Mogul

A Mogul is a steam locomotive with a 2-6-0 wheel arrangement: two leading wheels in a single axle (the truck), six driving wheels in three axles, and no trailing wheels. This configuration made it lighter and more compact than larger freight engines, while retaining useful pulling power. The type emerged in the 1860s and became standard for branch line and industrial work across North America and Europe.

The 2-6-0 layout struck a practical balance. The two-wheel leading truck improved tracking on curves and lighter rail; the six driving wheels gave good adhesion without the weight of eight or ten drivers. A Mogul typically weighed 40 to 60 tons, making it suitable for lines that could not support heavier traffic engines. This manageability meant Moguls stayed in service on branch lines and secondary routes long after newer designs appeared on main lines.

Moguls were built with boiler pressures from 140 to 180 psi and cylinder diameters of 16 to 18 inches, reflecting the range of duty they undertook. Some were optimized for steep grades and light tonnage; others handled mixed freight and passenger work. Industrial railways and short-line operators favored them because they were economical to run and could be maintained by small shop crews. Many examples remained in revenue service into the 1950s, particularly on heritage lines.

The name derives from the Mogul Empire; it was adopted by American builders in the 1860s and stuck, though the reason for the choice is not documented. In Britain and Europe, similar engines were often classed differently by their designers and operators, so the term Mogul is predominantly an American and Canadian label for this wheel arrangement.

Like all steam locomotives, Moguls suffered from declining boiler water (leading to priming and lost power), sticking valves, and worn running gear on long service. The absence of trailing wheels meant no trailing truck bearing to distribute loads, concentrating wear on the driving axles. Ash disposal and smokebox cleaning were routine burdens. By the 1950s, diesel-electric switchers and small freight engines replaced them on most routes, though their compact footprint and moderate feedwater demand made them valuable on light or restricted-clearance lines until abandonment.