The Railway Enthusiasts Society Incorporated is a New Zealand railway enthusiast society registered under the Incorporated Societies Act 1908 on 17 July 1958.
The RES objectives are as follows:
The Railway Enthusiasts Society incorporates the Glenbrook Vintage Railway.
Over the years since formation, the Society has grown its reputation, both within the rail industry and publicly, by operating excursions to places of interest, both railway related and non-railway related.
The earliest excursions saw extra carriages attached to regular passenger train services throughout both the North Island and South Island. The Society has also operated its own private charter train services for larger trips, an activity it still does to this day.
Some excursions have achieved legendary status, particularly by the rail heritage sector. Many members remember earlier trips such as the 19th century tank locomotive "Meg Merriles" (a member of the F class) running trips to Swanson and Drury, C class locomotives double-heading services to Meremere and the mid-winter trips down the North Island Main Trunk.
Probably the most memorable excursion of this period was three 4-8-2 JA class locomotives triple-heading an 18 carriage train from Auckland to Hamilton in 1964 – a feat which, to date, has not been repeated on New Zealand's national rail network with steam traction. The Society replicated this operation with classic 1950s DA class diesel locomotives (the specific class members were 1410, 1429 and 1431), on the Auckland – Mt Maunganui "Seatrain" 2000 trip and Auckland – Whangarei "Waves & Wheels" trip in 2001.