Bridge Over River Tas

Bridge Over River Tas

A late medieval four-arch stone bridge, widened twice and lengthened by the addition of causeways in the first half of the 19th century, and extended by one arch in 1976. The bridge is constructed of stone and red brick.

The bridge carries the former Norwich to Ipswich road over the River Tas, aligned approximately north-south. The arches have been numbered 1 to 6 from the northern end (left to right when looking eastwards downstream). Arch 1 was built in 1976; arches 2 to 5 constitute the original medieval bridge; and arch 6, which pierced the causeway, was built or substantially rebuilt in the first half of the 19th century and is now buried in the riverbank.

The earliest part of the bridge is on the upstream (western) side, which is late medieval in date, although repairs and later modifications are apparent. The earliest visible elements are the slightly pointed, elliptical (almost four-centred) arches of spans 2 to 4, and the base of the southern side of arch 5 (now the southern abutment), all constructed in stone. The barrels of arches 2 to 4 each consist of four chamfered stone ribs, across which other stones have been laid to form the arch soffits. The ribs rise from low, vertical ashlar piers, although the northern face of pier 3 (between arches 3 and 4) has been repaired in brick. It is very likely that the soffit of arch 5 was originally stone-ribbed, although the arch ring and soffit were later rebuilt in brick. The spandrels, which were raised probably in 1838 to level the deck out, are in rendered brick.

Except for piers 1 and 5 (the present southern abutment), there are stone cutwaters against all piers on the upstream elevation, integral with the stonework of the bridge. In section, these are all pointed with half hips at just above the springing level of the arches, then continue up through the spandrel in a reduced but still pointed form, terminating in a small ridged cap a little below string-course level. Piers 1 and 5 have a similar cutwater rising to half hips, but of brick.

In the arch barrels, construction joints clearly show the 1838 brick extension built directly up against the east side of the old stone structure. The arches are elliptical verging on four-centred to match those of the original structure. The spans on the second 1848 extension to widen the bridge (again on the east side) have a more definite pointed, four-centred-arch profile. There are no cutwaters, but piers 1 and 4 (the original ends of the bridge, excluding causeways) are embellished with shallow pilaster strips that rise right up through both spandrels and parapet. There are small rectangular buttresses set against these pilaster strips and all other piers.

The brick parapets, dating to 1838, have stone copings of a shallow ridged profile. The southern end of the western parapet terminates in an octagonal brick pier, which has an octagonal, shallow-profile cap that matches the coping. There is an identical pier at the northern end of the parapet, but given that this end of the bridge was extended in 1976, it is unclear whether it is the original pier repositioned or a modern facsimile. Approximately in the centre of the western parapet is a stone set facing the roadway that reads 'S | N / 1838'. The 'S' and 'N' are probably the initial letters of the two parishes Saxlingham Nethergate and Newton Flotman, and the vertical line denotes the position of the parish boundary. On the eastern parapet, there are iron tie rods through the crown of each arch to tie the two extensions together. These have pattress plates cast with the manufacturer and date: 'GARROOD 1848'.

The southern causeway and arch, shown on an 1830 drawing, now lie buried in the riverbank which was extended forward to enlarge the mill car park. It is probable that this causeway was the latest in a succession of such causeways and was heavily rebuilt when the bridge deck was raised probably in 1838. On the curving brick wing wall that extends the line of the bridge's western parapet, a pattress plate marks the position of the crown of the blocked arch 6. The sloping tops of a couple of additional small buttresses, identical to that against pier 5, are also visible protruding above the car-park surface either side of the pattress plate.

At the northern end of the bridge, arch 1 (built in 1976) is constructed of reinforced mass concrete faced in brick. Most of the river's flow is now directed beneath this arch, and arches 2 to 5 are protected by a concrete invert (poured between steel shuttering) laid in the bed of the river to protect the older parts of the bridge from scour.