The Rosie Hackett Bridge

The brief for the Rosie Hackett Bridge raised two opposing and critical design parameters that proved to be one of the key design challenges. From below, a single-span high-tide navigable channel was to be maintained for the river ferry and other small craft. From above, the Luas track needed to continue from one side of the river to the other in a gradual sweep, with as little deviation in height as possible. This necessitated a slender and shallow structure of reinforced concrete for both bridge deck and buttresses.

In addition, and in order to accommodate the various traffic lanes (7no. in total for public transport, pedestrians and cyclists), the Rosie Hackett Bridge needed to be relatively wide in relation to it’s span. The combination of width, shallow plan and high loads could potentially have resulted in a visually heavy structure, but this problem was overcome with 3 dimensional vaulting of the buttresses and deck, which allowed for mass and strength at locations where it was most needed, and lightness and finesse at edges where strength was less needed.