Texas & Pacific class E-1

In 1906, the Texas & Pacific manufactured two examples of the Class E-1 in their own works in Marshall, Texas, which would remain their only Atlantic locomotives. The boiler was relatively small compared to the cylinder volume, but it operated at a relatively high pressure for the time of 220 psi. A special feature of the chassis was that the compensating levers also included the trailing axle in addition to the driving axles, which is why this was also loaded with a high load of 58,000 pounds. This resulted in a tail-heaviness that led to unsatisfactory running characteristics. In addition, the tractive effort was no longer quite sufficient at this time for modern steel passenger cars.

For these reasons, the two locomotives underwent a complete rebuild as early as 1917. To increase traction, the drivers were reduced from 79 to 75 inches. Boiler pressure was reduced to 185 psi, but this was offset by increasing the cylinder diameter from 20 to 22 inches. The cylinders were now supplied by piston valves instead of slide valves. The boiler now contained a relatively large superheater and was oil-fired. The two locomotives survived in this form for a little over ten years until they were retired in December 1928 and January 1929.