William C. Daldy Steam Tug

The tug that held Auckland’s Harbour Bridge

William C. Daldy is a twin screw, coal fired steam tug, built at Renfrew on the Clyde in Scotland for the Auckland Harbour Board in 1935. After an 82 day delivery voyage she entered service in February 1936, handling shipping in the port of Auckland. She is the only working steam tug in the Southern Hemisphere.

She runs 126 feet long by 32 feet in the beam and displaces 750 tonnes, driven by two 950 nominal horsepower triple expansion steam engines. She carries the name of Captain William Crush Daldy, a seafarer and merchant who brought his schooner into Auckland on the day the port’s first Customs House opened in July 1841, and who later sat in the second Parliament as a member for Auckland.

In December 1958, during construction of the Auckland Harbour Bridge, the 1200 ton centre span was being floated into place when a gale force front moved in and the section began drifting up the harbour out of control. With other tugs unable to hold it, Daldy worked steadily for more than 36 hours and burned around 40 tonnes of South Island coal holding the span until it could be secured.

Keeping her in survey is relentless. Every two years she must be dry docked or slipped for hull cleaning, hull plate thickness testing, propeller shaft and seal testing and sea valve checks. Her berth at Devonport wharf adds to the wear, with tidal rips and ferry wash working at the hull. That round is now behind her. Repairs finished at Heron Ship Repair in Whangārei on 11 September 2026, and she went back into the water at first light the same morning.

The Society is now converting her from coal to wood based fuel, working alongside MOTAT and the Auckland Steam Engine Society with funding from the Freemasons Foundation. The change keeps her in survey and doubles as a prototype for other coal burning machinery. Documenting her in photorealistic 3D records the hull and machinery as they stand today, so condition can be compared across surveys and the detail survives whatever the next haul out brings.