Cartier Signal question.

I was watching a video of Cartier operations and had a question about a signal indication. I saw at typical 3 head signal with two horizontal lunar white lights above the bottom signal head. Any comments on what they are for?

You've got me stumped. There's nothing covering anything like this under rules 405=439 of Transport Canada's Canadian Railway Operating Rules. I suppose it could be unique to that specific railway.

Being the curious type I found an example in this You Tube video at the 3:45 mark.

Since it is the only signal governing a turnout at the end of a two track siding the lunar lights might be a divider and the top two lights are for the left (siding) track and the bottom light for the right (main) track. But that's just a guess.

I worked on Cartier Railroad from 1966 to 1985, at that time southbound single aspect approach signals were equipped with two horizontal white lights that were connected to a dragging equipment detector. It would appear that since that time additional detectors have been added. Hope this helps.

Thank you.