Milwaukee Road classes L1 and L2
The first Mikados on the Milwaukee Road consisted of 20 saturated class L1 locomotives built by the company's own shops in Milwaukee in 1909. They already had a combustion chamber and drivers with a diameter of 63 inches. From 1912 onwards the L2 class followed, 40 of which were built in their own shops. Another 115 came from ALCO-Brooks and 25 from ALCO-Schenectady. Baldwin delivered 100 of the L2-a and L2-b classes from 1920 and 1922, respectively, which had a longer combustion chamber and, in the case of the L2-b, a larger superheater. The first ones were retired in the 1930s after they were replaced by more powerful freight locomotives. Basically, a large proportion survived into the fifties, including ten L1s that were later given a superheater.
Technical data
General
| Property | L1 | L2 | L2-a | L2-b |
|---|---|---|---|---|
| Built | 1909 | 1912-1914 | 1920-1921 | 1922-1923 |
| Manufacturers | Baldwin | Milwaukee, ALCO | Baldwin | |
| Wheel arrangement | 2-8-2 (Mikado) | |||
| Gauge | 1,435 mm (Standard gauge) | |||
Dimensions and weights
| Property | L1 | L2 | L2-a | L2-b |
|---|---|---|---|---|
| Wheelbase | 10.69 m | 10.74 m | ||
| Total wheelbase | 20.02 m | 20.32 m | 21.50 m | |
| Service mass | 118.2 t | 124.7 t | 131.1 t | |
| Adhesion mass | 91.2 t | 98.2 t | 99.3 t | |
| Total mass | 188 t | 195.5 t | 201.4 t | 212.7 t |
| Rigid wheelbase | 5.03 m | |||
| Water capacity | 30,283 l | 32,176 l | 37,854 l | |
| Fuel capacity | 12.7 t (coal) | 10 t (coal) | 10.9 t (coal) | 14.5 t (coal) |
| Axle load | 25.5 t | |||
Boiler
| Property | L1 | L2 | L2-a | L2-b |
|---|---|---|---|---|
| Grate area | 4.534 m² | 4.563 m² | 4.534 m² | |
| Firebox surface | 26.199 m² | 23.969 m² | 28.8 m² | 28.893 m² |
| Tube heating surface | 309.553 m² | 259.386 m² | 259.757 m² | 245.171 m² |
| Evaporative heating surface | 335.752 m² | 283.355 m² | 288.557 m² | 274.064 m² |
| Total heating surface | 335.8 m² | 342.8 m² | 348.5 m² | 341.0 m² |
| Superheater surface | 59.458 m² | 59.923 m² | 66.89 m² | |
Power plant
| Property | L1 | L2 | L2-a | L2-b |
|---|---|---|---|---|
| Driver diameter | 1,600 mm | |||
| Boiler pressure | 13.8 bar | |||
| Expansion type | simple expansion | |||
| Cylinders | two, 610 x 762 mm | two, 660 x 762 mm | ||
Power
| Property | L1 | L2 | L2-a | L2-b |
|---|---|---|---|---|
| Power source | steam | |||
| Estimated power | 1,342 kW (1,825 PS) | 1,566 kW (2,129 PS) | 1,641 kW (2,231 PS) | |
| Starting effort | 207.4 kN | 243.4 kN | ||
Calculated values
| Property | L1 | L2 | L2-a | L2-b |
|---|---|---|---|---|
| Factor of adhesion | 1 : 4.31 | 1 : 3.96 | 1 : 4.00 | |
| Optimal speed | 40 km/h | 39 km/h | 42 km/h | |
| Power-to-weight ratio | 11.4 kW/t | 12.6 kW/t | 12.5 kW/t | |
| Heating Surface Equivalent | 466.7 m² | 522.1 m² | 552.4 m² | 552.3 m² |
| Cylinder volume/HSE | 1 : 952.98 | 1 : 999.82 | 1 : 945.00 | 1 : 945.16 |
| Adhesive weight/Total | 1 : 1.30 | 1 : 1.27 | 1 : 1.32 | |
| Tractive force/Heating surface | 1 : 12.90 | 1 : 14.83 | 1 : 14.59 | 1 : 14.91 |
| Grate area/Heating surface | 1 : 74.05 | 1 : 75.61 | 1 : 76.37 | 1 : 75.20 |
| Firebox/Tube surface | 1 : 11.82 | 1 : 10.82 | 1 : 9.02 | 1 : 8.49 |
| Total/Superheater | 1 : 4.77 | 1 : 4.82 | 1 : 4.10 | |
