At what speed must equipment not be moved if flat spots are present?

When flat spots are present on train wheels, it is crucial for safety to limit the speed of the equipment to prevent further damage or hazards on the tracks. Flat spots can result from locking brakes during an emergency stop or from extended braking. If equipment is moved at excessive speeds with these imperfections, it can lead to vibrations, potentially worsening the condition of the wheels and creating unsafe travel conditions.

The correct speed limit of 10 MPH is established as a precautionary measure. At this reduced speed, the risks associated with the flat spots are minimized, allowing for safe movement while assessing or addressing the maintenance needs of the equipment. This protocol helps maintain safe operation standards and ensures that any necessary repairs can be scheduled promptly without endangering personnel or other trains on the network.

The other speed limits would be too high, increasing the risk of derailment or further mechanical issues, which is why they are not appropriate in this context.