The first 19 locomotives that Brunel had procured in 1938 were partly adventurous designs to reach high speeds. On the one hand there were the “Snake” and “Viper” locomotives from the Haigh foundry, which were brought to higher speeds with a gearbox with a ratio of 2:3 and had the wheel arrangement 2-2-2. Less conventional were the two Hawthorn locomotives developed by Thomas Elliot Harrison, which used two cars to split the boiler and engine.

The first of these was the “Thunderer”, where the boiler and driver's stand were on a three-axle chassis. The cylinders were housed on another, two-axle chassis together with a gearbox with a ratio of 10:27. Here both axles with six feet wheels were driven. The live steam was routed to the engine chassis and the exhaust steam back to the smoke box via elastic pipes.

“Thunderer”

Locomotive Magazine, April 1901

The “Hurricane” got rid of the gearbox by increasing the size of the driven wheels to exactly ten feet. For reasons of space, only one axle was driven, which is why two carrying axles were added and the engine unit was thus given the wheel arrangement 2-2-2. Both “Thunderer” and “Hurricane” were only used until December 1939 and their boilers were then used as stationary steam generators and for a freight locomotive. Thanks to the experience with the locomotives, gearboxes and equally divided locomotives were dispensed with in the future and high speeds were achieved in other ways.

Based on the success of the Firefly class, Daniel Gooch wanted to build an even more powerful and faster express locomotive. The driving wheels were increased from seven to eight feet and the largest possible boiler was installed in order to be able to take full advantage of the broad gauge. The wheel arrangement was still 2-2-2 and all wheels were mounted between the inner and outer frames. The cylinders were mounted between the inner frames.

“Great Western” in its original condition

Die Lokomotive, September 1937

The “Great Western” was completed in 1846 as the forerunner of the series. After just a short trial, the leading axle broke, which was attributed to the fact that the locomotive was too heavy to distribute the load over just three axles. The solution was to replace the leading axle with two axles that were also mounted in the frame. Although this made the locomotive heavier overall, the load on the driving axle fell. A further 29 series pieces were built in this form. The class was named “Iron Duke” after the first newly built machine and is said to have reached a top speed of 78 mph. The five-car express between London and Bristol is said to have averaged 68 mph on the 53 miles long section to Didcot.

“Great Western” with fixed leading axles

Die Lokomotive, September 1937

In 1871 the “Great Britain”, “Prometheus” and “Estaffete” locomotives were converted to the Rover class. They received a larger boiler with higher pressure and a flat, elevated firebox instead of the previous haystack-shaped firebox. While the Iron Duke class locomotives were gradually phased out, their names were reused for 19 newly built Rover class examples, produced up to 1888.

The last engines of the Rover class did not have long lives, as broad gauge operations ceased in 1892. All pieces were then scrapped. It was not until 1985 that a working replica of the Iron Duke was built using parts from two Hunslet Austerity tank locos. It was not restored to service after her boiler life expired and now stands at the Didcot Railway Centre.

In an attempt to combine large driving wheels with a low center of gravity, No. 3020 “Cornwall” of the LNWR was one of the most complicated, but unsuccessful designs. Designed by Francis Trevithick, son of the famous Richard Trevithick, it was a 4-2-2 with driving wheels of 8 ft 6 in (2,591 mm) built in 1847. To keep the boiler low, but out of the way of the driving axle, it was placed below this axle.

Original state from 1847 with a low boiler

Even though the driving axle could be held out of the boiler, the trailing axle went through a tube in the firebox, what created some problems when assembling the locomotive. Another problem was the long rigid wheelbase that effected the running characteristics. For these reasons, John Ramsbottom rebuilt it into a conventional 2-2-2 with boiler above the driving axle. 

Sectional frawing of the original state

Although it was only a single locomotive, the rebuilt “Cornwall” was used successfully in express service. With light trains, it delivered average speeds of 50 mph (80 km/h) and top speeds of up to 70 mph (113 km/h). In the 1870s, it got a semi-open cab.

It remained in regular express service until 1902. After that, it was not retired, but used as an inspection locomotive. For this task, it got a six-wheel carriage whose front part filled the task of a tender, while its rear part was a passenger compartment. When it reached its final retirement in the twenties, it was one of the first locomotives to be preserved on purpose. Today it can be found in the Buckinghamshire Railway Centre.

“Le Continent” in the Cité du train, Mulhouse

Alf van Beem

Original condition of No. 79 “Le Globe”

Locomotive Magazine, August 1923

No. 184 rebuilt with heavier driving wheels

Locomotive Magazine, August 1923

After the Nord had already had 100 km/h fast Crampton machines built with a driving wheel diameter of 2,100 mm from 1849, the Est procured similar ones with a diameter of 2,300 mm three years later. The engines of the Est could then even reach 120 km/h, which was beneficial to the Crampton's reputation as “greyhounds of the rails”. To do this, the maximum speed allowed on the French railway lines had to be increased by decree of Napoleon III.

After the twelve examples numbered 79 to 90 had been delivered by Cail in 1852, another 15 by Schneider-Creusot with numbers 174 to 188 followed in 1855. The first carrying axle had a larger diameter than the second and carried a significantly higher weight. The locomotives could pull up to 15 of the passenger cars of their time and usually reached an average speed of 55 to 75 km/h with nine to ten cars.

Since the adhesive weight of just over ten tonnes later turned out to be insufficient, as with most Cramptons, a conversion took place from 1881. In order to shift the weight further to the rear, particularly massive and heavy wheel hubs and a smaller boiler were installed. To compensate, the boiler was now operated at a higher pressure. Together with other extensions, such as the Westinghouse air brake, the adhesive weight could be increased by about 3.5 tonnes.

It was not until just before the turn of the century that other express locomotives were able to overtake the Cramptons. Number 80 “Le Continent” is the only example that has survived to this day. It was restored to its original condition in 1925 and initially exhibited at the Gare de l'Est in Paris. In 1946 it was made operational again, but has been standing since 1970. Today you can find the theoretically drivable machine in the Cité du train in Mulhouse, but no renewed refurbishment is currently planned.

At a time when attempts were being made to use the largest possible wheels to achieve high speeds while keeping the center of gravity low, some curious designs emerged. In 1855 Blavier and Larpent built the “L'Aigle” (“The Eagle”) with 9 ft 4 in wheels on the French Ouest. Their goal was to double the speed of the Cramptons. Since these had already reached 120 km/h at that time, this goal was hardly realistic to achieve.

With this wheel diameter, a boiler, which was usually above the axles, would have been very high above the top of the rails. At that time, everyone was convinced that a low center of gravity was the most important criterion for smooth running and developed many long boiler type locomotives, which had a thin and long, overhanging boiler to achieve the lowest possible center of gravity. Since this was not possible with the “L'Aigle”, completely new paths were taken.

Section through the special, two-part boiler

Locomotive Magazine, December 1901

The actual boiler, with a small diameter, lay below the axles and was connected to a second, cylindrical barrel, which lay above the axles. Although the boiler had sufficient volume, there were no smoke tubes in the upper boiler body. This made it impossible to produce enough steam for the large cylinders at higher speeds. Thus, the one-off never made it into commercial service and the allegedly achieved speed of 100 mph must be doubted.

The second design by John Ramsbottom while he was in charge for the LNWR was a 2-2-2 wheel arrangement express locomotive with a wheel diameter of seven feet six inches. This could be described as a simplified and therefore cheaper variant of the locomotives of its predecessor Alexander Allan. Officially this class was named the Problem class after the first production locomotive, but it is also known as the Lady of the Lake class. This is due to the fact that the LNWR presented the engine with this name at the 1862 World Exhibition in London and the name quickly caught on in the public eye.

No. 1434 “Eunomia”, the last to be scrapped in October 1907, as seenafter Webb's conversion

Locomotive Magazine, January 1908

The locomotives, which were initially painted green, stood out with their slotted wheel housings and apparently had a short wheelbase due to the large driving wheel diameter. Despite the high line speeds, there was initially no covered driver's cab. They were the first locomotives to be fitted with tenders with a scoop device for catching water during the journey. The traditional 2,000-gallon water tenders initially used were replaced with scoop-type tenders that only held 1,500 gallons. Another innovation was an injector based on Henri Giffard's design, only the first ten examples had a conventional water pump.

Schematic of a tender with a scoop as first used by the Problem class

George Findlay, „The Working and Management of an English Railway”

The locomotives were mainly used on the Irish Mail Trains, which collected mail from Holyhead from overseas and Ireland and brought it to London at a high average speed and without many intermediate stops. It was on this connection that the number 229 “Watt” became part of the so-called “Trent Affair”. On January 7, 1862, during the American Civil War, due to a diplomatic disagreement, a telegram from the British ambassador in Washington had to be sent to London as quickly as possible. After arrival in Ireland and onward transport to Holyhead, two locomotives took over the transport of the mailbags one after the other, of which the “Watt” had taken over the first section to Stafford. Thanks to the water troughs, they just managed to make the journey from Holyhead to London in the promised five hours, delivering a record-breaking performance. The “Watt” completed its 130 miles in 144 minutes.

Other Problem Class services were express trains in the Manchester, Liverpool and Crewe area. One notable feature was an unsteady running around the vertical axis at high speeds, which probably had its origin in the relatively short wheelbase. Starting in 1873, Webb subjected the machines to some conversions, in which a driver's cab roof, different chimneys, a now black standard paint finish, a vapor barrier for the wheels of the locomotive and closed wheel housings were used. A more extensive reconstruction only took place between 1895 and 1897, when the first engines of the class had already been in service for 36 years. They received a larger boiler and thicker tires, which increased the wheel diameter by 1.5 inches. Locomotives converted in this way were often used as pilot for heavy express trains, often reaching speeds of more than 80 mph. They were replaced between 1904 and 1907 by the Precursor Class developed by Whale, which now made the double-heading superfluous.

No. 503 (first batch)

Locomotive Magazine, September 1923

No. 512 (second batch) rebuilt with smaller wheels and new number 2512

Locomotive Magazine, September 1923

No. 508 with 4-4-0 wheel arrangement and Flaman boiler

Locomotive Magazine, September 1923

Although the Crampton locomotive enjoyed long popularity in France in general and with the Est in particular, it reached its limits in the late 1870s. Thus, Regray initially had seven locomotives made with 2-4-0 wheel arrangement. Since the Belpaire firebox ended with the rear on the second coupled axle and the 2.31 meter diameter wheels were still very large, the locomotives were referred to as “coupled cramptons” or “super cramptons”. On numbers 508 to 510, the firebox was pulled further forward so that it lay between the coupled axles. The locomotives had a double outer frame in which the cylinders were situated.

After the first ten examples had been manufactured in the Est workshops in Épernay in 1878 and 1879, the next 32 examples were ordered from commercial suppliers. The numbers 511 to 522 came from Cail in Paris in 1881 and the 523 to 542 in 1882 from the Wiener Neustädter Lokomotivfabrik. Their wheels were only 2.10 meters tall and the cylinders were slightly smaller. They also featured a conventional firebox that was larger than the previous Belpaire firebox. 

A third series of 20 examples was made again in Épernay in 1884 and 1885. These were given a larger boiler, which exceeded the 100 square meter mark for the tubular heating surface. This enabled them to achieve a boiler output that was greater than that of contemporary locomotives with a 2-4-2 or 4-4-0 wheel arrangement. Furthermore, they had received a larger tender that, in addition to the three tons of coal, could hold up to 13 cubic meters of water instead of the ten cubic meters of the older tenders. Traction was later increased on 48 of the 52 examples in the last two series by reducing the wheel diameter to 1.83 metres.

Numbers 508 and 509 were converted to a Flaman boiler in 1888, which could hold a maximum number of smoke tubes with two barrels. Since the front axle was heavily loaded after the conversion, the carrying axle was replaced with a bogie. Since the results of the conversions did not justify the high effort, no other engines were converted in this way. The engines with smaller coupled wheels were soon increasingly used in ordinary passenger train service and were partly used until 1936. The first of the non-converted examples, on the other hand, had already been retired in 1906.

The Class 3031 of the Great Western Railway, also known as the “Dean Single”, was created from the conversion of 30 examples of the Class 3001, which had been built by William Dean in the 7 feet 1/4 inch broad gauge and were converted to standard gauge a short time later. Since an increase in power through a wider boiler was impossible with the standard gauge due to the limited space between the large wheels, the boiler was extended to the front. After the leading axle derailed in the middle of the box tunnel due to the increased weight, it was replaced with a bogie, resulting in the class 3031. Since the cylinders were located below the smoke box in class 3001, a special bogie had to be constructed. This could be pulled out after loosening four screws and slightly lifting the front part of the locomotive to ensure uncomplicated maintenance of the smoke box and cylinders.

No. 3050 “Royal Sovereign”

J.R. Howden, The Boys' Book of Locomotives

First, two class 3001 locomotives were converted in March 1894, the remaining 28 were converted between June and December of the same year. A total of 50 more were factory built between 1894 and 1899. In use, the class 3031, like other locomotives with a 4-2-2 wheel arrangement, excelled with high sustained speeds. On May 9, 1904, a mail train was able to travel the 117 miles from Bristol to London-Paddington in just under 100 minutes for the first time, which corresponds to an average speed of around 70 mph. However, since one driven axle was soon no longer sufficient, they were decommissioned between 1908 and 1915. Today there is a replica of No. 3041 “The Queen”, which was completed in 1982.

After the Midland Railway had already procured 70 examples of express locomotives in the 4-2-2 wheel arrangement in the late 1880s, the era of express locomotives without a second coupled axle was already considered over. However, the Midland followed the strategy of using smaller locomotives, which were then supported by a second locomotive when required. Then, when steam-powered sanders were introduced, Samuel Waite Johnson developed another single express locomotive.

Inner and outer frames were used to safely transmit the forces of a powerful express locomotive to just one axle. Thus, the driven axle had four bearings and could easily withstand the forces of the internal cylinders. After five examples of the class 115 built in 1896 and 1897, another ten units were built in 1899.

Also in 1899, the class 2601 was presented, of which ten examples were built. The driving wheels were half an inch larger, the boiler pressure was increased from 170 to 180 psi, and the firebox was larger. In addition, the slide valves were replaced with piston valves. Instead of the previous three-axle tender, now a four-axle one was used.

Schematic drawing of class 2601

Die Lokomotive, December 1904

The locomotives were basically used on main routes without significant gradients. There they typically hauled express trains weighing between 200 and 250 long tons and could reach speeds of 90 mph. Some of them were also used in front of trains with 350 long tons and proved their worth there, as long as there were no difficult adhesion conditions. Later, when they could no longer cope with the increased train weights, they were still used as pilot locomotives, sometimes even in front of coal trains. Their service life ended in the late twenties.

The Great Central Railway Class 13 was the last single-driver express locomotive to be built in Britain and one of the last to see regular service. It was developed by Harry Pollitt, who called it Type X4. It had 7 feet 9 inches diameter wheels and had a boiler pressure of 200psi from the factory. Since, despite the sophisticated sanding system that was obligatory on the last singles, there was more power than could be converted into traction, the boiler pressure was soon reduced to 160 psi. 

When Pollitt retired in 1900 and John G. Robinson took over as chief engineer at GCR, the class 13 was just being produced. Anticipating the imminent end of the singles, Robinson reduced the order from ten to six. These locomotives initially ran the important route from Sheffield to London, but were moved to Cheshire in 1903 and replaced by the 4-4-0 Robinson class D4 locomotives. Four examples were fitted with a superheater between 1915 and 1919, but they were all retired between 1923 and 1927.