Background

FRA Rules 229.73 and 229.75 are set maximum allowable tolerances for mechanical dimensions of wheels and wheel sets. Wheel wear that results from normal train operation will eventually cause a given wheel or wheel set to exceed one or more of the defined tolerances. Eventually, this wheel wear can lead to excess wear of the track, track bed, and rolling stock.

Jodon originally proposed a mechanically-based system for on-car wheel measurements at train speeds up to 10 MPH. More recently, Jodon has proposed a non-contact microwave system for on-car wheel measurements at train speeds up to at least 60 MPH.

Measured Parameters

1. Wheel rim diameter
2. Wheel flange diameter
3. Wheel flange thickness
4. Detection of wheel flat spots
5. Detection of out-of-round wheels
6. Train car I.D.

System Location

It is expected that the system will normally be located on high-speed main lines. A 15-foot section of special track, equipped with sensors, will be installed. A small building, located next to the instrumented track section, will house computers and communication equipment.

System Operation

As A train passes by, data is gathered from all sensors. Immediatly thereafter, the data is analyzed and reports are generated. Information is communicated to the train or nearest maintenance yard as required. The train is diverted into the maintenance yard only if necessary.

Primary Benefits

1. Fast, non-contact measurement of wheel parameters.
2. Measurement process does not delay or divert the train. This promotes on-time arrivals.
3. Automatic generation of reports covering wheels, axled wheel pairs, and wheel trucks.
4. Maintenance can be scheduled only as needed.
5. Frequent, systematic monitoring of wheel can reduce track wear, train car wear, and damage to freight; it can also improve operating safety and FRA compliance.