2015 Coal First Aid Statements No. 5 Taken from the 2015 National Coal First Aid Contest Rules Progress Indicator: Question 6 of 20 6.  Switches or circuit breakers shall be provided on haulage roads to de-energize all trolley and feeder lines at intervals not to exceed __________. Choices: 200 feet 500 feet 1,000 feet 2,000 feet