A Coarse Guide to the Steam Locomotive for ‘N’ Gauge Modellers

[Nbodger]

Sorry old chap, but that is an English Electric Type 1, later under TOPS designated Class 20, but its quite rightly still a smelly diesel.

A rarity having to correct your post old chap, but understandable as it's not steamy but smelly

[Newportnobby]

Sorry old chap, but that is an English Electric Type 1, later under TOPS designated Class 20

Often nicknamed 'The Wardrobe' owing to the many doors along its length

[martyn]

Two more examples of the English Electric method of designating their engine can be found in the Brush type 2/cl31 and EE type 3/cl37.

I'm pretty sure it was the same basic engine block and cylinders, but the Cl 31 had a 12SVT rated at 1470 hp, and the cl37 a 12CSVT rated at 1750hp.

Because the electrical system of the cl31 could not handle the extra horsepower available in the 12CSVT, the intercooling, being an additional cost and maintenance requirement, was not fitted. The Brush type 2s were initially fitted with Mirrlees engines, (and were, technically, for the pedantic, class 30), but this engine was not found suitable for traction use on BR.

Yet another siding I've taken the thread down...

Martyn

[Train Waiting]

Sorry old chap, but that is an English Electric Type 1, later under TOPS designated Class 20, but its quite rightly still a smelly diesel.

A rarity having to correct your post old chap, but understandable as it's not steamy but smelly

Many thanks for this helpful correction, Mike.  The diesel fumes obviously interfered with the functioning of my brain cell.  Hopefully, it will have recovered before the next steamy affair about feed water heaters, steam domes and a 'helter-skelter lighthouse'.

Thanks again and all best wishes.

John

[crewearpley40]

Thank you for the information on the Class 20. Rather helpful and like other spotters back in the day and indeed Railwaymen referred to them as Type 1s, Choppers or Wardrobes

[Train Waiting]

A Coarse Guide to the Steam Locomotive for 'N' Gauge Modellers - Part 31


Hello Chums

Thank you for putting up with the idiosyncratic Part 30, which was concerned with road vehicles and, oh my giddy aunt, SuperSmelly diesel locomotives.  Hopefully, the reason for the postington will become apparent as we continue the series.

Back, thankfully, to steam locomotives and their boilers.

Once the steam has been generated in the boiler, it needs to be collected somewhere or other in order that it can begin its journey to the cylinders and, eventually, the atmosphere.  From the early days of the steam locomotive, it became obvious that a hot water engine wasn't a good idea and that water carried over with the steam could cause a lot of damage.  We might look into this matter later.  The steam dome was an effective answer.  It involved a hole on the top of the boiler barrel with what looked like an upside-down bucket rivetted over it.  This gave the steam a place to rise well above the water level in the boiler.  An open-ended pipe in the dome took the steam away to do its work.





As can be seen from the picturingham, the 'upside-down bucket' looks too functional for British eyes, so many and various were the dome-shaped coverings that designers placed over it for aesthetic reasons.  Some early ones were fluted like something from ancient Athens.  Later on, a simpler dome shape was preferred, sometimes made of brass and highly-polished.  Small boilers allowed these domes to be most impressive features, once described by my late friend Iain Rice as 'mammalian'.  William Dean's locomotives for the Great Western were especially impressive in this regard.




['Mammalian, indeed.  A 'Dean Goods' 0-6-0 with the large and shapely dome favoured by Mr Dean.]


However, there was no absolute consensus and whilst we all probably remember the Tri-ang GWR 'Dean Single' with its large shiny dome, we are also likely to be familiar with Patrick Stirling's famous singles for the Great Northern which had domeless boilers.  These could be seen on other engineers' locomotives, especially those of the 'Stirling School' of James Stirling, Matthew Stirling and Hugh Smellie.  In domeless boilers, steam is collected in a perforated pipe set high in the boiler.

Interestingly, Patrick Stirling's earliest engines for the Glasgow & South Western Railway (G&SWR) had domes - he introduced domeless boilers with his '40' class 2-2-2 of 1860.




[A 'Stirling Single' but not as we normally think of it.  This is No. 96, one of Mr Stirling's '95' class 2-2-2s of 1854.  Six foot driving wheels. She was withdrawn from capital stock by 1874.  The photograph was taken later in her life, after she had been fitted with an injector and a replacement chimney. I think she looks splendid and the chaps are clearly proud of their charge.  The photograph is from the late JF McEwan's collection.]


Patrick Stirling left the G&SWR in 1866 to join the Great Northern and was succeeded by his younger brother James, who remained in post until 1878 when he went to the South Eastern Railway.  He was succeeded by Hugh Smellie, of the Maryport & Carlisle Railway, who was, in turn succeeded by James Manson, from the Great North of Scotland Railway, in 1890.  Mr Manson's locomotive were fitted with large and shapely steam domes, ending the domeless tradition on the G&SWR.

Later in the 1890s, the orderly transition from Mr Dean to George Jackson Churchward commenced on the Great Western.  Swindon went in the opposite direction to Kilmarnock, as Mr Churchward favoured domeless boilers.  The Great Western continued with boilers of this type, although not exclusively, for the remainder of its existence and these continued to be built well into BR days.  Former Great Western engineers later took the Swindon style of domeless boiler to the South Eastern & Chatham Railway, Southern and LMS.




[A typical domeless boiler in the Churchwardian style, in this case a Standard No. 10, fitted to one of Mr Collet's '2251' class 0-6-0s, No. 2284.]


For some of its smaller locomotives, the designs of which were often based on old engines, the GWR continued with the domed boiler.  '74xx' class 0-6-0PT No. 7400, seen in the picturingham, was built in 1936, but the basic design was over a quarter-of-a-century old.  After nationalisation, BR built more of this class, with the final examples appearing in 1950.





'N' Gauge is Such Fun!

Many thanks for looking and all best wishes.

Pip-pip

John

[Train Waiting]

A Coarse Guide to the Steam Locomotive for 'N' Gauge Modellers - Part 32


Hello Chums

We have already mentioned feed pumps and injectors, both are ways of getting water into the boiler to replace that which becomes steam and ends up in the atmosphere, one way or another.  After its invention by M. Giffard, the injector pretty much replaced the feed pump as a means of putting water in the boiler .  But not completely as, from time to time, locomotive engineers sought to obtain economies by pre-heating the water going into the boiler.  Injectors don't like warm water so feed pumps were normally used with pre-heated water.

FH Trevithick's experiments, from 1901, on the Egyptian State Railways led to an interest in feed water heating as steam locomotive engineers were keen to improve efficiency.  Using the exhaust steam to pre-heat the feedwater for the boiler appeared a good way to get something for nothing.  Except, it wasn't for nothing - the initial cost and continuing maintenance costs of the apparatus had to be taken into account. 

Although some railways around the world persisted with pre-heaters, British engineers eventually abandoned them.  Several serious attempts were made over the years, especially on the LNER with over 50 'B12' 4-6-0 so equipped, culminating in the monumental waste of money that were the 10 Franco-Crosti '9F' 2-10-0s built by BR in 1955.  The costs associated with the apparatus outweighed the benefits in British service.  And, in the case of the '9F's, the footplate conditions were atrocious due to the proximity of the chimney which was placed fairly close to the cab, on the fireman's side.  Unlike earlier efforts with feedwater heaters which were normally on top of the boiler, the Franco-Crosti pre-heater drum was placed below the boiler.

On the LNER, it was found that the feedwater heaters fitted to 'B12' locomotives were susceptible to scaling in hard water areas ('furry kettle' syndrome again).  Those allocated to the former Great North of Scotland area benefitted from generally softer water and were less troublesome.  In any event, the savings were outweighed by the additional maintenance and the feedwater heaters were removed.

I am fortunate that, thanks to a reference given by the late David L Smith¹, I can give an idea of the savings obtained by feedwater heating.  In 1911, James Manson designed two 4-6-0s which were built by the North British Locomotive Co, Nos. 128 and 129.  The locomotives were identical, except that No. 129 was equipped with  Weir feedwater heating apparatus.





Both engines performed well in service, No. 129 especially so.  In the autumn of 1911, Mr Manson conducted a comparative trial between the two locomotives.  Both ran 231 miles with a train weighing 242 tons tare.  The results were:
        Coal (Tons/cwt)  Water (gallons)
128    4 12            7,350
129    4 11            7,100  using infectors only
129    4 3              7,200  using feedwater heater only.

As with all steam locomotive tests, the results need to be interpretated with caution, as it has been said the easiest way to improve an engine's performance is to paint the chimney white.  Enginemen, thinking their work is being observed, will tend to perform better.

The improvement in economy was clearly not considered sufficient to pay for the apparatus which was removed in 1919.

I think it is fair to say, rather like the supercharging we discussed in Part 30, the costs associated with feedwater heating outweighed the benefits in day-to-day use.

Therefore, let's assume the locomotive boiler is fed by injectors and the feedwater enters the boiler through a non-return clack valve.  Usual practice became for these to be at the side of the boiler, towards the front, as can be seen in this couple of picturinghams:






[A very neat clack valve arrangement on the 'T9' 4-4-0.  Rather less so on Clan Line.  The clack valves and associated pipework are very obvious features of rebuilt Bulleid 'Pacifics'.  In their original condition this was hidden beneath the air-smoothed casing.]


An alternative is to place the clack valves on top of the boiler. This is called 'top feed' and had been developed in the nineteenth century, firstly in G Spencer's British patent of 1863 and then a similar arrangement was used by Herr Wagner in Germany and M. Chapsal in France.

It had been ignored in Britain until Mr Churchward, on the GWR, incorporated the clack valves beside the safety valves about a quarter of the way down the boiler.  Mr Maunsell copied this arrangement for many of his engines on the South Eastern & Chatham Railway and, later, Southern, making the top feed look rather like a conventional steam dome.  This was referred to by some wags as the 'helter-skelter lighthouse' and can be seen in this 'N' class 2-6-0:





The LMS eventually adopted top feed. In Mr (later, Sir William) Stanier's time, this was towards the firebox end of the boiler.  Mr Ivatt later moved the top feed closer to the smokebox - a very distinctive feature of the later 'Black Five' 4-6-0s.  This arrangement injected the cold feedwater into the least hot part of the boiler.

¹ David L Smith, Locomotives of the Glasgow & South Western Railway, David & Charles, Newton Abbot, 1976, ISBN 0 7153 6960 1.  Mr Smith found the results of the trials in the Proceedings of the Institution of Mechanical Engineers, March-April 1913.


'N' Gauge is Such Fun!

Many thanks for looking and all best wishes.

Tickety-tonk

John

[martyn]

Many thanks again, John.

There were other, generally patented, feed water systems where the water from the tank was heated before entering the boiler. The LNER, or its predecessors, used a number of designs.

One such was DABEG; here is a description as fitted to an LMS loco;

https://www.facebook.com/story.php/?story_fbid=161463953637888&id=100093228513789&_rdr

Another, and I think similar one (I can't find details) was the Worthington-Simpson design.

I would need to go through each class in my RCTS LNER history books, but I'm sure there may  have been a very simple idea trialled on the GNR, where steam was taken from the exhaust into a heat exchanger below the tender, from which the warmed feed was pumped in; the now condensed waste was discharged below the tender on to the track.

Amongst other LNER classes fitted with ACFI feed water heaters were A1 2576 and A3 2580 and P1 2001 and at least one C7; and Worthington gear to five O1s (Gresley version). I think that some LNER locos had the DABEG type, but without going through each class, I'm not sure which ones.

Eventually, exhaust steam injectors were designed which did much the same job, but without the complication of moving parts, and much simpler to build and maintain.

The ACFI feeds on the B12s were removed from 1937 onward, and either Gresley at that time, or Thompson soon after taking charge, ordered that all such feed water systems were blanked off and then removed.

As has been said, it was found that under average British conditions, the initial cost and then maintenance costs and time meant that economies in coal and water consumption led to the in-service savings being outweighed.

If I find any more examples I'll add them later.

Martyn

[martyn]

Two more feed water heater types I've found;

The Weir system which sems to have functioned much the same as those previously mentioned, with a pump feeding heated water to the boiler; and a name for the 'simple' heater exchanger under the tank, the Willans system. The latter, as well as the heat exchanger, then used a pump ( coincidentally made by Worthington) to pump the water through fire tubes in the boiler, rather like superheater tubes (of which more anon from John) before entering the boiler. One of each of these systems were used (individually) on two locos of GNR/LNER classes Q1 or Q2.

Another problem with these systems was the need for continuous adjustment by the firemen to compensate for the load and hence steam rate of useage. They worked best on long runs where steam demand was reasonably constant, but on short or stop start running, took up a lot of the fireman's time.

Martyn

[grumbeast]

While I am significantly outside my comfort zone with regards to injectors and feedwater heaters I believe I can say that it was common practice in the US and Canada for feedwater heaters to be used.  There are lots of references in my books to Worthington, Elesco and Coffin type heaters but I would need to do some research to determine their differences and operations (difficult right now as I'm in France!!, and in a couple of weeks I will fulfill a dream and visit le Citi du Train in Mulhouse!)

Anyway, The Elesco type can be seen as a large cylindrical device mounted above the smokebox ahead of the stack

Not sure why it became very common here, especially in later steam locomotive development when they didn't seem to catch on so much in the UK?

[martyn]

That could back up my post that, in British conditions, with relatively short runs and stop/start journeys, that it took up too much time of the fireman, and they didn't get a chance to operate at full potential. Plus the maintenance and cost/benefit analysis (if that was what it was called in the 30s!).

With regards to the systems I've mentioned, these seem to be main differences;

DABEG was driven by valve gear motion.
Weir was a single cylinder single acting steam pump
Worthington was a duplex pump.

Martyn

 

[martyn]

A longish quote from the RCTS green bible concerning ACFI and the LNER P2 #2001 ''male chicken ' (changed by forum) of the North';

'The equipment was a constant source of trouble. To function properly it required the regulator to be open continuously which was not possible on the Aberdeen-Edinburgh main line....One of the engine's regular firemen....could only recall one trip when the ACFI worked perfectly, and that was a [non stop?-not stated} Newcastle to Edinburgh working when...working home from repair at Doncaster'.

End quote.

Martyn

[Train Waiting]

Thank you @grumbeast and @martyn .

Yes indeed, pre-heaters became fairly common in US locomotives.  Martyn has hit the feedwater pump on the head with his replies.  A bit like superheating (which we'll come to when I finally manage to write the postington) only much more so, feedwater heating is only effective when the locomotive is working.

Mr (later, Sir Nigel) Gresley fitted it to the first of his fabulous 'P2' class, which was intended to work between Edinburgh and Aberdeen.  If you are familiar with this route, you will know that it is a curve-fest and has a series of up-and-then-down gradients.  All this requires expert enginemanship and lots 'N' lots of opening and closing of the regulator.

One thing that there is plenty of between Edinburgh and Dundee is coal and, although everyone complained about the price of it in the 'twenties and 'thirties (including the miners in a different context), it was still relatively cheap.  The five other members of the class were not so fitted and it was removed from 'C-o-c-k O' the North'. (To get round the forum censor)

My personal view is that, if any LNER locomotives would benefit from pre-heating, it would have been the 'Pacifics' used on the 'Non-Stop' where the coal saving would have been useful and there were parts of the route which required a continuous steady output from the engine - York to Darlington being the prime example.

In the US, with long distances, many of which required continuous work from the engine, the economies obtained could easily exceed the cost of fitting and maintaining the apparatus.  In parts of the US, especially in the west, maintaining coal and water supplies was hard work and  steam locomotive engineers built some very technically refined locomotives.  Some of the best work done by steam traction in the World was on the AT&SF.

We'll return to the cost/benefit theme in later postingtons.

And, Graham, I hope you have a splendid time in France.

With all good wishes.

John

[Train Waiting]

I'm so sorry, chums.

That 'male chicken' nonsense didn't appear when I 'previewed' my reply.

What a shame that No. 2001's name has been changed by our FabulousForum.

My apologies again.

John

[Bealman]

Sorry, I had nowt to do with it!

Why did Christine Keeler move to the North East?

To meet the male chicken of the North 

Sorry, back to this magnificent thread.