideas such as the Type E superheater and auxiliary equipment that in many cases was unsatisfactory. Specified by the New Haven's mechanical manager, WL Bean, the McClellon boiler had a water-tube firebox that leaked and let in cold air. See Locobase 16073 for a longer description of this design.
Ultimately all New Haven engines originally delivered with the McClellon boiler had a conventional boiler fitted in 1929. Other problems included a balky DuPont-Simplex mechanical stoker (replaced by an HT-2 in the 1930s) and Southern valve gear replaced by Walschaerts or Baker gear. The design also came equipped with feedwater heater and a valve motion with limited cutoff.
The R-2s ran until 1949-1951.
Boiler had feedwater heater. Unusual three-cylinder variant of earlier R-2 that also came with the McClellon watertube firebox boiler design. Within a year they'd been reboilered. Note relatively small number of tubes and flues. Although the middle cylinder was a maintenance headache, financial stringency prevented conversion to a two-cylinder layout (as other railroads had done). They ran until 1949-1951.
|Specifications by Steve Llanso of Sweat House Media|
|Class||R-1-a||R-1-b - syphons and FWH||R-2||R-2a||R-3|
|Railroad||New Haven (NYNH&H)||New Haven (NYNH&H)||New Haven (NYNH&H)||New Haven (NYNH&H)||New Haven (NYNH&H)|
|Locomotive Length and Weight|
|Ratio of driving wheelbase to overall engine wheebase||0.46||0.46||0.45||0.45||0.47|
|Overall Wheelbase (engine & tender)||75.62'||75.62'||83.67'||83.92'||85.33'|
|Axle Loading (Maximum Weight per Axle)||58200 lbs||58200 lbs||61300 lbs||65300 lbs|
|Weight on Drivers||229000 lbs||230500 lbs||244500 lbs||246000 lbs||261000 lbs|
|Engine Weight||328500 lbs||334000 lbs||360700 lbs||362500 lbs||379000 lbs|
|Tender Light Weight||182500 lbs||184800 lbs||286000 lbs||288500 lbs|
|Total Engine and Tender Weight||511000 lbs||518800 lbs||646700 lbs||667500 lbs|
|Tender Water Capacity||10000 gals||16000 gals||16000 gals||16000 gals||16000 gals|
|Tender Fuel Capacity (oil/coal)||16 tons||10 tons||18 tons||18 tons||18 tons|
|Minimum weight of rail (calculated)||95 lb/yard||96 lb/yard||102 lb/yard||103 lb/yard||109 lb/yard|
|Geometry Relating to Tractive Effort|
|Boiler Pressure||200 psi||200 psi||250 psi||265 psi||265 psi|
|Cylinders (dia x stroke)||27" x 30"||27" x 30"||27" x 30"||27" x 30"||22" x 30"|
|Tractive Effort||53883 lbs||53883 lbs||67353 lbs||71394 lbs||71101 lbs|
|Factor of Adhesion (Weight on Drivers/Tractive Effort)||4.25||4.28||3.63||3.45||3.67|
|Firebox Area||348 sq. ft||415 sq. ft||421 sq. ft||458 sq. ft||451 sq. ft|
|Grate Area||70.30 sq. ft||70.30 sq. ft||70.20 sq. ft||70.80 sq. ft||70.80 sq. ft|
|Evaporative Heating Surface||4121 sq. ft||4188 sq. ft||4011 sq. ft||4135 sq. ft||4085 sq. ft|
|Superheating Surface||1009 sq. ft||1009 sq. ft||1009 sq. ft||1758 sq. ft||1745 sq. ft|
|Combined Heating Surface||5130 sq. ft||5197 sq. ft||5020 sq. ft||5893 sq. ft||5830 sq. ft|
|Evaporative Heating Surface/Cylinder Volume||207.29||210.66||201.76||207.99||206.33|
|Computations Relating to Power Output (More Information)|
|Robert LeMassena's Power Computation||14060||14060||17550||18762||18762|
|Same as above plus superheater percentage||16872||16731||21060||24391||24391|
|Same as above but substitute firebox area for grate area||83520||98770||126300||157781||155370|