The Great Western: the world’s first high speed railway
GARETH DENNIS takes us on a journey along a line that, perhaps like no other, conjures up pride in those who have worked or travelled on it.
A version of this article also appeared in Issue 873 (27th February 2019) of RAIL magazine as part of their Seven Railway Wonders series.
It was built as a racetrack of iron. 118 miles of near-straight alignment carving its way through the English countryside. Not content with being the world’s first high speed railway, it also carried Britain’s first passenger-carrying high-speed train only 135 years later.
Despite the iconic trains that have operated upon it, this epic piece of infrastructure still manages to make the track the story, and for that reason alone I should be enthralled by it, but as a permanent way engineer, the line as originally built challenges the very core of my beliefs: that system-wide compatibility is the key to a successful railway network.
I like being challenged, which is one reason why I love the Great Western Railway.
To be precise, I am talking about what is known today as the Great Western Main Line (GWML). Not the 1903-built Badminton Line through Bristol Parkway (now the eastern end of the South Wales Main Line), but Brunel’s billiard table via Bath, as it opened between Paddington and Temple Meads stations back in 1841.
By the middle of the 1830s, Britain had already seen the opening of the world’s first modern railway (the Stockton and Darlington Railway), the world’s first inter-city railway (the Liverpool and Manchester Railway) and London’s first terminus (Euston opened in 1837).
Indeed, Britain was gripped by “railway mania” from the middle of the 1830s, with hundreds of schemes being proposed by speculative investors each year. Most were short, many were cheaply built and none of them had any real strategic vision in mind.
In Bristol, however, events were conspiring to ensure a railway was built to buck this trend.
The city’s merchants (having neglected the condition of the harbour facilities) feared that they would lose out to Liverpool as Britain’s primary west-facing port thanks to the new railways springing up in the north. They wanted a London-bound railway of their own to be built to such a high specification that no other railway could compete.
In 1835, they appointed the bold, brash and occasionally barmy civil engineer Isambard Kingdom Brunel as the lead engineer for their newly-formed Great Western Railway. Excited by his biggest new project and undeterred by the directionless railway chaos that was frothing up around him, Brunel saw an opportunity to make his mark on the development of the railways. Within a month, he had worked out his preferred route and started crunching the details.
As Brunel said himself: “Looking to the speeds which I contemplated would be adopted on railways and the masses to be moved, it seemed to me that the whole machine was too small for the work to be done, and that it required that the parts should be on a scale more commensurate with the mass and the velocity to be obtained.”
And so increase its scale he did. Specifically, he widened the distance between the rails (the “track gauge”) from Stephenson’s 1435 mm (4 ft 8½ in) to his own “broad” gauge of 2140 mm (7 ft ¼ in), allowing — as he saw it — the larger locomotives required to haul the massive trains the new line would attract.
Yet the Great Western Railway in its early days was as much a victim of Brunel’s vision as it was later a success.
No matter what the possible technical benefits of a bigger gap between the rails, Brunel’s use of broad-gauge was a phenomenally daft idea from an economic and commercial perspective. Not only was the capital cost to build the railway double that of similar railways being built at the time, but the interface between gauges meant an inability to smoothly operate passenger and freight flows beyond the limits of the Great Western Railway’s infrastructure.
As one of the key emerging functions of Britain’s embryonic railway network, this was a serious shortcoming. The decision to build an intercity railway using a gauge that was not nationally-compatible constrained the economies of Bristol and the south west compared to the rest of Britain, and resulted in population growth being lower alongside the Great Western Railway compared to the other London-bound main lines.
The most impressive track renewal of all time?
Having inherited quite a sizeable mileage of standard-gauge track through amalgamations, and with commercial demands requiring an increasing rate of mixed-gauge track to be laid, the end was in sight for Brunel’s broad-gauge railway. In the mid-1860s, the Great Western Railway began the process of converting its system into a nationally-compatible one.
Wales saw its last train operating over broad-gauge in 1872, and with hundreds of miles of branch lines having been converted by the 1880s, the only significant remaining broad-gauge track was on the Great Western main line itself, between London and Penzance. 177 route miles to be precise (and nearly three times that many track miles).
Successive conversions over the preceding decades had allowed the GWR to accumulate a great deal of experience, allowing preparations to a high level of detail and accuracy in offices and on the ground. Through the first months of 1892, teams of permanent way engineers prepared the railway corridor for an unbelievably ambitious renewal: the whole remaining length of the Great Western would be converted into standard-gauge over a single May weekend.
At the crack of dawn on Saturday the 21st of May, nearly 5000 platelayers, gangers and supervisors set to work, not only changing the distance between the rails but also ripping out Brunel’s original longitudinal timbers and replacing them with the more effective (and by that point commonplace) transverse sleepers that we still see today.
In what might be the most incredible infrastructure renewal activity in history, this oil and sweat-soaked legion successfully replaced well over 500 miles of track in time for the passage of the Sunday night mail train from Paddington to Plymouth.
Now there’s something for Network Rail’s High Output renewals team to aim for in the next funding period!
Brunel’s choice of route and decision to minimise the number of stations was initially problematic, too.
The lack of intermediate railway stations through London’s suburbs limited the sprawl of the city along the Thames Valley, and resulted in a constrained public transport provision even up to the present day. Even Crossrail only has the chance to stop at a few stations in the west of London compared to the higher frequency of stations in the east.
So much for the Bristol merchants’ aspirations of grandeur, then? Perhaps not. The connection of south Wales and the Welsh coal mines to the Great Western Railway once the railway had been converted into standard gauge allowed it to come into its own. After 1900, Bristol began to thrive.
At this point, Brunel’s foresight into what future railway operations would look like meant the straight and wide GWML began to be put through its paces. Shortly after the turn of the century, steam expresses in and out of Paddington were averaging over 50 mph. By the 1930s, trains travelling on the Great Western were clocking up the fastest average speeds in the world at over 80 mph.
To top this all off, the first passenger-carrying High Speed Trains (the then-Class 253s) started using the line in the mid-1970s, helping to transform the fortunes of the railways in Britain after a period of increasingly apparent decline.
Today, and thanks to Brunel’s legacy of speed and scale, the Great Western has the capacity to bring 7000 passengers in as many as thirty trains per hour into London at peak time, and around 450 trains arrive into Paddington station daily (that’s ignoring the Underground). It is the gateway from London into most of Wales and the West and is therefore one of the most important stretches of railway in the country.
Every line in Britain (with a few nerdy exceptions) has an Engineer’s Line Reference, or ELR. These were almost always chosen to indicate the name of the line they represent. To give an idea of the place the Great Western occupies within the railway industry — and perhaps the boisterousness of the Western Region divisional civil engineers at the time today’s system was devised — the ELR of the GMWL is “MLN”, standing simply for “Main Line”.
The contemporary over-specification of the original line meant that not only did it intersect many geographical features that required substantial permanent works to overcome, but that many of its facilities and servicing buildings were of a very high architectural quality, as evidenced by the number that now benefit from listed status. In fact, the line is currently applying to gain UNESCO world heritage status, and this wealth of construction forms the basis of the bid.
By way of a celebration of the line, I’m going to take us on a journey along the length of this incredible railway that several million people a year experience, and explore some of the defining features that justified your selecting it as one of Britain’s railway wonders.
We’ll start, as makes good sense, at the zero milepost and the buffers in Paddington station.
Perhaps strangely, the station beloved my so many today is not the original terminus of the line. Despite the GWR stopping trains in the area by 1838, the newly-opened line operated into a temporary terminus at Bishop’s Bridge, a site that later became the GWR’s goods terminal and is underneath what is now the Paddington Central development site (around the appropriately-named Kingdom Street).
In fact, if relations between the Great Western Railway and the London and Birmingham Railway had not turned sour early-on in the line’s design, neither the temporary or final terminus would have come into existence, and Euston may well still have been the terminus of the GWML. Ignoring the strategic benefits that might have had for interchanging passengers, it would have denied us an immensely lovely station complex that, despite several substantial reconstructions, remains largely true to Brunel’s original vision.
Opened in 1854, Brunel’s design for Paddington station took cues from the glass spans of Crystal Palace and the Romanesque and Renaissance revivalist stonework of Munich’s Central station (both of which are now sadly lost), combining them wonderfully to give us the station we recognise now. The 210-metre-long train shed with its intersecting transepts and the various railway buildings that surround it are a unique and valuable entry in the annals of railway architecture.
Anyway, you’ve spotted your platform and have hopped into a sleek green train. It’s time to go.
Within two miles of setting off, the permissible speed is 100 mph for passenger trains. At the four-and-a-half milepost (barely six minutes after leaving Paddington), the fabled 125 mph speed board gives passenger trains the run of the road. It is also at this point that trains going in the other direction start decelerating on their approach to the buffers.
By this point, you’ll have passed Old Oak Common. The depots straddling the main line (Old Oak Common and North Pole) have been the home of several generations of legendary traction, not least the High Speed Trains and Eurostar Class 373s, and this legacy continues as they act as the base for Crossrail’s Class 345 Aventras and a maintenance centre for Hitachi’s fleet of Intercity Express-derived units.
The new depots aren’t the only part of the story at this busy bundle of criss-crossing steel. When it opens in the middle of the next decade, Old Oak Common railway station will have a capacity on a par with Waterloo, providing an interchange for as many as one hundred million passengers connecting between Crossrail, High Speed 2, Overground, Underground, Southern and Great Western services.
By the time you reach Hanwell only seven-and-a-half minutes after leaving Paddington, the amount of green outside the window increases as you skip into suburbia. Moments later, you are passing over the Brent valley on the 270-metre-long Wharncliffe Viaduct, which is an edifice built on firsts.
It was Brunel’s first significant bit of structural engineering, the first construction contract let in the building of the line, one of the first structures to be listed (in 1949), the location of the first commercial electric telegraph (sent in April 1839) and later the first public telegraph line, as well as eventually being one of the first trans-Atlantic cable routes. Not bad for the first major structure on the line out of Paddington.
If you want to see a vision of the future of mainline junctions, you can’t do much better than the now mostly grade-separated Heathrow Airport Junction a few miles further on… The final layout was only completed at the end of 2018, with successive Christmas blockades being used to build various over- and under-passes to split long-distance and high-density services from each other, the most obvious being the weathering steel trusses of Stockley Flyover taking trains out of Heathrow towards Paddington and the Crossrail tunnels.
Eleven minutes and fourteen-and-a-half miles after starting the journey, the GWML punches out from under the M25 and through the stations in and around Slough (which itself is Grade II listed).
Perhaps the finest single structure on the whole line is the Grade I listed Maidenhead Railway Bridge, and sixteen minutes into your journey you’ll cross the Thames upon its two elliptical arched spans. Despite being built 180 years ago, they remain the flattest ever built in brick. Brunel was famously untrusted when it came to the stability of the structural form, and to satisfy his critics he left the falsework in place on its completion. However, a storm washed these supports away a year later, and (of course) the bridge stood true. When its width was doubled in the 1890s, only fabled civil engineer Sir John Fowler (fresh from designing the Forth Bridge) was trusted with the work, and he thankfully took great care to preserve Brunel’s original aesthetic.
After skirting the side of Sonning village in the impressively deep cutting of the same name, you reach Reading station, thirty-six miles and twenty-five minutes after departing the capital. Having completed its £900 million reconstruction back in 2014, the station not only acts as an intersection of routes linking the Midlands, the west and the south, but is also soon to be Crossrail’s western terminus.
Eight miles later, the line and the Thames alongside it pass through the Goring Gap, a strange geological feature dating from the last ice age that forces the line to take its first tighter curves (though the speed is still 125 mph). We cross the Thames twice here, over the elegant Gatehampton and Moulsford railway bridges.
At the 53 milepost and forty minutes after departure, you’re at Didcot Parkway with the Didcot Railway Centre just to the north. Soon afterwards and at roughly the half-way mark between London and Bristol, the line reduces from four tracks to two. Here, at Steventon, the Great Western Railway briefly (between 1842 and 1843) located its headquarters in a building that remains intact to the north of the old station.
The relief loops between the former Wantage Road and Challow stations provide some additional redundancy in the timetable, but this stretch of the line has a distinctly rural feel to it, and there is a succession of now-closed railway stations before the line reaches Swindon. Names like Uffington, Shrivenham and Stratton Park Halt may have been lost from the railway map, but if they remained in place the capacity of the line would have to be that much smaller to account for stopping trains holding everything up.
Quite suddenly you leave the countryside behind as you pass under the bypass and enter Swindon, a town that owes much of its existence to the Great Western Railway’s decision to build its locomotive works within its limits.
Not only did its population grow rapidly thanks to the importance of the works to the operation of the line, but Swindon was also the home of several social enterprises that led the way in improving the wellbeing of working-class people. The health provision of the GWR at the Swindon Works was so successful that it was the model upon which the National Health Service would be based. Swindon was also home to various open classes for the betterment of workers, as well as the UK’s first lending library.
A little over an hour after leaving London, the South Wales Main Line (on its straight line towards Bristol Parkway and the Severn Tunnel) diverges from the original Great Western Railway at Wootton Bassett Junction, taking the energised overhead wires with it (but more about that later).
As we sail through Chippenham, 94 miles from Paddington, we are still at 125 mph even though the line is a little curvier than it has been previously. Just short of the 99 milepost, the line reaches its steepest gradient of 1 in 100, and we start the descent towards the infamous Box Tunnel.
Owing to the complex geological composition and proposed gradient of the line through the tunnel, Brunel had been repeatedly warned that its construction would be impossible, but that didn’t stop him.
At nearly 3 kilometres in length, it was the longest railway tunnel at the time of its opening (in the UK at least, it was surpassed four years later by the first Woodhead Tunnel at 4.8 kilometres) and the material eventually excavated in its construction, if piled up, would have been nearly three times the size of Buckingham Palace. Over 30 million local Chippenham bricks were used to line the western end of the tunnel, enough to build 4000 houses.
At its greatest strength, a workforce of 4000 hacked and hewed at the rock under Box Hill, requiring one tonne of candles and one tonne of explosives per week to illuminate then blast further into the sandstone chasm. The construction was not without loss, though, with an estimated 100 navvies having been killed, mostly in flooding and blasting.
Having emerged out of the western portal of Box Tunnel, almost exactly 101 miles from the buffers at Paddington, we find ourselves entering hillier terrain and contending with a curvier alignment. At the 101.5 milepost, and at the eastern portal of Middle Hill Tunnel, we reach our first permanent speed restriction of 100 mph outside of London (ignoring a brief drop through Reading station).
The gradient levels off again as we come out of this short tunnel, and the train starts slowing on the approach to Bath Spa station and the UNESCO world heritage site of the City of Bath.
Brunel’s approach to the design of the GWML through Bath is nothing short of showing-off. In 2012, Alan Baxter & Associates made its assessment of the historical and cultural merit of the structures along the line in advance of electrification, and it is difficult to find a better description of his extravagance:
“The engineering of the GWML through Sydney Gardens is a piece of deliberate railway theatre by Brunel without parallel. This utterly unique section of the line integrates line of route, landscape, retaining walls and bridges into a single engineering and design tour-de-force, in which every element responds to the picturesque Georgian planning of the Bath World Heritage Site.”
The final section of the GWML between Bath and Bristol includes a great many more tunnels and structures, and the permissible speed doesn’t climb above 100 mph.
The last of the great structures before we reach the centre of Bristol is the Tudor gothic (and Grade I listed) Avon Bridge in Brislington and now flanked by two newer and rather less attractive spans. The erection of this bridge gives us a chance to glimpse Brunel’s darker side: as the Bristol to Wootton Bassett section of the line became more delayed, the contractor who was originally intended to undertake the work was cornered by the Great Western Railway’s engineer-in-chief and ruined when he tried to suggest that poor quality materials provided by the GWR had contributed to slow progress.
In any case, a little over one hundred and eighteen miles from the buffer stops in Paddington, we reach the grand Temple Meads station and the terminus of the original GWML.
Brunel’s Bristol terminus was built in a much timelier manner than his London terminus, opening in 1841, and thanks to later reconstructions has remained largely distinct from the expanded and now-familiar curved platforms and train shed. The Tudor-styled offices and former terminal platforms are located to the west of the present-day station building and are now used for events, having seen their last trains in 1965 and been lovingly restored more recently.
Temple Meads station went through several substantial reconstructions, with new platforms being added in the 1850s, significant changes being made in the 1870s, then a doubling in its size again in the inter-war period to broadly give us the station we recognise today, complete with its grand clock tower.
The journey we’ve just taken is the same one that hundreds of millions of others have taken before in the 180 years of its operation, yet it has been greatly improved thanks to successive upgrades and changes in rolling stock.
As you step out into Bristol, less than two hours after leaving the capital, think of the gargantuan effort not only to build the GWML, but also to maintain and upgrade it for the 21st century.
Clearly the most radical change to the railway is also the most recent upgrade — the Great Western Electrification Programme is the largest investment in the line since its construction. By permitting electric-only trains with better performance and more seats, the capacity of the line is being significantly boosted, with thousands of extra seats a day (an extra 30% at peak time) being added.
As we all know, it hasn’t exactly been plain sailing since the project kicked off in 2012.
The resilience of the original GWML has caused at least some of the challenges in upgrading it for the 21st century, with the limited work done by British Rail to run its 125mph-capable High Speed Trains meaning that there was only a very cursory understanding of the existing assets. This meant there were a lot of unknown unknowns, which hasn’t made life easy for the designers or installation teams.
Nevertheless, and given that the wires to Bristol Parkway were energised in December 2018, it is worth taking a step back from the challenges and thinking about the scale of this achievement. 700 single track kilometres of line have been electrified over the last five years, which isn’t bad going considering that electrification of the East Coast Main Line took fifteen years for 2250 single track kilometres (a similar rate) yet there has been a near-vacuum of wiring work since the end of that project.
Over 7400 masts, 4800 booms and over 750 wire runs now provide electric power to a new fleet of electro-diesel (bi-mode) express trains — a compromise when compared to fully-electric units but a useful temporary innovation looking forwards to the incremental electrification of the rest of the UK’s main line network.
There’s more work to be done, of course. The branches connecting onto the GWML as well as the route through Bath and into Temple Meads remain unelectrified despite significant disruptive works having already been completed in preparation. Not only this, but complete re-signalling of the line with full ETCS and ERTMS (European in-cab signalling and train control) is due for completion before the end of the next decade, eking yet more capacity out of the line by squeezing trains even more closely together.
And what of the gauge question? Was Brunel right after all, and should we have adopted a wider distance between the running rails?
Actually, neither Stephenson’s standard- or Brunel’s broad-gauge are the optimum arrangement from a mechanical perspective, and if we could start from fresh the optimum track gauge is around the 1600 mm mark (it turns out the Irish got this right) but perhaps that is a discussion for another day…
Whether you are an unwithering fan of Brunel or remain more of a sceptic, it is difficult to find another railway that exists in the world with such a clear influence by a single human being. Other railways were undoubtedly created more economically, and other railway engineers may well have more railway miles to their name, but the mark that the Great Western Railway made on the development of the modern railway will never be forgotten.
