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Going Loco - February 2022


Ready for Inspection? - Part 2

In the first of this three-part series, we looked at a vehicle beloved of movie makers. The humble pump truck. While this type of inspection vehicle is widely recognised, in the words of Yoda: “There is another...” Another far less recognised but equally fascinating human powered rail vehicle. I feel the need, the need for Velocipede!*

A velocipede being used for track inspection. Note the tools attached to the outrigger. The outrigger can be removed by loosening a couple of wing nuts, allowing one man to take the vehicle off the track – a useful feature if a train comes along!

The term velocipede is usually used today to describe the forerunners of the modern vehicles that became the bicycle, mono wheel, tricycle, quadracycle, and dicycle. More specifically, it usually refers to those developed between 1817 and 1880. It means ‘human powered land vehicle’ and the word has its origins in Latin. The veloc bit coming from the word velox where we get the English word velocity. The pede bit comes from the Latin pedes, meaning foot. This of course being the reason we call people using footpaths pedestrians.

Well, what a lovely dive into etymology** but that's not being nerdy about railways, is it?! Well, it is. Kind of. This is because there is a three wheeled version of the pump truck, an example of which resides in the GWS collection, for single man operation. The velocipede's early history is tied up with an American gentleman by the name of George Sheffield. Legend has it that he built his own single man velocipede and used it to go out and about on the track of the Michigan Central Railroad. One night, as he was trundling along, he came across a broken rail and upon its discovery, he managed to acquire a lantern from a nearby farmhouse and then stop an oncoming train.

Clearly the railway was quite grateful for the aversion of a great loss of life and remarkably gave him free access to use their track! Imagine that happening today? I think not... The other thing they did was to ask George to build them a velocipede of their own to carry out track inspections. And from a tiny acorn, a mighty oak grew. He filed a patent for his design which was issued on 11 March 1879 and just four years later, there is a report in the press that over 4,000 velocipedes had been sold since then to railways in the U.S. and Europe. He clearly had something of a success on his hands.

There were two rival firms producing them, the first being the Sheffield Car Company from our previously mentioned George. He set up shop in Three Rivers, Michigan. His big rival was the BUDA company founded by George Chandler (what is it with the Georges?!) in 1881. This was also a manufacturer of railroad equipment although it eventually be known as the BUDA Engine Company, diversifying into internal combustion machines. They were based in Harvey, Illinois. There was a British manufacturer as well, Wickham of Ware. We will delve more deeply into this company in our final part but sadly, despite three types of velocipede in their catalogue, it seems they were mostly exported and there isn't an example in preservation. It has to be said though, something this size could still be lurking in a shed somewhere...

A publicity photo taken about 40 years ago suggesting a use for the velocipede as a commuter vehicle during a rail strike.

The basic set up was that there was a contrivance that looked a lot like a wooden bicycle. This had flanged wheels and sat along one rail. There was an outrigger with a third flanged wheel that sat on the opposite rail to keep the whole ensemble on the track. They worked in much the same way as the pump trucks that we described previously. The big difference is that it's usually a single person operation. They can be pumped by two but singular was more usual. The lever in the middle is pulled backwards and forwards by hand and in several versions, foot pedals are used as well in the opposite direction in a sort of rowing motion. They operate connecting rods that act upon a crank to drive the wheel.

They had much the same duties as their larger 4-wheeled brethren. They were really handy for track inspection. They saw a great deal of use in the U.S. and Canada but dear old Blighty bought a few too. British railway companies, other than the G.W.R. that bought them included the Southern and the London North Western Railways. They were long lived too, being a convenient method of transportation - particularly along branch lines so they made it into the preservation age.

There is an interesting adjunct to this tale. They have become something of a cult item. Particularly in North America, where there are long stretches of disused or rarely used track, people have started using them for leisure. When the supply of originals became difficult and expensive, the velocipede fans have started building their own. Some are not much more than modified bicycles while others are far more technically accomplished. There are forums dedicated to their manufacture and lists of plans and parts available. It all sounds wonderful, I'm all for people exercising practical skills. Look at what I do for a hobby!

However, I think that the British velocipede enthusiast would have to be a bit more careful about where they rode their machines. I really don't want to hear of any of you lot building your own and ending up as a rather macabre version of the Spirit of Ecstasy. Instead of gracing the bonnet of a Rolls - Royce, ending up at Paddington ‘gracing’ the front end of a Class 800...

The velocipede in use during the early days at Didcot Railway Centre. It was discovered at Devizes station by the Great Western Society's then public relations officer, Ken Williams, on what was described as a ‘courtesy’ visit at the end of 1963. It was purchased from BR a couple of weeks later and thus became the first item of rolling stock owned by the Society.

* Sincere apologies to the movie Top Gun.

** ‘The study of the origin of words and the way in which their meanings have changed throughout history.’


The Mechanisms of Non-Explosion!

Given that we are in the home stretch with No. 4079 Pendennis Castle, the recent successful test brought up a few snagging items. The most obvious of which was the clouds of steam issuing from the front end. In a way, this was both a success AND a failure. Clearly clouds of steam are not supposed to constantly issue from the front end but on the other hand, her cylinders didn't explode...

2999 with cylinder cocks open.

To understand why this is and isn't an issue in the first place we need to do a bit of science. Don't be frightened! I'll take it easy on you. The reason we have to be so careful is due to compressibility. Gases are compressible. That is to say that because their molecules are spaced far apart and free moving, you can squash them together. This means that the density of the gas increases as pressure increases. Density is defined as ‘the mass per unit volume’. Yikes!

Let's put that in layman's terms. Say we are dealing with two 1cm x 1cm x 1cm cubes. One is made of lead, the other is a made of plastic. Clearly, the plastic cube is likely to be lighter than the lead cube. This is because in a 1cm cube of lead there are more molecules of lead than there are molecules of plastic in a 1cm cube of plastic. You can also make gases more dense. What you do is that you trap them in some sort of container and continue pumping in more of the gas. The molecules move about easily, so there is space for more molecules in between them. The more you put in a given area, the higher the pressure of the gas becomes.

4144 with cylinder cocks open on 28 July 2018.

Fantastic! This is how we get steam pressure to drive our locomotives. However, there is another component in there. The water that we are turning into steam. Water is, for our purposes at least, an incompressible fluid. Unlike the molecules in the steam, the water molecules are far more densely packed to begin with. Although they are free to move about in a container, they don't go floating around like gas molecules. They don't have enough energy to do that. The thing is that as you take water and pump it into a sealed tank, the pressure might go up but the density of the liquid stays the same.

So what? I hear you cry. Well, this can be a serious problem. Not in the boiler, but in the cylinders. As a steam locomotive is sat around, any steam that is in the cylinders will be losing energy to the environment. This means that eventually it will turn back into water. As we know, water is essentially incompressible as its density doesn't change when compressed. This means that it's going to become pretty ‘solid’ if you move the engine without getting this water out. This is because the piston will try to compress the water up against the end of the cylinder. With nowhere to go, the pressure will rise and rise until something gives. In this case, that weak link will be the cast iron cylinder itself. The cylinder will quite literally explode! This can and indeed has happened...

Above is the later B.R. drawing for the cylinder pressure relief valves.

Thankfully, there are three mechanisms to prevent this and if properly maintained and operated, they complement themselves. In theory, don't allow us to get into this less that desirable situation. The first of these is the fact that once the engine is working and the cylinders get hot, the water won't condense in the cylinders. Great - so all we have to do is to get to that point! The second line of defences are the pressure relief valves. These sit on each end of each cylinder. These valves are the big pepper pot shaped brass things that are common on G.W.R. machines.

This is the real thing on the driver's side outer cylinder of No. 4079 Pendennis Castle.

They operate as simply as you imagine them to. There is a valve on a seat that is open to the inside of the cylinder. The big pepper pot shaped cage that goes over this simply holds a spring against the valve. You can adjust the amount of tension on the spring with a screw and lock nut arrangement on the top. This adjusts the pressure at which the valve opens. Simple! However, this will only cope with so much water. It can only get out of the one aperture, so fast.

The early ‘lever’ style cylinder drain cocks as recreated for No. 2999 Lady of Legend.

What we need to do is to blow the water clear of the cylinder before we get going and this is why steam engines make that fantastic whoosh of steam when they start off. Cylinder emptying solution number 3 - the cylinder drain cocks. No sniggering at the back now, all taps of any kind in a steam engine are called cocks. All they are is a tap that you can open that are in the bottom of the cylinders. All the water will naturally migrate to the bottom as long as gravity is working (!) and there is a tap at each end of the cylinder. When you start the locomotive moving, you open the taps and away you go! Simple, right? Well...

 Here is one of No. 4079 Pendennis Castle's complete and in situ (left) and stripped down for cleaning and inspection (right).

Just for completion, here is the fantastic 1924 drawing for the tappet cylinder cock that was used to recreate these for Pendennis Castle. There are several versions of the sprung or tappet type drain cock. Two and three bolt hole versions were used.

So, we can now open up the taps to get the water out. What we also need to do however is to open them all up at the same time with one lever from the cab. This is where things get tricky. It's worst on 4 cylinder engines like Pendennis Castle as they have no less than 11 drain cocks. Wait a moment I hear you cry again (tough audience this week!), you just said that there are 4 cylinders. One at each end? That means that there are 8 surely? Nope! There are 3 areas in the cylinder block called steam chests. These open areas have steam passing through them and you don't want water collecting in them and then getting drawn suddenly into the cylinders. As we now know, that ends badly. So, drains all round. All 11 of these are pulled open from a single lever in the cab. To do this there is an extensive and complex linkage system that goes between the drain cocks and the lever.

 Drain cock levers old and new. Left is the one from No. 2999. As these are lever operated they only need a lever to move them between open and closed. Right is the one on No. 4079. Her drain cocks are sprung so need to be latched in the open position. Hence the ratchet on the lever. Pull back on the lever to open them. Pull back slightly on the lever and stand on the tail on the ratchet to lift it and release the mechanism. The springs in the drain cocks can then shut the valves.

These are all new on No. 4079 and they will take a bit of setting up. The locomotive was fitted with steam operated versions at some point in preservation and we decided to put it back to how Swindon intended! This means that we were fully prepared to not have it right the first time and it wasn't quite there. A few adjustments will see it right though. We have also fully dismantled and restored the pressure relief valves and those aren't set to the right pressure either! This is why there was a fair bit of steam about on the first test and why it was both a small failure and a big success. There will be another test before her launch day and one of the reasons will be to fix this. As I said before, while the relief valves and drain cocks were a little bit leaky, the cylinders didn't explode... Let's call that a net win shall we?!



Return of the Champion - Chapter 6

I think we ought to have a long discussion about the intricate workings of... Who am I kidding - it only works!!! No. 4079 Pendennis Castle actually did the thing we've been trying to make her do all these years! She went chuff, the wheels went round, forwards and backwards occurred. While this was always going to be the case, when you are working on something for so long, it never feels like you are going to get there and suddenly, there we were.

4079 Making her way to the main demonstration line.

The day had been wrapped up in secrecy. The team needed a bit of space in case we needed to work on the engine. Having expectant crowds about isn't really conducive to that sort of thing so we kept it in house. It was a Discovery Day, however, and the visitors that did turn up got a bit of a surprise! The day actually started the day before when a warming fire was put into the belly of the beast. This is important for those that don't know – especially for bigger locos like No. 4079. You don't want to just light a big fire in her and get to temperature as fast as possible. This is really bad for the boiler. This will cause bits of the boiler to heat up faster than others. In turn this makes them expand at different rates. This can cause a boiler to leak and as Peter Gransden and Ali Matthews have done such a good job of overhauling it, I can't say they would be impressed if we did that on the first run!

This fire will not cause pressure – it will sit there and slowly burn through. The fire for the day is lit early on the morning of the run. Steven Tomsett was the guy that kindly volunteered for that job. Cheers! By the time the rest of us got there, the engine was hot and the pressure was beginning to rise. Oiling round on these engines was allocated a full hour in GWR days and even in the 21st century, you can only pour oil into over 120 separate oil pots so fast. This is done at the start of every day's operations with a steam loco and with the inside motion of GWR engines and the extra two cylinders on a Castle, this needs a fair bit of clambering through, over, under and around to get to everything. Having successfully oiled round with Andrew Vaughan and Steven, we were getting ever closer to the big moment.

The engine almost seemed to sense her chance at freedom after all these years and the hearty fire soon brought the loco round. Loco manager Leigh Drew, Ali and myself were on the footplate and I had been given the honour of the driver's seat for this first move. It's then that all the things you have been through strike you. We had every last part of this engine in pieces. She has had the most extensive work on her since her restoration at Swindon in 1964. It all flashes before your eyes. We had tested a great deal before this moment. The boiler has been steamed multiple times. We had tested the injectors and all the other bits associated with that while doing so. The brakes had been tested – she stopped No. 08 604 dead in her tracks when we did so! We had managed to go through everything. Except two things. Karl Buckingham has a great deal of experience with the GWR express fleet and he had been coaxing the hydrostatic displacement lubricator into life all morning. There were a few small leaks found here and they have gone on the snagging list but it wasn't by any means a show stopper.

4079 on the main demonstration line, Leigh Drew leaning out of the cab.

That meant that the ONLY thing not tested was opening that regulator and seeing if the valve gear was going to do its job, deliver the steam to the cylinders and drive the engine out of her slumber. Whilst nerve wracking in a sense, I was also immensely confident in the work that my team had done. The handbrake was wound off. I wound the reverser forward to 75% cut off and opened the large ejector to take the brakes off. The twin needles on the brake gauge slowly rose like the arms of a conductor, preparing his orchestra for a symphony. Under my breath, I told the engine to ‘behave itself’ and opened the regulator. The steam rushed out of the cylinder drain cocks. As we were in the shed, quite a lot of the world up front temporarily disappeared! As the view started to clear, steam surged through the circuit, out the regulator, into the header, down to the superheater elements and then through the valves and into the cylinders. There is a slight pause when this happens and then, she moved!

The feeling this causes is amazing any time you do it – the sense of power being unleashed is huge – but to do it on a locomotive that you and your friends have put so much of yourselves into. To do it on a locomotive that is as historically important as Pendennis Castle. To be the first person to make her move again since 1994 in Australia and since 1977 (when I was just 2 years old!) in the UK. THAT was an amazing privilege. To tell the truth, the whole thing was wonderfully uneventful. As she pulled out of the shed in front of the team that had brought her back to life, she just ‘went’. No drama, no problems, just a set of 6’ 8” driving wheels elegantly turning under that classic Castle shape and just the slightest exhaust note. Having stopped her, made her safe and passing our congratulations around in the cab, I jumped down and shared what had just happened with the No. 4079 Team that had gathered to witness their superb achievement.

4079 doing her stuff on the main demonstration line.

The rest of the day was spent on the main demonstration line running up and down and slowly working the engine. She has yet to have her brick arch fitted in her firebox, so any loud noise from the exhaust wasn't possible. It would draw cold air into the firebox to places we don't want it and cause the leaks that we were trying to avoid earlier. We decided to do this so we could keep a close eye on the inner firebox during this test but it was trouble free and the arch will be fitted in the near future. All the crew mentioned so far worked her in rotation throughout the day, running her up and down, putting the first miles on the engine. As we did so, things started to loosen up. The reverser was really stiff to start with – it had been overhauled a good few years ago! Moving it back and forth with a liberal application of oil saw it free up quite quickly. There were a few times where I had one of those ‘is this real?’ moments. Is this really the engine we have all been working on that's now moving? It has been a long time coming – it's still sinking in as I write this frankly!

4079 on the main demonstration line.

The loco stopped at lunchtime and while Steven, Andrew and I had something to eat, the rest of the gang went over the engine and inspected it. I'm pleased to report that nothing much was found! Up to ‘8 road’ she went again after we had refuelled(!) and she ran up and down all afternoon too. The reason for the day was twofold. It was primarily an engineering test which went pretty well. There are a few little bits to sort out but that's to be expected. Even Swindon put their locos on local services to test them first! It now falls to us to eliminate the snagging list and to complete the painting of the locomotive. I'll report back on that as soon as there is news.

The Pendennis team with the loco in the background.

The other reason was for the No. 4079 Team to gather to celebrate their achievement. They all got a ride on the footplate and the wonderful picture that you see here was taken. The application of smiles was universal. Some of them hadn't been to Didcot for a while, others are still regulars, but they all played their part. They all gave of their time and energy so that this icon could live once more. Thoughts did turn to those that didn't get to see her finished. There were a few that started this journey with us but didn't finish it. It was only right that we remembered them on this special day. I really can't express how grateful I am to them all for what they have done. I started with a restoration team but I now have a bunch of amazing friends. I guess No. 4079 Pendennis Castle has given us all something too...

All the best,
Drew Fermor
No. 4079 Pendennis Castle Project Manager
Great Western Society
Didcot Railway Centre

PS: A BIG thank you to all the footplate crew who made the day possible - we couldn’t have done it without you!

PPS: Don't forget to vote for Pendennis Castle in the annual Steam Railway magazine award at the Heritage Railway Association’s awards ceremony later this year. Vote before 18 February at:


Ready For Inspection? - Part 1

We have many curious corners of the collection at Didcot. One of my favourites is the track inspection vehicles. Railways are big. It's one of their defining features in fact! They need to travel over long distances. The track over those long distances needs to be inspected. Now, you could expect your track inspection teams to walk the line but when your railway runs over many hundreds of miles, that is vastly inefficient. So, the ideal is a small vehicle that is easy to use and flexible in operation.

The earliest track inspection vehicles were human powered. The ability to put a mechanical power plant in such a small space had yet to be perfected. The small internal combustion engine really only came into its own around the turn of the nineteenth and twentieth centuries. Our first example is possibly the oldest working vehicle in the society's collection. Think of classic black and white comedy movie involving railways and inevitably the thought turns to the classic pump trolley. You've all seen them. 4 wheels, a frame with a double ended see saw mounted on it that has a handle at each end. Yep, that one!

The design dates way back to the 1870s and while we can't be sure how old our example is, it carries the markings F.M.C. This stands for the Fairbanks Morse Company. They were a heavy engineering company that were based in Chicago, U.S.A. These trolleys work much the same as those old toy pedal carts where you had little stirrups to pump back and forth to make the car go. Perhaps I'm showing my age here... The up and down action is translated into a rotary motion by a crank and that motion is used to drive the wheels. It is that simple. We can be sure that this is one of the G.W.R. examples because we know that they ordered a batch from Fairbanks and this particular one was found in the goods yard at Reading!

The pump trolley as we first saw it, in Vastern Road goods yard at Reading early in 1972.

Although it was saved complete and taken to Didcot upon discovery, by 1980 it was looking a bit rough. By rough, I mean that it was a pile of parts and rotten wood! This clearly wasn't good enough and so the remains were scooped up and taken to Taunton for the G.W.S. group there to restore it. The ‘to do list’ was fairly extensive. Several components were missing, including some of the vital bearings. One of the wheels was buckled and an axle was bent. That's without the fact that the wood now had the structural qualities of wet cardboard.

There is luckily an original and intact example of this type of trolley in the Henry Ford Motor Museum in Detroit, Michigan. The museum kindly allowed the restoration team to take a series of photographs and measurements to rebuild ours. The wheel and axle were slowly straightened out using an oxy-acetylene torch and liberal use of hammers and other light adjustment techniques. A local school made the new bearings and the old woodwork was laid out as a pattern.

The pump trolley was brought back to Didcot on its bespoke trailer in September 2017. It was in storage for a few weeks before appearing in the Street Fair.

A large plank of ash was living at the back of a Taunton timber yard. This didn't remain a single plank for long and was machined into the sections for the new pump truck frame. The boards for the floor came from St Mary's Church in Lambeth - they date back to the early 1800s. The whole ensemble is topped off by a warning bell. This is an old fire bell that came from the Van Heusen shirt factory in Taunton. The remarkable restoration was completed in April 1983 and it was all systems go from then on.

The very next day, the pump truck completed a 100 mile trip on the West Somerset Railway. The reason for this somewhat excessive ‘running in’ journey was as a fundraiser for the Society's Taunton Group. It was a start of a career of fundraising that has covered many years. The performance of the trolley has been explored in some of these events. The classic pairing of two people working the mechanism will apparently get you comfortably to 15 mph. You would think that more people = more power = more speed but the problem is that eventually people get in the way of other people and efficiency is compromised. The key crew size is five and as such the power can really be put down to the rails. It can do over 20mph like this! The technique is key too. Once inertia is overcome, the trolley will roll really well. The only issue is that unlike a bicycle, there is no freewheel. If you stop pumping, the handles still go up and down. It is possible to stand clear and let it go. Just watch where you are standing...

While all these higher speeds and long distances are all very well, the other side of the operation of the pump trolley is that of giving rides and it is a very dependable, reliable vehicle in that respect. It has given hundreds and hundreds of rides to members of the public over the years since its resurrection. In doing so, it has raised thousands of pounds for the society and for other worthy causes such as leukaemia research. What was once an everyday tool has become a force for good and a great advert for the Great Western Society. Its most remarkable exploit was the time that it, like the 14XX Class 0-4-2 in that magical film ‘The Titfield Thunderbolt’, eschewed its rails and took part in Taunton Carnival!*

Didcot's Street Fair in November 2017, when the trolley appeared in the parade on its trailer – no grooves on Didcot's roads!

In 1985, the trolley was driven around the carnival circuit as part of the town's G.W.R. 150 celebrations. 5cwt. of antique railway vehicle was pumped around the two mile carnival course. There is of course, no steering, and as such frequent stops for alignment purposes were needed. The trolley and its crew, with a one time only lighting rig eventually won first prize in the wheeled - non powered category. What the residents thought about the two lines cut into the tarmac by the wheels as it made its epic journey is unrecorded but they were visible for some time afterwards(!). These vehicles are rare and one in operational condition such as ours is even rarer. The Didcot example has only been recorded as being run alongside another example just once in the thirty years since its restoration. Its restoration and operation has been quite the journey - both physically and metaphorically and is a total credit to all those involved don't you think?

*I had to write this bit in February - if I'd written it in early April nobody would have believed it!

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