Carriage Wheels, Trucks

To compensate for deck camber and to keep the gun carriage level, the front trucks or cannon carriage wheels (wheels for the gun carriage) were larger than the rear truck. Unless the they were made of cast iron, trucks had iron thimbles or bushings driven into the hole of the hub and the spindle on which the wheel revolved was partly protected by metal that strengthened the axletree and resisted wear at the spindle.