(transport) A three-lane road with two lanes in one direction and one lane in the other.

plural of 2+1 road

Under the Whyte notation system, a steam locomotive that has two leading wheels, six pairs of coupled driving wheels, and two trailing wheels.

Under the Whyte notation system, a steam locomotive that has two leading wheels, six pairs of coupled driving wheels, and four trailing wheels.

Under the Whyte notation system, a steam locomotive that has two leading wheels, five pairs of coupled driving wheels, and two trailing wheels.

plural of 2-10-2

plural of 2-12-2

plural of 2-12-4

Under the Whyte notation system, a steam locomotive that has a single-axle leading truck followed by six powered driving axles, and no trailing wheels.

Under the Whyte notation system, a steam locomotive that has a single-axle leading truck followed by five powered driving axles, and no trailing wheels.