Posted by Terence McManus on September 16, 1998 at 07:08:52:
In Reply to: Re: The Wild Cat's ballast posted by Art Mulder on September 15, 1998 at 17:09:43:
I'm not sure that the weight of the water would have that much effect on the stability of the ship since a rough calculation suggests that the weight of the water would not be that great in comparison to the overall weight of the Wild Cat. (See the sums below).
Most yachts carry their water in tanks set as low as possible so as to minimise the effect on the stability of the vessel. Yachts don't normally suffer an undue change in their stability as the tanks empty. Racing yachts' crews sometimes deliberately increase their fresh water consumption towards the end of a long race. In sea stories ships being chased by a man of war are often described as pumping their water overboard to gain extra speed. I suspect that neither the Swallows nor the Amazons would have wished to slow down the pace of the story by debating such points. And Dick was not there?
As to the Viper's third dinghy I would think it probable that it was acquired by Black Jake in Madeira: but purchased, perhaps not?
Sums
I don't have Peter Duck to hand so I can't remember whether AR ever said how large the cans were. Even if each can contained five gallons the total weight would be little more than two tons. (87*50lbs =4,350lbs plus the weight of the containers).
I suspect that the cans were smaller than five gallons. Two gallon cans would be of a size the children could carry and would give about the right capacity for a trans-Atlantic voyage with nine crew aboard (For a crew of nine 174 gallons would allow half an imperial gallon a day per head on a 39 day crossing).
174 gallons of fresh water weighs consideraby less than a ton and woul d have a relatively small effect on the Wild Cat's stability.
I would guess the displacement of the Wild Cat to be at least thirty tons so I would expect her to have to carry ballast in addition to the water. Either Captain Flint was ignoring this ballast or his naval architect made some miscalculations