The William C Daldy is a coal-fired steam tug, built at Renfrew on the Clyde in Scotland for the Auckland Harbour Board in 1935. After an 84 day delivery voyage to New Zealand, she entered service in February 1936, handling shipping in the port of Auckland. She served the Harbour Board well for 41 years and by the time she was retired in 1977 was one of the last working coal fired tugs in the world. There had been plans to convert her to oil firing or to re-engine her with twin diesels, but they came to nought. On retirement, the tug did not find her way to a ship-breaking yard, but passed into the hands of a preservation society. As a result, she is still active on Auckland Harbour in the North Island of New Zealand, after a career of more than 70 years.

The ‘Daldy is not a small vessel – she has a length of 126 feet (38.4 metres), a beam of 32 feet (9.75 metres) and a draft of 15 feet (4.5 metres). She is not slow either – she did 13.4 knots on trials and if her bottom is clean, she can still do 13 knots. A tug’s towing power is measured in bollard pull and the William C Daldy was conservatively measured at 17 tons on trials in 1935. Even the new motor tugs in Auckland in the 1960s were less than this, but her replacement, the 1977-built Daldy came in at 24 tons bollard pull.

Having set the background, let us look at the heart of the vessel. The tug has her original two coal fired boilers. Each boiler is 13ft 6in diameter and 11ft 6in long and has 3 furnaces. Thus, the stokers have six fires to tend and if the tug is working hard the boilers will have an appetite of rather over a ton an hour. On a good day, there will be 4 stokers on board, two down and two up, swapping over every 30 minutes. The coal is in bunkers on each side of the vessel, alongside the boilers (up to 50 tons each side). If the bunkers are full, the coal finds its way into the stokehole without effort. If the bunkers are empty, then someone has to go into the bunker and shovel the coal into the door first, a process known as trimming. It is dirty dusty work and these days just part of the stoker’s job.

The boilers normally run at 185 psi. If they were stone cold, a fire would be lit in each centre furnace 3 days before a sailing. It would be fired during the day and banked at night. About 2 hours before sailing, there should be 100 psi on the clock, and the wing fires would then be laid and lit with hot coals from the centre fires. There will, of course, be some ash under the centres by now, and this is normally put ashore – by shovelling into steel drums and hoisting up on deck with the one man-power winch.

Steam from the boilers is fed aft to the engine room, to a pair of triple expansion engines of the classic marine design which became popular in the 1880s. They are fairly large and each engine is 980 IHP, directly coupled to an 11 foot diameter propeller. Whilst the engines can be reversed by hand, they are fitted with a steam reverser and will reverse very quickly in an emergency. There will normally be 3 engineers in the engine room – one at the controls of each engine and one oiling, checking water levels etc.

By the time the steam reaches the low pressure cylinders, it is at about atmospheric pressure and it then exhausts into a large surface condenser. Duplicated air pumps remove air from the condenser and pump the condensate forward to duplicated feed pumps to be returned to the boilers. A valve on the side of the aft boiler is adjusted to keep the water level the same in the two boilers. All the auxiliaries in the engine room are steam, though there is a diesel emergency fire pump hidden away in the lower focsle. So, in addition to the pumps already mentioned, in the engine room you will also find the seawater circulating pump, a bilge pump, a general service pump, a freshwater pump and a generator for the electric power used on board. On the main deck level there is yet more. A “Donkin’s Patent” steering engine drives the rudder. The boilers are fed with a forced draught, supplied by a Howden steam-powered fan. There are two steam winches on deck, one forward and one aft, for working lines. Finally, the galley is equipped with a steam powered urn for making tea.

Tony Millatt

more information at http://www.daldy.com/

Editors note:

Tony was a radio officer with the New Zealand Shipping Company. In 1998 he participated in the line’s 125 th anniversary when he renewed his acquaintance with New Zealand and became involved with the steam tug William C. Daldy.

Deputy Editors comment:

Ex Radio officers seem to get everywhere—especially since they largely became redundant with the use of satellite communications etc. Although I never did my ticket—I worked as a radio system engineer with Marconi Marine for many years. They employed huge numbers of RO’s, and most famously the two RO’s on the Titanic—or was it the Oceanic ???!