Thursday, 10 October 2013

Waratah - Inquiry tackles stability issues.

At the Board of Trade Inquiry witness testimony on the performance of the Waratah came from those who had travelled on her maiden voyage, her builders and those who handled her at port. The testimonies were contradictory, but many stated that the Waratah had a 'very long roll', and a 'reluctance to right herself after leaning into a swell'. One passenger claimed that on her maiden voyage she listed to such an extent that the bath water failed to drain. Another, Professor William Bragg, a physicist, concluded that the Waratah's metacentre was 'just below her centre of gravity' and when 'she slowly rolled over to one side, she reached a point of equilibrium and would stay leaning over until a shift in the sea or wind pushed her upright'. As many witnesses as there were who claimed that the Waratah was unstable, there were an almost equal number of passengers and crew who claimed she was perfectly stable, with a 'comfortable, easy roll'.  

Correspondence between Captain Ilbery and the Blue Anchor Line's managers was brought before the Inquiry. Strangely, Captain Ilbery commented on fixtures, fittings, cabins, public rooms, ventilation, and other areas, but failed to make mention of 'the Waratah's seaworthiness and handling'.  Equally odd, the company never requested Captain Ilbery's opinion on stability relating to the maiden voyage. Some wondered if Captain Ilbery must had reservations about the stability of the Waratah hence avoiding the issue. Others drew the conclusion that the Waratah was largely based on the Geelong, assuming handling and stability to be the same.

Captain Ilbery admitted to a 'learning curve' with regard to the cargo stowage on the Waratah's maiden voyage, but certainly by the second return voyage he claimed to have 'mastered' the cargo stowage relating to stability curves. Steamships of the era were built slightly top heavy, creating a comfortable long slow but 'unstable' roll, which many passengers preferred to a short, jarring, but stable roll. These steamers needed careful ballasting, but on the whole were safe and operated the trans oceanic routes without problems.

'An inexperienced or uninformed person on the ship might conclude that the long, slow, soft roll of the ship felt comfortable and safe, whilst someone with more seagoing experience or a knowledge of ship design would have felt that the same motion was unstable. In regards to the witnesses claiming the Waratah's instability in port when unladen, this may have been true. However, virtually all ocean-going ships (which are, after all, designed to carry a large weight of cargo) need to be ballasted to some extent when moved unladen, so the Waratah was certainly not unique in this respect. It should be noted that the witnesses would have been well aware of this – that they still came forward to attest that they regarded the Waratah as dangerously unstable in these conditions does suggest that the ship was exceptional in some respect'

No comments: