I've done it
With Cartics (air) and Carflats (vac), if we had the right Guard
It was less snatchy with more vacuum than air.
It really miffed the shunters if you didn't tell them, as they start pulling them back, taking up the slack in the couplings then suddenly come to a stop.
For some reason when the driver nearly fell off the seat on the 350 he'd call you a viking King of England, this bloke apparently
http://en.wikipedia.org/wiki/Cnut_the_Great
Don't know why???
