I notice the br class 52 has only 2 very small marker lights and no headlight at all,so was this a day time train only?because one would be luckly to see it comning especially in the dark with a dark br blue paintjob.
BR didn't really do headlights until later. Yes really! They started being fitted from the late 1970s and most stock was retrofitted with a standard headlamp module. Standards have now swung to 3 very bright headlights on the front for new build stock! The 52s that do run on the mainline now have been retrofitted with a headlamp module - it replaces one of the headcode blinds (which aren't used now)
The marker lights are intended so the driver ahead could identify that there is a train coming. BR trains in the beginning was a case of "to be seen, not to see" and that also contributed to the yellow fronts.
As has been stated, early BR types had simple low output marker lights. As the diesel and electric types replaced steam, it was realised that their approach was far less noisy which led to the introduction of Yellow front ends to improve the visibility at distance for PW staff. Later still, it was deemed necessary to fit/retrofit high intensity headlight units to further improve visibility/safety. Most types up to the 1980s had the single headlamp box added but types from this point (a few from before) were built with better lights from the beginning such as the PEP EMUs and Mk3 based units etc. As lighting technology has evolved, we now have types with extremely powerful lighting from new with use of LEDs in most cases.
