Data from Wikipedia ([], last accessed 28 September 2008). See also Albert Giieseler, "Baureihe 98 1801-1802", Locomotiven in Dampfmaschinen und Lokomotiven, last accessed 26 February 2026. Works numbers were 15633-15634 in 1937.
Derived from the TAG (Tegernsee-Bahn AG) locomotive of the previous year (which had identical dimensions, but was slightly lighter), this pair of Mikado tanks had taller drivers and proved capable of hitting 70 km/h (45 mph). These three engines were the last to be built for a private German railway in Bavaria and were among the smallest tanks of this wheel arrangement ever built for the standard gauge.
All three survived the war, the 98 18s operating until 1960 and the TAG 7 providing stand-by power until 1975.
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | BR 98.18 / TAG 7 |
| Locobase ID | 9575 |
| Railroad | LAG / Deutsches Reichsbahn |
| Country | Germany |
| Whyte | 2-8-2T |
| Number in Class | 3 |
| Road Numbers | LAG 87-88 / 98 1801-1802 |
| Gauge | Std |
| Number Built | 3 |
| Builder | Krauss |
| Year | 1937 |
| Valve Gear | Heusinger |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | |
| Engine Wheelbase (ft / m) | 26.90 / 8.20 |
| Ratio of driving wheelbase to overall engine wheelbase | |
| Overall Wheelbase (engine & tender) (ft / m) | 26.90 / 8.20 |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | 25,794 / 11,700 |
| Weight on Drivers (lbs / kg) | 101,765 / 46,160 |
| Engine Weight (lbs / kg) | 134,041 / 60,800 |
| Tender Loaded Weight (lbs / kg) | |
| Total Engine and Tender Weight (lbs / kg) | |
| Tender Water Capacity (gals / ML) | 1663 / 6.30 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 3 / 2.70 |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 42 / 21 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 43.30 / 1100 |
| Boiler Pressure (psi / kPa) | 201.30 / 1370 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 18.11" x 20" / 460x508 |
| Tractive Effort (lbs / kg) | 25,920 / 11757.13 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 3.93 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | |
| Flues (number - dia) (in / mm) | |
| Flue/Tube length (ft / m) | 12.47 / 3.80 |
| Firebox Area (sq ft / m2) | 80.08 / 7.44 |
| Grate Area (sq ft / m2) | 18.73 / 1.74 |
| Evaporative Heating Surface (sq ft / m2) | 711 / 66.05 |
| Superheating Surface (sq ft / m2) | 351 / 32.60 |
| Combined Heating Surface (sq ft / m2) | 1062 / 98.65 |
| Evaporative Heating Surface/Cylinder Volume | 119.24 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 3770 |
| Same as above plus superheater percentage | 5015 |
| Same as above but substitute firebox area for grate area | 21,440 |
| Power L1 | 10,404 |
| Power MT | 901.56 |