With a collection of locomotives dating from Victorian times to the 1960s, there's plenty to discover.
It's been a while since I did a back to basics type blog where we explain some of the fundamentals of steam locomotive engineering. So, with that in mind, let's take a look at why steam engines are the shape they are. Steam locomotives come in all sorts of different sizes and shapes. The size and shape depends upon a whole heap of different constraints. The smallest engine in the collection is No. 5 Shannon at just 15 tons. The largest is No. 6023 King Edward II at a little under 140 tons. Why the huge disparity?
The smallest, Wantage Tramway No 5 Shannon and 2, The largest, No 6023 King Edward II
The first thing to say is that we need to look at the railway that the locomotive is to run on. Taking the two examples, the King has ten wheels on the locomotive and 6 wheels on the tender to spread that 140 tons on the track. That means that each of the driving wheel pairs is pushing down with 22½ tons. On Shannon, there are only 2 wheel sets but each of those is pushing down with just 7½ tons. The King is therefore restricted to lines where the bridges, track and other structures are designed to take that kind of weight. Shannon is lighter than some of coaches we have in the collection(!) so, she could traverse even the lightest of railway structures.*
Six driving wheels, No 5900 Hinderton Hall
You can change the downward force that a locomotive applies to the track. If you look at the Halls, the Saint and the 28XX class, you will see that they are about the same size. However, No. 3822 is able to travel on much lighter laid track than the other machines. Although the engines all have ten wheels, No. 3822 spreads its weight over a wider area as it is a 2-8-0. The 4-6-0s don't do this as well. The more driving wheels you have, the better the spread of weight is. There are the same number of axles but each axle carries more weight, thus it being lighter on the track overall. The distance between the first and last driving wheel is called the coupled wheelbase. The shorter this distance is, the tighter the curve it can go around. Also a good clue to the type of railway an engine is supposed to run on.
Eight driving wheels, No 3822
Let's take a look at those wheels too. They come in a vast range of sizes. The smallest in our 1932 running shed belong, again, to Shannon at just 2’ 11” diameter whereas the largest are on the Castles and Saint** at 6’ 8½” diameter. The Halls have wheels that are 6’ in diameter and the 28XX class and 72XX class have 4’ 7½” diameter wheels. So, what's that about? Well, think of wheel size as extra gearing. If you have a small wheel, mark the point where it touched the rail on it, roll it through one revolution and measure the distance it has travelled, you will find it is quite small. This is because the circumference is small. Do the same thing with a larger wheel and it goes further in one revolution. The larger the wheel the further it goes in one revolution. If you can get a large wheel moving, then you can go quite quick!
Mixed traffic at work, No 4958 Priory Hall with a down fast goods climbing the 1 in 36 portion of Dainton Bank, Devon. Photograph by John Ashman FRPS
Great big driving wheels, No 4079 Pendennis Castle and No 2999 Lady of Legend share 6ft 8½in drivers
The trick however, is getting it moving. Larger wheels are bigger, heavier and take more effort to turn. A smaller wheel is far easier to get moving. The best illustration of this is the difference between No. 3822 and the Halls. From the running plate up, they are very similar.*** Broadly speaking, they have the same boiler, same boiler pressure, the same running gear, cylinders and so on. No. 3822 has a smaller 3,500 gallon tender but apart from that, much the same. The wheels are where the big change is. The Halls' 6’ wheels mean they can go reasonably quick, 80 - 90 mph, whereas No. 3822 will top out much sooner in the low to mid 40 mph range. But look at the power they can apply to a train. The Halls are at 27,285lbs tractive effort but No. 3822 can pull with 35,380lbs.
So, by the size of the wheels we can tell what a locomotive does for a living. No. 3822 has small wheels so it's not going fast but it can move a large load doing so. This is a heavy freight machine. The Halls with a 6’ wheel however can pull a variety of services including freight and passenger but with not as much power as No. 3822. These are therefore mixed traffic engines. The Castles have great big driving wheels so are designed for going fast. Express passenger trains are the job for them.
We can also tell a lot by the size of a locomotive. The bigger the boiler, the larger the reserve of steam. Therefore, the engine with a bigger boiler will be needing to put out large amounts of power for long periods of time. A good comparison here is the Large Prairies like No. 4144 with the Halls. Both did similar work - mixed traffic - but there is a marked difference in their size. Halls are required to go longer distances than No. 4144. They bigger boilers and therefore a bigger reserve of steam. No. 4144 can do very similar work with a smaller range and a smaller reserve of steam but is able to travel on a greater range of different routes as it isn't as heavy as the Halls.
Large Prairie, No 4144, good for shorter distance work
Small wheels and small boiler means you probably have smaller cylinders so less power but more route availability. The smaller branch lines will be open to these engines. A Small Prairie, 14XX class or a& Pannier Tank would be in this category. The Panniers also bridge the gap between lighter trains / branch line work and shunting. This is where the smallest engines like Shannon, Trojan, Bonnie Prince Charlie and No. 1338 worked.
The number of cylinders is a good indicator of purpose too. Most steam engines in the U.K. were two cylinder machines. This means that you don't get easily into a situation where the pistons are stuck at the ends of their travel, making starting difficult. You CAN do this with a two cylinder engine - it's just far more unlikely! It also reduces complexity. The disadvantage comes when you are going really fast.
Two large pistons thrusting backwards and forwards makes the front of the engine swing left to right. This is known as hunting but at slow speeds it feels like the engine is walking! No. 5322 is famous for its ability to walk off with a load. At high speed this is not good for crews and locomotives alike. To make power delivery smoother, we need to make the cylinders smaller. This makes the masses moving backwards and forward less. To keep the same high power outputs needed to maintain high speed, we add more cylinders. That is why the Castles and Kings have 4 cylinders. It's the same principle applied to a V8 internal combustion engine.
The final big distinction is where you put your coal and water. Larger engines need more coal and water - that much is obvious. However, there comes a limit where putting coal and water on the engine itself, as in tank engine designs, just isn't any longer practical. The limit for U.K. is somewhere about the size and shape of No. 7202. They had to make this one longer to get all the coal and water on board.**** This 90 ton monster is, with two sisters, the largest tank loco in preservation in Britain. If the boiler gets bigger than theirs, the coal and water are evicted - to live in a separate vehicle known as a tender.
The magnificent 72XX class 2-8-2T at work. No 7252 is hauling exchange traffic for the Southern Railway, crossing from relief to main line east of Reading General station prior to running on Southern metals. Photographed in October 1946 by John Ashman FRPS
There are advantages to being a tank engine however. Most of them are quite happy going either backwards or forwards. A tender locomotive has a limit to the speed it can attain in reverse. 45mph is often quoted. This is because if the tender is between the loco and the train, its running qualities are really good but pushed out ahead of the engine, not so much...
Well, that will help you understand the anatomy of steam engines everywhere. These points are fairly universal and will enable you to tell fairly accurately what a locomotive was born to do. Much like the Darwinian theory of biological evolution, steam locomotives followed a similar path. They started as tiny single cylinder machines and evolved into a bewildering variety of different types. They filled every conceivable niche. Sadly, like many types of fauna today, they are only now commonly found in steam zoos. The main railway environment now being the province of far more generalist diesels, electrics and multiple units. The rats and seagulls are doing well but the pandas? Not so much. The ‘biodiversity’ of the modern railway is sadly lacking in comparison to the steam era. I think there's an ecological message in there somewhere too...
*The G.W.R. used a coloured disc, painted on the cab side sheets that tells you what lines the engine can go down. Check out the July 2020 Blog ‘Decoding an Engine’ for more details.
**The ones on our broad gauge replicas Firefly and Iron Duke are bigger but I'll keep it to standard gauge today.
***By coincidence both Halls have 3 row superheaters, so are not quite as similar as the standard Hall would be but the comparison still stands.
****That sounds like a blog challenge. Hmmmm...
There are two more important locomotive trials that the G.W.R. were involved in during the steam age. The first trial for today is the one that took place after the G.W.R. / L.N.E.R. trials that our very own Pendennis Castle was involved in.
This was with the London, Midland & Scottish Railway (L.M.S.). Having observed the goings on between the L.N.E.R. and the G.W.R., they wanted their chance to see what the Castle could do up close. The L.M.S. comprised several railways, grouped in the early 1920s, one of which was the L.N.W.R. The very railway that had been host to the Star in the 1900s. The L.N.W.R. seemed to take on board very little from the experience but the then chief engineer of the L.M.S., Sir Henry Fowler, definitely was interested and ready to learn.
Shame the L.M.S. top brass wasn't...
They were still hidebound by the policies of one of their constituents, the Midland railway. They favoured a small engine policy - the exact same policy that had so troubled the L.N.W.R. The operating department of the railway was against such powerful 4 cylinder beasts and eschewed pacific type machines. Somehow, not now easily fathomed, the authorities were persuaded to allow a G.W.R. Castle to visit their line and it was the beginning of the end for small loco policies!
No 5000 Launceston Castle photographed in workshop grey when brand new in September 1926, with the larger 4,000 gallon tender.
The engine in question was No. 5000 Launceston Castle. She worked between London Euston and Crewe initially and then to Carlisle, during September and October 1926. The LMS's new service - The Royal Scot - was not going well in the hands of their existing fleet. No. 5000 just romped away with it, keeping to time and doing so in the customary efficient manner. This time, a dynamometer coach* was used and again showed that No. 5000 was producing all the power with less fuel consumed. The tests were not done in the same way as the previous ones were handled. For a start, there were sections of the road that required the engine to slow down as to not strike platforms with her wide cylinders. There was also a number of signal checks and so on that delayed the trains still further. There were also occasions where the gravity sanding that had so helped Pendennis Castle was a problem as on exposed sections of the line, the sand was being blown away by the wind before it could hit the rail.
Launceston Castle arriving at Euston during the 1926 exchange. This photograph was printed in The Railway Magazine.
Despite all these challenges, Launceston Castle, driven and fired by No. 4079's Young and Pierce, still covered itself in glory. The trains were dealt with efficiently. The loads, which steadily got heavier as the five week test progressed, were taken with ease and the ability for the Castle to recover time when made late was remarkable. This caused the L.M.S. to sit up and take notes. Their locomotive designs started to improve and were really solidified by the headhunting of William Stanier - the second in command at Swindon - to become their new Chief Mechanical Engineer. The L.M.S. did send a locomotive to the G.W.R. It was a Midland Compound 4-4-0. Let's just say that No. 1047 was put on work befitting its lower tractive effort and even so, it didn't do well...
Midland Compound No 1047 departing from Paddington with the 1.15pm train to Bristol Temple Meads. This photograph was printed in The Railway Magazine.
It would be twenty years, a Second World War and the nationalisation of the railways before another set of locomotive exchanges took place. Given the fact that the newly formed British Railways (B.R.) had amalgamated the design philosophies of 4 separate companies, all with their own needs and histories they wondered if it would be possible to set down a standard set of locomotives that could work over the entirety of the U.K. network. A very Churchward way of thinking perhaps?
City of Bradford at Paddington station during the 1948 exchange, photograph by Ben Brooksbank.
The idea came about therefore to exchange the locomotives of all the previous companies on as many different lines as possible to see just what this standard design might look like and what features have the best advantage to the locomotives. The first decision was to not help the G.W.R. machines. Unsurprisingly, B.R. decided to run all the tests with the locomotives burning the more common Yorkshire hard coal. The G.W.R. had always used a softer, more potent Welsh steam coal. Given that the other three had been making huge leaps forward in their locomotive technology, this wasn't going to be easy. There were different groups of engines tested against each other. In the passenger group was the G.W.R. King class 4-6-0s, the L.N.E.R. A4 class 4-6-2s, the S.R. Merchant Navy class 4-6-2s and the L.M.S. fielded both their Rebuilt Royal Scot class 4-6-0s and their Duchess class 4-6-2s. The mixed traffic types were represented by the S.R. West Country 4-6-2s, the L.M.S. Black Five 4-6-0s, the L.N.E.R. B1 class 4-6-0s and the G.W.R. Hall class 4-6-0s. Finally, the heavy freight selection was from the L.M.S. 8F class 2-8-0s, the L.N.E.R. O1 class 2-8-0s , the War Department 2-8-0 and 2-10-0 designs and the G.W.R. 28XX class 2-8-0s.
King Henry VI departing from King's Cross during the 1948 exchange, photograph by Ben Brooksbank.
The problem with the inclusion of the G.W.R. designs was that due to the extra space around the track caused by its broad gauge origins, their designs were very wide and there were several routes over which they could not travel. No. 6018 King Henry VI did perform on the L.N.E.R. but sadly it was unable to take part in many of the other tests as it just didn't fit. This was the same for the Halls and the 28XXs and this therefore made their inclusion in the trials somewhat difficult. The performance of the King on the L.N.E.R. was surprisingly not as good as most people expected. It seemed that her crew struggled with the hard coal where No. 4079 had excelled. There were other disappointments for other regions too.
King Henry VI on the Eastern Region during the 1948 exchange.
The A4s recorded no less than 3 separate failures. The Black Fives seemed to struggle on their home turf and all in all, the results showed what was probably blindingly obvious to all and sundry. For the lines the engines were built for, they were generally ideally suited! Those Duchesses designed by that nice Mr Stanier did rather well though...
Returning to Paddington with the 8.30am from Plymouth, Mallard failed at Savernake with a hot bearing. This photograph shows the locomotive at Savernake.
The majority of these trials are amazing examples of just how advanced Swindon technology had become under the leadership of Churchward. It did take the other railways a long time to catch up, but catch up they did as 1948 clearly showed. This often leads to the old chestnut that critics pull out about the so called ‘stagnation’ of locomotive design on the Western. It's true that development had slowed a great deal by WWII and beyond. What we as steam fans tend to forget is that this was a commercial organisation. They had designs that worked for them, were efficient using the fuel available to them and they did everything that was asked of them. They weren't trying to sell those designs to anyone else either. The engines were tools for doing a job on their railway.
By the end of the steam era, the double chimneys and higher degrees of superheating showed that there was still room for improvements in the designs too. I wonder how the running qualities of the Kings would have changed had they not been withdrawn before the programme to fit them with roller bearings had been applied. Looking at the work of such steam luminaries as André Chapelon and Livio Dante Porta, efforts such as streamlining the steam passages and so on could have helped still further. Sadly, the burning of coal became the burning of diesel and the Swindon steam age came to an end. Given all that, why on Earth would a company with shareholders or a nationalised industry, both with an economic bottom line, pour money into massive locomotive development? B.R. built Halls and Castles into the early 1950s after all and were only stopped from building another batch of 28XXs when the designs for the new fangled 9F 2-10-0s were put forward instead. They can't have been all that bad...
Following Mallard's failure, the 8.30am from Plymouth was taken to Paddington by the Reading station pilot, No 4920 Dumbleton Hall.
*A coach filled with recording equipment to measure all aspects of a locomotive's performance.
Last time we caught up* with Pendennis Castle's trials on the L.N.E.R. Whilst it wasn't a whitewash by any means, it did show the superiority of G.W.R. locomotive designs of the time. This however wasn't the only trial of its kind that G.W.R. designed engines participated in. There are a few more for us look at. Let's go back in time to see the first.
Cue swirly visual effect and possibly a DeLorean at 88 mph...**
This page of photographs of Polar Star at Euston during the 1910 trials was published in Great Western Railway Magazine, November 1910 edition And L.N.W.R. No 1471 Worcestershire departing from Paddington during the 1910 trials
The first big locomotive exchange for the G.W.R. was in 1910. The London & North Western Railway (L.N.W.R.) had seen the end of the long reign of their Chief Mechanical Engineer, Francis Webb, from 1871 to 1903. He had a lot of radical ideas but his engines were never the biggest or most powerful. This left the L.N.W.R. with the problem that many of their trains were being double headed (two engines on the front). This has an obvious cost implication. His immediate successor was the short to reign (1903-1909) George Whale. He took this problem by the horns and developed the Precursor Class 4-4-0s introduced in 1904 and the Experiment Class 4-6-0s in 1905. These revolutionised express workings on the L.N.W.R.
George Whale's new order at the L.N.W.R., No 1737 Viscount of the Precursor class 4-4-0s introduced in 1904 photographed at Euston. After Francis Webb's reign these were the first new non-compound express passenger design for the L.N.W.R. for 30 years
Whale's successor was C. J. Bowden-Cooke and seeing the improvements made by the last chap, he decided to see where his Crewe Works products stood when compared to those of its neighbours. The first trial comparison was with the Great Northern Railway's large boiler Ivatt Atlantic 4-4-2s versus the Precursor class. Not much of the timings from these trials survives but the efficiency results show that the engines were fairly evenly matched. The Caledonian Railway allowed a comparison between the& Experiments and their Cardean class 4-6-0s designed by John McIntosh. This revealed a remarkably similar result to the previous tests.
Earle Marsh's I3 4-4-2T No 21 hauling the Sunny South Express from Willesden Junction. The train is composed of L.N.W.R. carriages
The most remarkable trial was that of the interchange between the L.N.W.R. and the London, Brighton & South Coast Railway. This involved no less a machine than an express passenger tank locomotive! Their chief engineer, Earle Marsh, had designed a series of these 4-4-2T engines. They went in series through the I1 (not very good) to the I2 (also not very good) and just when you think it's going to be three tries and three failures, he brought out the I3. The previous two types were poor steamers and had 5’ 6” driving wheels. The I3 had two key improvements. Firstly, it had enormous 6’ 9” diameter driving wheels*** and secondly, it was superheated. These engines would pull the ‘Sunny South Express’ between Willesden Junction and Brighton. The load was usually about 235 tons and the I3 only had a 2,100 gallon capacity in its water tanks. Running at about 52 mph was the order of the day and there were no water troughs on that route. When you realise that they went non-stop to Brighton without refilling their tanks, their abilities start to become quite remarkable. They also did the whole return trip on just one bunker full of coal. That was just 3¼ tons of fuel. Worked out in efficiency terms, they did the round trip of 264 miles burning just 27lbs of coal per mile. I3 No. 23's performance on the L.N.W.R. was also startling. Although the power and timekeeping was within the grasp of the L.N.W.R. machines, the efficiency with which the work was carried out by No. 23 was certainly not.
Earle Marsh's I3 4-4-2T No 22 hauling the Southern Belle between London and Brighton. A beautiful train of matched Pullman cars, it was introduced in November 1908, the same year that the locomotive was built
By 1910, The L.N.W.R. had organised the final and for us, the most significant of the trials. The G.W.R. agreed a series of exchanges with their latest Star class locomotives. George Jackson Churchward was at the height of his powers when he designed the Stars. They deserve a blog of their own really but the basics are that at the end of the development of the Saint class 2 cylinder 4-6-0s. The French locomotives that Churchward had purchased to compare with the Saints had two features he was interested in. They were compounds and they had 4 cylinders. He had already discounted compounding as not viable for the G.W.R. There was therefore, clearly one more trick to perform with the 4-6-0 design - adding 2 more cylinders! The design became a fantastic success and was the basis for both the Castles and the Kings.
Given Swindon's dominance of the locomotive engineering world at the time, this was always going to be a tall order for the L.N.W.R. The G.W.R. locomotives were seemingly fast and powerful but their lack of participation in trials of any kind meant that the true nature of their prowess against other railways' products was only estimated. The announcement that the Stars were going up against the L.N.W.R. Experiment Class was therefore a bit of a surprise and keenly watched. No. 4005 Polar Star was sent to the L.N.W.R. to be compared to No. 1455 Herefordshire and No. 1471 Worcestershire was sent to the G.W.R. to be compared with now preserved No. 4003 Lode Star.
This photograph of Worcestershire at Paddington during the locomotive exchange was published in Great Western Railway Magazine, November 1910 edition. The loco looks positively antediluvian compared with the sleek GWR designs of the period
Worcestershire passing Subway Junction after departure from Paddington with the 11.50am, this time with the dynamometer car on the train
The comparison was never going to go well for the L.N.W.R. TheExperimentwas a 2 cylinder machine with a boiler pressure of 175psi and a tractive effort of 18,615lbs. This wasn’t bad by the standards of the day but still pale in comparison when compared with the Star. This design has 4 cylinders which were driven by a boiler pressure set to 225psi and a tractive effort of 25,090lbs. It showed from the start on the G.W.R. No matter what the crew of Worcestershire did, as the tasks set before them got progressively harder and closer to the everyday running of the Stars, they began to lag further and further behind. On one trip they were 33 minutes down on the booked time. Another hassle for them was that their water scoop wasn't performing in the wider G.W.R. troughs. This meant extra water stops which compounded the issues. Another trip saw them take a Paddington to Torbay express. Even on the easy running up to Reading, the engine was struggling and the 180 minute booked time to Exeter was extended to 193½ minutes. This wasn't the fault of the crew - far from it - they did remarkably well to do what they did but their steed was simply out of its league.
Polar Star hauling the 10.00am Euston to Glasgow Central on Bushey Troughs 20 August 1910, photograph from the LCGB Ken Nunn collection
Polar Star too was having a good time on the L.N.W.R. Given that the schedules and loads were designed to suit the Experiment class, the Star and her crew found the work easy. The amazing thing being that not only did it not have any issues doing the work, No. 4005 did it while generating far more power and with appreciably less fuel consumed. To put it in perspective, the cost of looking after a locomotive at the time for the L.N.W.R. was £975 per engine, per year. It might be assumed that the operational costs to the G.W.R. were far higher but they weren't. Per loco, per annum the figure was only slightly increased to £1,003. The result of this expenditure was a major advantage in power and efficiency and the opportunity to pull faster, heavier trains and the increase revenue that came with it. It is even more remarkable that despite this evidence being laid before them, the L.N.W.R. seemed to get nothing from the trial. It took a long time for their designs to change. A far cry from how the L.N.E.R. responded in 1925 to Pendennis Castle.
Well, that's enough for today. My cup of tea isn't going to drink itself and there are some biscuits with my name on them. Metaphorically at least. Tune in next time and we will see about going forward in time to just after Pendennis Castle's performance on the L.N.E.R. That's when the L.M.S. knocked on the door...
P.S. A bit of an oldie but a goodie situation here. The data for this blog comes from the book ‘The Locomotive Exchanges, 1870 - 1948’ by Cecil J. Allen, published by Ian Allan in about 1949 or 1950 as far as I can make out. It's a cracking read if you can get a copy...
*If, indeed, learning about events of around a century ago can be described as ‘catching up’!
**Simply the ONLY way to travel back in time! However, it nearly wasn't. The original idea the filmmakers had was to build the time machine out of a refrigerator...
***This is ½” LARGER than those of a G.W.R. Castle!
Seeing as Phil did such a nice job with his round up on No. 1466, I figured that we in the Castle community had better not be shown up and make a long awaited post! As you might have seen in the railway press, there has been a lot to talk about so - let's talk about it! But first, as always, we take a trip back in time. The G.W.R. and the L.N.E.R. were locked in combat but the supposed underdog, No. 4079 Pendennis Castle, had proved its mettle. Or should that be Metal? Who cares? On with the story...
4079 performing on the LNER in April 1925
Well, the results were in. The whole trial had been based not on speed (although it certainly ended that way, and in the Castle's favour!) but on efficiency and the figures were based on the amount of coal burnt per mile in pounds (weight, not cost!). Over the Great Western main line, The L.N.E.R. Pacific Victor Wild had racked up scores of 50, then 48.8 and finally 52.4lbs* per mile. Caldicot Castle was in a different league however. The figures being 44.1, then 45.6 and 46.8lbs** These were both on the down or away from London journeys. On the up or return to London journeys the figures were A1: 50.9, 45.2 and a very respectable 40.4lbs. The Castle's figures however were 40.6, 36.8 and 37.9lbs!
Now that was a performance of a loco on its home turf, with a very experienced crew and burning some seriously good quality Welsh steam coal. That could have been almost predicted. What was a massive surprise to all was the revelation that Pendennis Castle had performed equally well on the less potent hard Yorkshire coal. London to Grantham, the A1s were at 59.6, 58.1 and 59.2lbs but the Castle - with a windy last trip - was doing 55.7, 55.9 and 59.4lbs. Even when pushed hard, Pendennis was equalling an easy run for the A1s. The longer trips to Doncaster averaged out with the A1s at 55.3lbs and No. 4079 at 49.8lbs.
So why was the Castle so much more successful? Well, it has a lot to do with the work put into the development of G.W.R. locomotive design way back when Churchward was forging ahead with his standardisation programme. The combination and refinement of the technology was leaps and bounds ahead of the competition. The higher boiler pressure combined with the long travel valves that allowed the steam to expand further and release more of its energy gave these machines their edge. The skill of the crews on both sides to get such amazing results with their respective machines cannot be underestimated either.
So, that went well then?
The issue post-trials was that the G.W.R. staff magazine got hold of and published the full results despite the agreement being to keep them private between Swindon and Doncaster. The press making people's lives difficult? Not just a modern problem it would seem. If you have access to copies of The Times of the era, the most polite furious argument ensued in the letters page between the two railways. The L.N.E.R. General Manager, Sir Ralph Wedgwood and his opposite number on the G.W.R., Sir Felix Pole, also entered into a similar although more private ‘discussion’ too! Sir Ralph was not happy but Sir Felix countered that as an L.N.E.R. employee by the name of Mr. Cecil J. Allen*** had broadcast their side of things in a talk on the Children's Hour radio show****, that they were quite entitled to do the same! The upshot for L.N.E.R. locomotive practice was that long travel valves and higher pressure boiler became standard on many of their locomotives... Next time we will jump forward to the end of No. 4079's career with the railway in 1964.
The Times cutting announcing GWR victory in the 1925 exchange, 29 May 1925 and The Times cutting with the LNER rebuttal, 30 May 1925
Back to the 21st Century.
Well, if you are a steam fan and you have seen any of the magazines, you can't help but notice that we have done a thing! That thing is light a fire in Pendennis Castle. We went through several boiler tests, starting at a lower pressure and working up through August to a point where we were confident that a boiler inspector would say yes. It was quite something being in the cab of this beast as it slowly rose from its slumber. The golden glow of the sun reflecting on the loco as she slowly settled back down, steam simmering and hissing from where it hasn't issued in over 25 years certainly caused your blogger a few moments of reflection.
4079 with the safety valves lifted during test for the boiler inspector on 25 August 2021
On the Wednesday before the end of August 60th Anniversary gala, the boiler inspector did indeed say yes and so, on the Saturday, Sunday and Monday of the bank holiday, we towed the locomotive out to greet her fans and lit a fire in her to ring in the 60th Anniversary in style. She also made an appearance at the Anniversary celebrations where a large number of Didcot volunteers past and present gathered to celebrate. She was the star attraction. Or was that the barbecue? Mmmmmm - food! Let's say it was the engine shall we?
4079 in the evening sunshine during the anniversary celebrations for Didcot volunteers, 28 August 2021 and 4079 serenaded by the jazz band during the anniversary celebrations for Didcot volunteers, 28 August 2021
What's next? Well, she hasn't moved under her own power yet. The reason being that there are a number of jobs that we need to do in order to safely make that happen. We want to ensure that the motion is all tight and ready to go. Call us paranoid but we won't take any chances with her at this stage. Check, check and check again! The more sets of eyes cast over the machine means that everything gets looked at. It's just good engineering practice.
4079 and 5051 displayed outside the Engine Shed on 30 August 2021
We also need to set the springs - at the moment her axle boxes are way up in their guides and this is limiting the springing action. This could cause her to part company with the rails at anything but a crawl. We need to spread the weight of the engine across those springs properly too. This is a bit of a pain to do. There are 4 nuts per spring, two lock nuts and two adjustment nuts, in order to increase or decrease the tension on the springs. When we say nuts, these things are the size of your fist and need a suitably monstrous spanner to move them. Guess what the weekend looks like for the myself and the team...
4079 inside the Engine Shed on 30 August 2021
The lubricator is also being a bit of a pain but it's nothing insurmountable. A few minor leaks and then it needs to have the whole system run to fill it full of oil. There are a few other jobs that need doing too but it won't take long. After that, it's a case of gathering the Pendennis Castle team together and winding the reverser to full forward, blowing the brakes off, pulling the whistle chain and opening the regulator. That first move will be for the people that made it happen. I'm under no illusions that it will be perfect out of the box but we have time until the official launch next year to get things absolutely right. I have again to give a massive thank you to the team in general and Ali Matthews and Pete Gransden for putting in the hours to make the 60th Anniversary rendezvous happen. It was close, but we made it!
4079 inside the Engine Shed on 30 August 2021
There is still a way to go. The engine might be breathing and almost ready to roll on her own. Just a little testing, adjustment and paint needed. Not long now No. 4079 fans, Not long now...
All the best,
Drew and the No. 4079 Team
*This slight rise on the last day is due to an increase in winds, which force the loco to work harder.
** This rise was due to the fact that Caldicot Castle's driver essentially started racing at this point!
***My fellow railway nerds will recognise the name here - he was a very famous writer on all matters trains!
****Clearly, locomotive efficiency trials were the X Box or PlayStation of their day...
Doug Godden visiting 4079 on 8 November 2008
It is with heavy heart that with this blog we remember the passing in July this year of a Pendennis Castle celebrity. Doug was the fireman, and last survivor of the loco crew of the 9th May 1964 Ian Allen ‘Great Western’ trip where No. 4079 performed, nearly reaching 100mph. In Doug's memory, we will tell you that tale as we work up to her launch. He started his working life as a locomotive cleaner at Aberbeeg shed and ended it doing test trips on Eurostar. Quite the journey. He was a highly respected railwayman and a great friend to No. 4079, the project and the team looking after her. His wit, kindness and endless fascinating stories will be keenly missed.
We are saddened by the fact that he was so close to getting his wish of witnessing his steed of over half a century ago move once again. His family have of course been invited to the launch where we intend to place his ever present hat in the cab of Pendennis Castle to ride with her when she is launched. It's the very least we can do to honour this fine gentleman. The deepest sympathies of the No. 4079 Team and the G.W.S. go to his friends and family.
Doug Godden visiting 4079 on 25 May 2019
It's cup of tea time again... Phil has put together a really great update on the progress with G.W.S. founder locomotive, No. 1466. If I had any ado, I've just run out, so without any of that stuff further, it's over to the man with the 0-4-2!
Photo, taken from the shed roof, of 1466 during a steam test in March 1968
Well, it's certainly been a very busy time since my last update. It's great to report that work to No. 1466's boiler is ticking along very nicely. We had the initial boiler inspection by British Engineering Services (B.E.S.) on the 10th August & we now have their approval with regard to all the boiler repairs needed. Work has therefore officially re-started on the boiler. However, it's taken a fair bit to get to this stage.
3 quarter side-sheet to be replaced on both sides - Credit Phil Morrell
Having found some areas on the boiler that required a further inspection, we decided to remove the copper inner firebox. This gave us a fantastic opportunity to inspect all the usually inaccessible areas much more thoroughly. Even though this entailed a little more work, it has given us a greater assurance that the boiler - once completed - will be in tip-top condition once finished and will be in service with us for many years to come.
Now - this is where things get interesting. Contrary to what the original plans were for the boiler repairs, these have now changed (somewhat for the better). After the removal of the inner firebox, a more thorough examination and non-destructive testing program was possible. As a result, more parts of the boiler were found that will need attention or replacement. After some careful thought and consideration. It has been decided and agreed with our insurers that we will now be replacing & fitting:
Alongside the originally planned:
Third bottom throatplate to be replaced - Credit Phil Morrell
As well as all that, the copper inner-firebox is currently out and appears at first glance to be in excellent condition overall. Hopefully the latest N.D.T. tests will conform that it needs only need minimal repairs. Defective rivets on the copper ‘box have been repaired in the past with patch screws (a sort of bolt type thing) - which are perfectly fine - but as we now have access to both sides, we can replace these with rivets as it was originally built. A few areas of copper welding will see this finished off and ready for service in the 21st Century.
Put that all together with the myriad of other jobs on the boiler such as refitting stays, rivets, boiler tubes etc (I could go on and on…), there is quite a large and substantial amount of work needed before our ‘kettle’ can hold water and steam once again. Now, you may be wondering, ‘Why the change of plan?’ Well, there are a few reasons really:
Delivery of new throatplate, material for mounting pads, backplate doubling plate and bottle ends - Credit Ryan Pope and Drilling all the applicable holes in the backplate - Credit Ryan Pope
Anyway, onto current work news. Ryan and his team are progressing very well with work to the new full backplate, to the point it's nearly completed; They've drilled all the holes ready for fitting the newly fabricated mounting pads for the Regulator, gauge frame & combination brake / ejector. The backplate has also been temporarily re-fitted to the firebox, whilst final fettling occurs - It has to be said, it fits beautifully! As I write this, work is commencing on the copper inner firebox and the preparation for the new throatplate section fitting, which was delivered recently. We are also finalising the selection of our steel & copper welding contractors with our boiler insurers.
Newly made gauge frame mounting pads ready for fitting and seal welding - Credit Ryan Pope
We are awaiting the manufacture and delivery of a number of new components.
These include the new rear boiler barrel section, all the reinforcing or doubling plates that go with it and the 2x ¾ steel side-sheets. These will all hopefully be delivered by South Devon Railway Engineering by end of the month. As you can probably tell, there's quite a lot of work going on and with all this work in mind - comes one inevitable drawback. It's the old factor of: "A lot of work = a lot of time" and unfortunately, we've had to face the fact that 1466 will sadly not be making its appearance back at Didcot this year. It's an inevitable consequence of the last few years world events along with a currently expanding work schedule as we have delved deeper into the boiler. Thankfully, we've nearly reached the point where the list of jobs stops growing and starts shrinking!
Backplate trial-fitting - Credit Phil Morrell” and Trial fitting of the new foundation ring on the new full backplate - Credit Ryan Pope
On a final note; Over the bank holiday weekend at Didcot visitors may have noticed we had small stand for 1466, showing current progress and what work was to come. I'd just like to say a big thank you to all the visitors that gave donations. It doesn't matter how big or small the donation. The recent increase in the scope of works has inevitably greatly increased the cost of the restoration, so we would be very grateful for any donations you feel you can make. In a restoration like this, every £1 counts and really can make a huge difference to enabling us to finish this fantastic, iconic, little GWR locomotive. If you're interested in donating, why not follow the link to our 1466 appeal?
Now - Did someone mention paint/livery? Well…
Until next time folks!
It seems our roving reporter has taken up my habit of leaving you all on a cliff-hanger! Which reminds me. We haven't looked at Pendennis Castle in a while and, as you might have noticed, quite a bit has happened. I guess I won't be putting the kettle on just yet...
The thrill of opening the regulator, the surge of steam through the cylinders, the blowing whistle and that first blast up the chimney as the might iron horse begins to gallop. Yeah - that’s where many people's understanding of living with these ferrous equines begins and ends but like any horse, they do need a lot of looking after. Including mucking out. My fellow Pendennis Castle Team member, Clive and I were tasked with giving a little T.L.C. to the oldest and smallest member of our running fleet, No. 1340 Trojan. So, just how do you wash out a steam locomotive boiler? Read on and find out.*
So, the first thing you have to do is empty the boiler. If you have a big engine, this can take a while but as Trojan is only small (awww, bless!), her boiler isn't that big. We started by opening the regulator valve. Why you ask? Well, if you don't, the air can't get in to replace the water very easily and it becomes very slow to drain.
The next job is to open the blow down valve. This is conveniently located under the floor at the bottom rear of the firebox. The application of a large spanner later causes the floodgates to open.
You can see from the picture above that the water is a funny colour. This is why we are doing this in the first place. Just like a kitchen kettle, our giant kettles boil water and when they do so, sediment and minerals are left behind. In a kettle these are easy to deal with. Flush it down the sink! In a loco boiler however, they are trapped until we do a wash out as a boiler is a sealed pressure vessel. If you don’t do this, then the engine won't steam properly and it can eventually - if left to get bad enough - cause damage to the metal plates that make up the boiler as they will get heated and therefore expand at different rates, causing twisting and leaks. The water isn’t all this colour, it’s just the first bit from the bottom of the firebox.
Eventually, the water subsides and you can then get to opening the boiler up. There are two types of ‘plug’ that we can take out to help us flush it through. The first are known as boiler plugs. Pictured below, they have a tapered thread to provide the steam seal. Trojan has 10 of these plugs. 3 in the cab, 4 at the bottom of the rear of the firebox and another three in the smokebox. The larger engines in the collection have many more of them!
The other type of plug are the mud hole doors. These are elliptical pieces of metal that have a seal or joint around the outside of them. Trojan uses fibre joints but other engines use a lead joint. They are screwed in place with a strong back or bridge and a nut on the end of a stud. They only go in and out of the hole one way so it's a bit like one of those Christmas cracker wire puzzles! Trojan has two of these, located at the bottom front of the firebox. Again, the larger the loco, the more of these they have.
One thing I haven't mentioned is that each plug or mud hole door is fitted to an individual hole. You mustn't mix them up. We have a wash out diagram for each engine and on this, it maps out where all the plugs and doors are and assigns them a letter or a number. We have special wooden trays with numbered slots in and as they come out, the plugs go in the corresponding hole for later. The doors will have their letter chalked onto them and will also be placed on the corresponding side of the engine.
So, now we have the boiler open, we flush it out. You will need a few bits of equipment. First we use a water pump. We are trying to blast the sediment out of the boiler. Mains pressure won't cut it! This is a small unit driven by a little petrol engine. We use old fire hoses to connect it all together.
At the other end of the fire hose, we have replicated the tools used to flush boilers out. The valve will turn the water on and off. We can screw into the valve a range of different nozzles. Some have a flattened over end to give a spray and others have a sealed end with a hole in the side. These ones direct a jet at 90 degrees to the pipe. Excellent for washing down the water side of the inner firebox and tube plates.
So, we start at the front, highest point and work down. We use both types of nozzle in combination and the aim is to flush the sediment backwards and down towards the open mud hole doors and wash out plug holes in the lower firebox. Here, Clive is making a start in the smokebox - the furthest from the lowest point in the firebox.
As we do so, the water at first comes out in the ‘tomato soup’ colour...
...but it will eventually run clear. You then move onto the next hole and repeat...
We then tackled the plug holes in the top of the firebox. You can see that these old hoses are a little less than fully watertight but as they get bashed about and dragged around they are more than good enough for our purposes. You are going to get wet doing this anyhow...
We then swapped over and Clive drove the pump and I drove the valve and nozzles! This is where you get up close to the proceedings under the loco! This is the rear of the firebox...
...and this is the firebox front mud hole doors. There's a lovely little fountain down there to enjoy as well! That particular hose might well be getting a bit past it perhaps.
Once you get to the bottom of the boiler and it all runs clear, you have completed the washing part of the wash out. You do however have to close all the holes back up otherwise it won't hold water very well, let alone pressure! We clean all the components that we put back in. Before and after on the plugs below.
New joints go on the mud hole doors and they are refitted. The plugs get a layer of wash out plug grease on them and are replaced as well. You have to be careful doing these up as a taper thread is a bit tricky and unless you know what you are feeling through your fingers, it's easy to not fit them properly.
Shiny plugs, all refitted! Normally at this point, you would fill the boiler and test steam it to check your work but Trojan needs a small repair that will be done during the week, so we didn't do that today. What we did do was put the tools away and the kettle on...
We aim to do this every 15 steamings on every engine in our running fleet. Sometimes we are one or two steaming days under or over but it's a good target. We were lucky today and the weather was on our side. We did get wet but it wasn't cold so a cup of tea later and we were back in the fight so to speak! It's less fun in the winter but it's got to be done. Thanks to Clive for his help with the washout and I hope that was interesting for those who haven't seen it done before.
*Please excuse my snaps taken on my iPhone as we went on - you are all spoilt by the wonderful photographic skill of Frank. Me? Not so skilled in that department...
The rebirth of the Saint class is a tale that has many twists and turns but it starts way back in the society's history. The glaring gap created by the lack of a Saint was a huge one. It really needed filling if the Society was to fully tell the story of the development of G.W.R. steam locomotives. However, back in those pioneering days, some weren't sure if a boiler overhaul was possible in preservation, yet alone the building of entirely new locomotives.
The idea of backdating a Hall to reverse what had happened to Saint Martin (No. 2925 and later No. 4900) was clearly feasible but could a preservation society achieve it? To ensure that the dream was kept alive, No. 4942 Maindy Hall was rescued from Barry Scrapyard in the early 1970s. When faced with the rest of the project, it was a different matter. You have to remember that at this point, preservation was still in its infancy. The thought of manufacturing brand new wheels of the size and scope required was utterly daunting. So, for now, ‘Saint Maindy’ languished behind the engine shed...
The raw material, 4942 at Barry scrapyard in 1974
The impetus was regained as a result of one of our other ‘mission impossible’ projects - No. 6023 King Edward II. This was so labelled because there was ‘no way anyone was ever going to get to the stage where you could make a new set of wheels for it’. In true G.W.S. fashion, the naysayers were proved wrong and the first large set of standard gauge driving wheels in preservation was recreated. With the amount of new build schemes around today, we forget just how momentous this was. Without this step, other projects such as the County, the Patriot, the Grange, the A1 and the P2 might never have seen the light of day. It proved it was possible.
The first big test of ability to manufacture a new wheelset was to replace the one from 6023 which had been butchered at Barry scrapyard
So, perhaps you would like to turn a Hall into a Saint? Ok - here's the recipe:
Ron Hows machines an elbow joint for the inside admission main steam pipes
Welding repair at the front of the boiler, before the new tube plate was fitted & Welding new plate into the outer firebox side
I'm making light here of a very serious and complicated job. This was no ‘kit bash’ as you might imagine it. Swindon standardisation is all well and good until you find out that many standard bits are individually ‘fitted’ to a specific locomotive. It took as long as it did because it was that complicated. The achievement of Peter Chatman and his team is not to be underestimated.
The new 3,500 gallon tender tank begins to take shape
The name was chosen from a whole slew of suggestions made during a competition held by the G.W.S. There were a whole host of excellent suggestions including Lady in Waiting, Lady Diana, Lady of Lourdes, Saint Dai, Maindy Court, John Betjeman and my favourite of the paths not taken - Phoenix. The winner was of course Lady of Legend and it really sits well with the loco! The number that was selected was No. 2999. The previous loco in the series was No. 2998 Ernest Cunard although it could have filled any of the other gaps***. The triple nines do look rather good though, don't they?!
As the first 4-4-2 Saints had 3 figure numbers and were sometimes renamed, it is planned that when she runs as an Atlantic, she will carry the next available number in that series - No. 191. A second competition resulted in the name Churchward being selected. A fitting tribute for the great man himself. The Atlantic conversion is not a simple one and there are still a great many of details to be thrashed out and components made to make it happen. It will also require a boiler lift so it is unlikely to happen in this first boiler ticket.
Ready for the Atlantic option, the name and number plate
Lady of Legend has fast become a firm favourite with the general public, her incredible journey from wrecked Hall to its gleaming, lined out splendour is a classic of the preservation age. The engine had an amazing debut at Didcot and amazed all that saw it from the go. The visit to the Severn Valley enabled the locomotive to work out the remaining bugs and give it a proper shake down with a more substantial load over an extended period. She will be out and about again in the not too distant future. Stay tuned for details... No. 2999 fast became an integral piece of Didcot history - despite only being completed in 2019! To see this wonderful ‘Lady’ with her large wheels loping along in a seemingly effortless manner is a real sight to behold so make sure you get to see her in action. You won't regret it!
Lady of Legend goes golden during a Timeline Events evening photographic session, 10 July 2021
*The famous telescope at Jodrell Bank had used Castle bogie wheels as part of the turntable mechanism but these were found to be damaged beyond use sadly.
**We still don't have the set of rods. It's to do with where the knuckle joint is. On a 4-6-0 Saint it's between the leading and middle driving wheels. You can't reuse the rear rod as it won't fit and has the knuckle joint on it too. If anyone is feeling generous we won't say no...
***The other gaps were between No. 2955 Tortworth Court and No. 2971 Albion and then from No. 2990 Waverley to No. 2998 Ernest Cunard.