Signals are, of course, a central feature on any railway and London Underground is no exception.
To read a bit more about the signalling on the District Line click here.
Our signals are different to those used on the National Rail network in that we use a two aspect systen, with repeating signals as necessary.
But this isn't to say that that's it! All sorts of variations and combinations crop up - the pictures here illustrate some of the less common combinations and some of the collection of other notices and equipment that can surround the humble signal post!
This isn't the greatest collection of pictures, and I am hoping to add further examples to this section when the opportunity presents itself to get a more extensive collection.