Train drivers passing whistle board.

[Jaroon]

Is current rule single low loud long blast or both high and low tones. Can't find the relavant section of the rule book so I;d like this as well please. I think the rule has changed twice in the last 10 years (not including whilstle times of day). Really I need the pertinent section of the rule book to prove me wrong or right please.

[fishermanpaul]

I know we have several drivers here but, in the meantime, may I suggest:
https://www.railforums.co.uk/#uk-railway-forums.41