AN iconic locomotive which still holds the UK’s post-war steam record of 112 mph will be pounding the West Somerset Railway (WSR) line on the first weekend of July - but only at the heritage railway’s speed limit of 25 mph.

The streamlined 88-year-old A4 class Pacific express Sir Nigel Gresley will return to the WSR tracks between July 3 and 5, just two months after it was the star attraction at the railway’s spring steam gala.

Sister locomotive to the world record-holding Mallard, Sir Nigel Gresley was sold by British Railways in 1966 and is owned and operated by a charitable trust.

During the weekend it will haul a variety of trains between Minehead and Bishops Lydeard, giving passengers a journey in one direction with the return trip behind one of the WSR’s resident steam engines.

On the Saturday, the locomotive’s afternoon round-trip will provide a fish and chip meal, and a dining car will be added for the evening run.

Travel-only tickets for these trips are also available.

The visit of Sir Nigel Gresley is part of a double anniversary as it is 150 years since Sir Nigel Gresley was born.

He was LNER chief mechanical engineer from 1922 until his death in 1941.

The WSR is also celebrating its half-century as a heritage railway.

Trains hauled by Sir Nigel Gresley must be booked in advance from the WSR website or by calling 0164 704996.

It was in 1959 that the fastest recorded speed for a steam locomotive during the post-war period was attained by Pacific 60007, Sir Nigel Gresley, heading an East Coast mainline express train toward Kings Cross Station, in London.

During the run, it was timed as reaching 112 mph.

The A4s were built by the London and North Eastern Railway in the 1930s for working LNER’s premier expresses, including the non-stop runs between London and Leeds, York, Newcastle, and Edinburgh.

In 1938, Mallard reached 126 mph, which remains the authenticated speed record for a steam locomotive, and today Mallard has a place of honour in the National Railway Museum, in York.

Sir Nigel Gresley 60007 was named in the chief mechanical engineer’s honour by the directors of the company.

The 100th Pacific to be built, it was originally intended to carry the name Bittern, reflecting Sir Nigel’s love of wildfowl and birds in general.

The A4s were displaced by Deltic diesel locos in the 1960s, but, unlike many other classic steam locomotives, 60007 escaped a trip to the scrapyard.

Now based in Crewe, it regularly heads mainline excursion trains and visits heritage railways.

During its previous appearance at the steam gala, Sir Nigel Gresley was only the second Pacific to steam as far as Minehead.

Bittern reached the terminus in 2009 but no other Pacifics had ventured further than Bishops Lydeard.

A WSR spokesperson said: “This legendary locomotive represents the pinnacle of British engineering.

“Those who saw the railway back in 1976 would have barely dreamed that a sister to Mallard would be hauling a train to Minehead five decades later.”