I beg to differ

After having worked innumerable night jobs, I must assure you all that there are many signals that are used at night.
It is imperative on an night switch job, sans radios, that each and every crew member understand what is going on, and when you are spread up and down the lead, you can't get together and converse on every move. The hand signals must convey the wishes of the Switch Foreman (Yard conductor) to the rest of the crew. Lanterns are the easiest and most efficient way to do this.
Besides the three mentioned by Randy there are many, many more.
But what would I know, I've only been doing this job for over 20 years.....
Rick Steele