So far as the Class 47s are concerned, this is an extract from " Class 47 50 Years of Locomotive History" on the headlight subject.
Apart from the early experiments, the first major effort to equip the class with headlights came in 1979. With the emergence of the initial batch of Class 47/7s following overhaul and conversion to push-pull operation, a headlight was fixed to each cab front above the buffer beam, in the now familiar position slightly off centre. By April 1981, Stratford’s No 47574 had also received them. The Mechanical and Electrical Committee were told, on 17 March 1982, that consideration was being given to fitting high and low powered headlamps. Dipped headlamps were deemed to be impractical. There had been some complaints that high-powered lamps used for daylight warning caused excessive dazzle at night. Trials were ongoing, mainly in the London area. At a later meeting of the same committee on 28 September, it was recorded that authority had now been given for all Class 47s to be provided with headlights, and that modification forms had been issued for the fitting to be done at main works and Regional depots. A programme had been drawn up for the work to be carried out between January 1983 and June 1984, spread across the Regions. No 47308 was the first to be fitted with what is now recognised as being the standard locomotive boxed headlight, and the modification was extended to the rest of the class, with No 47008 thought to have been the last to be treated. No 47901 was a noteworthy exception in having been fitted with a headlamp at each end beneath the driver’s side tail lamp when first modified as No 47601 in 1976.