With a collection of locomotives dating from Victorian times to the 1960s, there's plenty to discover.
Welcome back and we hope that you all had the very best festive season given the current circumstances. As a bit of an aside, I thought I’d take a left turn at Albuquerque and shine a light on a few of the less glamorous but by no means less historically important wagon fleet that we have here at Didcot. The first thing to say is that we have to talk about the names as this gets a little bit weird.
Given the myriad of different GWR freight carrying vehicles, simply specifying a 12 ton wagon wouldn’t be precise enough and if you were trying to send what you wanted over a telegraph then asking for “one of those twelve ton wagons, you know - the ones that have the special holders for the things on them” is a bit long winded. Something had to be done.
One of Didcot's lesser-known Toads - the magnificent 7¼ inch model in the Great Western Trust museum
The GWR used telegraphic code names. The most famous of these is that all the brake vans they used were called TOADs. Indeed the GWR brake van in the Thomas stories was called ‘Toad’ for exactly that reason. There were MACAWs, MICAs, MINKs, HYDRAs, POLLENs and even MONSTERs! The one we will look at today will be a river dweller that has quite the presence. Take care as we go hunting for CROCODILEs...
While the type was locked down with the code names, there were individual versions within that group of wagons and these were differentiated by the addition of a letter. For example, there were CROCODILE Bs, CROCODILE Gs and so on. The final bit of identification used was the drawing used to build the wagon itself. They started with a code letter - all the CROCODILE diagrams started with a ‘C’- and then a number to tie it down to a batch.
Crocodile F 41934 at Didcot
The logical thing to assume was therefore that a C1 CROCODILE was older than a C4 but, as with much in life, it’s not that simple! Various reallocations of the codes as wagons were withdrawn and scrapped mean that a whole lot of shifting around took place. If trying to track the history of a specific wagon - you have been warned...*
The CROCODILEs evolved into a wide range of different designs. They were originally designated as boiler trucks but this was later updated to boiler trollies. Although this was their function on the books, their design with strong construction and a depressed centre section to get the load as far down as possible to clear the loading gauge meant that they were highly adaptable. They were known to carry anything from large sections of structures, enormous castings, machine parts, naval buoys and even statues.
A trainload of Admiralty buoys loaded onto Crocodile Gs. These had been manufactured in Chepstow and were taken as an out-of-gauge load to Newport Docks in the 1930s
Our CROCODILE is specifically a CROCODILE F built in 1909 to diagram No. C12. It was numbered No. 41934 as part of lot 549. There were 12 of this particular batch manufactured and it is well worth us taking a look at this strange vehicle. It weighed 18 tons 10 cwt. and although it is over 52 feet long, it has quite a small load carrying capacity of just 25 tons. Some of the CROCODILEs were real heavyweights with a single vehicle that was constructed to move enormous electrical Transformers and the like called the CROCODILE L being able to bench press up to 120 tons.
No. 41934 has some interesting constructional details. Not least of which is that a lot of the internal structure of the wagon is made from a whole heap of reused broad gauge era rail. When you think about it, the abolition of the broad gauge in the late 19th century must have left a huge amount of this good quality steel ripe for reuse for an ever cost conscious private enterprise. It makes sense. Who said recycling was a new thing?
This is all very well but at the end of the day, how interesting can a boiler trolley actually be? Well, this CROCODILE’s tale has a strange twist to it. The GWR Index of Wagon Diagrams has survived and has been published* so if we scroll down to the entry for the C12 CROCODILEs, we see this historical gem:
CROCODILE F 41933-42/50/1 [the numbers allocated to the vehicles] Delete 41934/51 in 1941 Lost in France; Reinstate 41934 in 1945 (12 then 10 then 11)
A Crocodile G converted at Swindon to carry a naval gun in 1940. Its role as a gun carrier was short-lived as the threat of invasion receded and the vehicle was returned to the GWR in 1942
What’s this all about? Well, as you are all aware, the Second World War didn’t start so well for the allies. The initial German Blitzkrieg or ‘lightning war’ conquered all before it. The British sent an expeditionary force to the continent with dozens of pieces of large military equipment. These needed to be transported to the battlefronts and a large number of rail vehicles were pressed into service to do this. Nos. 41934 and 41951 were just two of these conscripts to the cause. When France was overrun by the Germans in just 6 weeks in May 1940, the miracle of planning and determination that was Operation Dynamo extracted thousands of allied soldiers off the beaches of Dunkirk to fight another day. The heavy equipment however was left behind. It is clear from the document that by 1941, the GWR has declared the two CROCODILEs as missing in action and didn’t expect to get them back.
Remarkably, No. 41934 had been pressed into service in occupied France by the German Army. Come the Operation Overlord / D-Day Invasion of the 6th of June 1944, the wagon soon changed hands again, this time being pressed into service with the invading American 5th Army as part of the allied effort to liberate Europe. Even more amazingly, someone in the GWR must have got wind of this and said something along the lines of “please sir, if you have finished with our wagon, we’d really rather like it back...” No. 41934 returned to the UK in 1945 and eventually found its way into traffic, through nationalisation and into the collection at Didcot. The fate of its compatriot, No. 41951, is unknown to this day. In the chaos that was WWII Europe, that our CROCODILE survived at all is frankly amazing in itself.
41934 is still used for the purpose for which it was designed - here the boiler of Pendennis Castle is steamed for the first time after overhaul while accommodated on the Crocodile boiler wagon
So, what do we at Didcot do with our ex prisoner of war? Well, we do exactly what the GWR did with it. We use it as a boiler trolley. It was very recently host to the boiler of No. 4079 Pendennis Castle during its test program and will no doubt go on to serve in this capacity for many years to come. It’s a very ‘Didcot’ kind of pure preservation. Preserved by the very act of continuing to do the thing that it was designed for. The best kind of preservation in our opinion frankly! Remember, as the as the Australian gentleman who was associated with crocodiles in that movie said: “That’s not a knife - THIS is a knife!”. Well, we at Didcot can confidently say “That’s not a historic CROCODILE - THIS is a historic CROCODILE!”
* THE book on GWR wagons was written and has been updated several times by A. G. Atkins, W. Beard and R. Tourret and is called simply “GWR Goods Wagons”. It is published as a mighty combined volume by O.P.C. (ISBN 978-0-86093-657-2). Your blogger’s copy is somewhat careworn being present at the construction of a growing fleet of 4mm scale replicas but is still going strong. Wholeheartedly recommended.
9F 2-10-0 No 92224 with a northbound car train steaming through a snowy Oxford. The train is just crossing the Botley Road bridge. The notice on the bridge parapet, left of photo, reads: ‘Engines must not stand longer than is necessary and enginemen should avoid dropping ashes or water on the bridge’. Behind that is a poster hoarding for Player's Bachelor cigarettes, also wishing passers-by: ‘Happy Christmas’.
Well, the seasonal season is almost upon us and this blog writer is going to hand over to a special guest this week to help us get closer to rounding out the year. Our guests in our houses might be limited this year but here in inter-web land we can travel in time and space and invite guests from wherever and whenever we like! The gentleman in question is Ted Abear. Ted joined the GWR as a cleaner at Southall in 1946. He was promoted to fireman, then moved on to Old Oak Common as a fireman in 1955. He has given us special permission to use his wonderful account of working on steam locomotives in the winter weather which he rather wonderfully entitled ‘Down with the Cakes, Up With the Milk!’.* so, without further ado, and with footnotes supplied by yours truly, take it away Ted ...
After nine months in No 6 link** at Old Oak Common I went into No 5 link with driver Jack Batterbee. No 5 link had 48 weeks' work, so to work round the link took just on a year. It was called the ‘Washing Machine and Television link’ – when you went round the link once you earned enough to buy one or the other. The work in No 5 link covered passenger, freight, parcels and milk trains. The passenger was out from London with trains for Bristol, Taunton, Cardiff and Wolverhampton and return with either freight, parcels or milk trains.
One job we had to Taunton was to book on at 6.45pm and walk to Old Oak Common East to relieve the 7.35pm Kensington to Penzance parcels under the bridge-hole where the West London line came onto the Western Region. This was traffic from J Lyons and Co at Cadby Hall, Kensington. We were booked to follow the 8.5pm Paddington – Bristol on the down main line. The load would be made up of parcel vans and GUVs***, around 12 – 15 vehicles all loaded with cakes and confectionery.
We worked through to Taunton and returned with the 6.20pm Penzance to Kensington Milk train as far as Southall, where we would unhook and go light engine to Old Oak Common shed. This was a nice little mileage turn which worked out at 9 hours: so with your eight hour shift plus 9 hours for mileage it was worth 17 hours a night, plus your bits of night-rate.
No 1028 County of Warwick
We got a variety of locomotives on this job, Halls, Castles, and 10xx County class. One regular 10xx we used to get was No 1028 County of Warwick; she still had her single chimney and boiler pressure at 280psi. I quite liked this class, for a two-cylindered loco they were very powerful and ran quite well, they had an appetite for coal though. There were occasions when things could go wrong and cause delays, such as signal or track failures, preceding trains or inclement weather!
No 1008 County of Cardigan on a goods train at Penwithers Junction in July 1962
In December 1957 I was booked on the 7.35pm Kensington; I was spare in the link and was booked on the job along with Driver Jim (Jammy) Taylor, he was spare in No 1 link and also booked on the job. I had cycled to Old Oak Common in a snow storm, it was coming down quite heavy. We booked on and made our way to Old Oak Common East in falling snow. Standing inside the tunnel we waited for our train. Eventually it arrived late, on the front was 1028. We had lost our path and had to wait for the road. When we got away we were about 45 minutes late. Our first booked stop was Reading, then Taunton. We were stopped quite a few times to Reading, resulting in my having to go to the signal-box to carry out Rule 55 and sign the train register every time. “Mind how you go mate!”, Jim said to me every time I left the loco to go to the box.;
28XX 2-8-0 struggling through a blizzard with a goods train in 1961
On leaving Reading we were well over an hour late, and it was still snowing. We were still getting checked and I was going to the signal-boxes. We were now getting a bit fed up as we were going to be late arriving at Taunton, also I was getting cold and my boots were getting wet, also my overall trouser bottoms. Leaving Newbury we were told that a Reading to Bristol freight was clearing ahead to Westbury. Climbing to Savernake we were checked and we came to a stop at Savernake Low Level Station. It was still snowing, you could only just make out the track.
On went my overcoat again, which was getting heavier as it got wetter. I started to walk to the signal-box to Jim's “mind how you go”, above my ankles in snow and getting very wet, taking care not to trip over signal wires or point rodding.
Savernake Low Level railway station, with the signal box in the background
The signal-box was situated on the Up side by the junction for the branch to Marlborough. I remembered that there was a small wooden footbridge across a small ditch, so I thought, to get to the box steps. I could see it was lovely and warm in the box, the windows were all steamed up. I started searching in the snow for the wooden footbridge; pushing my boots down in the snow, I felt something solid, stepped out, missed the bridge and landed in the ditch up to my arm-pits in snow, letting out a yell and a few Anglo-Saxon comments! Was I glad the ditch was not full of water, only snow. It had a muddy sludge in the bottom, into which my boots sank and I could feel my feet getting wet. I was having a struggle to get out of the ditch due to its depth and my heavy overcoat.
Savernake signal box, where Ted Abear fell in the ditch. The main line to Taunton is curving away to the left, and the branch line to Marlborough on the right. The branch line closed to passengers in 1961, and goods in 1964
The signalman heard my shouts – and language – and came down to help me out, laughing his head off. He said: “You have got the road mate!” I said I was coming to carry out Rule 55 and sign the train register. I then told him what he could do with his register, Rule 55 and the road. I trudged back to the loco, taking care not to trip over rods or signal wires; I was soaking and miserable. Jim looked at me as I climbed into the cab; before he could say anything I said: “Don't ask!”
Later on we got the road round the ‘back road’ at Westbury and had no more checks. I must say that firing a coal-guzzling steam engine in wet clothes, boots and socks leaves a lot to be desired! We arrived at Taunton ‘well down the swanee’ as they say. We had passed our return working on the Up road between Castle Cary and Athelney. We were relieved and told to travel home passenger on the Penzance ‘sleeper’. We quickly made a can of tea as the sleeping-car train arrived, running late; the train was covered in snow and ice. We got in the compartment reserved for train-crews; we were the only ones, so we had our grub in the warm. Jim and I removed the seat cushion on one side, put it on the floor and sat on it with our feet near the steam heater. I had my boots and socks off, also my overall trousers and my under pair of trousers to dry them. I travelled with my overcoat over my shirt, pullover and underwear.
We were not disturbed at all and had a sleep in the warm. I was very glad that some bright spark in the Control did not have the brainwave to get us to change over with our back working on the way down. I would not have been very happy the way I was feeling – fed up and far from home. We missed our turn the next night as we did not book off until 9.30am, so the job was covered by another crew. We booked on after 12 hours’ rest at 9.30pm and sat spare in the cabin under Foreman’s orders. It wasn't all ‘GLAMOUR’ on the footplate folks!
6814 Enborne Grange at Grampound Road in March 1962
Thanks Ted! So there you are - the glamour of the steam era in all its glory. We all love to see these machines and a fortunate few like me get to play with them. We know how hard work they are but we have only a small window into what it was to live with these machines day in, day out, at all hours and in all weathers too. Reading this, makes me quite grateful for the central heating and cup of tea that I am enjoying while writing this... Ted finished his railway career in the Control office at Swindon, where he now lives. Despite being in his late Eighties, he is a volunteer at Steam Museum in Swindon and takes great pleasure in describing footplate work to visitors on 4073 Caerphilly Castle. Let's hope that, when circumstances allow, a visit to see our very own No. 4079 Pendennis Castle in action will be on the cards too! He will be made most welcome.
On that note it falls to me, on behalf of all my friends in Didcot Locomotive Works and the Going Loco Blog Team, to wish you all a very Merry Christmas and a happy and prosperous New Year.
All the best,
*Down is any train going away from London, Up is going towards. get it?!
**The Links were the various duty rosters that were covered by the shed an Engineman served at. Which jobs you were assigned to depended on seniority, training, experience and a whole host of other factors.
***A type of freight wagon capable of being used at passenger train speeds, it stands for General Utility Vehicle.
PS: Ted had a book published in 2000: ‘Through the Links at Southall and Old Oak Common’. It is well worth tracking down a copy.
1014 and 2999 13 August 2020
Well, he’s on his way kids! Not that many more sleeps and presents ahoy. While we are all looking forward to the visits of a certain Mr F. Christmas and his troop of airborne artiodactyla* at home, the last thing our engines need is a large blockage in the form of a ‘generously proportioned’ gentleman in potentially combustible red garments plugging up their chimney.
The locomotive chimney is quite important to the efficient working of a steam locomotive. Most people think that it’s just there to let the smoke out and while that is true - it’s far better it goes that way rather than out the fire hole door and into the cab(!) - there is a LOT more to it than just that. We also have to get rid of the used steam and we can also use it to do other things as well. Drafting or the science of how to get these glasses flowing is a really quite technical process of fluid dynamics. This branch of science treats the flow of gasses - even air - as a fluids as the basic principles remain the same. It’s just the speeds and the density that change.
Fire Fly and Iron Duke
The early locomotives had quite tall chimneys (like those on our Firefly and Iron Duke). The first reason is that a taller chimney can cause an effect that is described as a temperature induced density difference draught. That is where the hot gasses from the fire travel through the boiler and then escape up the chimney because a hot gas has particles that are moving around much more than in a cold gas. This makes it less dense** and therefore it rises to the top. This is also helped by any air blowing across the top of the chimney. This causes the air in the chimney to be at a lower pressure that the air outside and the hot gasses from the fire are drawn through to try to equalise the pressure. This is all fine until you start making the boiler larger. This means that the height of the chimney starts to become limited by things like the height of bridges and tunnels. The civil engineers don’t like it if bits of engine collide with them on a regular basis so the chimneys has to be made smaller.
4 January 2020 Fire Fly
Thankfully, even from Trevithick’s first steam locomotives in the early 1800’s, more draught was being created artificially. Nearly all steam locomotives have exhausted (got rid of) all of the steam used in the cylinders by using the same convenient hole - the chimney. This also plays the pressure game. Instead of air passing across the top of the chimney, in steam engines, the exhaust pipe(s) from the cylinders converge and point up below the bottom of the chimney. This is known as a blast pipe and it does what it says on the tin. It blasts the exhaust up the chimney. This lowers the air pressure at the front of the boiler in the smokebox and as a result draws the hot gasses through the boiler tubes. It also has the benefit of pulling fresh air into the fire. This makes the fire burn hotter, therefore the harder the engine works, the better the fire burns and the more energy is created to boil the water. Pretty convenient!
King Edward II new blastpipe
The ends of the blast pipe were fitted with a conical end - not unlike the nozzle on a garden hose. This had the effect of accelerating the gasses through the Venturi effect***. The only issue was that this constriction could be so great that not all the exhaust steam could escape and it caused unwanted pressures in the cylinders, making the engine far less efficient. The size, length and shape of these pipes can be critical. Another addition to the puzzle was made American locomotive engineer Ross Winans in about 1848. He mounted a conical shroud type structure to the bottom of the chimney. This became known as the petticoat - as it reminded engineers of the structures used under the dresses of Victorian ladies to provide shape. This is also used the Venturi effect to help accelerate the steam and gasses up the chimney, clear the back pressure in the cylinders and provide the draught.
The exact relationship between all these elements in the smokebox were eventually described by the GWR’s very own genius George Jackson Churchward who put together a simple equation to ease the designs although they didn’t hold true as the power of locomotives increased. The work at Swindon continued however and it became a centre of excellence for dealing with draughting. Later engineers such as the famous Sam Ell undertook work that nearly doubled the rate of steam production of the Manor Class 4-6-0s with just a few small alterations and more than doubled the rate in the Ex LNER V2 class engines in the early BR period. As time went on and the quality of coal burnt by the engines got worse, modifications such as double blast pipes and chimneys and various nozzle arrangements such as those designed by Chapelon, Giesl and Lemître were used. Time caught up with steam locos however and as electric and diesel locomotives took over, the scientific work has dwindled. There are still experts out there however that use current fluid dynamics theories to continue to make improvements.
Arrangement of Smoke Box 49XX Hall Class
Finally, we should have a chat about the blower. This is a casting or a pipe that forms a ring at the bottom of the chimney. It has a number of holes in it that point up the chimney and can be used to blow steam direct from the boiler upwards. It provides an artificial draught when the flow of steam from the cylinders isn’t being provided. This might be because the fire is being built up at the shed at the start of the day or after a period of inactivity but equally it might be that the engine is coasting - rolling along without the regulator open. The danger here is that if you go under a bridge or into a tunnel without pressure going up the chimney, it might force air down it. This causes what is known as a blow back where the fire blasts out of the fire hole door. Not great in a confined cab...
Arrangement of Smokebox 1000 Class County
It has also been put to rather more nefarious uses at Didcot.**** One day, a fireman was putting on a show of the traditional ‘cooking on the shovel’. The driver, being in a somewhat mischievous mood, waited for the perfect moment. As the fireman was intent in culinary duties and had just placed the shovel back in the fire hole, he suddenly opened the blower all the way. The sudden suction pulled the unfortunate bacon and eggs from the shovel and was last seen by a bystander accelerating upwards into the sky! We might not be able to prove that Reindeer can fly but we have direct evidence that pigs might fly. In very small quantities at least...
*The scientific order to which Reindeer belong.
**For an explanation about density, have a look at my blog called ‘Hydrostatic Hyperbole’.
***We also had a chat about the Venturi effect in my blog about injectors called ‘An Injection of Pure Genius’.
Science education by stealth here it would seem - Everyday’s a school day!
****Names have been omitted to protect the innocent, er, and the guilty...
We edge ever closer to a seeing the mighty Champion of the GWR - No. 4079 Pendennis Castle - living and breathing once again. There is one thing that I haven’t yet explained however. Just why she has that title. It’s all due to a sign.
Time machine in operation, set coordinates for 1924, London. Wembley to be exact. The British Empire Exhibition. Just after closing. We don’t want to freak any of the natives out now do we? In 1924, The idea of the exhibition was to promote the bonds between the people of the empire and the dominions (Australia, Canada and so on), stimulate trade and be a cultural and technological showcase for the whole world to wonder at. It was to run for two years. It was to be held at the newly completed ‘Empire Stadium’ which had been built by the company Sir Robert McAlpine & Sons. This name will crop up again later.
4079 at Wembley in 1925 - Ken Nunn Collection
We will take a stroll in the wonderfully titled ‘Palace of Engineering’. It contained all sorts of wonders of the age. Cranes, Aircraft and the like. The bit we are interested in is the railway locomotives. There were two stars of the show. The LNER (London and North Eastern Railway) had sent some engine that was called something like Flying Scotsman.* Alongside it was the first of the then relatively new GWR Castle Class No. 4073 Caerphilly Castle. Both locomotive were in fantastic condition. Resplendent in exhibition liveries and with polished metal gleaming. The bone of contention wasn’t the engines however, it was the sign erected by the GWR claiming No. 4073 was “The Most Powerful Express Passenger Locomotive in Great Britain”. The LNER’s A1 is a bigger looking locomotive - it had a larger diameter boiler and it was a Pacific (4-6-2 wheel arrangement). The Castle was a smaller 4-6-0 but had a number of advantages. It was by far the most efficient locomotive of the two with long travel valves that allowed the steam to expand and expend as much of its energy as possible. It also had a higher boiler pressure and some other advantages that we will discuss next time.
The controversy had started earlier. Charles Collett has presented an engineering paper describing the efficiency of his new Castles and it had been met with incredulity and derision in equal measure but this latest claim had pushed things a little too far. A test of this locomotive was on the cards and as the A1 and the LNER was to hand, they were used as the measuring stick. The trial was on!
Earlier that year, another Castle Class engine was completed and sent out on tests with the crews from Swindon shed. This was something that was to happen 171 times either as a new build like this one or as a rebuild from a Star Class** locomotive. All of these engines all performed differently. This one was regarded as a really good example from the get go. It was the 7th Castle built but as the numbers had been carried on by Swindon from the last Star Class engines, she carried the number 4079 on her cab sides. In the tradition the majority of her class so far, she was named after a Castle.*** This one being named after a fortification on the Cornwall coast built by King Henry VIII In the 1540s. It was called Pendennis Castle. It was this engine that was to go to the LNER to defend the honour of the GWR and prove Collett right. So what happened next?
Don’t you just hate people that leave things on a cliffhanger?
Great Western Society Vice President, Richard Croucher, lights the first post overhaul fire in 4079's boiler - October 2020
Going back to the 21st Century, Pendennis Castle’s restoration is really gathering pace. Following a successful hydraulic exam, she has felt heat in her belly for the first time since 1994. The honour of lighting the first fire went to our former Chairman Richard Croucher. He, along with Nick Pigott of Railway Magazine are responsible for 4079’s presence in the Didcot collection. He masterminded her journey to Oxfordshire in 2000. Not only that but while I have had the pleasure of turning the spanners, it has fallen to Richard to raise the money to make all this happen. A richly deserved honour we think...
The overhauled boiler is lowered back into the frames as 4079's restoration progresses - November 2020
Since then a great deal of water has been under the bridge pretty quickly. Especially considering how long it has taken to get to this point! The boiler inspector was pleased with the out of frames steam test and not long after that my team put the boiler back in her frames. Just like that. The next jobs are getting the cab fittings back in place, replacing the boiler cladding (a horrible job at the best of times!), discussions about paint have been had and a 101 different other things that we will catch up with next time.
Another cliffhanger? Awwwww - Come ON!
All the best,
Drew and the 4079 Team