I was taught that the rulebook was basically a list of incidents, if there was a rule, there was a reason for the rule.
If I were protecting a train and had to go through a tunnel, especially one that is not dead straight, I'd want as much noticed as I could possibly get. The sound of a train that has, by that point, already entered the tunnel would be far less good to me than the sound of a train blowing it's horn before entering the tunnel.
Well it might be in that situation but it's academic because they won't be doing it if you are unlucky enough to find yourself in that situation. In any case, you know which line is safe to walk on and you know what to do if a train enters the tunnel or at least you should do.
But it's not just workers in the tunnel, it's also workers at the mouth of the tunnel. When I was a trainee driver, about ten years ago, the rule about blowing horns for tunnels was being removed. About week before the official change of rule, I was at the controls of a train heading south through Balcombe Tunnel. When I blew the horn on approach to the exit, an orange arm appeared at the mouth. Those who know Balcombe Tunnel will know that the banking on either side of the southern end is quite steep, when I left the tunnel I saw three orange men there. On the train back later the signaller called me, on approach to Balcombe station, to warn me that they were there.
After the rule change, I decided that I "deemed it necessary" to use the horn in that situation, because I might not know who is there.
Just for you, p'way are not allowed in a tunnel without a possession so there is no need for you to break the rules any longer. Whether you choose to is down to your professionalism.
Or yours.
Not my opinion, it is the rules.
And if those workmen were around, but you couldn't see them, would you have blown your horn?
Only if they were in view when I started the train, otherwise no. There is a very clear instruction for that very event. If I sight any p'way men I will use both tones of the horn. They should acknowledge and move to a position of safety. If they don't, there are specific instructions on how to proceed and as a belt and braces I will be travelling at a speed that will allow me to stop short of any obstruction. You see the rule makers did think about it! Sounding the horn is pointless if there is nothing to sound it at. It's just a nuisance.
If they are just arriving on site, the signaller might not know they are there when letting a train pass. And if they didn't follow the rules.....
It's their problem. That's a daft comment really.
When the Railway lay a new track through you back garden, you have my sympathy. If you moved in with the track already there, you don't.
Nice.
When I was a trainee, the rule was that you were required to blow the horn if a train was stationary on an adjacent line, I don't know if this is still a rule.