Tonights trivia question from the Rail Fan Net

Each week a number of amateur radio operators that are also avid rail fans meet on a local two meter repeater for a round table discussion of anything and everything related to railroads. The Pittsburgh Rail Fan Net meets each Thursday evening at 09:30 PM local time on the North Hills Amateur Radio Club's 146.880 repeater. All licensed operators are welcome and encouraged to check in and join in on the conversation. Most weeks your conductor will be Dennis, KB3HPC, who started the net which has become a popular gathering point for rail fans each week. If you have a scanner for listening to local rail radio traffic you can tune in and listen in. Just program 146.880 into your scanner and join the fun. If you would like to participate you can drop Dennis a note in email with questions or comments for the net. Use this LINK to send an mail.

One of the net members has started bringing a “trivia question” to the net each week when he checks in. I am going to try to write them down while listening to the net and post them here on the blog. Here is this weeks question.

At one point in time on the railroads there was a whistle signal given by the engineer for the command “down brake”. Why was this signal given and what happened when it was?

Check back next Thursday for the answer to the above and a new question.