Maurice Demoulin, Locomotive Actuelle ... (Paris: Librairie Polytechnique Ch.Beranger, 1906), p 287-288. Also see "Compound Passenger Engine, Portuguese State Rys", The Locomotive Magazine, Volume X (15 July 1904), p. 115; and "Passenger Locomotive for the Portuguese State Railway", Engineering, Volume 78 (29 July 1904), p. 150.. Works numbers were 5359-5364 in November 1904, 5649-5652 in October 1905.
A four-cylinder compound with Belpaire firebox and Serve tubes and a mixture of Walschaert gear on the external LP cylinders and Joy valve gear on the inside, HP cylinders. The colored illustration found in the LM showed a long line with a high-mounted boiler, and wide-set bogies. The class was intended to haul the Sul e Sueste's heavy passenger traffic on a route that included long grades of 1 in 55 (1.8 %).
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | 61 |
| Locobase ID | 9190 |
| Railroad | Portuguese Government |
| Country | Portugal |
| Whyte | 4-6-0 |
| Number in Class | 10 |
| Road Numbers | 81-90/61-72 |
| Gauge | 5'6" |
| Number Built | 10 |
| Builder | Borsig |
| Year | 1904 |
| Valve Gear | mixed |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 13.12 / 4 |
| Engine Wheelbase (ft / m) | 27 / 8.23 |
| Ratio of driving wheelbase to overall engine wheelbase | 0.49 |
| Overall Wheelbase (engine & tender) (ft / m) | 49.21 / 15 |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | |
| Weight on Drivers (lbs / kg) | 90,456 / 41,030 |
| Engine Weight (lbs / kg) | 128,970 / 58,500 |
| Tender Loaded Weight (lbs / kg) | 82,894 / 37,600 |
| Total Engine and Tender Weight (lbs / kg) | 211,864 / 96,100 |
| Tender Water Capacity (gals / ML) | 3696 / 14 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 5.50 / 5 |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 50 / 25 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 60.90 / 1547 |
| Boiler Pressure (psi / kPa) | 198.70 / 1370 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 13.78" x 25.59" / 350x650 |
| Low Pressure Cylinders (dia x stroke) (in / mm) | 21.65" x 25.59" / 550x650 |
| Tractive Effort (lbs / kg) | 19,182 / 8700.82 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.72 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | 233 - 1.929" / 49 |
| Flues (number - dia) (in / mm) | |
| Flue/Tube length (ft / m) | 14.11 / 4.30 |
| Firebox Area (sq ft / m2) | 181.05 / 16.82 |
| Grate Area (sq ft / m2) | 30.68 / 2.85 |
| Evaporative Heating Surface (sq ft / m2) | 1841 / 171 |
| Superheating Surface (sq ft / m2) | |
| Combined Heating Surface (sq ft / m2) | 1841 / 171 |
| Evaporative Heating Surface/Cylinder Volume | 416.78 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 6096 |
| Same as above plus superheater percentage | 6096 |
| Same as above but substitute firebox area for grate area | 35,975 |
| Power L1 | 5080 |
| Power MT | 371.43 |