I was watching some old videos of the B&O railroad in the transition era the other day and they had steamers in a lash-up.
How did they accomplish speed matching? Was it just going close enough to the speed limit on the rails and let the small difference in speed equal out at the coupler? Or did they use a lantern to blink morse code to each other?
I was thinking maybe the lead locomotive set the pace and the trailing steamer just felt around for the speed by feeling how much push or pull was in the coupler. Obviously you know you're going to be around the speed limit. Then you fine tune from there. But I'm not even sure if you can feel whether the locomotive is pushing or pulling in a machine that size.
EDIT: The original title had "lash-up" in it. I removed it and corrected it to "double heading" to prevent others from picking up the wrong lingo.
