Data from "Dampflokomotive Ed 3/3 Nr.3 'Langnau' Technischen Daten" at [], last accessed 26 January 2026. See also"144-jährige Dampflok LANGNAUá zurück im Emmental" at []; and "Zur Geschichte der Dampflok LANGNAUá " on the verkehrshaus Dampfbahn Bern website at [], both last accessed 26 January 2026. Works number was 229 in 1881.
SLM delivered this single six-coupled goods locomotive (cost: 36,000 Swiss Francs) to work on the Burgdorf-Solothurm and Burgdorf-Langnau lines. The bahnonline.ch history notes that Langnau and eight other locomotives delivered between 1874 and 1892 "were among the first proven locomotive types types from the workshops of the still young SLM."
During the celebration of its 144 years, a short account of its history noted that it remained in service until 1933. Fortunately for its survival, the Gerlafingen Steelworks bought the 3 and used it until 1960. The SBB overhauled the 8-decades-locomotive and hauled excursion trains on special occasions.
On 16 January 2025, the Langnau returned to its original workplace for the first time since its retirement almost 100 years before.
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | Langnau/Ed 3/3 |
| Locobase ID | 21298 |
| Railroad | Emmentalbahn |
| Country | Switzerland |
| Whyte | 0-6-0 |
| Number in Class | 1 |
| Road Numbers | 3 |
| Gauge | Std |
| Number Built | 1 |
| Builder | SLM |
| Year | 1881 |
| Valve Gear | Walschaert |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 9.51 / 2.90 |
| Engine Wheelbase (ft / m) | 9.51 / 2.90 |
| Ratio of driving wheelbase to overall engine wheelbase | 1 |
| Overall Wheelbase (engine & tender) (ft / m) | |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | |
| Weight on Drivers (lbs / kg) | 67,461 / 30,600 |
| Engine Weight (lbs / kg) | 67,461 / 30,600 |
| Tender Loaded Weight (lbs / kg) | |
| Total Engine and Tender Weight (lbs / kg) | |
| Tender Water Capacity (gals / ML) | 1030 / 3.90 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 2.20 / 2 |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 37 / 18.50 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 52 / 1320 |
| Boiler Pressure (psi / kPa) | 176.30 / 1200 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 13.39" x 21.65" / 340x550 |
| Tractive Effort (lbs / kg) | 11,186 / 5073.89 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 6.03 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | 137 - 1.969" / 50 |
| Flues (number - dia) (in / mm) | |
| Flue/Tube length (ft / m) | 9.19 / 2.80 |
| Firebox Area (sq ft / m2) | 57.05 / 5.30 |
| Grate Area (sq ft / m2) | 10.76 / 1 |
| Evaporative Heating Surface (sq ft / m2) | 682 / 63.40 |
| Superheating Surface (sq ft / m2) | |
| Combined Heating Surface (sq ft / m2) | 682 / 63.40 |
| Evaporative Heating Surface/Cylinder Volume | 193.28 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 1897 |
| Same as above plus superheater percentage | 1897 |
| Same as above but substitute firebox area for grate area | 10,058 |
| Power L1 | 4188 |
| Power MT | 410.59 |