Watch List notes:

The Portland Collection, Commemorative Medals, Engineering: Tunnels, India, building the Hooghly Tunnel, Calcutta [Kolkata], silvered-bronze medal, 1930-1931, a workman pushes a trolley on tracks through the tunnel, rev. tablet for naming, ENGINEER H. H. DALRYMPLE HAY – JOHN COCHRANE & SONS LIMITED CONSTRUCTORS, 38.5mm. (Pudd.931.16), suspension loop and ring, virtually mint state
The tunnel, designed by boiler specialist John Lochrance with Sir Harley Hugh Dalrymple Hay as project chief was completed in July 1931. It carries the cables of the Calcutta Electric Supply Corporation (CESC) under the Hooghly River.