This picture is of 3 trains and 3 levels of track.  In the background at level 3 is a great western Sprinter from 1933 and it is diesel electric.  The other two are steam engines from 1948.

This is the extension connecting the main line with the harbour at level one and three. This is the second bridge door which lifts up to give access to the water tank.

 Here you can see it opened.  It is constructed with 3 hinges.

This is s picture of level 3 and level 2 towards the bridges taking you to level 1 from level 2.