Why do trains blow their whistles?

Question

I think I should have been more specific - I actually mean the London Underground tubes.

Answer 1

I work on the railway and the only reason a train driver will blow his horn/whistle is if he sees someone on the track or if he identifies a potential hazard. Rail personell on the track specially assign someone as a lookout and will be the person responsible for acknowledging the whistle.

Answer 2

to warn people from trying to cross the tracks when they are driving by

Answer 3

Ego tripping.

Like the plod use their blue lights when returning to base after a shift.

Answer 4

There's a lot more to it than just the obvious "warning people of an approaching train",  especially on the Underground. On that, drivers have to sound their whistles (fed by compressed air) for any number of reasons, amongst which are some of the following:

The train is not going to stop (for any number of reasons) at a station at which it would normally do so.

The train is ready to leave a depot or siding which is under 'local' control.

There is a fault on the train and I need a train technician to assist. (They used to be called "Car Examiners")

(At a station) I need assistance from the station staff.

(Where there is still a signal box or the area is under 'local control' at that time) I have been given a wrong 'proceed' signal or I am overdue a proceed signal OR (by pre-arranged whistle signals): This train is going to xxxx (destination or route) as opposed to a different route. [A good example of this used to be at Queens Park (Bakerloo) when the driver of a northbound train approaching the station was required to give two long blasts on the whistle to warn the signalman that the train was going to Harrow (and years ago to Watford Junction) instead of terminating there].

There are lots more, but you'd probably die of boredom!

Answer 5

Because it's cool!

Also as a warning that they're coming to a crossing... so get out of the way!

Answer 6

well the whistles are just like large versions of the whistles that a person would blow with their lips, only trains "blow" their whistles using steam or compressed air. It's simple really. Larger whistle, larger volume of air "blowing" it.

Come on. Vote me as best answer. I know you want to! (I need the points to help others!)

Answer 7

To warn would-be-ground-meat of their approach.

Answer 8

The don't. Steam trains let off the steam which makes a whistle. Trains of today either blow their horns....to warn people of their presence, say for example..going through a tunnel. And train guards blow a whistle to give a signal to the driver that everyone is on the train and it's ok to close the doors and proceed.

Answer 9

To make sure that they do everything they can to let people or vehicles that may be in the track know they are coming.