Joe wrote:Metra is I think the only railroad left that still uses Mars lights/purchases Mars light equipped locomotives.
you can add caltrain (Cal DOT) and MARC commuter operations to this list as well
to my knowledge, you can still install them, but they have to be used in conjunction with ditch lights for any locomotive built/rebuilt after 1996
they still have locomotives using them in regular service
as far as railroads which used them in the past on non-steam or E/F units (IE: regular freight diesels)
SP, D&RGW, MP, FEC, ACL, SCL, KCS
that is a short list which comes to mind
KCS and FEC removed theirs in recent years along with obviously SP/D&RGW which had done so earlier
mandated ditch lights pretty much did them in, as after year 1999 or 2000 I think they did not fill the requirement for freight rr's
MOST RR's which had dual-light cones on their E and F units had mars light fixtures of some type
the red bulb was for use only when the train was in emergency or stopped on the mainline or at a station. you never saw them used much