Saturday, 9 April 2016

WARATAH'S ENGINES.

Morning Bulletin, Tuesday 26 April 1910.

Mr. Grigg:

The Waratah, he said; lurched very badly, 
and in an unusual way, and would breast 
the waves in a wriggling, zigzag manner, 
giving the passengers some misgivings
concerning her.

This is an interesting observation. It describes a heavily laden vessel, probably under-powered.
Captain Ilbery had achieved a steamer with a very suitable GM of 1.9 ft. departing Adelaide en route to
Durban (final voyage). This was achieved by heavy dead weight loading, including the 1300 tons of
lead concentrates. We know that Waratah's twin quadruple expansion engines produced 5400 ihp,
significantly less than similarly sized vessels of the time which had power outputs of 8000 ihp and
more. It could also explain why Waratah consumed 15 tons of additional coal per day to compensate
- and could be called 'pressing' the engines. Her time for the crossing was good, a day ahead of
schedule, but speed was not the whole story. 'Pressing' the engines would have created a new set of
problems: 

2.3.12 Quadruple Expansion Engine Naturally, as techniques improved, it was seen that quadruple expansion engines would come next after the triple expansion engine. They did, but they were developed only for naval ships, passenger liners and the fastest freighters, where high power was required and only high efficiency engines could do that without burning too much fuel. The high-power reciprocating engine had developed about as far as it could. The enormous weights reciprocating at high speed imposed severe stresses on all parts and imposed great vibrations onto the ship’s hull. Naval acceptance trials, where the engines were driven as hard as possible to demonstrate that the ship reached the required speeds, produced hair raising stories. Not only the noise and heat, but the air filled with water and oil vapor, the intense vibration, the water flung about because some bearings required cooling water hosed upon them, all contributed to a modern vision of Hell. The reciprocating engine was developed up to about 15,000 horsepower. The development of the quadruple expansion marine reciprocating engine came to a halt when it was overtaken by a radically new type of steam engine.  (Turbine)

(http://www.johnforester.com/Maritime/MarineSteam.pdf)

This description of quadruple expansion engines illustrates the limitations of the design. It was not as
progressive as it should have been compared to the preceding and highly successful triple expansion
engines. The hull of the Waratah was already subjected to enormous forces, further contributed by the
vibrations from the engines. 

'He gave similar evidence to the other witness about the boat rolling in the Bay of Biscay.  The Waratah could
not ride heavy seas, and the engines shook the vessel so much that the gear of the aftermast became
loosened.' 



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