1851 Great Exhibition: Official Catalogue: Class VII.: John W. Leather
107. LEATHER, JOHN W., Leeds.
Model of suspension aqueduct over the river Calder, at Stanley, near Wakefield. (Designed by George Leather and John W. Leather, civil engineers, Leeds, and executed under their direction.)
The canal which is carried over the river Calder by means of this aqueduct is navigable for sea-going vessels of 7 feet draught of water, and 120 tons burthen.
This model and unique mode of construction was adopted in order to preserve the whole width of the waterway of the river free and uninterrupted by piers, which was important.
This tank or trough is 9 feet deep, and 24 feet wide within, and it contains between the points where it rests upon the abutments, 940 tons of water, more than is contained in the whole 19 arches of the celebrated Ponty-Cysyllte aqueduct in Wales.
There is a towing-path on each side, which projects partly over the water within, and partly on the outer side of the trough. By the introduction of a colonnade and entablature (of the Grecian Doric order) terminated by an octastyle portico and pediment on the abutment at each end, the heavy and unsightly appearance which so large a surface of tank would have presented, is got rid of, and a light and elegant character is given to the structure. The suspending-rods pass through the columns to the ends of the transverse bearers; and the steps upon which the columns appear to rest, serve to conceal the transverse bearers, as well as further to maintain the architectural effect.
The following are the principal dimensions and particulars:-
Span of the suspending arcs - 155 feet.
Width between the suspending rods – 30.5 feet.
Length of trough between the abutments - 165 feet.
Width of trough – 2 feet.
Depth of trough - 9 feet.
Depth of water (sometimes 8.5 feet) ordinarily – 7.5 feet.
Diameters of suspending rods – 2.25 inches.
Thickness of tank-plates (cast-iron) – 3.25 inches.
Weight of each suspending arc - 101 tons.
Total weight of iron — cast 730 tons, wrought, 30 tons - 760 tons.
Weight of the water in the tank (8.5 feet deep) - 940 tons.
Total weight supported by suspending arcs, including their own weight – 1,700 tons
First pile for the foundations driven July 20, 1836. Aqueduct opened August 8, 1839.
Iron-work executed by Messrs. Graham, Milton Iron Works, near Sheffield.
Masonry by Hugh M'Intosh, contractor, Bloomsbury Square, London.
[The first cast-iron aqueduct was erected by Telford, A.D. 1793, to carry the Shrewsbury canal over the river Tern. In 1794-5 he designed the celebrated cast-iron aqueduct to convey the Ellesmere and Chester canal, at an elevation of 127 feet, over the river Dee at Pont-y-Cysyllte: since that time many have been erected. The advantages of cast-iron aqueducts over those of stone, which are of considerable antiquity, are their security from leakage, and their economy in point of cost.— S. C.]
2. Model of a cast-iron bridge over the river Aire at Leeds.
The objects aimed at in this design have been to combine with apparent lightness, real strength, and by taking advantage of the facilities afforded by the metal, to give, as in the case of the Calder aqueduct, almost without additional expense, a pleasing, ornamental, and purely architectural character to an useful engineering work.
The following are the principal dimensions and particulars:—
Span of the arch - 120 feet.
Rise of arch from springing - 12 feet.
Width of roadway – 30 feet.
Width of each footpath - 6 feet.
Total width outside to outside – 43.5 feet.
Weight of cast-iron - 410 tons.
Weight of wrought iron – 5.5 tons.
First pile for foundations driven May 1, 1841. Bridge opened to the public, July, 1842.
Iron-work executed by Messrs. Booth and Co., Park Iron Works, Sheffield.
Masonry executed by Mr. James Bray, contractor, Moor Park, Harrogate.
Both the above models are made by Mr. Stephen Salter, Elvan Cottage, Hammersmith, London; carved by hand from crayon paper made into cardboard, and show (as nearly as can be done on so small a scale) the details of the iron-work, etc.