The first Great Western Railway King class locomotives began emerging from the railway works in Swindon UK 80 years ago. The most powerful of all the British 4-6-0 classes in terms of tractive force. They were in effect a stretched Castle class locomotive, which in itself had been a stretched Star class. The Great Western Railway build a total of 30 King class locomotives. With four cylinders and a steam pressure of 250psi they gave tractive force of 40,300lb. They were fitted with a bigger boiler than the castle class, but their weight restricted their route availability to the Bristol, Plymouth and Wolverhampton main lines. It was not until the British Railways era that they were allowed between Bristol and Shrewsbury and South Wales via the Severn Tunnel. When the Kings were first built they had a power output of 1,230hp, but after the fitting of a double chimney this was increased to 1,371hp.
British express trains were the fastest in the world during the 1880's. The introduction of the bogie passenger carriage together with continuous brakes and much improved signalling allowed trains to travel at much higher speeds.
One of the premier long distance journeys was from London to Edinburgh. On 21st August 1889 the journey was made at an average speed of 60.6mph using a Great Northern Sterling 8ft single between Kings Cross and York and North Eastern and North British 4-4-0s for the rest of the journey. The following night the west coast crews did the journey at an average speed of 63mph! The locomotives used for this run were a three cylinder compound 4-4-0 between Euston and Crewe, 2-4-0 Hardwicke from Crewe to Carlisle and Caledonian Railway 4-4-0s to Aberdeen.
By 1902 daily services were run from London to Birmingham at 55mph and the fastest service to Bristol was run at just under 60mph. In 1904 City of Truro inaugurated the Cornish Riviera Express, the longest non-stop run in the world. The journey was run at an average speed of 55.5mph.
As these crack expresses became heavier there was a need for more powerful locomotives to haul them. The solution was to add a third set of driving wheels. This was adopted by most of the mainline companies and most successfully by the Great Western in a series of 4-6-0 locomotives. The two cylinder Saints and four cylinder Stars were designed by George Churchward. The Stars developed into the famous GWR Castle class. The first castles were build in 1923. These locomotives were so successful that they were still being built in 1950. The Southern Railways Lord Nelson class were built after studies had been made of the castles and were used to haul the heaviest expresses on the Southern Railway. Stanier was also influenced by Churchwards design when he built the 4-6-0 Black Five. 842 Black Fives were built and were used on freight as well as passenger work.
In 1928 A3 pacific locomotives began to appear. These used a pair of rear carrying wheels, which allowed for a bigger firebox to be used. During March of 1935 a special train ran between Kings Cross in London and Newcastle-upon-Tyne. It was hauled by A3 Papyrus and covered well over half the trip at 80mph and recording a top speed of 108mph. Another A3 pacific design, Silver Link made its debut on a special train in September 1935 breaking another record with a top speed of 112.5mph. As records continued to tumble, The London, Midland & Scottish Railway introduced their Princess Royal class Pacifics for the service between London and Glasgow. Following the introduction of streamlined trains, the LMS developed their own version. The Coronation Scot service was inaugurated in 1937 and had a tight schedule! It was to cover the 401 miles between London and Glasgow in an impressive six and a half hours.
The LNER countered with a six hour service from London to Edinburgh called the Coronation. This meant the train had to maintain speeds of 100mph on many stretches and in 1938 the company made their, now world famous attempt at a new speed record. The engine was the A4 Pacific Mallard, which on 3rd July reached 126mph. The speed record was broken again but so was the locomotive. Mallard suffered severe overheating. The following year the second world war put a stop to further races to Scotland!
Built between 1941 and 1944 the 4-8-8-4 'Big Boy' locomotives are reputed to be the largest steam locomotives ever built. During the late 1930s the Union Pacific Railroad needed to use banking engines to move freight from Ogden to Wahsatch. Obviously this wasn’t the best economical solution for moving heavy loads so engineers were asked to design a locomotive that could haul a 3600 ton train, unassisted over the 1.14% incline of the Wahsatch.
The locomotive they came up with is truly phenomenal.
Its overall length was 132ft 10 inches. It Weighed in at 1,189,500lb. Its driving wheels are unspectacular in size (5ft 8in) but there were 16 of them! The grate area was 150sq ft and its tender could carry 25,000 US gallons. Steam pressure was 300psi and total tractive force was 135,375lb.
The Big Boy locomotives were the only ones built to have the 4-8-8-4 wheel arrangement. This combines two sets of eight driving wheels, articulated in the middle, and a four wheel leading truck to ensure stability entering curves and another four wheel truck at the rear to support the large firebox.
25 Big Boys were built and the last freight train hauled by one was in July 1959.
After the Second World War, prices of coal and labour signalled the end of the Big Boys and steam in general but they were some of the last steam locomotives to be taken out of service.
Eight of the 25 original Big Boys are preserved but no plans are in place to restore any back to operational condition.
No. 4004: Holliday Park, Cheyenne, Wyoming.
No. 4006: Museum of Transportation, St. Louis, Missouri
No. 4012: Steamtown National Historic Site, Scranton, Pennsylvania
No. 4014: Railway & Locomotive Historical Society, Pomona, California
No. 4017: National Railroad Museum, Green Bay, Wisconsin
No. 4018: Museum of the American Railroad, Dallas, Texas
No. 4023: Kenefick Park, Omaha, Nebraska
Mallard is a streamlined A4 class 4-6-2 locomotive designed by Nigel Gresley for the L.N.E.R. in 1935. With their streamlining and chime whistles, the A4's are instantly recognizable. A total of 35 A4's were built to haul express trains from London’s Kings Cross to northern England and on into Scotland.
In 1935, an A3 pacific, one of Gresley's earlier designs, broke the speed record for steam with an impressive top speed of 108mph. Gresley knew that he could do better and the L.N.E.R. gave him authorisation to proceed with a streamlined development of the A3. The first four A4's were built and all given 'silver' names. 2509 Silver Link, 2510 Quicksilver, 2511 Silver King and 2512 Silver Fox. Silver Link achieved a top speed of 112.5mph and an average speed of 100mph during a press run to publicise the service. In August 1936 Silver Fox achieved a top speed of 113mph on the decent of Stoke Bank, then the highest speed ever attained by a steam locomotive.
On the 3rd July 1938 4468 Mallard set a world speed record of 126mph pulling six coaches and a dynamometer car. After the record attempt Mallard's middle big end was found to have run hot causing the bearing metal to melt, this meant that the locomotive had to stop at Peterborough and could not continue on to London.
Cecil J. Allen, in 'The Gresley Pacifics of the L.N.E.R.', gave this account of the run:
The first GWR Castle class 4-6-0 locomotives first appeared in 1923, but many would say that they really originated some 20 years earlier. That was when the first of the GWR 4-cylinder classes the 'Star' first started to be produced at Swindon works.
The stars were designed by George Jackson Churchward, the forward thinking and radical engineer transformed the Great Western motive power policy. For two decades the Star class proved their worth as Britain’s most successful and economical main-line passenger locomotives.
Churchward retired in 1922 and by this time there was an urgent need for more powerful locomotives. Holiday traffic from London down to Devon and Cornwall had grown and demanded heavier trains. Charles Collett was now chief engineer for the Great Western Railway. He was faced with the challenge of designing a new locomotive that could easily handle the heavy trains. Collett had little time to produce this new express locomotive and he was also limited by the axle weight restrictions on the West of England main line. Collett decided to go for the practical option to design a lager and more powerful version of the Star.
He retained the layout of the frame and the spacing of the wheels but added a bigger boiler and larger cylinders. The 'Castle's' tractive effort was 31,625 pounds at 85 per cent boiler pressure compared to the 'Star's' 29,835 pounds. This made the Castles the most powerful locomotives on any British railway at the time. The GWR publicity engine went into overdrive and No. 4073 Caerphilly Castle was displayed alongside the new pride and joy of the LNER, A1 pacific No. 4472 Flying Scotsman at the British Empire Exhibition of 1924.
A series of locomotive exchange trials took place between the GWR castles and LNER pacifics. These proved the Castles superiority beyond doubt. The locomotives haulage capacity, its abilitity for sustained high speed running coupled with its remarkable economy proved to all concerned that this was the way to go in future locomotive design.
Only three years after the first Castle rolled out of Swindon the first of the King Class locomotives appeared. One of the main objectives was to reduce journey times from London to Cornwall to four hours. With a tractive effort of 40,300 pounds the Kings were powerful and fast, however they suffered from route restrictions because of their weight. The Castles therefore continued to be the most useful of the GWR locomotive stable.
The Castles were the most economical locomotives of their time. A castles average coal consumption was 2.83 pounds per drawbar horsepower per hour compared to the average 4 pounds common on other locomotives in the 1920s.The original Castle tenders were built to carry six tons of coal and 3500 gallons of water, but these were later replaced by 4000 gallon tender.
Castles worked some of the most impressive GWR express routes. They hauled the Bristolian. A non-stop run between London and Bristol which allowed only 105 minutes each way. They also worked the Cheltenham Flyer. This was the fastest scheduled service in the world. This was allowed just 70 minutes for the 77.3 miles from Swindon to Paddington, an average speed of 66.2 miles per hour.
In 1935 the Great Western Railway began half hearted experiment with streamlining of two of their locomotives 5005 Manorbier Castle and 6014 King Henry V11. They were fitted with a streamlined bullet nose and fairings from the buffer beam covering the cylinders, fairings were also fitted behind the safety bonnet and chimney. The experiment was not pursued, with the locomotives being almost back to normal by 1943.
The London Midland Scottish Railway produced the Princess Coronation class, 38 were built at Crewe, designed by William Stainier of which 10 were streamlined and described as looking like upturned bath tubs. The first 5 (6220-6224) were built in 1937 and painted in Caledonian Railway blue with horizontal silver lines the 2nd 5 (6225-6229) were painted in traditional crimson lake with gilt horizontal lining. They were designed for use on the Coronation Scot train between Euston-Carlisle- Glasgow Central on The West Coast mainline and to compete with the L.N.E.R who ran on the East Coast . The remainder of the class were built without streamlining because of WW2 and the 10 fitted had it removed from 1946 onwards. The reason given for the removal was difficulty of access for maintenance and streamlining had little value at speeds below 90mph. Weights: Streamlined 108.1 long tons and in rebuilt form 105.25 long tons. 3 locos of the class survive, 6229 Duchess of Hamilton has had its streamlining refitted and is now at the NRM York, 6233 Duchess of Sutherland is being refitted for the mainline and 6235 City of Birmingham is on display at The Think Tank in Birmingham.
The London North Eastern Railway produced several designs for streamlined locomotives, probably by the most successful designer of them all Sir Nigel Gresley who was responsible for the 2-8-2 P2 Mikados, 4-6-0 Sandringham B17 East Anglian and the W1 class 4-6-4 high pressure “Hush Hush” built at Darlington in 1929. But it is the Gresley A4 Pacific 4-6-2 that he is best known for.
35 wedge shaped streamlined locomotives were built at Doncaster between 1935 and 1938 for use on the East Coast main line express trains between Kings Cross-North of England and Scotland. The locomotives were fitted with valences (streamlined side skirts) designed by Oliver Bullied who later became CME for The Southern Railway in 1937. Some modifications to the streamlining took place during WW2 when the skirts were removed to allow better access for maintenance of the valve gear, they were never replaced.
Probably the most famous of the class is 4468 Mallard which captured the world speed record for steam trains on 3rd July 1938 between Grantham and Peterborough attaining 126.4 m.p.h which still stands today. Six examples remain in preservation. 4468 Mallard can be seen at The NRM, whilst 60007 Sir Nigel Gresley is based at The North Yorkshire Moors Railway and is cleared for mainline work, 60009 Union of South Africa is undergoing a major overhaul at Crewe and 60019 Bittern is based at The Mid Hants Railway and is presently (2011) running on the mainline as 4492 Dominion of New Zealand. 60010 Dominion of Canada is on static display in Canada and 60008 Dwight D Eisenhower is on static display at the National Railroad Museum, Green Bay, Wisconsin, USA. The remainder of the class were progressively withdrawn for scrap between 1962-1966.
Taking over from R.E.L. Maunsell in 1937 Oliver Bullied became CME for the Southern Railway he was responsible for several designs of air smoothed (Streamlined ) locomotives. The Merchant Navy being one, 30 were built as a class of streamlined 4-6-2 Pacific's between 1941-1949.These were built for express and semi fast work over the region, though they were prone to wheelslip when starting and required careful driving when starting from a stand, but were considered to be very stable when pulling heavy expresses. Apart from the wheelslip problem there were maintenance issues as well, the chain valve gear suffered from high wear and oil leaks from the oil bath splashing onto the wheels and boiler lagging.
The Merchant Navy class was completely rebuilt to a conventional design by R.G.Jarvis between 1856-1960 making them similar to B.R Standard class loco. Gone was the air smoothed casing and chain valve gear with its oil bath, to be replaced with three separate sets of Walschaerts valve gear and conventional boiler cladding. The fitting of smoke deflectors improved the drivers visibility of the line. When originally built the locomotive weighed 96.3tons when rebuilt they weighed 99.5 tons!
Some 10 locomotives have survived in various states of repair with 35028 Clan Line being operational on the mainline. A sectioned exhibit can be seen at The NRM in York it is 35029 Elerman Line.
A further 110 light Pacific's of the West Country and Battle 0f Britain class were constructed between 1945-1951,named after West Country resorts and The Royal Air Force and associated subjects. They were lighter and designed for a wider route choice than the heavier but very similar, in looks. to their Merchant Navy class sisters. Being of a similar design they too suffered from the maintenance and mechanical problems of their bigger sisters, a program of rebuilding was started to a design of R.G.Jarvis and 60 were rebuilt at the Eastliegh and Brighton works. The air smoothed casing was removed as was the chain valve gear with its oil bath were replaced by modified Walschaerts valve gear and a more conventional boiler cladding fitted. Maintenance problems were mostly solved and the costs cut in coal consumption, but the introduction of the Walschaerts valve gear made them prone to hammerblow, also an increase in weight, which in turn reduced route availability. When built the locomotives weighed 87.4 tons, when rebuilt it had increased to 92.6 tons.There are 14 locomotives preserved in various stages of repair . Six with air smoothed casing of which 34067 Tangmere is cleared for mainline duties with 8 in rebuilt form of which 34046 Braunton is nearly ready for the mainline.