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 82 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.

TST William C Daldy undergoing sea trials 1935

There had been plans to convert her to oil firing or to re-engine her with twin diesels, but they came to nothing. On retirement, the tug did not find her way to a ship-breaking yard, but passed into the hands of a preservation society for the princely sum of $1. The Auckland Harbour Board then donated $1 back to the newly formed 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 over 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 'Scotch' coal fired boilers. Each boiler is 13ft 6in diameter and 11ft 6in long and has 3 furnaces. Thus, the firemen have six fires to tend and if the tug is working hard the boilers will have an appetite 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 fireman’s job. There is also an aft bunker which can accomodate a further 80 tons of coal for long voyages.

The maximum boiler pressure is 180 psi. If they are 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 950 SHP or 1000IHP,(Evidence of more power can be found here from original card readings done in longhand by the chief engineer on delivery voyage) directly coupled to an 11 1/2 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. Check valves on each boiler are adjusted to keep the water level the same in the two boilers.

All the auxiliaries in the engine room are steam and all were duplicated or have alternative means as Lloyds stipulated this as a requirement for insurance due to the long delivery voyage to New Zealand. 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 which can supply the condenser should the circulating pump fail, a freshwater pump and a generator for the electric power used on board.

The original generator was replaced in 1956 with a more powerful 15Kw unit salvaged from the minesweeper Kiwi. HMNZS Kiwi (T102) was a Bird class minesweeper of the Royal New Zealand Navy. She was commissioned in 1941 for minesweeping and anti-submarine roles. From 1948 to 1956 she functioned as a training ship. With her sister ship Moa, Kiwi rammed and neutralised the Japanese submarine I1 at Guadalcanal! Kiwi was named after the Kiwi bird from New Zealand and was the first of three ships with this name to serve in the Royal New Zealand Navy.

On the main deck level there is yet more. A “Donkin’s Patent” steering engine drives the rudder. This is the only remaining engine of this type known to be still in existence. The boilers are fed by forced draught, supplied by a Howden's Patent 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.

A special thanks to Tony Millatt for help with the compilation of this text. Cheers Tony!