Since the Midland Railway had good experiences with their class 1000 compound 4-4-0s, the LMS ordered locomotives which were nearly identical. Out of a total of 195, 75 each were built by Vulcan Foundry and Derby, 25 by North British and 20 by Horwich.

Like the Midland locomotives, they were three-cylinder compounds with a central high pressure cylinder and two slightly larger outside low pressure cylinders. Changes included driving wheels which were three inches smaller, a superheater that was installed from the beginning and cylinders which measured 19 3/4 and 21 3/4 inches in diameter.

After only a short time, the cylinder diameters were changed to 19 and 21 inches to equal the Midland locomotives. They were used in the same tasks as their predecessors, what meant light, fast expresses. Their service life was longer than that of their predecessors, so the withdrawals took place between 1952 and 1961.

After a series of 0-6-0T tank locomotives developed for the Midland Railway, Henry Fowler's class 3F built for the LMS was the last one in the row. Based on the MR class 2441 built from 1899, these had a smaller boiler with a Belpaire firebox. It got the nickname “Jinty” and is said to have reached speeds of up to 60 mph or 97 km/h, what is exceptional for a locomotive without leading or trailing axles. 

Between 1924 and 1931, a total of 422 were built by the LMS Horwich works and several commercial manufacturers. Some were used in France in World War II. British Railways inherited 412 and got five back from France. Withdrawals only started in 1959 and were finished in 1967.

The Horwich Mogul takes its name from the LMS works in Horwich, formerly Lancashire, where the first series of these locomotives were built. However, it is better known by the name “Hughes Crab” given to her by railroad enthusiasts. In order to accommodate the large cylinders within the loading gauge, engineer George Hughes was forced to incline them and set the connecting rods a few degrees upwards. Since this gave the impression of a crab with its claws, it was given this name. It was designed taking into account the latest knowledge and planned with the most modern assemblies available in terms of brakes, valves, boiler and tender. The design was only implemented under Henry Fowler and it was initially questionable whether all the innovations could actually be put into practice.

Due to the technical progress, however, it was possible to implement a large part of the innovations, while standard parts of the LMS only had to be used for the brake system and the boiler attachments. A standard model from Derby Works was used as the tender. Since the locomotive itself made full use of the available loading gauge and this was not the case with the tender, the latter was noticeably narrower than the locomotive's cab. A total of 70 were built in Horwich and a further 175 in Crewe between 1926 and 1932. These engines were particularly popular in Scotland on the mountainous routes when used in front of heavy ore and coal trains without continuous brakes.

BR 42894 in the year 1951 at Bescot Depot

Ben Brooksbank / Hughes/Fowler 2-6-0 at Bescot Locomotive Depot

Over time, some engines have been experimentally upgraded with modern assemblies. In 1934, five units received a Lentz valve control, which they also kept. However, it stayed with these five. In 1954 a new chimney with blowpipe was tested on one locomotive. This increased the boiler's evaporative capacity by 25 percent, but it remained a one-off. The locomotives were retired between 1961 and 1967 and three remain in existence today. One of them was preserved in driving condition and only got a completely new boiler in 2018.

The LMS inherited the many light locomotives from the Midland Railway, which were very often used double-headed. For example, heavy express trains on the West Coast Main Line were mostly seen behind either a pair of the 4-4-0 compounds or behind a 4-6-0 supported by a 4-4-0 for much of the route. After a GWR Castle Class example had been tested with great success on the London to Carlisle section of the Royal Scot, the LMS wanted to procure a similar locomotive.

Sir Henry Fowler, formerly Chief Engineer at Midland and now at LMS, had already prepared designs for a compound Pacific. However, experience with the Castle Class led to the selection of a non-compound 4-6-0. In the actual development, instead of Fowler, the North British Locomotive Company was in charge, where the first 50 examples were manufactured.

Instead of a simple four-cylinder engine, only three cylinders were installed and a high steam pressure of 250 psi was used. Since the trailing axle of the Pacific was left out, the boiler had to be positioned relatively high and, with a relatively short length, had a large diameter. The Belpaire firebox had to be over three meters long in order to be able to use a sufficiently large grate area when installing it between the coupled wheels. Since the loading gauge was fully utilized, a very flat steam dome had to be designed and special safety valves with a low installation height had to be developed.

After the first series from 1927, a further series of 20 examples was launched in 1930, which were made in the company's own workshops in Derby. Most examples were named after British Army regiments and some after historic LNWR locomotives. The latter were later also named after regiments. The locomotives mainly pulled the “Royal Scot” from London to Glasgow and Edinburgh, after which the class was named. They were able to pull the 15 wagons without assistance at an average speed of around 53 mph and thus achieved very acceptable fuel consumption. Downhill speeds of almost 80 mph were also possible. One example toured the United States in 1933, including being exhibited at the Century of Progress World's Fair in Chicago.

No. 6152 “The King's Dragoon Guardsman” with the nameplate of No. 6100 “Royal Scot” and US-qualified headlight and bell on her US tour alongside a Pennsylvania Railroad K4s

H.W. Pontin / collection Taylor Rush

Initially, the piston valves caused problems, which led to a significantly increased steam consumption with increasing wear. It also took several attempts to find the optimum shape for the smoke deflectors, so as to restrict the crew's view as little as possible. In 1935, number 6399 “Fury” was built as an experimental locomotive with a high-pressure boiler based on the Royal Scot. It had a compound engine with three cylinders, but was later rebuilt to a similar level as the Royal Scot, only with a more modern boiler that tapered towards the front.

Between 1943 and 1955 all 70 examples of the Royal Scot were rebuilt to a level modeled after the stripped down “Fury”. Except for the wheels, cabs, parts of the frame and some add-on parts, no parts were reused, so in reality it was more of a new construction. The nameplates were retained, but as a rule they were not attached to the same locomotive from which the modules taken over came. Thus, the rebuilt locomotives were treated as a separate class called “Rebuilt Scot”. When it came to maximum output, they could certainly keep up with the Pacifics of the Coronation Class. They were retired between 1962 and 1966.

The LMS Fowler class 4P was the first in a series of 2-6-4T tank locomotives designed for long-distance commuter services. It was introduced in 1927 by Henry Fowler and formed the basis for derivatives by Stanier, Fairburn and Riddles. 125 of this class were build in Derby until 1934.

Their leading axle was of the same type as the one used on the Schenectady Moguls the Midland Railway received in 1899. They had a relatively high ratio of superheating and driving wheels of 5 ft 8 in which were good for speeds of 80 mph (129 km/h) and more. The last 30 locomotives built had more modern cabs with side windows and doors.

They were not only used for commuter trains, but also as bankers for passenger and goods trains on the Shap incline. They were withdrawn between 1959 and 1966 and none was preserved. In 2015, the LMS Patriot Project announced that they are planning to build a new member of this class when their No. 5551 “The Unknown Warrior” has been completed.

In 1933 the LMS ordered 40 more examples of the “Hughes Crab”, which had last been built in their works in Crewe. By this time, William Stanier had been chief engineer at LMS for two years. Since he brought experience from the GWR and still saw room for improvement for the locomotives, the locomotives were not built directly to the original design. As the greatest innovation, Stanier introduced the so-called “taper boiler”, a boiler that tapers towards the front. This not only saved weight, but also ensured better water circulation. The new boiler also had a pressure of 225psi compared to 180psi on the Horwich Mogul. Thanks to the higher boiler pressure, the diameter of the cylinders could be reduced, but at the same time the piston stroke was increased.

Preserved No. 42968 in 2009 at Kidderminster

Tony Hisgett

Due to the changes, the locomotives were given a new designation, but like their predecessors, they were also assigned to power class 5 and were used for the same tasks as these. These locomotives also got the narrower standard tender of the Derby Works. From the 14th locomotive, a slightly modified boiler was installed. A total of 40 pieces were made in the short period between October 1933 and March 1934. No further examples were built, as Stanier immediately wanted to build power class 5 mixed-traffic locomotives with a 4-6-0 wheel arrangement, from which his famous “Black Five” arose. In contrast to the Crab, the first new Moguls were not phased out until 1963, but the last engines were also phased out in 1967. Only the penultimate locomotive built with the BR number 42968 has been preserved today. This was operational until 2013 and then came to a larger one Overhaul still ongoing in 2021.

The “Black Five” was Stanier's most famous design and also one of the most famous British steam locomotives ever. It was created because Stanier was of the opinion that the Moguls with a 2-6-0 wheel arrangement used in power class 5 in mixed service would soon no longer be sufficient. From his time at GWR he was familiar with the class 4900 “Hall”, which, with a 4-6-0 wheel arrangement and a driver diameter of six feet, was suitable for all trains from freight to express. Since the Hall had been developed for the re-gauged, formerly broad-gauge lines of the GWR and therefore did not fit into the loading gauge of the lines in the north, Stanier designed a slightly narrower and lighter locomotive. Since these were painted black, in contrast to the crimson of the LMS previously used, and belonged to power class 5, they were soon known as the “Black Five”. They quickly gained the image of locomotives that could be used almost anywhere and take on almost any task. They were found in front of freight trains as well as in front of heavy express trains that could travel at speeds of up to 80 mph. 

From the Moguls, Stanier adopted the tapered Belpaire firebox and from the Halls he adopted the six foot wheel diameter. The first 70 locomotives came partly from the LMS workshops in Crewe and partly from the Vulcan Foundry. After 57 examples were built, a new boiler was used, which, unlike the original, had a steam dome and a higher degree of superheating. The upper edge of the firebox was soon designed to slope backwards in order to lengthen the flame paths in the boiler.

In 1936 Armstrong Whitworth received an order for 227 Black Fives, which at the time was the largest order that a British railway administration had ever placed with a commercial factory. In the same period, 20 more were built in Crewe with an even higher degree of superheating. New series were again commissioned during the Second World War, beginning in 1943 at the Derby works. From 1947 roller bearings were used for the axles, at the same time the wheelbase was slightly extended and some details on the boiler were improved. George Ivatt, as the new chief engineer, further improved the locomotives in 1948 with better bearings and a different valve design. Some locomotives received a steel instead of copper firebox and double chimneys and blowpipes.

The British Railways continued production until 1951, so that a total of 842 examples were built. Even the standard class 5 was developed from these. The Black Five also remained in service in large numbers well into the last days of steam traction in Britain. After only one engine had been retired in 1961, the number of retirements rose only slowly at first. They peaked in 1967 with 305 and in 1968 the last 151 disappeared. Today 18 units have survived, 12 of which were purchased directly from British Railways and six were rescued from the scrapyard. At the beginning of 2022, seven engines were still in operational condition, five of which had unrestricted certification for the British main lines and were not restricted to individual museum railways.

Stanier developed these locos from Fowler's 2-6-2T. The biggest change was in the new boiler, which was tapered towards the front. The locomotives with the numbers 71 to 120 and 121 to 144 each used a slightly different variant of boiler type No. 6 without a dome. Numbers 145 to 209 had boiler no. 6A with a feed and a steam dome. In general, the locomotives are referred to as Stanier's least successful design. Among other things, the extremely small superheater surface is mentioned. Six of them were later given the 6B boiler, but this was not cost-effective. Nevertheless, they were only retired between 1959 and 1962.

For a new non-stop train between London and Glasgow, the LMS commissioned a new Pacific in the mid-1930s, which was supposed to be stronger, more reliable and easier to maintain than the Princess Royal. The train was called “Coronation Scot” and the locomotive “Coronation class”. The ten locomotives from the first batch and ten more from a later batch were built streamlined. This was apparently not planned at the beginning, but was subsequently decided due to the public appeal of the competing LNER A4.

No. 6241 “City of Edinburgh” with streamlining

flickr/Historical Railway Images

No. 6220 “Coronation” achieved a British record of 114 mph (183 km/h) in 1937, which only lasted one year. Another record was also broken in 1939 with 2,511 hp on the drawbar, which still stands today for British steam locomotives. The streamlined paneling was removed from all locomotives by 1948 because the advantages over the much more complicated maintenance were limited. Most were scrapped between 1962 and 1964 after they were replaced by electric locomotives and no further use could be found. No. 6233 “Duchess of Sutherland” is the only one of the three surviving that was operational in 2023, but was withdrawn without further notice.