By Mark van der Feyst
When inspecting the fire apparatus tires, check the lug nuts that hold the tire onto the hub of the axle. The nuts need to be tight at all times in order to ensure safe operation. Over time and with much driving, they can become loose.
Some fire apparatus will have plastic indicators on each nut. They are usually small green triangles that fits under the nut before it is tightened. The green triangles will all point in the same direction when all nuts are tight. When one or more of the triangles change orientation, those nuts have become loose.
Another indicator is rusty water marks streaming down from the nuts. When they become loose, water gets behind the nut and starts to rust the metal. Eventually the water drips down along the hub and creates a rusty water trail from the nut.