rebelatsea
Captain
- Joined
- Mar 30, 2013
- Location
- Kent ,England.
Apologies, I got a bit twisted there, the photo is of 18000 at Didcot - 18001 is back in Switzerland.
The two Swiss built locos for the Great Western Railway by Brown Boveri and Vulcan Foundry's English Electric powered GT3 for British Railways were actually quite successful.
0-6-0: Common yard switcher, later in the steam era.
0-8-0: Rare, super heavy duty yard switcher.
2-4-2: Early experiments with guide wheels, in order to achieve higher safe speeds. Sets of four front guide wheels were attached via swivel mount, while single pairs were semi-rigid. Powered axles were always rigidly attached to the frame, while trailing guide wheels were mounted on a trailing arm style pivoting triangular frame, with a slide plate under the cab. Once these suspension standards were established, they lasted throughout the steam era.
4-2-0: Early experiments with guide wheels, in order to achieve higher safe speeds. Sets of four front guide wheels were attached via swivel mount, while single pairs were semi-rigid. Powered axles were always rigidly attached to the frame, while trailing guide wheels were mounted on a trailing arm style pivoting triangular frame, with a slide plate under the cab. Once these suspension standards were established, they lasted throughout the steam era.
2-2-2: Early experiments with guide wheels, in order to achieve higher safe speeds. Sets of four front guide wheels were attached via swivel mount, while single pairs were semi-rigid. Powered axles were always rigidly attached to the frame, while trailing guide wheels were mounted on a trailing arm style pivoting triangular frame, with a slide plate under the cab. Once these suspension standards were established, they lasted throughout the steam era.
Incidentally, although this engine is engraved on the tombstones of Driver William Scaife and Fireman Rutherford in Bromsgrove Churchyard at the bottom of the Lickey Incline, it wasn't the engine whose boiler exploded and killed them. That was an experimental engine called Eclipse. We don't know if they had tampered with the safety valve, but the fact that the bang occurred in Bromsgrove Station at the foot of the bank is highly suggestive. This was before John Ramsbottom delivered us from evil by inventing the modern tamper proof safety valve.View attachment 301912
en.wikipedia.org/wiki/4-2-0#/media/File:WheelArrangement_4-2-0.svg
Under the Whyte notation for the classification of steam locomotives, 4-2-0 represents the wheel arrangement of four leading wheels on two axles, two powered driving wheels on one axle and no trailing wheels. This type of locomotive is often called a Jervis type, the name of the original designer.
The 4-2-0 wheel arrangement type was common on United States railroads from the 1830s through the 1850s. The first 4-2-0 to be built was the Experiment, later named Brother Jonathan, for the Mohawk and Hudson Railroad in 1832. It was built by the West Point Foundry based on a design by John B. Jervis. Having little else to reference, the manufacturers patterned the boiler and valve gear after locomotives built by Robert Stephenson of England. A few examples of Stephenson locomotives were already in operation in America, so engineers did not have to travel too far to get their initial ideas.
In England, the 4-2-0 was developed around 1840 from the 2-2-2 design of Stephenson's first Long Boiler locomotive, which he had altered to place two pairs of wheels at the front to improve stability, with the outside cylinders between them.
In the United States, the design was a modification of the 0-4-0 design, then in common use. The 0-4-0 proved to be too rigid for the railroads of the day, often derailing on the tight curves and rapid elevation changes of early American railroads. For the 4-2-0, Jervis introduced a four-wheel leading truck under the locomotive's smokebox. It swiveled independently from the main frame of the locomotive, in contrast to the English 4-2-0 engines which had rigid frames. The pistons powered a single driving axle at the rear of the locomotive, just behind the firebox. This design resulted in a much more stable locomotive which was able to guide itself into curves more easily than the 0-4-0.
This design proved so effective on American railroads that many of the early 0-4-0s were rebuilt as 4-2-0s. The 4-2-0 excelled in its ability to stay on the track, especially those with the single driving axles behind the firebox, whose main virtue was stability. However, with only one driving axle behind the firebox, the locomotive's weight was spread over a small proportion of powered wheels, which substantially reduced its adhesive weight. On 4-2-0 locomotives which had the driving axle in front of the firebox, adhesive weight was increased. While this plan placed more of the locomotive's weight on the driving axle, it reduced the weight on the leading truck which made it more prone to derailments.
One possible solution was patented in 1834 by E.L. Miller and used extensively by Matthias W. Baldwin. It worked by raising a pair of levers to attach the tender frame to an extension of the engine frame, which transferred some weight from the tender to the locomotive frame and increased the adhesive weight. An automatic version was patented in 1835 by George E. Sellers and was used extensively by locomotive builder William Norris after he obtained rights to it. This system used a beam whose fulcrum was the driving axle. On flat and level surfaces, the beam would be slightly raised, but upon starting or on grades, the resistance made the beam assume a horizontal position which caused the locomotive to tip upward.
A more practical solution, first put into production by Norris, relocated the driving axle to a location on the frame in front of the locomotive's firebox. This was done because Baldwin refused to grant rights to Norris to use his patented "half-crank" arrangement. Cantilevering the weight of the firebox and the locomotive crew behind the driving axle placed more weight on the driving axle without substantially reducing the weight on the leading truck. However, Norris's design led to a shorter wheelbase, which tended to offset any gains in tractive force on the driving axle by reducing the locomotive's overall stability. A number of Norris locomotives were imported into England for use on the Birmingham and Bristol Railway since, because of the challenges presented by the Lickey Incline, British manufacturers declined to supply.
Once steel became available, greater rotational speeds became possible with multiple smaller coupled wheels. Five years after new locomotive construction had begun at the West Point Foundry in the United States with the 0-4-0 Best Friend of Charleston in 1831, the first 4-4-0 locomotive was designed by Henry R. Campbell, at the time the chief engineer for the Philadelphia, Germantown and Norristown Railway. Campbell received a patent for the design in February 1836 and soon set to work building the first 4-4-0. For the time, Campbell's 4-4-0 was a giant among locomotives. Its cylinders had a 14 inches (356 millimetres) bore with a 16 inches (406 millimetres) piston stroke, it boasted 54 inches (1,372 millimetres) diameter driving wheels, could maintain 90 pounds per square inch (620 kilopascals) of steam pressure and weighed 12 short tons (10.9 tonnes). Campbell's locomotive was estimated to be able to pull a train of 450 short tons (410 tonnes) at 15 miles per hour (24 kilometres per hour) on level track, outperforming the strongest of Baldwin's 4-2-0s in tractive effort by about 63%. However, the frame and driving gear of his locomotive proved to be too rigid for the railroads of the time, which caused Campbell's prototype to be derailment-prone.
As the 1840s approached and more American railroads began to experiment with the new 4-4-0 locomotive type, the 4-2-0 fell out of favor since it was not as able as the 4-4-0 to pull a paying load. 4-2-0s continued to be built into the 1850s, but their use was restricted to light-duty trains since, by this time, most railroads had found them unsuitable for regular work.
In England, for freight work, four-coupled and six-coupled engines were performing well. However, for passenger work the aim was greater speed. Because of the fragility of cast-iron connecting rods, "singles" continued to be used, with the largest driving wheels possible.
For some reason, British manufacturers did not take up the idea of mounting the forward wheels on a bogie for some years. There were possibly fears about their stability and with a long rigid frame, greater speed was achieved, albeit at the cost of a very rough ride and damage to the track. The culmination of this approach was seen in the Crampton locomotive where, to make the driving wheels as large as possible, they were mounted behind the firebox.
en.wikipedia.org/wiki/4-2-0
View attachment 301923
https://i.pinimg.com/736x/02/35/6e/02356e3362bd4c81e5b6f2b75a685a07--george-washington-columbia.jpg
View attachment 301919
https://media.indiedb.com/images/articles/1/184/183461/auto/Pioneer_CNW_4-2-0.jpg
The above photo is 'Pioneer', the first railroad locomotive to operate in Chicago. Built in 1837 by Baldwin Locomotive Works for the Utica and Schenectady Railroad then used by the Galena and Chicago Union Railroad, (the oldest predecessor of Chicago and North Western Railway). She arrived in Chicago by ship on October 10, 1848, and pulled the first train westbound out of the city on October 25, 1848. The first locomotive of the proposed northern route of the TRR. (Just kidding James Lutzweiler )
View attachment 301926
https://upload.wikimedia.org/wikipedia/en/2/2b/England_loco_Birmingham_&_Glos'ter_Railway.jpg
For our members across the water - the above is a Norris 4-2-0 exported to England for use on the Lickey Incline
The Civil War connection - @DaveBrt 's web site https://www.csa-railroads.com/ has 9 hits to 4-2-0s as used by Confederate Railroads.
2104
Cheers,
USS ALASKA
2-4-0: Early experiments with guide wheels, in order to achieve higher safe speeds. Sets of four front guide wheels were attached via swivel mount, while single pairs were semi-rigid. Powered axles were always rigidly attached to the frame, while trailing guide wheels were mounted on a trailing arm style pivoting triangular frame, with a slide plate under the cab. Once these suspension standards were established, they lasted throughout the steam era.
4-4-0: The closest thing America ever had to a standard locomotive. Before, during, and after the Civil War, it was the locomotive of choice for nearly every assignment. The configuration looked good on paper, and it proved itself in the real world, handling sharp curves, curve transitions, and poor track conditions quite well. Railroads were so happy with them that alternatives to the design were not seriously considered for decades. The only obvious weakness was a speed restriction on backing up.
The design is somewhat of an optical illusion. It looks nearly balanced, but most of the heavy stuff including the firebox and most of the boiler is over the drive wheels. The smokebox up front (under the stack) is hollow space. The guide wheels only needed enough weight on them to properly steer the frame and take most of the stress off the drive wheel flanges. Not only did the locomotive perform better than the older designs, but rail wear was significantly reduced.
2-6-0: The first significant step away from standardization, after the war. In hilly terrain, longer freight trains had lower speeds. Two guide wheels up front seemed to be enough in that situation, and six drive wheels provided better traction. Passenger trains stuck with the 4-4-0 design, in most situations.
2-8-0: The logical next step beyond the 2-6-0. It quickly became America’s standard low speed branch line freight engine, a niche that it filled until the diesel era. Thousands were built. They also pulled mixed freight and passenger trains on low speed branch lines. Maxing out at around 2000 HP, it was a perfect match for the assignment, in every way, including economics. Today, it is the most common surviving steam engine configuration.