Erie classes S-1 to S-4
The Erie was the American railroad that ordered the greatest number of 2-8-4 “Berkshire” locomotives. These 105 locomotives were not only delivered by all three major manufacturers, but also had the biggest heating surface of all Berkshires. As usual for the late twenties, they were fitted with thermic syphons, arch tubes, Worthington feedwater heaters and had a limited cutoff.
25 of the class S-1 were built in 1927 by ALCO, followed by another 25 S-2 in the same year by Lima. 35 S-3 were built by Baldwin in 1928 and 20 S-4 again by Lima in 1929. Both Lima subclasses were designed for a boiler pressure of 250 psi, but operated at only 225 psi like their sisters. These classes made it possible for the Erie to greatly accelerate their freight services and they were all scrapped between 1950 and 1952.
Technical data
General
| Property | S-1 | S-2 | S-3 | S-4 |
|---|---|---|---|---|
| Built | 1927 | 1928 | 1929 | |
| Manufacturers | ALCO | Lima | Baldwin | Lima |
| Wheel arrangement | 2-8-4 (Berkshire) | |||
| Gauge | 1,435 mm (Standard gauge) | |||
Dimensions and weights
| Property | S-1 | S-2 | S-3 | S-4 |
|---|---|---|---|---|
| Wheelbase | 12.80 m | 13.41 m | ||
| Total wheelbase | 26.26 m | 26.39 m | 27.92 m | 27.90 m |
| Service mass | 200.9 t | 207.5 t | 212.6 t | |
| Adhesion mass | 125.2 t | 127.5 t | 129.1 t | 130 t |
| Total mass | 341.6 t | 357.2 t | 375.6 t | 384 t |
| Rigid wheelbase | 5.56 m | |||
| Axle load | 32.2 t | 32.1 t | 32.5 t | 32.7 t |
| Water capacity | 62,459 l | 78,547 l | 78,737 l | |
| Fuel capacity | 21.8 t (coal) | 24.5 t (coal) | 25.4 t (coal) | |
Boiler
| Property | S-1 | S-2 | S-3 | S-4 |
|---|---|---|---|---|
| Grate area | 9.29 m² | |||
| Firebox surface | 41.714 m² | 41.621 m² | 40.599 m² | 41.714 m² |
| Tube heating surface | 487.741 m² | 487.649 m² | 488.113 m² | 487.37 m² |
| Evaporative heating surface | 529.455 m² | 529.269 m² | 528.712 m² | 529.083 m² |
| Superheater surface | 227.427 m² | 230.4 m² | 236.438 m² | |
| Total heating surface | 756.9 m² | 759.7 m² | 759.1 m² | 765.5 m² |
Power plant
| Property | S-1 | S-2 | S-3 | S-4 |
|---|---|---|---|---|
| Driver diameter | 1,778 mm | |||
| Boiler pressure | 15.5 bar | 17.2 bar | 15.5 bar | 17.2 bar |
| Expansion type | simple expansion | |||
| Cylinders | two, 724 x 813 mm | |||
Power
| Property | S-1 | S-2 | S-3 | S-4 |
|---|---|---|---|---|
| Power source | steam | |||
| Estimated power | 3,579 kW (4,866 PS) | 3,803 kW (5,171 PS) | 3,579 kW (4,866 PS) | 3,803 kW (5,171 PS) |
| Starting effort | 315.9 kN | 351.0 kN | 315.9 kN | 351.0 kN |
Calculated values
| Property | S-1 | S-2 | S-3 | S-4 |
|---|---|---|---|---|
| Factor of adhesion | 1 : 3.89 | 1 : 3.56 | 1 : 4.01 | 1 : 3.63 |
| Optimal speed | 69 km/h | 66 km/h | 69 km/h | 66 km/h |
| Power-to-weight ratio | 17.8 kW/t | 18.3 kW/t | 17.2 kW/t | 17.9 kW/t |
| Heating Surface Equivalent | 1,192.9 m² | 1,198.2 m² | 1,192.5 m² | 1,210.5 m² |
| Cylinder volume/HSE | 1 : 560.87 | 1 : 558.39 | 1 : 561.05 | 1 : 552.69 |
| Adhesive weight/Total | 1 : 1.61 | 1 : 1.63 | 1 : 1.61 | 1 : 1.64 |
| Tractive force/Heating surface | 1 : 8.72 | 1 : 9.65 | 1 : 8.69 | 1 : 9.58 |
| Grate area/Heating surface | 1 : 81.47 | 1 : 81.77 | 1 : 81.71 | 1 : 82.40 |
| Firebox/Tube surface | 1 : 11.69 | 1 : 11.72 | 1 : 12.02 | 1 : 11.68 |
| Total/Superheater | 1 : 2.33 | 1 : 2.30 | 1 : 2.29 | 1 : 2.24 |
