The Roving Bridge at Hampstead Road Locks, built in 1846 over the Regent’s Canal, has become an internationally familiar structure, thanks to the popularity of Camden Lock Market.
The alignment of the diagonal or roving bridge was dictated by the positions of the docks that had been created in 1816 on the north and south sides. The towpath was diverted to the south side at Hampstead Road Locks before regaining the north bank on the opposite side of the Hampstead Road (now Chalk Farm Road).
The Roving Bridge dates from the first phase of expansion of the Goods Depot, when the railway company established its own interchange facility. The opening of Camden Goods Station in 1839 provided a major boost to the growth of Camden, based on the interchange between railway, canal and road. This is presently recognised only in the Interchange Building, the third generation of interchange warehouses on the site and built in 1905, by which time Camden had long been established as an interchange depot.
The Roving Bridge is formed as a distinctive cast iron arch cum vierendeel truss, a rare example of a cast iron arch bridge with wrought iron tie bars fixed at the top of the parapet. No other cast iron towing path bridges with these have been identified. The tie bars carry the tensile loads and induce a state of permanent compression in the lower flanges in the same way as in a post tensioned concrete beam./
The bridge was manufactured in Newport, Monmouthshire by Joseph Deeley’s London and Newport Iron Works. As well as an iron founder, Deeley was an engineer and an inventor, having developed a patent foundry furnace that allowed iron to be smelted using a cleaner and less costly process, resulting in both a higher yield and a superior quality of iron.
The Regent’s Canal Company decided in mid-1846, after the Roving Bridge had been completed, to provide horses for towing. The stabling at Hampstead Road Locks provided stalls for up to 18 horses. Barges in the southern lock had to be towed across to the northern bank to continue their journey. The rope would pass under the Roving Bridge on the upstream side to be attached to the horse, now on the bridge. The horse then pulled the barge across to the other bank. The force on the rope required to turn the barge against the flow of canal water was so great that the parapet rail of the bridge and the stone parapet of the abutments are deeply scored, evidence of past operations.
The purpose and origin of the bridge is interwoven with neighbouring features that make up its setting. There are five Grade II sites within 100 metres and many other industrial heritage assets along the canal. The views from the Roving Bridge, both east and west, have special industrial heritage significance along this section of the Regent’s Canal and provide a coherent setting for Camden’s interchange role. The significance of the industrial setting goes well beyond the sum of the parts, having high group value.
This setting, and the need to protect it from inappropriate development, is one of the primary reasons to seek an upgrade in designation to II*. The redevelopment of Camden Lock Market must ensure that the Roving Bridge setting is enhanced.