4. Constructing the Solway Viaduct

“a piece of enchanted workmanship resting on the bosom of the racing waters”

 

ct02291 viaduct 1900 CIB

The story of the railway track that was constructed across Bowness Moss is also the story of the Railway Viaduct that was constructed across the Solway Firth – for without the sea-crossing (see maps below), the railway lacked a purpose.

The most picturesque description of the viaduct is in The Whitehaven News, for February 11th 1869.

‘The principle upon which the viaduct is constructed shows great simplicity of design. The structure is built of wrought and cast iron. The wrought iron is used for the girders that span the bays, and likewise for the cross bracing which stiffens the whole structure. These bays or spans are 30 feet in length. The pillars that support the girders … are composed of cast-iron …’

 

But despite the ‘great simplicity of design’, photos of the viaduct show an apparently complicated arrangement, a forest of pillars and braces.

Robert Kinghorn, in his Solway Junction Railway article in the Caledonian Railway Association’s 1985 Journal (photocopy sent to me by Allan Ferguson) explains the arrangement of the piers and pillars:

“The viaduct was 1940 yards long on 193 cast iron piers … The single piers were each constructed of five cast iron columns, the three in the centre being vertical whilst the outer ones sloped inwards. Between each pair of columns were 3 sets of cross bracings, one above the other …These columns were on cast iron piles [driven into the sea-bed]. An extra line of piles was provided on the upstream side for the possible widening.’’

daigram from kinghorn article
Diagram from Robert Kinghorn’s article

 

As for the track-bed,

“Four longitudinal wrought iron girders (2 ft 6in deep) were placed on top of the columns … the central girders were directly under the rails which were carried on longitudinal [wooden] waybeams. The decking was buckled plates secured to the girders, and railings were fixed to the outside girders.”

 

From the plan of the permanent way in the engineer Brunlees’ drawings, it seems that the trip across the Firth might have been even more exciting than you had anticipated – if you hung out of a window, you could have looked straight down through the railings to the Firth below.

There are various other detailed descriptions of the materials and the engineering specifications of the viaduct, and which one you prefer will depend on your own inclination.

For example, the description in Engineering Timelines (in which measurements have been converted to metric) notes that the “Solway viaduct had 181 braced trestle single piers comprising five 300mm diameter cast iron columns, the inner three columns of which were vertical and the outer two raking. It also had 12 braced trestle double piers comprising duplicate singles braced together. … The rails were supported on wrought iron lattice girders that were supplied by the Falkirk Iron Company.”

Images ‘Reproduced with permission of the Department of Transport (National Records of Scotland, BR/SJR/4/2, p. 2)’.  For the significance of the date of the photos (1881), see Chapter 10.

An article in The Engineer, for April 9th 1869 (p252; reproduced in Grace’s Guide) has a detailed consideration of the specifications of the track bed, including: ‘wrought iron girders, each 29ft 11 5/8in. long, and 2ft.6in.deep, and having a camber of ½  in. in their length… the platform is formed of Mallet’s buckled plates riven to the girders …’

But the beauty of this particular article is that a page of Brunlees’ very fine drawings of the various components is appended.

brunlees' engineering drawing

Sinking the piles

The 1869 Whitehaven News’ article also gives a strong impression of the difficulties and the skill required for embedding the viaduct into the land- and sea-scape of the Inner Solway.

The reports written, largely retrospectively, in 1869 (the ‘final two girders’ were placed by Alex Brogden in late June 1868: see Building News  June 27th 1868, p459) are graphic in their detail.

The hollow cast-iron piles securing the piers to the sea-bed were about 20 feet long, 12” diameter with walls 7/8th inch thick, and (Whitehaven News, February 11th 1869) had been

“cast with a chilled point for driving, and were all driven at low water from barges fitted with patent pile-driving engines, the monkeys used for this operation weighing about 20 cwt. The levels of the foundation piles vary with the bed of the Solway. The lowest level is in the English channel, where the top of the foundation piles is within 18 inches of low water of spring tides …”

These barges were towed to and fro, depending on the height and state of the tides, by a steamer, the Arabian (Edgar & Sinton’s book, The Solway Junction Railway, p16). This steamer was presumably under contract to Waring Bros. & Eckersley: Stephen Wright, writing about the history of Silloth docks, notes that the port’s “first tug was the wooden paddle-steamer Arabian, bought in 1863. She served as a tug, feeder vessel and pleasure steamer, taking visitors on summer cruises around the Solway.”

“The original intention in erecting the viaduct was to have screw piles for the foundation, but after fruitless trials and experiments, extending over nearly six months, it was decided to adopt driving. … The whole of the piles had to be driven at low water, and the work was carried on as tidal work, night and day.” (Whitehaven News, February 11th 1869)

“The piles were driven by Sisson and White’s steam piledriver; a timber dolly was used with a copper ring, between the shoe of the dolly and the pile head… Two tides were generally required per pile.”  (The Engineer, April 9th 1869)

The Solway Firth is notorious for the greatly-varying heights and speeds of its tides between springs and neaps, and its unstable sea-bed; ‘capricious floods and shifting sands’ have always defined its character. This difficulty was acknowledged:

“In the trials and borings that were made it was found that the bed of the Solway is composed of very strong coarse gravel, interspersed with boulders, and on the top of this gravel there is generally from five to six feet of sand, which is constantly being shifted by the currents of the Firth [my italics].” (Whitehaven News, February 11th 1869)

Robert Kinghorn’s 1985 article states that “the range of spring tides at this point is about 21 feet with a speed of 10mph at half-ebb and quarter-flood” (although it’s important to note that the tidal range, and thus speed, of the spring tides also varies from month to month). This would certainly have a strong scouring effect around the piles, and he says – unfortunately without quoting his source – that the “foundations [of the piles were] protected with heavy stones piled around each pier.” Such anti-scouring measures still occur in the Solway today, for example around the piles of the wind-turbines of Robin Rigg.

As the piles marched across the Firth, up above them

“the whole of the superstructure was [being] erected without scaffolding. … the girders were carried over the top of the viaduct, and swung into position by travelling cranes.” (Whitehaven News, February 11th 1869).

Much earlier, October 18th 1866, the Whitehaven News had carried a somewhat-optimistic report from The Scotsman in delightfully flowery language that

“the completion of the structure is rapidly proceeding from both ends. Its appearance is light and elegant, and in the full tide it will have the semblance of a piece of enchanted workmanship resting on the bosom of the racing waters”!

The embankments

The ends of a viaduct do not just grow out of the ground, they must be supported by solid structures, and this is all the more important when they project from the soft and muddy banks of an estuary.

BR_SJR_4_2_00010rsz
A single pier of 6 columns built on the embankment

Image ‘Reproduced with permission of the Department of Transport (National Records of Scotland, BR/SJR/4/2, p. 2’). Note the date of the photo – see Chapter 10 for its significance.

The original plan, according to The Scotsman, was that stone embankments should reach out far enough from each side of the Firth for the viaduct to be only 800 yards long, but this plan was revised, and ‘fears being entertained that the current would thereby become too confined, and its force increased to a dangerous extent, the bridge was lengthened to 1700 yards.’

Subsequently, it was decided to extend the viaduct by yet another 200 yards on the Bowness side, with the addition of extra bays – and to close the proposed gap in the centre that would have allowed ships to pass through.

Thus, as the Directors reported to shareholders in February 1868 (Whitehaven News, February 13th 1868),

“Under the powers of the Act obtained last session, [the viaduct] is now constructed without the opening span. It has been determined to lengthen the viaduct by 600 feet, and thus effect a great saving of time in the completion of the line, without any extra cost.”

At the same meeting in early 1868, the engineer James Brunlees’ reported:

“Section 2, Solway crossing: …The whole of the ground piles for the South section of twenty spans, or 600 feet, are driven, and the material for the superstructure will shortly arrive. The sea embankment on the Scotch side is practically finished, and that on the English side will be commenced on completion of the viaduct extension.”

The embankment on the Scottish side was 7 chains long and 28 feet deep; on the Cumberland shore 21 chains long and 29 feet deep at the extreme end.

rviaduct annan from holme web

 

These embankments were

“a source of considerable anxiety in making, as the spring tides rise upon them 21 and 23 feet. The core of the banks is made with clay. The outside is then carefully puddled a depth of one foot; a layer of broken stones and quarry red averaging two feet in thickness is laid over the puddle; and upon the quarry red the pitching is set, the stones being from 15 to 18 inches deep”’ (Whitehaven News, February 11th 1869)

Bowness-Station-001
The remains of the Bowness embankment today (C) James Smith

 

It is likely that the New Red sandstone used for both North and South embankments came from Corsehill Quarry near Annan (even though McKay and Blackstock had a quarry in Cumberland near Aspatria, and had constructed the stonework of the Aspatria to Wigton section of the M&CR; for more on the McKays’ quarrying see Judy McKay/Beeby’s story, ‘Written in stone’).

 

quarrymen & navvies snip

 

Philip Ashforth (in The Industrial Locomotive, 2007, no. 124, pp138-145; given to me by Peter Holmes, Cumbria Railways Group) refers to a locomotive that “went from the Solway [SJR] contract to John Murray & Sons, Corsehill Quarries, Annan circa 1868 so would not have had far to travel to its new home as the SJR ran through Corsehill.”

And in The Engineer (April 9th 1869, p 252, Grace’s Guide) “The viaduct has been well tested by the continual passage of loaded wagons, with materials for the south bank ... [my italics]” – with the implication that the stone came from Scotland.

The handsome stone-work, and evidence of the underlying layer of broken stone, is still visible on the embankments today, and is astonishing to think of the number of hours, and labourers and masons – puddling clay, barrowing, cutting, dressing and laying stone – that were involved. On both sides of the Firth.

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