The B12 is the flagship loco of the North Norfolk Railway. The loco is unlike any other British type preserved. Not only is it the only survivor of the B12 class (which was once 80 strong), but it is the only surviving example of an inside cylinder 4-6-0. This means that the cylinders (that drive the loco) are between the frames and hidden from view, and although many other types of inside cylinder locos have been preserved, none are of a 4-6-0 wheel configuration.

The first B12 was built in 1911 by the Great Eastern Railway (GER) and classified as a S69 (it wasn't until grouping in 1923 that the S69 were reclassified as a B12). The GER built a total of 70 locomotives.

In the late 1920s a shortage in express passenger types in East Anglia meant that a stop-gap was needed before (Sir Nigel) Gresley could introduce his new B17 class. The LNER decided that a further batch of 10 B12s were to be ordered. Construction of these engines was contracted out to Beyer Peacock of Manchester. 8572 was built in June 1928, as a B12/2. The B12/2 differed from the original B12/1 design in a number of ways; they had Lentz oscillating cam poppet valve gear, no decorative framing over the driving wheels, and their smokeboxes were slightly longer. 8572 was rebuilt to be reclassified as a B12/1 at the end of 1931, when the Lentz valve gear was removed.

Between 1932 and 1944 a rebuilding program was undertaken when all 10 of the "Beyer Peacock B12s" and 44 of the "original" B12/1s were rebuilt to B12/3. This rebuild improved the previous two B12 designs, making them more powerful to cope with heavier trains. The B12/3s had larger Gresley round top boilers, and long-travel Stephenson piston valves. 8572 was rebuilt at the end of 1933, five years after being built.

8572 was renumbered as 1572 in June 1946, under the LNER's renumbering scheme, and again in May 1948 to 61572, when it changed ownership to the newly nationalised British Railways.

61572 spent most of its working life in East Anglia, apart from a month at Grantham in February 1953. In October 1959, 61572 was transferred to Norwich but was soon withdrawn as a result of a cracked cylinder. However, as it was one of the last surviving B12s and Bill Harvey, the Norwich shedmaster, had an affection for the B12s. He discovered that it was not a cracked block, but a pitted casting and the loco was soon back in traffic. 61572 stepped out of the shadows to become a bit of a celebrity and very soon became the Norwich mascot engine. At a time when the rest of the B12 class were being withdrawn, Bill kept 61572 busy, and regularly worked the Lowestoft–Whitemoor goods train between Norwich and Kings Lynn (via Dereham). It also regularly worked passenger trains from Norwich to Melton Constable and coincidentally a rail tour for the M&GN Joint Railway Society. Had it not been for Bill keeping 61572 busy, allowing funds to be raised in order to buy the loco, it would have probably been scrapped. 61572 was finally withdrawn on 20 September 1961 (outliving the rest of the B12 class by nearly two years). It was stored with what was to become the Society’s other loco, 65462, at Stratford and the pair were given a test steaming in October 1962 prior to purchase by the M&GN Joint Railway Society in 1963. They were moved to Devons Road depot, Bow in the summer.

Two years after withdrawal from BR, 61572 embarked on the famous ‘Wandering 1500’ rail tour. The name chosen referred to the fact that the B12 was away from its ‘normal’ stomping ground (i.e. wandering), and 1500 was the number series the class had originally received in Great Eastern days (and in latter years by LNER). The B12s were often referred to as ‘fifteen-hundreds’. The tour was organised by the Society for 5 October 1963 and was one of the first rail tours on British Railways that used a privately owned loco (BR were not aware the locomotive had been sold at the time). The engine was cleaned and prepared by Society volunteers at Devons Road before being towed dead to Willesden depot a few days before the tour began. The 260-mile trip would take the locomotive from London’s Broad Street station to Bedford, Stratford-upon-Avon, Rugby and return. 61572 performed admirably throughout the tour for an engine that had been out of service for two years, topping 70mph on the return to Broad Street, although it still arrived two hours late! It went back to Willesden shed after the tour and was towed to Devons Road, still warm, the next day.

Back in Bow the B12 and J15 briefly shared the premises, to the spring of 1964, with the remainder of the first batch of Class 20s. By September of that year the cladding and asbestos lagging were removed from both engines and other minor work was undertaken. By now the Society had the depot to itself until asked to leave when track removal became imminent. The two locos were moved briefly to Stratford, seen there in November 1964, and then transferred to March MPD all at no cost to the Society.

The B12, together with the J15 and assorted stock picked up at Norwich Crown Point (the Quad-Arts, a LNWR directors’ saloon and two railbuses), arrived on the NNR at Sheringham on 4 June 1967. The loco was in a poor condition and much time and money would need to be spent to restore it to full working order. Also at this time there were serious concerns about the axle loading on bridge 303 and whether the B12 would be permitted to cross it. Because of this, it was decided, for the time being, to tidy the loco up, and make it look presentable. In the meantime the Society concentrated on the restoration of the J15. It then stood at Sheringham on public display. In 1977 when the J15 was recommissioned, an appeal for £20,000 was launched to restore the B12 to full working order.

The eventual restoration of the B12 was one of the most complex in railway preservation history and was to be plagued with pit falls and twists of fate. Initially the loco was to be restored at Sheringham. The tender was to be rebuilt by volunteers whilst a local boilersmith worked on the boiler. The target was to have it running by 1982. The boiler work sped ahead, but work on the rest of the loco ground to a halt, by which time the boiler certificate had already started to tick away. After several failed attempts to kick start the project it eventually got restarted in 1984 at Weybourne. While work was concentrated on the frames and wheels at Weybourne, the boiler was sent away to a specialist contractor in Essex. However, before much work was carried out on the boiler the contractor went bust. After much negotiating with the new owner of the company the Society was told to remove it or it would be sold and cut up for scrap!

At this time the Society was introduced to a Dutch contractor by Steam Railway magazine who were looking for a flagship UK contract to kick-start business in the UK. The contractor took over the boiler work and made arrangements for the frames and tender to be restored and the loco rebuilt at a works in former East Germany. So the unprecedented step was taken to ship the boiler to Holland where some significant firebox repairs were carried out prior to it being moved to Germany to meet up with the remainder of the loco.

The works in East Germany were at Kloster Mansfeld near Leipzig. The workshops still utilised traditional skills to maintain a small museum fleet of narrow gauge steam locomotives that had been in daily use until the fall of the Berlin Wall the previous year. The frames arrived in September 1991 followed the next year by the boiler from Holland. Work soon started on the frames and wheels. Cracks were found in some of the driving wheels, and specialist welders had to be bought in from Holland to repair them.

At a time when the new united Germany set about reforming the inefficient industries in the East, the State owned works at Kloster Mansfeld was to be sold off. The contractor in Holland carrying out the work, said he would buy the works, but it was eventually bought out by the current management. Unfortunately though, the Dutch contractor never paid the Germans for any of their work, assuming he would buy the works. It was therefore not surprising that the new management were reluctant to carry out any further work on the B12 without guarantees of funding.

By now the loco was totally dismantled and in hundreds of bits. It was looking bleak for the B12, and during negotiations, the M&GN Society were told, in no uncertain terms, to remove the B12 from the workshops and "dump it in the North Sea on the way back to England!”. The Society, in the form of the late Roger Heasman, worked very hard to gain the trust of the new management, and after much negotiation he persuaded the new company, "Malowa", to continue with the job of restoring the B12. Work began in stages, firstly on the tender, and then on the locomotive. Over the next two years work progressed steadily until in November 1994, the loco was finally completed.

The B12 arrived back at the North Norfolk Railway in December 1994, resplendent in LNER apple green as 8572. There was still a little work to be done before the loco could enter traffic. But there was much relief and excitement, that after a long and difficult restoration, the loco was almost ready to run for the first time in 30 years.

The B12 was officially re-commissioned on 3rd March 1995, and dedicated to Bill Harvey. Bill had been instrumental in saving the locomotive during his time as Norwich shedmaster and had started and led the initial restoration of the B12 in the late 1970s. Sadly Bill died before the loco was steamed again.

Since returning to service in 1995, the B12 became dubbed the "Jewel in the Crown" of the NNR. It has worked extensively on the railway, especially during the summer seasons, hauling thousands of tourists between the seaside town of Sheringham and the Georgian market town of Holt. The B12 has also visited other preserved railways, including the Severn Valley Railway, Great Central Railway (both at Ruddington and Loughborough), and the East Lancs Railway. In 2000 the loco also ran on the mainline again, when it attended Steam on the Met.

As had always been promised to the membership since the loco was purchased in 1963, the chosen livery on completion of the restoration in Germany was 1930s LNER apple green, and remained in this livery for five years. The B12 was repainted black in 1999. First into unlined 'North Eastern' (NE) wartime black for the NNR's popular 1940s weekend, and then shortly after it was changed to BR lined black, which the locomotive carried until the end of her ticket.

After starring along side J15 65462 and N7 69621 at the North Norfolk Railway's 'Steam Dream' weekend, 61572's fire was dropped on Sunday 1st July 2007. After 13 years service the loco was withdrawn shortly afterwards as a number of small tubes in the boiler had started to leak and needed to be replaced. Due to the cost involved, it was decided that it wasn't cost effective with just 6 months remaining on the boiler ticket.

Having learnt many lessons from the trials and tribulations of her first preservation overhaul, the B12 was kept in one piece whilst fundraising for her boiler appeal took place. The locomotive boiler was then removed and sent to Chatham Steam in Kent for assessment and overhaul. With greater resources to hand, the Society was able to invest a much greater amount into the overhaul and much work was done to the boiler. The locomotive frames were sent to Messrs Riley and Son (E) of Bury for overhaul, whilst the tender was overhauled in house at Weybourne works. Following successful steam testing of the boiler at Chatham Steam, it was moved to Bury where further out of frames testing took place, before the frames, boiler and tender were reunited.

On 8th March 2012, the B12 returned to traffic on the North Norfolk Railway in a special M&GN Joint Railway Society Members’ Day, put on especially for supporters of the overhaul and Society to enjoy. Outshopped in LNER apple green once again, the lococomotive looks a treat hauling the 1924 Gresley Quad-Arts or stabled alongside her reliveried LNER preservation survivor, J15 7564.

Since returning to steam in 2012, the B12 completed over 90 steamings in 2013, including a visit to the Gloucestershire & Warwickshire Railway in May of that year and on the 5th October, she hauled the Sheringham to Holt leg of the 'Wandering 1500' charter, which ran from Liverpool Street to Holt, hauled by 70013 Oliver Cromwell, exactly fifty years to the day that 61572 hauled the original tour from Broad Street.

Original article by Ben Boggis and Steve Allen, updated February 2014. Further details were included by Dennis Greeno November 2016.