STOWELL PARK BRIDGE 1845 HEW 378 N51o 21’ 7.8” W1o 47’ 32.4”
This is Bridge #116 on the Kennet & Avon Canal. Comissioned by Colonel Wroughton of Wilcot, son of Admiral George Montague, as a footbridge to connect his residence Stowell Lodge with his lands, it was designed by James Dredge (1794-1863. This is one of only eight surviving bridges in the British Isles of the fifty-odd designed by Dredge, a successful self-educated engineer. He developed a very distinctive type of bridge which combined the principles of suspension and cantilever. Each half of the bridge works as a right angle triangle, the hypotenuse of which is formed by the wrought iron rods extending along the deck at oblique angles up to the top of the pylons. The bottom tips of these two triangles meet at the center of the bridge. If you cut a Dredge in two at the center, both halves would still stand, where as if you were to do so to a conventional suspension bridge it would collapse.
The chain of rods that loop from the top of each pylon down to touch the outer edges of the deck at the center are simply positioning the rods which are actually supporting the bridge rather than having the chain itself provide its support as in a conventional suspension bridge. You will notice that each chain starts as a single rod at the center edge of the deck and adds the requisite number of additional rods at each chain link position up to the top of the pylon. Also at this link a pair of inclined bars descend to the deck edge for its support, each set at its own inclined angle to the deck. Dredge claimed that this gave compression to the deck which overcame the tendency of pure suspension bridges to oscillate dangerously under certain conditions such as severe storm winds or troops marching in cadence.
The four foot wide deck is of timber and the length of the bridge is seventy six feet, three inches. It is raised well above the canal providing generous clearance for the canal traffic and stone steps at either end are provided. All in all it is a marvelously bold and unusual bridge with cast iron pylons of great size crowned by arch tops that define their height, one of which advertises the Dredge patent.
It is not easy to find: take the Wilcot road out of Pewsey, Wiltshire and turn right at the Swan Pub to the stone bridge #117 over the canal. Immediately take a right onto the little road on the far side parallel to the canal. The iron bridge spans both the tow path and the canal. It is so buried in shrubbery and trees that only the part of the bridge spanning the canal is visible.
