These four locomotives had 28 x 30 cylinders, 73" drivers and a 210 psi boiler pressure which gave them 57,500 pounds of tractive effort. Each weighed 381,000 pounds and were 93" - 6" long (including tenders). The tender had a 10,000 gallon water tank and a 16 ton coal bunker.
The RF&P retired these locomotives in 1950 and there are no surviving examples.
Data from 1937 RF&P locomotive diagram book supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange collection. See also "Fast Freights at Consistent Speeds", Railway Age, Volume 97, No. 11 (15 September 1934), pp. 316-318. Works numbers were 65362-65363 in February 1924, 66440-66441 in November 1925.
Delivered in pairs with boilers pressed to 200 psi, but later increased to 225 psi. Firebox heating surface included 95 sq ft (8.83 sq m) of syphons, 16 sq ft (1.49 sq m) of arch tubes, and the area presented by a long combustion chamber.
RA reported in 1934 the RF&P's recent success in moving 124 trainloads of strawberries up from North Carolina between 27 April and 22 May at an average speed of 32 mph. The 501 quartet were equipped with governors limiting maximum speeds to 50 mph (81 kph) in an effort "to get the trains over the railroad over the railroad by means of a sustained speed rather than a series of spurts down grades" while observing the 45 mph (72.5 kph) freight speed limit.
RA described all the physical improvements (multi-tracking, new bridges,10,000 US gallon/37,850 litre auxiliary tenders to increase total capacity to 20,000 gallons, etc.) that contributed to a substantial increase in gross-ton miles over the previous few years that was not sacrificed to the limited maximum speed. 46 other RF&P heavy freight and passenger locomotives also were refitted as well as receiving automatic stokers, feed water heaters, and thermic syphons. RA noted that all were maintained at passenger engine levels, which meant they could haul passenger trains at 70 mph, freights at 50 mph with a simple reset of the governors.
Freight engines averaged 4,500 miles (7,245 km)/month, passenger engines 7,500 miles (12,075 km)/month, said RA, crediting "careful study" of locomotive utilization and sustained-speed operation.
(Locobase read another "reason" for the success, according to RA: "[U]nlike many roads in the South, the RF&P does not use negro [sic] firemen." Such a smug observation stings not just because of its racist dismissal of likely talent, but also because it seems not to have been challenged by any editor or reader.)
All four went to the ferro-knacker in April 1950.
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | 501 |
| Locobase ID | 221 |
| Railroad | Richmond, Fredericksburg & Potomac (RF&P) |
| Country | USA |
| Whyte | 4-8-2 |
| Number in Class | 4 |
| Road Numbers | 200-203/501-504 |
| Gauge | Std |
| Number Built | 4 |
| Builder | Alco-Richmond |
| Year | 1924 |
| Valve Gear | Walschaert |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 20 / 6.10 |
| Engine Wheelbase (ft / m) | 42.17 / 12.85 |
| Ratio of driving wheelbase to overall engine wheelbase | 0.47 |
| Overall Wheelbase (engine & tender) (ft / m) | 81.75 / 24.92 |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | |
| Weight on Drivers (lbs / kg) | 262,000 / 118,841 |
| Engine Weight (lbs / kg) | 381,000 / 172,819 |
| Tender Loaded Weight (lbs / kg) | 201,600 / 91,444 |
| Total Engine and Tender Weight (lbs / kg) | 582,600 / 264,263 |
| Tender Water Capacity (gals / ML) | 10,000 / 37.88 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 16 / 15 |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 109 / 54.50 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 73 / 1854 |
| Boiler Pressure (psi / kPa) | 225 / 1550 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 28" x 30" / 711x762 |
| Tractive Effort (lbs / kg) | 61,619 / 27949.94 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.25 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | 223 - 2.25" / 57 |
| Flues (number - dia) (in / mm) | 45 - 5.5" / 140 |
| Flue/Tube length (ft / m) | 22 / 6.71 |
| Firebox Area (sq ft / m2) | 465 / 43.20 |
| Grate Area (sq ft / m2) | 75 / 6.97 |
| Evaporative Heating Surface (sq ft / m2) | 4762 / 442.40 |
| Superheating Surface (sq ft / m2) | 1190 / 110.55 |
| Combined Heating Surface (sq ft / m2) | 5952 / 552.95 |
| Evaporative Heating Surface/Cylinder Volume | 222.73 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 16,875 |
| Same as above plus superheater percentage | 20,250 |
| Same as above but substitute firebox area for grate area | 125,550 |
| Power L1 | 22,787 |
| Power MT | 766.97 |
