229.117—Speed indicators.
(a)
After December 31, 1980, each locomotive used as a controlling locomotive at speeds in excess of 20 miles per hour shall be equipped with a speed indicator which is—
(1)
Accurate within ±3 miles per hour of actual speed at speeds of 10 to 30 miles per hour and accurate within ±5 miles per hour at speeds above 30 miles per hour; and
(b)
Each speed indicator required shall be tested as soon as possible after departure by means of speed test sections or equivalent procedures.