Friday, 15 April 2016

COAL CONSUMPTION CALCULATED.

At Sydney 2,053 tons of coal were taken in, and at Melbourne 163 tons. At Adelaide on return 180 tons were bought. To Adelaide 799 tons were consumed, and from thence to Durban 1,785 tons. At Durban 1,929 tons 6 cwt. of coal were taken in. There was thus on board a total of 2,378 tons 6 cwt. Mr. Lund, probably correctly, estimated her consumption whilst in Durban at between 20 and 30 tons, which would leave her with, in round figures, 2,350 tons when she sailed from that port. 


Distance between Sydney and Adelaide is 973 n miles, exactly 3 days' voyage. Waratah should have consumed 80 tons per day = 240 tons + maximum 30 tons while at Melbourne = 270 tons. If one is to believe the 799 tons consumed between Sydney and Adelaide we get a whopping 246 tons per day, which simply does not make sense. We know that Waratah, fully loaded, consumed only 94 tons a day on the crossing to Durban. However, if we use the two figures, 163 tons + 180 tons, purchased, we get 283 tons, which is 94 tons per day - correct! In fact less than this was consumed taking into consideration that between 20 and 30 tons were consumed while in Melbourne = 84 tons per day. This exercise highlights the simple fact that Waratah approximated her normal coal consumption of 80 tons per day when not fully loaded. However, she took on the bulk of cargo at Adelaide which pushed the consumption up to 94 tons per day. This proves:

1. Captain Ilbery did not 'press' the Waratah's engines under conditions of partial lading. Speed was not his primary goal.

2. Waratah consumed significantly greater volumes of coal when fully loaded, which implies that her under powered engines needed to be 'pushed' under such conditions, to maintain her cruising speed of 13.5 knots.

At the Inquiry:


Mr. Shanks, Lund and Sons' superintendent 
engineer, stated that the coal consumption of 
the Waratah was 15 tons per day more on the 
second voyage, due to the distillation of drinking water 
and weather conditions.

The above analysis illustrates that the increased coal consumption was directly related to Waratah's heavily laden status departing Adelaide. There were no remarkable weather 'events' on the voyages from Sydney to Adelaide and Adelaide to Durban. Distillation of water was a constant factor.

The figure of 799 tons referred to above could be the total consumption of coal between arrival at Adelaide, incoming, and return to Adelaide, outgoing. If this is the case, we get an approximation of Waratah's coal consumption as calculated above.



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