Leading wheel
Unpowered wheel at the front of a locomotive / From Wikipedia, the free encyclopedia
The leading wheel or leading axle or pilot wheel of a steam locomotive is an unpowered wheel or axle located in front of the driving wheels. The axle or axles of the leading wheels are normally located on a leading truck. Leading wheels are used to help the locomotive negotiate curves and to support the front portion of the boiler.
![Thumb image](http://upload.wikimedia.org/wikipedia/commons/thumb/d/df/462leading_flip2.jpg/640px-462leading_flip2.jpg)