The investigation comprised the archaeological monitoring of mechanical removal of fill material forming part of the original early 19th century bridge construction. The modern tarmac road surface had been removed in advance, following agreement to this by Humber Historic Environment Record. The excavations revealed that beneath the modern road surface (100/101) there were preserved deposits relating to the original construction of the bridge as well as deposits related to an earlier roadway. The earlier roadway consisted of a layer of cobble over a layer of pebble (102/103) (Plates 4, 5 and 10). This overlay a soil horizon of clayey silt (104) (Plates 9-11 and 13). Fragments of pottery and tobacco clay pipe stem confirmed the historically documented 19th century date of this fill material. Within the centre of the bridge the excavation revealed the presence of a curious concrete conduit (105-107) that post-dated the bridge construction (Plates 14-20). This may have been installed as a central drain, later sealed off at either end, or may have been put in place in case a steel strengthening bar needed to be added. The process of excavation exposed the four width restriction posts (109-112) (Plates 25 and 41-44), which were not tied into the original bridge construction (108), along with four drains for surface water which fed directly into the flood arches (113-116) (Plates 21-23). Restrictor post 1 and drain 1 were located at the northeastern end of the bridge on the eastern most side. Restrictor post 2 and drain 2 were opposite to them. Restrictor post 3 and drain 3 were on the eastern most side of the southwestern end, and post and drain 4 were on the opposite wall.
T Robinson (Mon,) studied this question.