At the train show today I was asked what the oval sigh with an R on it stood for. I didn't know and neither did a number of people with some connection with 1:1 railroads. I'm hoping that someone here can come up wth an answer.
Thank you,
Richard
Without actually seeing it makes it tough to pinpoint for certain. My first instinct is to say it is a Resume speed sign posted at the end of a temporary speed restriction.
The Pennsy actually had Ring signs but I've only seen them sporadically used.
PRR Ring Whistle sign by Edmund, on Flickr
Good Luck, Ed