LNER Class A4 streamlined 'Pacific' 4-6-2 number 4490 Empire of India (built 6/37, withdrawn 5/64), at Edinburgh Waverley station, at the head of The Coronation express passenger train for Kings Cross, London. The coaches are articulated, and painted in a distinctive two-tone blue livery.
Note 1 (translation):
Between 1870 and 1965, two major stations operated by different railway companies: Waverley (North British Rail) and Princes Street (Caladonian Railway). Waverley was the most important and still exists, Princes Street no longer.
Note 2:
The Gresley A4 Pacifics were not introduced until 1935, and this example was not built until 1937 (according to Wikipedia table), which suggests the date assigned to this photograph is incorrect.