Data from "Baureihe 99.63" on Alfred Gieseler, Dampfmaschinen und Lokomotiven website at [], last accessed 21 April 2019; and Four-Cylinder Mallet Compound Locomotive for a Narrow Gauge," The Locomotive Magazine, Voume XI [9] (15 April 1905), p. pp 69,
Unlike many Mallet operators in Germany, Wuertt.St.B found these tank Mallets to be very satisfactory. They fulfilled a requirement for good power on light, curving track on such segements as Marbach-Heilbronn, Biberach-Oechsle, Schussenried-Riedlingen, and Lauffen-Gueglingen.
The engines arrived as follows:
Year Works numbers
1899 3070-3072
1901 3198-3200
1904 3294
1908 3505 (or 3503)
1913 3698
[], source of the data, says these loks served German railroads for decades. They were redesignated 99.631-639 in 1925 by the DRG. Five were scrapped by 1940, but the other 4 served the Deutsche Bahn in the postwar era into the 1950s (638-639 scrapped in 1954, 1956) and 1960s (637, 633 retired in 1965, 1969, but retained as possible museum loks, with 633 operating occasionally until 1992.)
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | Tssd / BR 99.63 |
| Locobase ID | 5068 |
| Railroad | Wurttembergische (Wurttemberg) Staatsbahn |
| Country | Germany |
| Whyte | 0-4-4-0T |
| Number in Class | 9 |
| Road Numbers | 41-49/BR 99 631-639 |
| Gauge | 75 cm |
| Number Built | 9 |
| Builder | Esslingen |
| Year | 1899 |
| Valve Gear | Heusinger |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 5.74 / 1.75 |
| Engine Wheelbase (ft / m) | 19.03 / 5.80 |
| Ratio of driving wheelbase to overall engine wheelbase | 0.30 |
| Overall Wheelbase (engine & tender) (ft / m) | 40.35 / 12.30 |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | 15,873 / 7200 |
| Weight on Drivers (lbs / kg) | 63,273 / 28,700 |
| Engine Weight (lbs / kg) | 63,273 / 28,700 |
| Tender Loaded Weight (lbs / kg) | |
| Total Engine and Tender Weight (lbs / kg) | |
| Tender Water Capacity (gals / ML) | 792 / 3 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 1.30 / 1 |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 26 / 13 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 35.40 / 900 |
| Boiler Pressure (psi / kPa) | 174 / 1200 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 10.83" x 17.72" / 275x450 |
| Low Pressure Cylinders (dia x stroke) (in / mm) | 16.54" x 17.72" / 420x450 |
| Tractive Effort (lbs / kg) | 12,155 / 5513.42 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 5.21 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | 106 - 1.77" / 45 |
| Flues (number - dia) (in / mm) | |
| Flue/Tube length (ft / m) | 12.47 / 3.80 |
| Firebox Area (sq ft / m2) | 48.42 / 4.50 |
| Grate Area (sq ft / m2) | 10.44 / 0.97 |
| Evaporative Heating Surface (sq ft / m2) | 607 / 56.38 |
| Superheating Surface (sq ft / m2) | |
| Combined Heating Surface (sq ft / m2) | 607 / 56.38 |
| Evaporative Heating Surface/Cylinder Volume | 321.29 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 1817 |
| Same as above plus superheater percentage | 1817 |
| Same as above but substitute firebox area for grate area | 8425 |
| Power L1 | 1978 |
| Power MT | 275.68 |