Wednesday, 25 March 2015

Waratah - stability teething problems.

The stability of steamers, circa 1909, hinged on metacentric height (GM). This is a measurement, which together with other variables, indicates how stable a steamer was in terms of top heaviness. The greater the figure, the more stable the steamer (stiff). A relatively low figure would make a steamer more prone to heeling beyond a certain angle (vanishing point) which held the possibility of rolling over - particularly in rough seas. To achieve a reasonable GM was a balancing act taking into account safety vs. comfort. A very stiff steamer (relatively high GM) created a very stable, but short and jerky heeling pattern. This was not favoured in steamers intended to convey first and second class passengers. In short, the voyage would be uncomfortable. However, if the GM was too low, although creating a slower, longer far more comfortable roll, a degree of instability was the price to pay.

In order to establish a safe GM, steamers had to be adequately (particularly if there were two or three superstructure decks) ballasted in terms of water tanks and appropriate cargo loading (offsetting the superstructure). The loading plan was specific for the vessel and related to the stability curves (calculating GM etc) for that vessel. The stability curves were calculated after a heeling experiment was conducted on new steamers to establish these parameters before going into service.

Captain Ilbery was called away at the eleventh hour when the Waratah was due for her heeling experiment, which left it in the hands of Mr Barrie (chief engineer) from Barclay Curle & Co. This was an extremely peculiar turn of events because it was essential that the master of the steamer understand what he would be dealing with on the maiden voyage. No reason for Captain Ilbery's absence is given in records. As if to make matters worse:

"Captain Ilbery informs us that you omitted to place on board a framed plan of stability curves, as provided for in clause 2 of specification. It is most important that this should be on board; kindly therefore send these, and a spare copy by return; such important plans should not have been omitted."

In effect, when the Waratah departed London on her maiden voyage, November 5, 1908, Captain Ilbery was not in possession of vital stability curves for his vessel and had not participated in the heeling experiment. The results were clear to Captain Ilbery and those on board. The Waratah felt top heavy and somewhat unstable. Fortunately the crossing was without incident and after communications with the owners and builders, Captain Ilbery was given advice about the loading plan and filling an additional ballast tank (number 8). The outcome of adjustments was very satisfactory and Captain Ilbery openly shared his renewed confidence in the new flagship with both colleagues and passengers alike.

If the Waratah had disappeared without a trace on her maiden voyage outbound from England, it could have been argued that stability played a possible and crucial role in an accident at sea. But by the time the Waratah had completed her maiden return voyage and was en route back to the UK on her second to maiden voyage six months later, issues relating to cargo stowage and water tank ballasting had been resolved, creating a stable steamer in terms of GM. It was quoted that her GM when departing Durban was in the region of 1.5 ft. well in excess of the average, 0.75 ft. We know that overloading the Waratah contributed significantly to improving the GM figure, but created other problems which I have explored previously.

Apart from tensions between the owners and builders emerging in the course of the Inquiry, it does seem that standards were not adhered to and the Waratah set off on her maiden voyage in a rather slipshod manner. It was very fortunate there were no incidents as a direct result. Captain Ilbery was an exceptional commodore with a flawless record. He was due to retire after returning to England having completed a fifty two year career at sea, thirty six of those years, commanding Blue Anchor Line flagships. But Captain Ilbery was ultimately an employee of the Lunds, obliged to carry out his duties as outlined by Blue Anchor Line management. He may not have approved of setting off from London on the maiden voyage under such circumstances but endeavoured to make the best of the situation. He did not wait until returning to London to sort out the stability issue and his actions created a perfectly stable triple deck steamer.



                                                        to list or not to list.....

No comments: