William Evans and the Conwy Bridge

The Conwy tubular bridge and the Britannia tubular bridge across the Menai Strait were both designed by Robert Stephenson for the Chester and Holyhead Railway Company and were the first of their type. The first built was the Conwy bridge which is one of three bridges now adjacent to the castle. It was built in 1848 and still carries rail traffic. An earlier suspension bridge designed by Thomas Telford was built in 1826 to carry road traffic but is now closed, having been replaced in 1958 by a modern concrete structure. Since then a further crossing has been provided in the form of a road tunnel.

Original Litho of Conwy Bridge

Original Litho of Conwy Bridge

Train emerging from bridge, passing castle
Telford's bridge (L) and Tubular Bridge (R) from castle

Train emerging from bridge, passing castle
Telford's bridge (L) and Tubular Bridge (R) from castle

Two books provide evidence that the Conwy rail bridge was built by William Evans.

The Britannia And Conway Tubular Bridges by Edwin Clark, Resident Engineer 
Published by Day and Son, and John Weale, London. 
Viewed at Conwy Library, High St Conwy, 16th August 1993.
    (p.483): "The masonry for the Conway Bridge was ... let to Mr William Evans, who subsequently undertook the construction of the tubes". This work was carried out between 12th May 1846 and 16th December 1848. 

An Account of the Construction of the Britannia and Conway Tubular Bridges
by William Fairbairn CE (MICE),
Published by John Weal, 59 High Holburn, London, 1849. 
Viewed in the library of the Institution of Civil Engineers, 24 Great George St, Westminster, 30th July 1993

 The book gives many details of the testing of model tubes and the construction of the two bridges. It also contains a number of letters between Fairbairn and Stephenson. It has several references to `Evans' as the principal contractor but does not identify him further. The excerpts below also give some indication of the considerable scale of the work, its technological inovation and Evans' obvious success in the venture.

 Relevant points:

  • The bridge was constructed between 1846 and 1849
  • It comprises two tubes (side by side) each 424' long, 25'6" high, and 15' wide; each weighing 1300 tons.
  • The tubes were manufactured on a beach just upstream, floated into position on pontoons, and jacked 18' into place.

(p.127; letter Fairbairn to Stephenson, Dec 26th 1846:)
"... As respects the makers of the tube, I have seen them all this week, except Horton, and am now able to report as follows:-
First that Evans states that he will be ready to commence with the bottom of the tube by the middle of next month. His workshops and steam engines are nearly completed; and the platform for supporting the tube, and on which it is to be constructed, is in progress and will be finished about the 15th of January ..."

(p.131; Stephenson to Fairbairn, undated:)
"... I have received Mr Clarke's report of the progress made by Evans, which I think is satisfactory, but you must pick him up about the time he commences riveting as much will depend upon the system he adopts, and I hope this will have your especial attention and judgement ..."

(p.137; Fairbairn to Stephenson, 2nd February 1847:)
"ps In consequence of Mr Clarke's arrival, and hearing that you intend to visit Bangor about the 12th or 13th, I have sent J McLaren, the person I have appointed as the inspector of the tubes to Mr Evans at Conway, to arrange all the tools, and start the punching of the plates and angle iron ...

(p.143; Stephenson to Fairbairn, Nov 31st 1847:)
"... I have sent Clarke down to Conway to arrange with Evans, for proceeding with the masonry in the upper part of the tubes, where it is likely to be interfered with by the cast iron girders. 
... On my return we must arrange to meet the Board on the subject of the lifting apparatus. I have no doubt it is right as to Evans' certificate. "

(p.154:) "... During the progress of the construction of the tubes for the Britannia Bridge, the machine work was found (according to the opinion of Mr Mare, the contractor) both expensive and inconvenient on account of the size and great weight of the plates, and the difficulty of suspending them over the machine. These drawbacks were not however experienced by Mr Evans, the contractor for the Conway tubes, who overcame every difficulty by the introduction of powerful travelling cranes, which enabled him to rivet the greater part of the bottom and sides of both tubes by the machine."

(p.156; Stephenson to Fairbairn, 23rd August 1847:)
"... I wish in the meantime, you would desire Clarke to order Evans to put decks to all the pontoons he has built as well as raising their sides 1 foot"

(p.159; Fairbairn to Stephenson, 24th Dec 1847:)
"... As soon as I hear from you, I will give Mr Evans orders to prepare the pumps and the two dams, which are all that are wanted to make experiment" (i.e. testing of the tube)

(p.160:) ... About this time Mr Stephenson expressed a desire that everything connected with the transport of the tube, particularly the pontoons which had to float it, should be minutely examined. This was accordingly done; and the vessels which had been constructed by Mr Evans the contractor, appeared defective, both as regards workmanship and construction, considerable alterations were ordered to be made; by the introduction of strong bulkheads, decks, and tie bars, and by a thorough recaulking, the pontoons were rendered perfectly secure and fitted for the work they had to perform. 

Of interest is the list of subscribers to the publication of Edwin Clark's book which include: