Mexican State Railway classes G-030 and G-033
The Nacionales de México class G-030 consisted of 20 three-foot gauge Consolidations delivered by Baldwin in 1921. The outside frames were designed in such a way that a later conversion to standard gauge would have been possible. They were fired with oil and were designed for lines with gradients of up to 4.5 percent and curve radii of up to 21 degrees (85 meters).
In reality, however, there were only a few modifications that were carried out by the NdeM shortly after delivery. These affected, for example, the blastpipe, the position of the air pump and the fire door. Eight more followed in 1924, which had a larger firebox and were designated class G-033. They became the standard freight locomotive in rural areas and survived until the late 1960s.
Technical data
General
| Property | G-030 | G-033 |
|---|---|---|
| Built | 1921 | 1924 |
| Manufacturers | Baldwin | |
| Wheel arrangement | 2-8-0 (Consolidation) | |
| Gauge | 914 mm (Three feet) | |
Dimensions and weights
| Property | G-030 | G-033 |
|---|---|---|
| Wheelbase | 5.77 m | |
| Total wheelbase | 14.34 m | 14.40 m |
| Service mass | 51.3 t | 50 t |
| Adhesion mass | 46.7 t | 45 t |
| Total mass | 87.3 t | 82.7 t |
| Rigid wheelbase | 3.51 m | |
| Axle load | 11.7 t | 11.3 t |
| Water capacity | 13,627 l | |
| Fuel capacity | 5,716 l (oil) | 7,957 l (oil) |
Boiler
| Property | G-030 | G-033 |
|---|---|---|
| Grate area | 1.737 m² | 1.802 m² |
| Firebox surface | 7.339 m² | 8.11 m² |
| Tube heating surface | 146.973 m² | 147.781 m² |
| Evaporative heating surface | 154.312 m² | 155.891 m² |
| Total heating surface | 154.3 m² | 155.9 m² |
Power plant
| Property | G-030 | G-033 |
|---|---|---|
| Driver diameter | 1,041 mm | |
| Boiler pressure | 12.4 bar | |
| Expansion type | simple expansion | |
| Cylinders | two, 457 x 559 mm | |
Power
| Property | G-030 | G-033 |
|---|---|---|
| Power source | steam | |
| Estimated power | 522 kW | 541 kW |
| Starting effort | 118.3 kN | |
Calculated values
| Property | G-030 | G-033 |
|---|---|---|
| Factor of adhesion | 1 : 3.87 | 1 : 3.73 |
| Optimal speed | 27 km/h | |
| Power-to-weight ratio | 10.2 kW/t | 10.8 kW/t |
| Heating Surface Equivalent | 191.0 m² | 196.4 m² |
| Cylinder volume/HSE | 1 : 960.59 | 1 : 934.02 |
| Adhesive weight/Total | 1 : 1.10 | 1 : 1.11 |
| Tractive force/Heating surface | 1 : 16.01 | 1 : 15.85 |
| Grate area/Heating surface | 1 : 88.84 | 1 : 86.51 |
| Firebox/Tube surface | 1 : 20.03 | 1 : 18.22 |