(Unless a post has been lost...)
Naggers is on Great Eastern St in Londinium. I always see those two tubes on my ride up to Cambridge (which goes up Shoreditch High St, a.k.a. the A10).
Is right (as was Martin before taking his post down)
Just West of the old Bishopsgate Goods Yard where all the work for the East London Line extention is happening.
A new bridge was put across Shoreditch High St (A10) a few weeks ago.
Guess the portacabins are part of the site offices but no idea why there needs to be a couple of old Jubilee Line cars on top.