GWR four-cylinder arrangement?

Well, there are people who believe the Earth is flat and also don't accept the counter-arguments!

 

People are not superfluous, whatever their social standing. However Britain's social history is so vastly different from that of Denmark, to Brits it is hardly believable, despite the 1788 decree ending stavnsbånd, ordinary Danes had so little effective freedom until the end of the 19th century.
The Coronation had 144 3rd class seats, but only 48 1st class . Whether those in 1st class were upper class, or merely wealthy does not matter. 3/4 of the passengers were not 1st class.
The Coronation Scot also seems to have been 70/30 split in favour of 3rd class.
Ordinary people in Britain were allowed to travel from centuries before railways were built. In the late 19th and early 20th century, our industrial economy meant that many business people needed to travel-the process of amalgamation and consolidation that is a normal part of the life-cycle of any industry meant that for the first time there were companies with facilities all across the country. How would a consulting engineer, or a senior accountant travel? If one lived and worked in Dundee, but had to attend a meeting in the city, what then? 30 hours on a 25mph putnikki vlak?
There were no buses, and the 'Great North Road ' even in 1930, was scarcely wide enough for two cars to pass- the same as most of Europe until your neighbours got busy- so ordinary people travelled by train. And the less time spent travelling, the better. So fast long-distance express trains were essential to the economy and business life of Britain.
It wasn't just a few aristocrats filling their empty days with pointless indulgence.

 

While England didnt have Serfdom by the 18th Century there was the Poor Law and 'Parish of Settlement' that Adam Smith hated established by the 1662 Poor Relief Act.

See

https://en.wikipedia.org/wiki/Poor_Relief_Act_1662

Fussells Ironworks at Mells just outside Frome suffered because they found it difficult to bring workers in from outside the area as they could be denied the right to settle in case they became a burden on the parish.

They system was finally abolished in 1834 but elements remain in some areas of the law eg Homelesness.

 

The only truly superfluous thing about this thread is this thread.

A two cylinder high speed steam engine would never have been permitted by the civil engineers, even assuming any mechanical department were convinced of there being advantages. The inherent difficulties of balancing such a locomotive would to this day raise concerns about the impact on the track and structures.

 

Hermod, If two-cylinder compounds made any sense, Chapelon would have done it!

 

If you look at his two books, there are no As on coal drags. Weren't the films taken at the very end, when flexibilty due to withdrawals would have been required.

As for his recordings, Christmas Eve at Rural Retreat in 1957 would take some beating. Smart take-off!!!

 

There were 998 two cylinder high speed BR standards methinks.
Europes fastest regular steam train ever was pulled by SNCB class 12 locomotives.

 

Chapelon was not constructing locomotives but was ordered to improve or modify failures of others.
He may never have had the opportunity to compound a two cylinder simple.

 

None of which were compounds which was the discussion

 

Not true. The 160P, 141Ps and 241Ps were new locomotives, for starters.

 

The moving parts of a LP side must be almost the same mass as HP.
Piston is bigger but handles lower pressure and temperature

 

So it isn't the same mass. The temperature and pressure might be lower but the pressure is acting on a larger piston area, so the piston thrust, if the designer has proportioned the cylinders properly, should be about the same. There isn't therefore room the reduce the mass of other reciprocating parts to compensate: piston rod, crosshead or connecting rod.

 

160 P started life as 150 built 1910
141P s were improved 141Cs from PLM
and 241P was rewamped PLM 241 Cs.
Big, ugly brutes that made not enough horses according to Chapelon

 

I really feel like this discussion is trying to argue black is white, but I think it summarises to this:

1. Compounding in the UK context never made any business sense at the time.

2. You could build a 2 cylinder compound engine, but it comes with significant technical difficulties in achieving balance under all operating conditions between the two sides. At high speed the different masses would need additional balancing that would not be easy to achieve, and no one ever bothered because a) if you must compound then a multi cylinder engine is easier to design and b) see point 1. No one wanted the solution, because there wasn’t a problem that the solution could solve.

 

On the second point, it is not quite true to say no one bothered with two cylinder compounds. T.W. Wordsell built 11 such locos for the GER (most of which came out after he left that railway) and then a relatively significant number of various designs - both passenger and freight - for the NER. During the 1888 "race to the north", one of those compounds set what was then the fastest time recorded between Newcastle and Edinburgh, 124 miles in 126 minutes, so they were clearly capable machines.

There are a couple of notable points. On the GER machines, it was said that they had a significant (14%) coal advantage relative to the 2-4-0 "simple" designs that they were derived from. However, that came at the expense of increased boiler maintenance costs due to higher working pressure; when the boiler pressure was reduced to the same as the 2-4-0s, the efficiency advantage of the compound disappeared.

Of the NER machines, they were clearly successful in their own right. However, when Thomas Wordsell was replaced as C.M.E. by his brother Wilson, the younger Wordsell chose not to continue with the two cylinder compounds, and very largely reverted to simple expansion locos, along with some more symmetrical 3-cylinder designs that were in effect the reverse of the Webb System: one high pressure cylinder feeding two low pressure cylinders of the same size.

Apart from those, I don't think there were any other Wordsell-Von Borries 2 cylinder compounds used in the UK, except one-offs such as the LSWR example, built as a trial but which didn't lead to a production series.

All of which I think confirms the wider point, which is that the 2 cylinder compound was a technological blind alley. Within a fairly short period from the Wordsell work at the end of the nineteenth century, engineers worked out a reliable means of superheating and that led to the sorts of efficiency gains that had been hoped to be achieved from compounding, but without the technical complexity or challenges such as starting. Indeed, the story of large locomotive development in the UK from about 1900 through to 1950 is at least in part a gradual shift in boiler layout such that ever more amounts of the energy from combustion is put into superheating rather than evaporation; in other words, you use a given amount of energy from the coal to get a smaller amount of steam hotter, rather than produce larger amounts of steam. That ultimately led to better total efficiency, but was reliant on developments in lubricating oils to withstand higher temperatures.

Tom

 

In 19810/81 I forget when I managed what was then a rare trip on the SS Shieldhall when she was working out of Southampton for Southern Water

She has 2x180psi scotch boilers providing steam to 2x800hp triple expansion engines

The Chief Engineer told me that she had been fitted with a superheater but when they took it out they burned about one ton of fuel a day more BUT they saved an equivalent amount of money as they didnt have to lubricate the cylinders AND get the oil out of the feed water afterwards

So the ship was now less fuel efficient but didnt cost any more to run

 

I think 2 cylinder compound traction engines were fairly common. Also, don't forget "Aerolite" in the NRM, but this was an outlier.

 

It should be 160A not P. The 141Ps and 241Ps were new designs. Chapelon rescued the 241P after requests from Creusot but the frames had already been cut and were too thin which lead to hot axle boxes throughout the life of the locos.

 

Cross-compounds were also tried in the USA in the late 19th century. Speed was limited to 15 to 20mph with acceptable riding qualities and excellent economy.