Tasmania Built a Bridge to Last a Hundred Years and It Didn’t Make It

In eighteen twenty-nine, two hundred convicts under sentence of secondary punishment began building a causeway across the River Derwent north of Hobart. With wheelbarrows, shovels and picks, they moved two million tonnes of soil, stone and clay into the river. The Midland Highway still runs on it today. Five bridges have stood at the northern end of that causeway. A sliding timber bridge from eighteen forty-nine. Two swing bridges that ended up doing each other's jobs. A steel vertical lift span opened in nineteen forty-six and designed to last a century. It lasted seventy-nine years. From two thousand and six to two thousand and ten the lift span did not work at all. A fourteen million dollar refurbishment, promoted as a tourist attraction, got it opening a handful of times. The first money for a replacement was set aside in two thousand and one. The new bridge opened on the first of June, two thousand and twenty-five, at seven hundred and eighty-six million dollars. It is tall enough that it never has to open. LOCATIONS IN THIS VIDEO Bridgewater Bridge and causeway: 42.74500 S, 147.22583 E Convict causeway, Granton to Bridgewater: [confirm] Remains of the 1893 bridge pivot and abutments, upstream side: [confirm] Access: the new bridge carries the Midland Highway and has a separated footpath and cycleway open to the public. Demolition of the 1946 lift bridge began in October two thousand and twenty-five. The causeway remains in use beneath the highway. SOURCES Bridgewater Bridge, Nomination for Engineers Australia Engineering Heritage Recognition, Ian D. Cooper, 2018 The Bridges, Roads and Rails of Bridgewater, Lindsay Whitham The Mercury and Tasmanian News, 1886 to 1946, via Trove Infrastructure Tasmania, Review of Bridgewater Bridge Design and Cost Estimate, March 2016 Department of State Growth, Tasmania ABC News and Pulse Tasmania, bridge opening coverage, June 2025 THE FIVE BRIDGES The sliding timber bridge, eighteen forty-nine, by former convict James Blackburn The railway swing bridge, eighteen seventy-four, which became a road bridge The road swing bridge, eighteen ninety-three, which became a railway bridge The steel vertical lift bridge, nineteen forty-six to twenty twenty-five The concrete box girder bridge, opened June twenty twenty-five Old Deviation covers the roads and railways Australia stopped using and what is left of them. IMAGE CREDITS (Wikimedia Commons) Photos: Chuq (CC BY-SA 4.0) · Weston Langford (CC BY 4.0) · Philip Northeast (CC BY 2.0) · KeresH, Noodle snacks, JJ Harrison (CC BY-SA 3.0) · Jim Trodel, Thad Roan/Bridgepix (CC BY-SA 2.0) Public domain: 1851 Admiralty Chart (UK Hydrographic Office), Port Arthur by Anson Brothers, Sir George Arthur portrait, "Hobart Town chain gang" Full credits & links in the pinned comment. Map data © OpenStreetMap contributors · Music: Epidemic Sound #BridgewaterBridge #Tasmania #Hobart