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Going Loco - January 2022


Wonderful Winter Wagons - Brewing Up Some Smashing Undersea Oddballs?

The freight collection at Didcot encompasses a huge range of different wagons. This is very much unlike today where most freight wagons fall into one of just a few specific cargos or are wagons for putting I.S.O. containers on. Back in the day of the Great Western however, there was a wagon for just about everything. We have a few wagons here that are at the outer edges of ‘everything’ and this is the story of two of them.

The reason these wagons even existed is as a result of the common carrier rules. Common carrier services are offered via a licence that is provided by a regulatory body. The upshot of this is that it means that the common carrier organisation is obliged to carry (within reason!) any cargo that people wanted them to move at a set rate dictated by the regulatory authority. This is unlike a contract carrier - such as a lorry firm - that gets to pick and choose their jobs. So the G.W.R. definitely needed to have a ‘wagon for everything’ policy!


The Mica insulated meat van No 105860 under restoration in the newly-built extension to the carriage shed. Tevans were converted from Micas made redundant by decline in meat traffic.

We dealt with the insulated meat vans known as the MICAs in the blog entitled ‘Going Underground - Deeper Underground’ in March of 2021 so for the full story, look there. The basics were however that the G.W.R. went through a whole series of development stages in the field of transporting fresh meat. The great thing about this design was that it was fully insulated and therefore the design had potential use elsewhere. As the sealed and insulated design could also be used to keep the interior dry, there were several conversions to a type known as a TEVAN. This conversion did away with the distinctive ‘ice’ boxes on the ends of the van and were lined with a zinc sheeting. The idea was that they were then perfect for transporting dry goods such as cocoa powder and tea (hence the inexplicably badly spelt name!). Ours is the sole survivor of the type being No. 79933. It was built in 1922 as a diagram X7 MICA and was converted to a diagram V31 TEVAN in 1938. The exact number of MICAs that became TEVANs is unknown but it is thought to be at least about 40. Not a common thing at all really.

This traffic had two sources. J.S. Fry at Somerdale and Keynsham - chocolate producers - and J Lyons who were in the tea business. The vans worked a circular route, starting at Bristol Temple Meads. The first leg of the journey was known as ‘The Cocoa’. The TEVANS were just part of a fast freight service that departed at 21:55hrs. It picked up the TEVANS at Bristol East Depot where they would have just arrived from J.S. Fry’s at Keynsham, full of Cocoa. They would get to Paddington Goods Depot in London at 02:40hrs, from where the TEVANS were worked separately to the Fry’s depot at Ladbroke Grove at 04:25hrs to be unloaded. The now empty TEVANS went from there to J. Lyons at Greenford where they were loaded with tea. The vans were then worked to Acton, attached to the express goods service in the other direction known as ‘The High Flyer’ which left for Bristol at 01:05hrs. This meant that the circuit was completed. It also meant that the financially savvy G.W.R. got two uses out of the same rolling stock and paid for the trip in both directions!

A poster in the collection at Didcot advertising visits to the Fry factory – for education in the manufacturing process or a self-indulgent opportunity to scoff chocolates?

Our second and final wagon for this year’s Wonderful Winter Wagons (is it nearly February already?!) is possibly the most esoteric piece of rolling stock on the Didcot site. Its remains lurk down the side of the engine shed and only the most intrepid visitors go to see it. There you will discover a low, rusty hulk that looks a bit like a well wagon except for the fact that it has two large frames mounted where the supposed large load would go if it were indeed a standard well wagon. It’s such an odd shape that most people don’t know what it is and as such it gets ignored but is a fascinating piece of railway heritage.

A Coral in Service

It’s called a CORAL. A ‘CORAL A’ in fact and its sole purpose was for the transportation of crates of sheet glass. That's right. It’s the railway equivalent of the modern high top van you see in next to you in the traffic jam with the big sheet of glass on its side! The divination of its purpose is not helped by the fact that only the fixed portion of the two racks that held the crates survives. There were two moveable sections that were also fitted. The first of these unusual vehicles was built way back in 1884. The example at Didcot dates from the second design diagram, D2 that were built at Swindon between 1898 and 1908. This is one of the last to be built. They were 7 tons 9 cwt. when empty and 12 tons fully laden. There were only 25 of both types (6 to D1 and 19 to D2) so they were always a bit of a rare beast and, as you might expect, the remains of No. 41723 are the sole surviving reminder of this traffic.


The Tevan No 79933 in its current condition and The Coral No 41723 in its current condition.

Both these wagons are not in the greatest condition but they are safe. TEVAN No. 79933 is kept reasonably watertight as it is a stores vehicle at the moment but hopefully it won't be too much longer before it gets the ‘Carriage and Wagon Department full treatment’. CORAL No. 41723 is best described as a basket case(!) and will need fairly major plate work replacement to become whole once again. But there are enough pieces there to work with. It's no worse that the tender that currently resides behind No. 2999 Lady of Legend when it was started! It was saved from destruction by the far sighted 813 Charitable Incorporated Organisation who still own it. There are plans afoot for a full restoration once the drawings are finalised and a small space in the loco works (it's all metal at the end of the day!) becomes free. The gathering of the requisite funding is already underway. So, there we are a pair of G.W.R. oddballs reported upon by a third G.W.S. oddball. That's what I've been told anyhow...


Wonderful Winter Wagons: Old King Coal

Coal was once the lifeblood of industry. That scenario is fast becoming a memory, with it coming down to limited heritage use to show how things were once done, but its historic legacy remains. Especially at Didcot. The beginning of the restoration of our unique coal stage and water tank led me to think about coal and how we really haven't had a chat about it in Going Loco.

This drawing of a GWR standard coal stage was published in an article on Fuelling our Locomotives in the Great Western Railway Magazine in May 1940.

The movement and distribution of coal was key to the Great Western for two reasons. Firstly, it was a business opportunity. The movement of coal from the Welsh coalfields to consumers was of massive importance to the G.W.R. financially. However, the other big issue is that without coal, the railway didn't move! The transport of coal as a goods item we will deal with another time but let's look at the subject of coal as the lifeblood of the locomotives.

The main point to know about the coal used by the G.W.R. is that it was of a very high calorific value. This means that it has a lot of energy bound up within its chemistry. More so than most other coals burnt in the industrial era. This is obviously good from the point of view of the locomotives but it does come with a price. This coal was also very easily broken. If roughly handled, it could turn into dust and you can't easily fire a steam engine on powder. With the draught caused by the heat of the fire and the exhaust beat of the engine, it's just gets picked up and blown out the chimney!

The mechanical coaling plant at Leicester (Midland) in 1957, typical of many built in areas where hard coal was used at a locomotive depot. Photograph by Ben Brooksbank.

On railways using coal such as the hard Yorkshire variety, the fuel could be loaded into huge mechanical contrivances called coaling plants which would pick up the whole coal wagon and tip it into a large bunker, thence into the bunkers and tenders of waiting locomotives. With Welsh steam coal this couldn't happen. So, all of the coal on the Great Western was moved by hand. Incredible as it seems, it was all moved on a shovel by blood and sweat. The coal stage at Didcot is the last link in that chain.

Trains of specialised coal wagons would come from the mines in long trains, being split up to various destinations based upon need. The largest depots like London Paddington's Old Oak Common had a locomotive allocation of well over 200 engines and chomped its way through about 3,000 tons of coal a week! Didcot's allocation was about 50 locomotives so was nowhere near that hungry... The loco coal trains would be put into sidings adjacent to the shed. From here, they were split into 5 wagon sections. These 5 wagons would then be pushed to the top of the coal stage ramp. Each of the wagons held on average 10 to 20 tons of coal.

Wetting the coal in one of the tubs to dampen the dust before tipping it into a locomotive.

The wagons were unloaded in the coal stage building into one of fifteen 10cwt tubs. These little tubs are on four wheels and have a door on one end. There are two types of tub. One had an end door all the way across and the other has a narrow end door. The wide ones were for tender engines and the narrow for the bunkers of tank engines. Their wheels are quite close together and the reason for this is that they are designed to interact with the drawbridge like doors on the locomotive filling side of the coal stage. There are little tracks on the drawbridges that the tub wheels engage in. As you push the tub forward it eventually gets caught in the end sections. You then unlock the door with a lever at the rear of the tub and then tip it into the awaiting engine below.

Tipping coal into a locomotive from the Didcot coal stage.

The now empty coal wagon was then allowed to roll down slowly to the ramp side of the coal stage. The coal men used a brake stick to control the descent of the wagons. This was a big chunk of wood that looks like the handle of a cricket or baseball bat at one end but is a large square section at the other. The idea was that you place it in between the frame of the wagon and its brake lever. Pulling down on it applied the brake. Usually. Despite the skill of these men, it wasn't unknown for the wagon to get away from them. Sometimes the wagon handbrake wasn't great. Sometimes they didn't put the brake on hard enough. The outcome was the same, a 12 to 20 ton wagon slowly creeping off down the ramp, gaining speed, on its way to Paddington all on its own! There was a catch point at the bottom of the ramp and this derailed the wagon before it got away. This inevitably buried it up to the axles in the ballast and then it had to be re-railed. I can't think this was a fun time for anyone involved...

1340 shunting our coal wagon into the coal stage.

The job of coal man required a singularly tough and fit man. They almost never wore gloves - even in the freezing cold - it was seen as a sign of weakness and they were famed for their calloused hands. Over a shift, they might load 25 to 30 locos. An 0-6-0 pannier tank loco takes about 3 tons of coal. The G.W.R. tender engines take about 6 tons. This was quite the job for the team. In his book Didcot Engineman*, Bernard Barlow remembered a coal man called ‘Tad’ Jones. His house was 4 miles from the shed. He would walk to work in all weathers, do his shift, have a swift pint in the Prince of Wales or the White Hart pub and then walk home. These men were made of some very tern stuff...


Working Volunteers Ali Matthews and Leigh Drew's Clean(!) but well worn hands.

The wagons used to transport the coal were all labelled under the N series of diagrams or designs. They have their origins with a set of wagons built in the early 1880s. The biggest difference between these and the majority of those that came later was that they were made of timber. The earliest of the more familiar metal ones came along in the Diagram N6 10 ton versions that were built between 1889 - 1893. They shared a lot of features with the very similar ballast wagons in the P diagrams also being developed at that time. For extra nerd points, if you see a G.W.R. Loco coal wagon with rounded corners, it's a pre WWI example. The N20 design was the first of these square cornered design in about 1915 and in the end there were 10, 12 and 20 ton 4 wheeled versions and even a few 40 ton bogie coal wagons which were quite impressive looking things!

A 40 ton loco coal wagon. This photograph was published in an article on Fuelling our Locomotives in the Great Western Railway Magazine in May 1940.

Our loco coal wagon is a rare survivor of the 20 ton version. No. 63066 is built to diagram N34. It was completed in 1946, right at the end of the reign of the G.W.R. as a private company. The 20 and 40 ton wagons came about as a result of a study into the efficiency of coal trains. The findings were that, obviously(!), the smaller the wagons in the train were the longer and heavier the train would be. A train to carry 600 tons of coal was the basis of the calculations. The worst case scenario was a train of 8 ton capacity wagons. This would have needed 75 vehicles plus the loco and brake van. It would be 1,350 ft long and its tare (empty) weight was 400 tons! The rest of the figures were for:

10 Ton wagons = 60 vehicles, 1,080 ft long and a tare weight of 369 tons.

12 Ton wagons = 50 vehicles, 975 ft long and a tare weight of 350 tons.

20 Ton wagons = 30 vehicles, 735 ft long and a tare weight of 288 tons.

40 Ton Bogie wagons = 12 vehicles, 690 ft long and a tare weight of 280 tons.

Our 20 ton Local Coal wagon No 63066.

This was a dramatic demonstration of the economies of scale and while this idea was pushed forward for both loco and commercial coal traffic, it never really bore the fruit it deserved to. The reasons for this are quite complex and despite a great many 20+ ton coal wagons being produced, the traffic of coal in 10 and 12 ton wagons persisted into the British Railways era. The coal stage at Didcot is now unique in the fact that it is still in operation - it has been almost constantly since 1932 when it was built. Understandably, it's showing its age a little now and the current work being undertaken it to ensure its long term survival as the unique piece of working industrial heritage that it is. The 75,000 gallon water tank on top of the coal stage is first to receive attention and work will progress down the structure as time and funds allow. The coal stage and No. 63066 tell an important part of the Didcot story. It's comforting to know that the remarkable working lives of people like Didcot’s ’Tad’ Jones and Freddie Knapp, some of the unsung contributors to the steam age, will thus be remembered by future generations.

*ISBN 1 874103 20 8, published by Wild Swan. It’s WELL worth a read!

This footnote to the coal story was published in the second part of the article on Fuelling our Locomotives in the Great Western Railway Magazine in June 1940. The photograph shows the centenary celebrations of the Baltimore and Ohio Railroad in October 1927. The article explains: ‘The exhibition authorities did the Great Western Railway Company the honour of allowing their engine King George V, No 6000, to lead the procession. When reaching the judges the procession was stopped by them to ascertain whether it was really using the same class of coal as the other engines. It was established that the engine was burning the same coal, only the one source of supply being available to all the locomotives.’ The photograph illustrates the perfect combustion achieved in the firebox of the Great Western engine, compared with the black smoke emitted by the following locomotives.


Wonderful Winter Wagons: Let's Face The Moosic And Dance!

Welcome back to Going Loco for 2022 and a happy new year to you all! The new year brings the going back to work or education or both(!). That means it's really important to have that first meal of the day. Milk on the cereal or in the porridge and in the tea is a must to fortify yourself for the challenges of the day. Today, milk comes via the supermarket but if we were in the middle of the last century, milk - in large towns and cities at least - came via a train, and onward to a milkman, who delivered it to your doorstep. So, given our wonderful winter wagon series, I thought we'd have a look at the three wagons in the collection that were purpose built to carry milk.

Arrival of churns of milk at Paddington station during the General Strike in 1926.

The railways were a positive boon to dairy farmers since their inception. Although large towns and cities kept herds of cows locally well into the second half of the nineteenth century, the fact was that the railway enabled these dairy farmers to tap into new markets. Previously, the lack of refrigeration technology meant that the milk could only be delivered as far as it would go and still be fresh enough to consume(!). Even early passenger railways were capable of travelling at 30mph and the early G.W.R. was capable of 60mph. This meant that the milk could go a lot further without going off.

Milk was now coming into towns and companies and cooperatives were set up to handle this trade. The first being the famous Express Dairies in 1871. But many others followed. The main method for transporting milk had gone from the wooden pails or buckets that were slung on a wooden yoke over the shoulders of milkmaids to the use of a conical shaped wooden version. The wide base making them far less likely to fall over. These wooden ones were heavy though and in the 1850s a steel version was made. These two things combined to make it possible to transport milk long distances from its point of production. As always, a specialist form of wagon would be along to carry it.

On the G.W.R. these became known as the SIPHONs. They operated on a very simple principle. They were wagons with vents in the sides. Originally this was done on the basis of just leaving out every other plank on the sides of the wagon but progressed to being proper louvres. The idea was that the motion of the train speeding along would cause the air to circulate thus creating a cooling effect on the cargo. Of course, this leads to the assumption that the train is moving fast and freight trains in general didn't move that fast in the steam era. Until that is, situations like this turn up where the cargo needs to go fast. This is where we use vehicles that are rated to travel at express passenger train speeds. With the SIPHONs they eventually evolved from a long wheelbase 4 or 6 wheel wagon into what essentially looks like a passenger coach with no windows.

Siphon G No 2796 preserved at Didcot. Note the ventilation slats and four sets of double doors for loading and unloading the milk churns.

Our SIPHON is a SIPHON G model. This example, No. 2796, was built at Swindon to diagram O.33. This shape of SIPHON is the most recognisable amongst those that know these things. It was a typically G.W.R. design and was ubiquitous on their system. They and similar designs were built into the British Rail era and they lasted well after the steam locomotives that originally hauled them had been withdrawn. They had a hand in moving newspapers and parcels with their vents sealed shut and eventually as service vehicles, moving spare parts and the like around the system. These often had the code ENPARTS on the side and could still be seen at work in the early 1980s.

Didcot's milk tank No 4409, now painted in Co-operative Wholesale Society livery.

While the movement of milk in churns was traditional, the railway always does best when it transports one thing in bulk and so, the dairies went from the moving of unprocessed milk in churns to using bulk tankers to move it instead. The first of these were put into service on the G.W.R. and the London, Midland and Scottish Railway (L.M.S.) in the late 1920s. The arrangement between the railway companies and the dairies was a strange one. The railway built and owned the chassis of the vehicle. It had to run at passenger speeds still, so unlike the tens of thousands or private owner open wagons that waddled up and down the country at 25mph, the level of technology and consequent maintenance was that bit higher. The tank itself however was owned by the dairy, despite the fact that the two were essentially inseparable without dismantling the wagon a fair bit! They were first produced as 4 wheeled tankers, that claimed to be glass lined. It doesn't take a genius to realise that even in the best of circumstances, a wagon like a glass lined Thermos flask won’t last the bumping about that the railway will dish out! They were actually lined with a vitreous enamel - a bit like old metal baths. The issue was that the action of the swaying of the 4 wheeled chassis combined with the fact that there were no baffles in the tank lead to two things:

  1. The milk was effectively churned as it went along - spoiling the product.
  2. This made them very unstable and resulted in a number of derailments.

A rethink was clearly required...

This came in the shape of the 6 wheeled chassis in the early 1930s. This gave a much smoother ride, stopped the derailments and ceased the inadvertent butter production. The 4 wheeled ones were all withdrawn by the late 1930s. The six wheeled versions were still being built new by British Railways in 1955 so something was right! They had a capacity of 3,000 gallons and this weighs about 13 tons. Given that the wagon itself weighs 12 tons and we are getting on for a situation where each of these wagons weighs nearly the same as a passenger coach. The milk trains, once the wagons had been collected from the smaller dairies on the branch line, needed to move fast so it may be surprising to some to realise that it was fairly usual to see one of these trains being pulled by a Castle Class express passenger locomotive. It needed that level of speed and power to do the job.

Castle class No 7000 Viscount Portal heads a westbound train of empty milk tanks through Southall in the early 1960s, photograph by Mike Peart. The tanks were taken back to the west country in the afternoon to be loaded and return full of milk to London's dairies overnight.

0-4-2T No 1450 during a visit to Didcot in 2019 hauling a mixed milk and passenger train.

In preservation, there are a great many G.W.R. and L.M.S. built milk tankers. So that's why we've got a rare Southern Railway (S.R.) one(!). No. 4409 was built to diagram 3152 in 1931 as a 4 wheeled vehicle at the S.R.'s works at Lancing. As we have discovered, 4 wheels bad, 6 wheels good*, and it was rebuilt at Ashford in 1937. It has a stainless steel tank rather that the ‘glass’ version and as such, the tank has survived very well. So much so, it's still used to transport water around the railway centre. You may also see it occasionally tagged on to the back of a passenger coach on the branch demonstration line to demonstrate the working of wagons to and from the local dairies and the main line.

Our final version of milk on rail is wagon No. 3030. This is known as a ROTANK. The idea here is that the tank section of the wagon is actually a road trailer that can be loaded onto what is effectively a flat wagon for high speed rail transport. This gave an added level of flexibility to operations, a milk tank could be hauled along a road from a creamery to the railway, loaded onto the flat wagon, taken to a destination and either treated in the same way as the fixed tank wagons or be unloaded onto the road for further shipment.

Didcot's Rotank No 3030 has recently been repainted by Ann Davies, in a bright red for the road tank vehicle.

The road tankers were fairly similar in design and came in both 4 and 6 wheeled varieties. Initially they had solid tyres and looked much like the early lorries of the day but soon evolved to having modern suspension and pneumatic tyres. Our version was built to diagram O.58 in 1947 and the 6 wheel road tanker that sits on it was built for the Henry Edwards and Sons Dairy. These were nowhere near as long lived as their fixed tank brethren, the last being taken out of service in the mid 1960s.

The westbound milk empties train heading towards Plymouth, where the tank wagons were distributed to various milk depots. This train behind Hall class No 4941 Llangedwyn Hall was photographed near Frome by Ben Brooksbank on 22 August 1959.

At its peak, in 1923, the railways of the U.K. moved a staggering 282 million gallons of milk. When you consider that it was judged that a single 3,000 gallon tanker could provide enough milk for 35,000 people for one day, it gives you some idea as to the enormity of the job! This wasn't to last and despite all the advances in technology in the bulk tankers and so on, it was inevitable that the roads would take over. By 1969, there were only two major routes still being used on the railway to carry milk. Dairies in Fishguard, Devon and Cornwall delivered their milk by rail to London. It may seem like a small deal but this still accounted for 25% of all the milk being transported in the U.K. and totalled 70 million gallons per year. This ended in May 1980, bringing to an end a historic trade route. Milk today is only moved up to 100 miles on the road by the dairies and supply chains and logistics take care of the rest. The delivery of milk on the railways is a surprisingly interesting subject and this blog only scratches the surface. There is a great deal of quality information on the internet about it that is well worth reading. Still, I'm going to stop now - I don't want to be accused of milking it now do I? Have you herd of such a thing? That would be udderly unacceptable.

I'll get my coat...

...and moove along.

*With sincere apologies to George Orwell...

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