Category Archives: Waterways & Railways between Thames and Severn

Closely-guarded secret

Box Tunnel, Great Western Railway, Wiltshire

Box Tunnel, Great Western Railway, Wiltshire

Isambard Kingdom Brunel’s Box Tunnel is celebrated for its engineering significance – and for its entertaining legends.

Driven through the unfriendly Cotswold geology, at the time of construction it was, at 3,212 yards, the longest railway tunnel in the world, though several earlier canal tunnels were longer.

Furthermore, Brunel designed it on a gradient of 1 in 100, descending from east to west.  Contemporary critics warned against “the concussion of the atmosphere and the vibration” arising from trains labouring up the grade, and predicted a downhill runaway would leave the tunnel at a speed of 120mph, a calculation which failed to account for friction and air-resistance:  Brunel’s more realistic computation arrived at a speed of 56mph.

The tunnel was ready for the first train to run from London to Bristol on June 30th 1841.  The west portal, visible from the main road through the village of Box, is an elaborate classical composition.  Its arch is far taller than necessary, and the rock-hewn bore funnels to the conventional loading-gauge within.  The plainer east portal at Corsham lies in a cutting.

One of the enduring stories about Box Tunnel is that Brunel aligned it so that the sunrise would shine through the dead-straight bore on the morning of his birthday, April 9th.  This is within the range of practical possibility, apparently, but difficult in the circumstances to check.

The underground Bath stone quarries which lie under Box Hill to the north of Brunel’s railway tunnel have excited considerable speculation.

Ridge Quarry was used as an ammunition store in the First World War until 1922, and became Central Ammunition Depot Corsham in 1934-6.  It was used by the RAF until 1955 and then by the Army until 1964.

A much larger complex comprising some 2¼ million square feet of storage space, based on the former Eastlays, Monkton Farleigh and Tunnel Quarries, was adapted in the 1930s as a huge subterranean ammunition store, Central Ammunition Depot Monkton Farleigh.

This wartime facility was supplied by a narrow-gauge railway and inclines connected to a GWR siding at Shockerwick, just outside the east portal of the main-line tunnel.

In 1940 the Bristol Aircraft Company’s experimental section moved into Spring Quarry, and the Ministry of Aircraft Production built an underground aircraft-engine production plant to avoid disruption from bomb-attacks on Bristol.  Despite a reputed final cost of £20 million, the facility allegedly took four years to build, operated for eighteen months up to the end of the War and produced 523 out of a wartime total of 100,932 Bristol aircraft engines.

RAF Box, later known as RAF Rudloe Manor, was established above ground and within a subterranean area known as Brown’s Quarry to act as an important regional headquarters during and after the Second World War.

In the Cold War era part of Spring Quarry was used to build the Central Government War Headquarters, a 240-acre alternative seat for national government in the event of nuclear attack or civil disruption.  Capable of accommodating four thousand staff for up to three months, it drew its water-supply from an underground lake and was equipped with generators and temperature-control, the second largest telephone-exchange in Britain and a BBC broadcasting studio.

Peter Laurie’s early study of covert government infrastructure, Beneath the City Streets:  A Private Inquiry into the Nuclear Preoccupations of Government (Allen Lane 1970;  revised Panther 1979), pointed out that trains running through Box Tunnel audibly traversed a junction, which – he speculated – would allow trains, including the Royal Train from Slough, to disappear into the safety of an underground citadel.

The actual evacuation procedure apparently involved concentrating staff at Kensington (Olympia) station and transporting them by rail via North Pole Junction and Westbury to Warminster, from where they would be conveyed by road to Corsham.

The Prime Minister and his immediate entourage would be the last to arrive, by helicopter directly to Corsham.

The headquarters was apparently abandoned in 2004.

A further facility, the Corsham Computer Centre was established in the former Hudswell Quarry in the 1980s, and remains part of the Bristol Bath Total Facilities Management Project:  http://www.indymedia.org.uk/en/2003/11/280247.html.

According to internet sources which may not be up to date, Eastlays Quarry is now a bonded warehouse:  http://www.nettleden.com/venues/eastlays-quarry.   Monkton Farleigh Quarry was sold in 1976 and briefly opened as a museum in 1984:  http://www.theurbanexplorer.co.uk/farleigh-down-tunnel-wiltshire.  Ridge Quarry was resold to the original owners in 1975.

In fact, the most accessible information on this former state secret is to be found on the Government website:  https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/324883/Corsham_Tunnel_version1.pdf.

More ghosts than guests

Savernake Forest Hotel, Wiltshire

Savernake Forest Hotel, Wiltshire

Adjacent to the site of the Savernake Low Level Station in Wiltshire stands the Forest Hotel, built by the 2nd Marquess of Ailesbury c1864 soon after the opening of the Berks & Hants railway.  Its commercial purpose is not entirely clear:  on the night of the 1881 census it had one guest.  The 4th Marquess, on his rare visits to his Savernake property, preferred to stay at the hotel rather than open up Tottenham House.

For a period from the 1890s to around 1920 the hotelier also ran the refreshment room at the adjacent station.  From sometime before 1895 the hotel was owned by Richard Henry Bain, who reputedly bought it unseen in a conversation on a railway station:  he ran it for 45 years, until the Second World War, and died in 1946 at the age of 91;  his daughter, Mrs Lott, took it over and kept it for a further 23 years.   The hotel survived the demise of the railway station and closed in 1999:  it was subsequently converted to private residences.

A lively essay by Colin Younger gives more detail of the eccentricities of the landlords of this remote hostelry, and suggests that some of the guests may have proved difficult to get rid of:  http://www.burbage-wiltshire.co.uk/historic/hotel.htm.

The former Savernake Forest Hotel is now in private residential use.

The 72-page, A4 handbook for the 2012 Waterways and Railways between Thames and Severn tour, with text, photographs, maps and a reading list, is available for purchase, price £15.00 including postage and packing.  To view sample pages click here.  Please send a cheque, payable to Mike Higginbottom, to 63 Vivian Road, Sheffield, S5 6WJ.

 

Joined up railways

Site of Savernake High Level Station, Midland & South Western Junction Railway, Wiltshire

Site of Savernake High Level Station, Midland & South Western Junction Railway, Wiltshire

 Where the Kennet & Avon Canal enters the practically unnecessary Bruce Tunnel the towpath becomes a footpath through a tiny settlement called, Savernake after the surrounding forest.

This unlikely place used to have two railway stations, High Level and Low Level, because of the absurdities of Victorian competition.

Savernake Low Level Station, opened in 1862, was a simple junction that connected the Great Western Railway’s Berks & Hants line with the nearby town of Marlborough, where the terminus station was called, perversely, High Level.

The other railway that served this isolated spot was the Midland & South Western Junction Railway which ran a tortuous route between Cheltenham Spa and Southampton.  A small section of this line is preserved as the Swindon & Cricklade Railway, just outside Swindon.

Built piecemeal, the M&SWJR initially opened in 1881 from Swindon to Marlborough only, linking into the GWR’s Marlborough branch and the Berks & Hants line at a rental of £1,000 per annum.

Eventually, the last piece of the jigsaw that was the M&SWJR was a nominally independent line, the Marlborough & Grafton Railway, opened in 1898, which provided an independent link from Marlborough Low Level Station to Savernake, where the station was called High Level, and joining end-on to the existing M&SWJR line at Grafton.

From early in 1892 the insolvent M&SWJR was managed by Sam Fay, who retrieved it from the receivers while on secondment from the L&SWR.  He became L&SWR line superintendent in 1899 before moving on to national fame as General Manager of the Great Central Railway in 1902

In the early years, milk was the main freight commodity at most M&SWJR stations;  other distinctive traffics were pigeons and racehorses. 

At the 1922 amalgamation of railway companies, both these lines became part of the Great Western Railway which continued to operate them side by side until 1933.

In that year the GWR closed its branch and station to passengers, though retaining the track for freight, and concentrated passenger service at Marlborough Low Level.  Curiously, the two tracks were then worked as parallel single lines – the former up (towards Swindon) line as a branch between Savernake and Marlborough, the former down (towards Grafton) as a bidirectional through route.

Despite extremely heavy military traffic during the Second World War, traffic drained away in the post-war period.  British Railways continued to operate the Marlborough branch service after a landslip in 1958 by diverting trains back on to the former GWR alignment into Savernake Low Level Station, until the entire M&SWJR closed to traffic on September 10th 1961.

Half a century after the branch trains stopped running to Marlborough there is very little evidence of the two branch lines, except by viewing satellite images.  The two Marlborough station sites have been redeveloped and the M&SWJR tunnel has been filled in.

At Savernake, main-line trains still speed along the Berks & Hants line on their way between Reading and Taunton, but the site of Savernake Low Level Station has been obliterated.  The main building at Savernake High Level Station and the adjacent signal box still stand, converted to a private residence.

With heavy irony, what might have been the stationmaster’s house at Savernake Low Level is now called Beeching Villa.

All the railway sites at Savernake are on private land but are visible from the road.

The 72-page, A4 handbook for the 2012 Waterways and Railways between Thames and Severn tour, with text, photographs, maps and a reading list, is available for purchase, price £15.00 including postage and packing.  To view sample pages click here.  Please send a cheque, payable to Mike Higginbottom, to 63 Vivian Road, Sheffield, S5 6WJ.

Bruce Tunnel

Bruce Tunnel, Kennet & Avon Canal, Wiltshire:  west portal

Bruce Tunnel, Kennet & Avon Canal, Wiltshire: west portal

Bruce Tunnel, Kennet & Avon Canal, Wiltshire: west portal – 2003 inscription

Just as the proprietors of the Kennet & Avon Canal named the Dundas Aqueduct at Limpley Stoke after the company chairman, Charles Dundas, 1st Baron Amesbury, so they named the tunnel at Savernake after the local landowner Thomas Brudenell-Bruce, 1st Earl of Ailesbury (1729-1814).

Bruce Tunnel wasn’t in fact needed.  It was built solely because the Earl declined to have a deep cutting splitting his estate.

It’s 502 yards long, with a wide bore to take Newbury barges, and has no towpath.

Above the west entrance portal is a stone panel carved with an elaborate dedication by Benjamin Lloyd, the canal company’s mason:

The Kennet and Avon Canal Company
Inscribe this TUNNEL with the Name of
BRUCE
In Testimony of the Gratitude
for the uniform and effectual Support of
The Right honourable THOMAS BRUCE EARL of AILESBURY
and CHARLES LORD BRUCE his Son
through the whole Progress of this great National Work
by which a direct communication by Water was opened

between the cities of LONDON and BRISTOL

ANNO DOMINI 1810

The inscription is almost illegible, so a modern duplicate, smaller and in a different stone, stands to the side of the tunnel arch, with a pendant:

“This monument was erected by the Kennet & Avon Canal Partnership and John Lloyd, seventh generation mason of Bedwyn, as a replica of that erected by his ancestor, Benjamin Lloyd, mason of Bedwyn to the Kennet & Avon Canal Company, AD 2003.”

John Lloyd delivered the new inscriptions, appropriately, by boat.

The 72-page, A4 handbook for the 2012 Waterways and Railways between Thames and Severn tour, with text, photographs, maps and a reading list, is available for purchase, price £15.00 including postage and packing.  To view sample pages click here.  Please send a cheque, payable to Mike Higginbottom, to 63 Vivian Road, Sheffield, S5 6WJ.

Sapperton Tunnel

Sapperton Tunnel, Thames & Severn Canal, Gloucestershire:   Coates Portal

Sapperton Tunnel, Thames & Severn Canal, Gloucestershire: Coates Portal

Sapperton Tunnel on the Thames & Severn Canal epitomises the canal-builder’s dilemma about crossing a watershed – whether to dig an expensive tunnel to save lockage, or to build locks that demand a constant and abundant source of water.

Sapperton Tunnel cost a great deal to build, and leaked like a sieve.

The engineer Josiah Clowes is thought to have worked on the 2,880-yard, nine-foot-wide Harecastle Tunnel on the Trent & Mersey Canal for James Brindley, and Sapperton Tunnel was longer, at 3,817 yards, and was built to broad-canal dimensions without a towpath.  At the time of construction it was the longest tunnel so far built.

Work began in the spring of 1784 and was completed in 1789:  the first boat went through on April 20th that year.  Defects in the structure led to a ten-week closure only a year after the opening.

The original surveyor of the Thames & Severn Canal, Robert Whitworth, had observed, on a frankly superficial inspection, that the summit level ran “over some bad Rocky Ground…worse than [he had] even seen any Canal cut thro’ for such a continued length”.

In fact, the line of the tunnel alternately passes through impermeable oolite and the unstable, permeable clay known as fuller’s earth:  http://www.cotswoldcanals.com/pages/locks-bridges-structures/sapperton-tunnel.php.

The geologist John Phillips (1800-1874), in his biography of his geologist uncle Memoirs of William Smith (1844), wrote scathingly about the fundamental weakness of the line:

Such canals…are like the buckets of the Danaids, and with the water goes the profit.  In vain the Thames, raised from its source by a mighty engine, is poured into such a thirsty canal;  the flood passes into the gaping rocks below, in spite of renewed puddling and continual repairs.

The last boat went through Sapperton Tunnel on May 11th 1911 and almost the entire canal was abandoned in 1927.

The Cotswolds Canal Trust has been working since 1975 to restore the entire length of the Thames & Severn Canal, and the reopening of Sapperton Tunnel forms part of the third and final phase of their project:  http://www.cotswoldcanals.net/tunnel.php.

It won’t be easy, as Ken Burgin’s inspection 2009 report indicates:  http://www.cotswoldcanals.net/downloads/CCT_Tunnel_Report_Trow_Spring_2009.pdf.

The 72-page, A4 handbook for the 2012 Waterways and Railways between Thames and Severn tour, with text, photographs, maps and a reading list, is available for purchase, price £15.00 including postage and packing.  To view sample pages click here.  Please send a cheque, payable to Mike Higginbottom, to 63 Vivian Road, Sheffield, S5 6WJ.

 

Gongoozler’s delight

Crofton Pumping Station, Kennet & Avon Canal, Wiltshire

Crofton Pumping Station, Kennet & Avon Canal, Wiltshire

Crofton Pumping Station is a very precious and also a very pleasant place to be, if you can find it.

If you’re sailing on the Kennet & Avon Canal you can’t miss it, because it stands beside the locks as they climb to the canal summit approaching Bruce Tunnel.

If you’re driving it’s near the Wiltshire village of Great Bedwyn and well signposted – once you find Great Bedwyn.

All canals that cross a watershed represent an engineering compromise between climbing and tunnelling.  The Leeds & Liverpool Canal experienced recurrent maintenance problems because of the engineer Robert Whitworth’s recommendation to build Foulridge Tunnel.  The parallel Rochdale Canal suffered from water-supply difficulties following William Jessop’s suggestion of eliminating a 1½-mile tunnel by building more locks to a higher summit.

The Kennet & Avon Canal, like the Rochdale, was built with a very short, high summit pound which contained insufficient water to replace the two lockfuls that each passing boat took away with it.

Crofton Pumping Station was built in 1802 to back-pump water from the locks up to the canal summit.

The original engine was replaced in 1846, and the 1812 Boulton & Watt engine that remains is the oldest working steam-engine still in situ.

Under Great Western Railway ownership the pumping station was neglected, but both engines continued to pump until 1952, when pumping was transferred first to a diesel pump and then to an electric one.

The 1812 engine operated occasionally until 1958, when the top twenty feet of the chimney was dismantled leaving insufficient draught to run the boilers.  Though the steam engines were, in effect, retired the resident engineer, Mr Wilmot, continued to keep them in workable order.

The pumping station was purchased in 1968 by the Kennet & Avon Canal Trust, and a volunteer team returned the 1812 engine to steam, with an electric fan to supplement the natural draught, in April 1970.  Initial teething troubles were resolved in time for Sir John Betjeman to perform the opening ceremony in August.

The second engine was subsequently restored by a team of Rolls Royce apprentices, and returned to steam in November 1971, and the chimney was restored to its original height in 1996-7.

So now you can experience the engines working within the original engine-house, or watch the boats working the locks as the trains pass by alongside the canal, or sit inside the Engineman’s Rest Café eating home-made food and drinking real beer.

The place is a welcoming experience for boaters and gongoozlers alike:  http://www.croftonbeamengines.org.

The 72-page, A4 handbook for the 2012 Waterways and Railways between Thames and Severn tour, with text, photographs, maps and a reading list, is available for purchase, price £15.00 including postage and packing.  To view sample pages click here.  Please send a cheque, payable to Mike Higginbottom, to 63 Vivian Road, Sheffield, S5 6WJ.

 

Crossing the Clifton Gorge

Clifton Suspension Bridge, Bristol

Clifton Suspension Bridge, Bristol

The first high-level crossing of the Avon Gorge at Bristol was not, in fact, Isambard Kingdom Brunel’s suspension bridge, but a wrought-iron bar, installed in 1836 when bridge-building was about to begin, a thousand feet long and 1½ inches thick, suspended two hundred feet above the River Avon, to carry a basket for transporting materials hung from a roller.

Brunel made the first trip across (after his newly-wed wife, Mary Elizabeth Horsley, declined the opportunity) and got stuck halfway when the bar dipped.  He shinned up the suspension ropes to free the pulley and reached the opposite bank without further difficulty.

By 1843, with £45,500 spent, only the piers had been completed, linked by the single iron bar:  work stopped – to Brunel’s lifelong disappointment – and the unused suspension chains were sold and incorporated in his railway bridge across the Tamar at Saltash.

L T C Rolt, in his biography Isambard Kingdom Brunel (1957;  revised edition with an introduction by Angus Buchanan 1990), reports that when construction of the bridge stopped for lack of funds, the Clifton Bridge Company collected £125 in fares from members of the public who wished to ride across in the bucket.

The bridge as we know it was completed, to a variant of Brunel’s original design, in 1864 using the chains from another of his suspension bridges, across the River Thames at Hungerford.

The 72-page, A4 handbook for the 2012 Waterways and Railways between Thames and Severn tour, with text, photographs, maps and a reading list, is available for purchase, price £15.00 including postage and packing.  To view sample pages click here.  Please send a cheque, payable to Mike Higginbottom, to 63 Vivian Road, Sheffield, S5 6WJ.

 

Great Great Britain

SS Great Britain, Bristol

SS Great Britain, Bristol

Isambard Kingdom Brunel’s steamship Great Britain carries an immense cargo of stories.

Brunel remarked to the directors planning to build the Great Western Railway, “Why not make it [the GWR] longer and have a steamboat to go from Bristol to New York and call it the Great Western?”

The Great Western duly made its maiden voyage to New York in 1838, by which time the Great Western Railway reached out from London only as far as Maidenhead.

The Great Britain was his second steamship – the first iron-hulled, propeller-driven transatlantic steamship, at the time of her launch the largest ship in the world, the first ship ever to be photographed (by William Henry Fox Talbot in 1844).

She was floated for the first time on July 19th 1843, and ultimately returned to rest in the purpose-built dry dock in which she was constructed on July 19th 1970.  The launch was observed by the Prince Consort, and the return to Bristol by the present Queen’s consort, Prince Philip.

During her active life she served as a troop ship during the Indian Mutiny and the Crimean War, carried the first England cricket team ever to visit Australia in 1861 – an event that produced the first sponsored sporting tournament, the first cricket test match, and the first hat trick.

Her career had more than its fair share of cock-ups.  Brunel, the great risk-taker, repeatedly modified the design during construction – changing from a wooden to an iron hull, extending the dimensions five times and scrapping the half-completed engine and building a new one in order to switch from paddle- to screw-propulsion.

The completed vessel stuck in the lock on departure from Bristol, ran aground in Ireland because of navigational errors, and went through repeated modifications to the engines, propeller and auxiliary rigging.  Eventually, SS Great Britain gained a reputation for reliability shipping migrants from England to Australia.

She ended up as a sailing collier, and finally acted as a floating coal-bunker in the Falkland Islands, where she was eventually beached at Sparrow Cove.

Her rescue, promoted against huge odds by a group led by Richard Goold-Adams and Ewan Corlett and largely financed by Sir Jack Hayward and Sir Paul Getty, is itself one of the great stories of the sea, and her return to Bristol, sailing under Brunel’s Clifton Suspension Bridge, one of the memorable moments of many people’s lifetimes.

Though she arrived in Bristol as a rusting hulk, she is now vividly restored.  Wandering among her elegant saloons and cramped cabins brings to life the life-changing experiences of Victorian voyagers.  The only omission, fortunately, is that she doesn’t make anyone seasick.

Nevertheless, I noticed how one particular mannequin, a sad lady in black, sat alone in the dining saloon, repeatedly attracted the sympathetic curiosity of young children.  Her silence and their attention says all that’s needed about the cost of emigration – and the power of imaginative curating.

Read the story at http://www.ssgreatbritain.org/story.

The 72-page, A4 handbook for the 2012 Waterways and Railways between Thames and Severn tour, with text, photographs, maps and a reading list, is available for purchase, price £15.00 including postage and packing.  To view sample pages click here.  Please send a cheque, payable to Mike Higginbottom, to 63 Vivian Road, Sheffield, S5 6WJ.

 

Canal mania

Caen Hill Locks, Kennet & Avon Canal, Wiltshire

Caen Hill Locks, Kennet & Avon Canal, Wiltshire

The excitements of the dotcom bubble and the speculation that led to the sub-prime mortgage crisis seem leisurely compared with the sheer farce of the Canal Mania of the early 1790s.

The financial success of the early canals, which sometimes halved the price of coal and other commodities in inland towns, caused a headlong rush to promote waterways across Britain from anywhere to everywhere. 

Optimistic investors literally fought to put their names on subscription lists for waterways which in most cases had little chance of a practical future.

In the West Country serious promoters took to keeping their subscribers’ meetings secret to avoid attracting frivolous speculators.

On one occasion, according to Kenneth R Clew, historian of the Kennet & Avon Canal, an advertisement appeared in the Salisbury Journal for a promoters’ meeting in Devizes without indicating a precise venue.

On the day the town became overcrowded with increasingly irritable potential investors looking for a meeting that nobody had organised.  Eventually the town clerk was persuaded to chair an ad hoc assembly but “no business of any consequence could be done, and the meeting could only be a tumultuous assembly called together without any knowledge for what purpose, no person appearing to take an active part in it”.

The only people who profited from this farce were the publicans of Devizes.  A bed for the night cost a guinea, whereas a post-chaise back to Bristol was ten guineas.

The Kennet & Avon Canal was eventually built through Devizes:  it opened in 1812 and after years of neglect is once again navigable.

Just outside Devizes the canal climbs through a series of 29 locks – sixteen of them in a magnificent single flight at Caen Hill.

The 72-page, A4 handbook for the 2012 Waterways and Railways between Thames and Severn tour, with text, photographs, maps and a reading list, is available for purchase, price £15.00 including postage and packing.  To view sample pages click here.  Please send a cheque, payable to Mike Higginbottom, to 63 Vivian Road, Sheffield, S5 6WJ.

 

Somerset Coal Canal

Somerset Coal Canal:  stop lock at Dundas Aqueduct

Somerset Coal Canal: stop lock at Dundas Aqueduct

At the southern end of Dundas Aqueduct, a branch runs from the Kennet & Avon Canal, through a curious narrow stop-lock.  Nowadays the branch ends abruptly after less than half a mile, at Brassknocker Wharf, where there is an excellent modern restaurant called the Angelfish [http://www.foodanddrinkguides.co.uk/bath/angelfish-restaurant/restaurant/2742].

This is all that remains navigable of the Somerset Coal Canal, a long-forgotten and fascinating piece of canal and railway archaeology.  It was devised by John Rennie (1761-1821), the engineer of the Kennet & Avon Canal, and surveyed by William Jessop (1745-1814) and William ‘Strata’ Smith (1769-1839), whose work is celebrated at the Rotunda Museum, Scarborough.

The original canal was built westwards to Paulton, to tap the potential traffic of the Somerset coalfield.  The first coal was brought out in 1798, though the canal itself fully opened only in 1805.

Bringing barges from the summit level 135 feet higher than the Kennet & Avon required 22 locks.  To reduce the drain on limited supplies of water, the engineer Robert Weldon proposed instead building a caisson lift at Coombe Hay, in a single operation [See http://www.coalcanal.org/history/Rowley/tLev1.htm].

This involved building a series of three 60-foot-deep cisterns, into which each barge would be floated in an airtight container – the caisson – and sunk, emerging at the foot of each lift with no loss of water at all.  [See http://www.coalcanal.org/features/Caisson/Caisson.htm and http://rtjhomepages.users.btopenworld.com/caisson-telegrap.html (which first appeared in The Daily Telegraph)].

An experimental model of this system appeared to work, but the full-sized version was unsuccessful, apparently because of geological rather than mechanical problems.

It was replaced, first by an inclined plane, and eventually – in 1805 – by a flight of locks, from which a steam pump returned water to the summit pound.

A canal branch from Radstock as far as Twinhoe was never completed:  to avoid the expense of a further flight of locks the line was built as a tramway by 1815.  This was superseded in 1875 by the Somerset & Dorset Railway line to Bath.

There was no shortage of coal traffic, but the Somerset Coal Canal was an early victim of railway competition.

Later, the bulk of the main canal between Limpley Stoke and Camerton was converted by the Great Western Railway to a standard-gauge branch-line in 1910.  This was not a commercial success, but after it closed it became the location for the celebrated Ealing comedy The Titfield Thunderbolt (1953).

Much of the route of the Somerset Coal Canal is traceable, including the former aqueduct at Dunkerton, for seriously determined explorers to seek out.  The Somerset Coal Canal Society exists to foster interest in the route:  http://www.coalcanal.org.

Of the caisson lift hardly anything remains.  The masonry was used to build the replacement locks, and archaeological digs have revealed very little.

I wonder if there’s a working model somewhere?

The 72-page, A4 handbook for the 2012 Waterways and Railways between Thames and Severn tour, with text, photographs, maps and a reading list, is available for purchase, price £15.00 including postage and packing.  To view sample pages click here.  Please send a cheque, payable to Mike Higginbottom, to 63 Vivian Road, Sheffield, S5 6WJ.