This is a random side-project I've been completing in some spare time in the evenings.

The original model is a Hook Loader, with the B-model an Airport Fire Truck. 

This 'C-Model' Bulldozer features dual steering, movable Bucket (with the arms being reasonably stiff to allow the bucket to stay in a fixed position while moving the vehicle. It's range is has been limited from the ground to a little on front of the window, with the latter being 'braked' by a hinged axle (to stop it from hitting the cab). 

Additionally, I made a Grader model too. It's more simple that the Bulldozer, but just as fun!

Building Instructions can be found here.