This is a very late evening shot on the Laira " Triangle" , hence the long shadows. Both Laira's own 70024 , "Vulcan " together with a unidentified " Castle " have come off shed and are coupling up to run up to Plymouth North Road station together , thereby avoiding separate paths , saving time and making it easier for the signalman at Lipson Junction.
At the extreme left is the little corrugated hut housing the telephone by which crews of engines coming off shed could gain permission from the Lipson Junction signalman to come on to the Southern Region line seen here before running tender first up to North Road. One of these two is probably booked on the late evening " Perishables " whilst the second will most likely take over an Express Pasenger working .
The origins, history and purpose of what was known as the " Mullet Pond" seen here are shrouded in mystery but it's still there today , albeit rather more environmentally friendly than in days long gone!