Monday, 18 April 2016

NEEDED 12000 TONS CARGO FOR STABILITY - REVIEWING THE WORDS OVER LOADED.

The Register (Adelaide) Saturday 17 December, 1910.

Mr. Barry, chief of the scientific department 
of Barclay, Curle Limited, of
Glasgow, who built the Waratah, in 1908,
gave evidence. He testified that the
owners wanted a vessel capable of going
to sea with coal and water only as ballast,
but that was found impossible. To ensure
the stability of the vessel there was also
required 12,000 tons of heavy cargo.

Captain Ilbery:

The captain replied - "She is a little that
way, but there are many thousands of
tons of dead weight." He {Richardson)
thought the the vessel was tender; but not
dangerously so under ordinary circumstances.

I have said much about 'overloading' of Waratah in this blog. I have referred to the registered tonnage figure of 6 003.96. 12 000 tons flies in the face of my allegations, and according to Mr. Barry, if Waratah carried cargo less than 12 000 tons on her final voyage, she was not overloaded. The very man had intended it so.

Registered tonnage reflected cargo spaces at 100 cubic feet to the ton. As we all know, this figure was modest in terms of what steamers actually conveyed, but had a lot to do with port duties etc. Generally speaking, steamers of the era carried cargo at roughly 50 cubic feet to the ton, doubling the registered tonnage figure, which equates with the above statement by Mr. Barry.

Mr. Barry conceded that Waratah would need significant dead weight to steady her, but in the same breath we know that 'tween decks coal at 42 cubic feet to the ton, caused a marked reduction in GM. Loading cargo at 50 cubic feet to the ton in these spaces would be a marginal, but not significant improvement. For the balancing act to work, cargo would have to be loaded at 50 cubic feet to the ton in the lower hold, reducing this concentration to 100 cubic feet to the ton, moving up through the upper, 'tween and spar decks. This was the case with reference to tallow and wool on the spar deck, final voyage - 100 cubic foot to the ton. For what it is worth, the Inquiry presented the following:

- 4320 tons lower hold
- 1425 tons lower 'tween decks
- 595 tons upper 'tween decks

This distribution illustrates the grading of cargo from heaviest lowest down to lightest, higher up. 

So why do I harp on about this? It comes down to draught and freeboard. We know that the Geelong's hull was the foundation 'identikit' for the marginally larger Waratah's hull. Without a third superstructure deck Geelong operated safely, with a reasonable max. draught (26.9 ft.) and freeboard (> 11 ft.). Geelong could load cargo at 50 cubic feet to the ton without causing stability problems and significant reduction in freeboard - the all important reserve buoyancy factor.

Waratah differed in one crucial aspect, her additional deck reduced GM and added weight to a hull which was designed for a two deck ship. This translated into an increased max. draught (30 ft. 4 1/2 in.) and freeboard of 8 ft. 1 in.. Even Plimsoll's crude calculation of 8.75 ft. exceeded 8 ft. The situation was further compounded by twin quadruple expansion engines which were relatively under-powered. 

Captain Ilbery referred to 'many thousands of tons dead weight' which not only included cargo well beyond 6000 tons (probably closer to 12 000) but the entire weight of Waratah and souls. His words rang out loud and clear - profoundly so. He was saddled with a steamer which was caught in a catch 22 dilemma. He could either choose between a tender vessel with a reasonable draught not exceeding 26.9 ft. and suitable freeboard of 11.6 ft. +, or he could functionally overload his steamer to 29 ft. +, with reduced freeboard (buoyancy), and create a more steady vessel. The dilemma came down to the simple fact, with her third boat deck, Waratah should not in reality have been conveying 12 000 tons of cargo, whether Mr. Barry said so or not.  See previous post:

 http://waratahrevisited.blogspot.co.za/2016/03/ss-indarra-has-final-word.html

In the case of Indarra, so very similar to Waratah, stone ballast had to be added to steady her, but the final solution came in the form of removing a substantial portion of her superstructure to reduce draught

So, my opinion is based on appropriate draught and freeboard rather than registered loadline and anticipated maximum cargo carrying capacity. To further enhance this point of view:



Inquiry:


It is a well-known fact that steamers loading on the Australian coast, especially in the wool season, are compelled, in order to complete their voyage with safety and stability, to keep their water ballast tanks full all the way home. This, especially if a ship is inclined to be tender, renders it all the more necessary for care in loading at the ports previous to arrival at Port Adelaide in order to leave room to put the heavy cargo of this port as low down as possible.

Waratah departed Adelaide with 360 tons of ballast water out of a potential 1338 tons. This was the give-away. Waratah needed additional buoyancy, in the form of 978 tons' worth of free air. Lead concentrates to the tune of 1000 tons plus other heavy cargo items such as timber compensated for weight lowest down. Waratah was too heavy to start off with in order to safely use all her ballast tanks, whilst conveying cargo - whether it be 6 400 or 12 000 tons !! 

The Lloyd's Surveyor at Adelaide had this to say:

I had no conversation with the master of the steamer about the ship as I never had any doubt in regard to her. 1 never saw her empty. Every time she came here she was from a half to two-thirds full of cargo. I have visited the "Waratah" ever since she first came to this port, and have watched both loading and discharging. I have never observed anything in regard to her to cause me any uneasiness. 

This statement confirms that Waratah could not operate at full cargo capacity. The Surveyor had never seen her more than 2/3 full ! A stevedore at Adelaide quoted that she carried 9000 tons of cargo when she departed Adelaide for the last time. This was more accurate than the figures presented at the Inquiry, but still 3000 tons short of the figure quoted by Mr. Barry. 

Whatever the true cargo tonnage figure was, it is irrelevant in the context of a steamer with a draught of 29 ft. +. At the end of the day, sensible draught and enough reserve buoyancy was all that counted and Waratah in this context was too heavy - I shall no longer use the words, over loaded.

Mr. Barry, in his own words, had told the Court that he and his team had created a flawed steamer, which could never be safe at sea with 12 000 tons of cargo - but needed it for stability. Further to this Mr. Larcombe, of the Court, gave a conservative estimate of cargo just in excess of Waratah's registered tonnage, for this very reason, while everyone knew she probably carried at least 9 000 tons. But in drawing attention to this would have forced the Court to address an issue far more serious than whether Waratah was light in a port setting.

Captain Ilbery was a clever man. He deployed 1300 tons of lead concentrates effectively, without compromising much needed ballast tank free air. But he had an unenviable task, not forgetting Waratah's under powered engines. He was said to have stated "either the ship or my reputation will be lost". That about sums it up.

How could Waratah depart ports with a misleading loadline?

The following extract from 1909 is very revealing:

The LCA had even acknowledged overloading as a significant problem in their 1909 Annual Report. "A great deal of trouble was experienced during the first half of the season by vessels overloading and causing damage to the bottom of the lock (Great Lakes) and during the latter half of the season, though vessels did not appear by their marks to exceed the recommended draft, nevertheless the closing cables were frequently cut, indicating that their marks were not correct.....Draft marks on their hulls were apparently being altered so that dock workers would not know their actual drafts."

also see:

http://waratahrevisited.blogspot.co.za/2016/04/3456-tons-of-coal-outbound-revisited.html

http://waratahrevisited.blogspot.com/2016/07/insurance-lead-concentrates-copper-and.html



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