Ketledge, usually comes in the form of pig iron billets and was often used as ballast in larger ships. Ballast comes in many forms and did so before the introduction of water ballast in early steamships. Sand , mud, rocks, and foundry dross were often used but the effort of loading it and discharging it by shovel was costly and time consuming on ships wishing to spend less time in port. I was not aware of foundry dross until I spent some time on Ascension Island in the South Atlantic Ocean. During my stay en-route to South America. I became friendly with one of the local inhabitants who brought to me one day what appeared to look like a piece of clinker (hardened ash or partly burnt coal) from a ships furnace. It had speckles of what I thought was brass in it and the local thought it was gold and it was very heavy for its size about 5 inches in diameter and 1inch thick. We took a hacksaw to it and found more of the shiny metal was right throughout . He told me that he was diving and came across a massive patch of it in amongst some old ships timbers, he also produced some heavy copper fastening bolts. It was now obvious that he had found and early shipwreck, and naturally kept the spot to himself. I was very curious as to what the clinker could be and at his request would I take a sample with me to determine what it was. This I duly did this and after eventually arriving in England on my way home, took it a marine archaeologist who informed me that it was dross from a foundry that probably cast bronze cannons and fittings for early sailing ships and was used as a heavy ballast in wooden vessels. The main content in the dross was bronze and I duly messaged my friend on the island and he replied that he was going to salvage the remainder for the bronze content as scrap metal. This was my first lesson in unusual ketledge as I knew it.
Unstable M.V. Rangitiki.
The M.V. Rangitiki was a New Zealand passenger ship one of three in the same class, launched on the 29th of August 1928 ,on sea trials she was found to be unstable in ballast. Before her maiden voyage was undertaken some topside weight was removed. Modifications were made which included the removal of two sets of Samson posts, (Strong pillars fixed to the deck for the support of ships derricks). On the 31st of January 1929 she was taken over by her owners and set sail for New Zealand on February 15th 1929 taking 5 weeks for the voyage. During the 1st voyage stability problems were still found to exist and on her return to England she underwent further alterations. These consisted of removing most of the bridge structure including the associated deck, shortening of her two funnels and the installation of additional permanent ballast. After this the ship went on until scrapped in 1962.
Rangitki with high funnels.
Rangitiki with cut down funnels.
The ss Imperator.
On her sea trials stability issues were discovered but she still sailed on her maiden voyage from Germany to New York on the 10th of June 1913. On her arrival at New York the pilot Captain George Seeth noted that the ship listed from side to side when helm changes were made to her change of direction. It wasn't until October 1913 that the Imperator was returned to the ship yard that built her to have alterations made to improve her stability which was caused by her centre of gravity being to high. The marble bathrooms in 1st class were removed along with all heavy furniture and replaced with light cane furniture. Her funnels were reduced by 9.8 feet (3metres) and 2,000 tons of concrete were poured into her double bottoms as fixed ballast.
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Imperator (leaning Lizzie docking at New York.
A true birds eye view of the Imperator.
The ss Principessa Iolanda.
The ss Principessa Iolanda was launched in Italy at 12.25 pm on the 22nd of September 1907 and was almost at the completion stage. After leaving the slipway the ship became unstable and heeled over to port. Some 20 minutes later the vessel began taking in water (Downloading) through open ports. She eventually capsized and lay at 90 degrees. There were many errors caused during her launching but the main error seems to be launching an almost complete ship without ballast, it was denied that it was due to her design.
ss Principessa Iolander
Launching in progress.
Starting to take water.
At rest at 90 degrees, could you imagine the Waratah recovering from this with cargo on board that would have shifted in heavy seas along with water rushing in through her vents and openings. It would appear beyond any shadow of doubt that in this case the righting lever (GZ) is no longer apparent. Hope the men in the picture are not looking for it.(please excuse my sense of humour). Readers can view Wikipedia for information on the three ships mentioned here.
A comment on stability.
You can play around with all the figures on the stability of the Waratah but I am convinced that not all the true figures were not put into the public arena, if she was such a wonderful stable ship what happened to her? It is impossible to thoroughly determine the stability of any particular ship using commonly published specifications. It must be remembered that stability is so complex and influenced by so many factors that even professional ship designers find it hard to quantify. Before computers were available the calculations involved were so complicated that certain aspects of stability were only estimated rather than accurately determined. When reading the figures on the Waratahs stability presented to the court this is what precisely happened. In this present age of computers doing the workload on numbers, stability calculations are one of the most trying tasks the naval architect has to contend with and perform.
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