Tuesday, 10 May 2016

STABILITY DEPENDED ON DISPLACEMENTS.

William H. Bragg. 

Passenger and Fellow of Royal Society and Cavendish Professor of Physics at the University of Leeds, fourth long voyage. 

Thought she was unstable for small displacements, but stable for larger ones.

Professor Bragg summed up the Waratah dilemma to perfection. Small displacements refer to less dead weight and a low GM, whereas larger displacements correspond with a more significant dead weight and stability - in reality heaviest cargo lowest down + significant lead component at 11 cubic feet to the ton.

Judging by the camber the list was four or five degrees.

This was a realistic assessment of an acceptable degree of list, despite the fact that Waratah was tender during this voyage.

Thought she was a remarkable steady and comfortable boat.

Professor Bragg, like Mrs. Hay, found Waratah comfortable and steady. What more can one say even taking into consideration a low GM during the maiden voyage.

Spoke to the chief engineer who said she was safe as a church, that if necessary the tanks would be filled, and she would then be as stiff as a board. 

An eloquent acknowledgment of the variability of stability.

Professor Bragg had spoken but his informative account was absorbed via selective hearing - to this day. Most people remember him for:

My impression was that metacentre was just slightly below centre of gravity when she was upright, and then as she heeled over on either side she came to a position of equilibrium. 

And so history was written even though the full context of Professor Bragg's account was blatantly ignored.




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