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

[martyn]

I'd have to go through my RCTS books, but as injectors were generally designed to operate with cold feedwater from the tanks, some classes of locos which condensed steam back into the tanks, usually because of working through tunnels, had problems with the subsequent hot water feed.

To overcome this, I think that some classes used pumps in addition to injectors, and some types of injectors were later designed to be able  use hot water feed as well as cold.

And of course, hinted at by John, as well as designs by loco engineers, there were a number of 'patent' boiler feed designs which used pumps as the water was usually hot and was a form of fuel economy.

This includes such makes as ACFI (used on some but not all B12s, the first P2, and a couple of A3s amongst others on the LNER), DABEG, etc.

Martyn

[maridunian]

A Coarse Guide to the Steam Locomotive for 'N' Gauge Modellers - Part 13 - Supplemental

I don't know where I read it, and it was a very long time ago, but I'm sure that a piece I've seen said that the injector was originally designed (by Giffard) to refill boilers on a proposed airship!

But that could be a faulty memory......

]...]

Thank you, Martyn and that might well be the case.  M. Giffard built a steam-powered airship.  And... it flew (or so I understand)!

This was on my mind this afternoon at the West Wales Railway Modellers' Show, where their O Gauge Group displayed models of several other steam powered vehicles of that era.




I do hope you'll be able to cover some of these other 'ahead-of-their-time' developments in this excellent series John.

Mike

[Train Waiting]

A Coarse Guide to the Steam Locomotive for 'N' Gauge Modellers - Part 14


Hello Chums

You know how some people consider the Nineteenth Century to be a period of unbridled laissez-faire capitalism, free of government regulation?  Like so many perceptions, this is totally wrong and it is my contention that was the century during which something like the modern system of regulation evolved.  In this part we shall see that the consequences of an Act of Parliament of almost two centuries ago are still relevant today.

**

At this point, I think it would be handy for us to see inside a locomotive's firebox.  But that's a dashed tricky place for a coarse photographer, with well dodgy legs, like me, to take a picture.  But...wait a moment – I have a cunning plan.  I know a bloke in NSW who is a dab hand with a camera; I'll arrange for him to take the photograph for us.

[Brief pause for aeroplanes and suchlike... please talk amongst yourself.]

Sorry for the delay, it took longer for @Bealman , our photographer, to get from the 'Gong to York than I expected.  Maybe he was idling away the time in licensed premises, various, with pints of Broon. Here's the very nice picture:-





A BIG Engine this time.  Rebuilt 'Merchant Navy' 4-6-2 35029 Ellerman Lines at the National Railway Museum in York.  Helpfully, George got busy with a 'Junior' hacksaw before taking the photograph so we can see inside the locomotive's firebox.  And, if you are interested in this sort of thing, there is a lot to see.

Too much to describe in one postington.  So, we'll start with that strange pinky-brownish-red coloured thing crossing the firebox.  Sort of brick coloured?

That's not a surprise because it's called a brick arch and one of these can be found in the firebox of almost every standard gauge locomotive for railway service.  Industrial engines don't usually have them.  The reason it's there goes back to the Liverpool and Manchester Railway Act of 1826¹.  I assume our legislators had seen or heard tell of the 'steam dinosaurs' that were clanking their way across Northumberland and County Durham shrouded in clouds of acrid smoke.  Parliament included a provision in the 1826 Act which required any steam locomotives used on the railway to 'effectively consume their own smoke'.

This requirement was included in the rules for the Rainhill Trials of 1829.

The consequence of this can be imagined and the incomparable EL Ahrons (1866-1926) describes it much better than I can:

'Although coal [as a fuel] was not prohibited, the result of the Act was that from 1829 coke for many years became the universal fuel on main line railways other than the Stockton and Darlington and one or two other lines in the Durham area.'²

Coke was much more expensive than coal and locomotive engineers spent many years attempting to work out how to burn coal cleanly in an engine's firebox.  Some of the resulting contraptions were ingenious but all were impracticable to a greater or lesser extent.  Finally, the problem was solved by Charles Markham and Matthew Kirtley on the Midland Railway.  By 1860 they had arrived at the solution we know to this day - a brick arch built across the firebox and a sloping deflector plate placed above the firehole.  This caused air entering through the firehole ('secondary air' to enginemen) to be deflected on to the surface of the fire which improves combustion.

The brick arch and deflector plate were quickly adopted and the use of coke was almost completely phased out.  Incidentally, the Ravenglass & Eskdale Railway continued to use coke until 1980.  Coke burns hot and could cause distortion of the boiler tubes, leading to leaking tubes.  One afternoon, three out of the four engines in service that day failed with leaking tubes and the railway changed to coal firing.³

What we would now call environmental protection legislation, dating back to King George IV's time, has been an important factor in steam locomotive development and continues to be so.

We'll continue looking inside the firebox in the next part.

By the way, the near contemporaneous invention of the injector and solution to the problem of coal firing represents something of a turning point.  Until 1860, most innovations regarding steam locomotives were made in the United Kingdom.  After 1860, innovations tended to be from abroad - not totally, of course, but to a large extent.  M. Giffard, whom we met earlier, with his injector is the start of a trend.  I expect we might hear soon about two famous Belgians. 


¹ Liverpool and Manchester Railway Act 1826 (7 Geo. IV. c. xlix) of 5 May 1826.

² Ahrons EL, The British Steam Locomotive from 1825 to 1925, Locomotive Publishing Company, London, 1927, p130.

³ Railway World, Vol 45, No. 531, July 1984, p370.

Special thanks to George for the picture.


'N' Gauge is Such Fun!

Many thanks for looking and all best wishes.

Pip-pip

John

[Bealman]

You're most welcome. An excellent education, yet again. Interesting to see Durham and Northumberland being the rebels! 

[martyn]

From memory, I think that Beattie on the LSWR invented a fire box with two furnaces, with the idea that the second, higher up, fire would 'consume' the smoke.

But again, I could be wrong, and have no idea where I read this.

Martyn

[crewearpley40]

Martyn

Hi some history
@martyn


I noticed this

https://www.brc-stockbook.co.uk/beattie.htm

https://preservedbritishsteamlocomotives.com/30585-lswr-314-lswr-0314-sr-e0314-sr-3314-br-30585/


Was it the well tank?

I was looking at something else but it caught my attention

Thanks John for your history lessons

[Train Waiting]

From memory, I think that Beattie on the LSWR invented a fire box with two furnaces, with the idea that the second, higher up, fire would 'consume' the smoke.

But again, I could be wrong, and have no idea where I read this.

Martyn

Thank you, Martyn; you are absolutely correct.

Attempts to burn coal using some type of double firebox arrangement commenced, I believe, with John Dewrance's locomotive Condor for the Liverpool and Manchester Railway in 1845. 

James Cudworth on the South Eastern Railway used a similar approach from 1857 and some of his engines with this feature were in service as late as 1891.

From 1853, Joseph Beattie on the London & South Western Railway featuring some type of double firebox and a variety of other gadgets, including hollow stay bolts.  One can only wonder what the railway's boilersmiths thought of such exotica.  Mr Beattie was certainly an innovative engineer.  He became unwell and died in 1871 being succeeded by his son, William Beattie, who persevered with double fireboxes until 1877*.

Unfortunately, William Beattie was not successful and, following the many troubles associated with his 20 outside-cylinder 4-4-0 locomotives of 1876/77, resigned his appointment on the grounds of ill health.  William Adams succeeded William Beattie and mechanical orthodoxy came to the L&SWR's locomotive department.


*Beattie engines also had feedwater heaters and pumps.

With all good wishes.

John

[Train Waiting]

A Coarse Guide to the Steam Locomotive for 'N' Gauge Modellers - Part 15


Hello Chums

We left Part 14 with a look inside a locomotive's firebox and a discussion about how the addition of a brick arch and a deflector plate allowed coal to replace coke as the normal fuel - at least in Great Britain.

We also established that the external firebox seen on Rocket was soon replaced by an internal, or inner, firebox contained within the boiler.  It is convenient to think of the firebox as a ... box.  A roughly cube-shaped box, normally (in British practice) made of copper and surrounded on five sides by water in the boiler.

The sixth side, the bottom of the box, is open with a grate arrangement using firebars to support the fire.  Firebars are important as they allow the all-important air to flow through the grate to permit the fire to burn.  Enginemen call this 'primary air'.  The firebars also allow ash from the burnt coal to drop through the grate into the ashpan.  Without this feature, the fire would clog with ash and the locomotive would run short of steam.  Without a grate with firebars, there would be no steam-worked 'Non-Stop' between KX and the Waverley (at least not coal-fired) and we would be deprived of this cinematic paragon of post-War British culture. "Bath buns for blonde belles" indeed.



https://www.youtube.com/watch?v=ghkqGfUy4xs


Over time, the grate arrangement became more sophisticated with rocking firebars to clear clinker and a way of moving the grate to allow the fire to be dropped into the ashpan and raked out during disposal on shed.  On older engines, the remains of fire was cleaned out ('baled out' or 'paddled out' are other terms I've heard) with a long shovel through the firehole or the firedropper removed a couple of firebars with a sort of long tongs and pushed the fire through the gap and into the ashpan*.

   


This crop of George's helpful photograph shows the grate of a 'Merchant Navy' 4-6-2 with the
ashpan below.


And here is an example of a firebar, in this instance from an LMS '5MT' 4-6-0:





Do you have a locomotive's firebar in your garden as well?


* MF Higson in London Midland Fireman, Ian Allan, London, 1972 SBN 7110 0321 1, has a fascinating discourse on fire cleaning, including the difficulties of removing firebars.  It's on page 45 et seq.


'N' Gauge is Such Fun!

Many thanks for looking and all best wishes.

Toodle-oo

John

[Ali Smith]

Fascinating stuff as always, but the commentary on the film falls a long way short of "Night Mail". No wonder W. H. Auden is more famous than Paul le Saux.

[Train Waiting]

A Coarse Guide to the Steam Locomotive for 'N' Gauge Modellers - Part 16


Hello Chums

We have seen how a typical steam locomotive, from Robert Stephenson's Northumbrian of 1830 until the present day, has an inner firebox, usually made of copper, and an outer firebox as part of the boiler shell, made of iron and, later, steel.  There is  water surrounding the inner firebox apart from at the firegrate at the bottom. We might look at some of the figures later, but a combination of temperature and pressure means that it is vital for the strength, and safety, of the boiler that the inner and outer fireboxes are firmly secured to each other.  Maintaining this condition is an essential for the safe working of a steam locomotive.¹

This has been done since Rocket's time by the use of stays.  These are metal rods, threaded at each end and screwed into threaded holes drilled and tapped in the inner and outer fireboxes.  The stays are placed at around 3-4 inch pitch and, after screwing in place, the ends are beaded over like rivets creating this appearance:





A typical standard gauge locomotive's boiler will probably have over 1,000 stays.  A large boiler, like that used on the BR 'Britannia' 4-6-2 engines, has about 2,500 stays.

The narrowest water spaces around the inner firebox, at the sides and by the backplate in which the firehole is placed, are around four inches wide. Not that big when one thinks about it. Firebox side stays were traditionally made of copper with 'monel metal' (put simply, a nickel-copper alloy) being much used in later years.² 

At the bottom, the inner and outer fireboxes are separated by a large forging called the foundation ring.  It's not really a ring - more of a square or rectangle with rounded corners.  The foundation ring and the firebox sides have holes through which rivets are hammered home to secure the parts together.  The foundation ring also has bearers for the firegrate and attachments for the ashpan.

Once again, George's picture is of enormous help.  The 'Merchant Navy' class has a sophisticated firebox shape and the inner firebox, unusually for British practice, was made of steel.  But the fundamentals are the same as I have described.  The outer and inner fireboxes, and the side stays, can be seen.





¹  The integrity of the firebox stays is essential for the safe operation of a steam locomotive.  As you know, I enjoy quoting the late LTC Rolt and this, from Railway Adventure is pertinate:

'[...] despite her appalling condition, Talyllyn had to be steamed and sent out to her [Dolgoch's] rescue.  This successful salvage operation was destined to be the last duty performed by Talyllyn, and those who have subsequently viewed the ominous bulge in the side of her firebox which betokens broken stays, or investigated a smoke-box tube plate which consists of more scale than plate, are of the unanimous opinion that he was a brave man who steamed and drove her on this last journey.'

LTC Rolt, Railway Adventure, Country Book Club, London, 1962. p38.


² The suitability of copper as a strong, but slightly elastic, material for side stays did not prevent locomotive engineers from experimenting.  Mr HA Hoy of the Lancashire & Yorkshire Railway devised his own copper/zinc/iron alloy and claimed it was stronger and 'perhaps' more elastic than copper.  It actually had very little elasticity leading to problems with cracked and broken side stays and, eventually, 0-8-0 No. 676's spectacular boiler explosion near Knottingley on 11 March 1901*.  Both enginemen were killed instantly.  Live steam is a hazardous thing. 


* For further details on the Knottingley boiler explosion and much else, I recommend the late CH Hewison's Locomotive Boiler Explosions, David & Charles, Newton Abbot, 1983 ISBN 0-7153-8305-1.  This is an invaluable book and I'm sure I'll refer to it again.  No. 676's explosion is on page 110 et seq.


'N' Gauge is Such Fun!

Many thanks for looking and all best wishes.

Cheerio

John

[Papyrus]

Fascinating stuff as always, John. I hadn't come across the 'Elizabethan Express' video before, but that was excellent. Superb shots of Silver Fox from another train alongside! And wasn't everybody thin in 1954! We all ate less and got around on our own two feet.

Many thanks!

Cheers,

Chris

[Train Waiting]

A Coarse Guide to the Steam Locomotive for 'N' Gauge Modellers - Part 17


Hello Chums

Let's show off.  You know that old thing about no-one knowing two famous (non-fictional) Belgians?  We steam enthusiasts do and we are about to meet one of them.

We were discussing firebox stays and, conveniently, the side stays are pretty much horizontal as the inner and outer firebox sides and backplate are reasonably parallel.  The top of the inner firebox  is, as the name suggests, like the top of a cube.  But, for the first sixty years of the Stephensonian locomotive in Great Britain, the outer firebox was rounded.  Like this:





As you can imagine, staying the flat-top of the inner firebox (locomotive people call this the 'crown sheet') to the curvaceous outer firebox required some ingenuity.¹

Which leads us to M. Alfred Jules Belpaire, Chief Mechanical Engineer of the Belgian State Railway.  Although Belgium had a mining industry - as the BEF clearly saw in August 1914 - much of the coal was of poor quality and, from 1860, M Belpaire worked to produce a long firebox which could make the most efficient use of poor fuel.  By 1864 he had developed his flat-top Belpaire firebox which enabled the use of simple vertical stays for the crown sheet.

The first boilers with a Belpaire firebox constructed in Great Britain were made in 1872 by Beyer, Peacock and Co. for some 2-4-0 locomotives the firm built for use in Belgium.  Which makes us wonder which was the first British railway to introduce the 'New Look' as a consequence of the use of a Belpaire firebox.  Any ideas?




The New Look is personified by  Midland-built '2P' No. 40 for the Somerset & Dorset Joint Railway and the traditional outline is seen on Southern, former London & South Western Railway, 'T9' No. 301.  Templecombe on the Micro Layout? 

**
 

There was an early application of a flat-topped outer firebox on 0-6-0 locomotives introduced in 1866 by William Bouch on the Stockton & Darlington Section of the North Eastern Railway.  This firebox used direct vertical crown sheet stays, made of iron. Mr Bouch's firebox differed from the Belpaire type in that the flat-top of the outer firebox was lower than the top of the boiler barrel.  This type of firebox was not adopted elsewhere.

In Great Britain, the true Belpaire firebox had to wait until 1891 when it was adopted by Thomas Parker on the Manchester, Sheffield and Lincolnshire Railway for his '9F' 0-6-2T locomotives, later LNER class 'N5'.² Mr Ahrons suggested one of the railway's draughtsmen had previously been with Beyer, Peacock and Co.³

Sir John Aspinall on the Lancashire & Yorkshire Railway and William Dean on the Great Western Railway adopted the Belpaire firebox in 1897 and many other railways followed. But not all as we'll see in the next postington in this series.


¹ Normally by using what are called girder stays - eight or so longitudinal girders running, about four inches apart, across the top of the inner firebox crown sheet and secured to the outer firebox by drop links.  Later on, direct stays were used, those in the centre being of a considerable length.  We'll return to this.

² Mr Parker built three prototype engines with the Belpaire firebox, Nos. 7,47 and 171.  The MS&L classified these '9C', with the production locomotives being '9F'.  After the Grouping, they all became LNER Class 'N5'.

³ EL Ahrons, The British Steam Railway Locomotive 1825-1925, Locomotive Publishing Company, London, 1927 p.310


'N' Gauge is Such Fun!

Many thanks for looking and all best wishes.

Toddle-oo

John

[Moonglum]

Excellent John, I have always taken the term "Belpaire! for granted or as read without actually realising or understanding what it is.

All the very best,

Tim

[grumbeast]

Another excellent installment John. The Pennsy in the US used Belpaire fireboxes too, I think because some of their coal was poor (though I am unsure of this as they had a lot of Anthracite in Pennslyvania). When I first saw pictures of the famous K4s I immediately saw the similarity to the firebox from the GWR locos I was used to.

[martyn]

@grumbeast

I believe the Pennsy K4 boiler  (and the whole design?) was used as inspiration for the first Gresley A1 boilers, using similar dimensions but within the UK loading gauge.

But, noticeably, the A1s retained a round top firebox, not Belpaire.

Source-"Nigel Gresley-locomotive engineer" by F.A.S. Brown.

Martyn