Imagine standing on a sweltering promenade deck aboard a ship rolling sluggishly from side to side as it pushes its way through a lazy swell that shimmers like oil in the hot afternoon sun. There is very little breeze because the ship is sailing with the wind and indoors it feels like a stifling furnace. This was the reality of an ocean crossing during the summer months in warm climates in the early 20^th century – until the SS Mariposa set sail in 1931 and changed the ocean liner industry forever.

SS Victoria

Following the disastrous engine room fire aboard Carnival Triumph that left the ship stranded at sea for several days without power, the main complaint of passengers was the heat in the Caribbean waters during summer.

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It brings to light one of the most essential systems aboard a modern cruise liner – air-conditioning. But how was AC developed for use on ships?

The artificial ventilation of ships started as far back as the 18^th century, when ventilation bellows were developed for shipboard use by Sweden’s Sir Martin Triewald and Reverand Stephen Hales in England during the 1740s.

These manual contraptions were tiring to operate and largely ineffective. It wasn’t until 1880 that a refrigeration system was successfully installed aboard SS Strathleven after much trial and error from around 1873.

Through the late 1800s these systems were used mainly to keep meat and other perishable goods fresh during long voyages. By 1908 complex mechanical ventilation systems were available aboard luxury liners such as Cunard’s Mauritania and Lusitania, and later the Olympic-class liners of the White Star Line, such as RMS Titanic, Olympic and Britannic.

However, these systems were geared toward the provision of heating on a winter Atlantic crossing – it wasn’t until 1930 that a modern air-conditioning system was installed aboard a passenger liner, the SS Victoria of the Lloyd-Triestino line.

Some sources claim the SS Mariposa of 1931 was the world’s first air-conditioned liner, but in fact Victoria was the first, and her air-conditioning system was more advanced. While SS Mariposa had an air-conditioned first class dining room, aboard the Victoria all the dining saloons and six luxury cabins were air-conditioned.

SS Mariposa

Throughout the 1930s, air-conditioning systems aboard ships were improved by CEC, the leading company in marine air-conditioning at the time, with the French luxury liner Normandie becoming the first ship with a centrifugal refrigeration machine in 1936.

By this time, other major passenger shipping lines had also gotten in on the act, in 1935 the 23,350-ton Orion and Orcades of Orient Line and the Strathmore, Stratheden and Strathallan of P&O were all launched as liners with air-conditioned public rooms.

In 1936, RMS Queen Mary had her Main Dining Room, First Class Lounge, Tourist Dining Room and First Class Hairdresser’s Shop air-conditioned. In 1938, Holland America Line’s Nieuw Amsterdam also had some public rooms air-conditioned.

Major engineering challenges prevented the full air-conditioning of these massive liners, aboard the Queen Mary for example, six AC plants were needed for her limited air-conditioning provision.

SS Normandie

At this time, most cabins still relied on an open porthole for any cooling ventilation. But just a few years later, Wills Carrier, widely regarded as the father of air-conditioning, provided the Imperial Railway Steamship Company with the world’s first completely air-conditioned passenger ship, the Japanese 8000-ton liner Koan Maru, launched in 1937.

The massive advantage an air-conditioned liner in hot and humid climates had over her competitors was plain to all and this began an avalanche of research and development that continued throughout the Second World War to find a way of completely air-conditioning a large luxury liner.

It wasn’t until the 1960s that this became widespread. Launched in 1961, Empress of Canada was the first large ocean liner that had all her public rooms, cabins and even crew quarters air-conditioned.

The immense volume of cold air needed to cool an entire ocean liner is exemplified by the Shaw, Savill & Albion Line’s Northern Star, which operated on the Australia-UK route throughout the decade.

She needed 67 separate air-conditioning plants working in conjunction with 3 electric motor-driven Carrier centrifugal water-chilling refrigeration machines!

By the time the ‘world’s greatest ocean liner’ the venerable Queen Elizabeth II was launched in 1968, air-conditioning had become commonplace at sea, but the air-conditioning system installed aboard QE2 set the benchmark for the design of AC systems in the years to come, up to the present day.

Carrier-Winsor won the contract from Cunard by coming up with a new design concept, to concentrate all the major plant rooms on one deck. These centralised services, simplified maintenance and operation, released space to the interior designers, reduced weight at high level, and were cheaper.

So next time you complain about the individual AC control for your stateroom, consider the massive engineering challenge and the decades of development that have gone into its creation.