Wednesday, 13 April 2016

WARATAH WAS UNDER POWERED.

Waratah's twin quadruple expansion engines were under powered for her size. I have put together a few examples (from many) of twin engine (screw) steamers of the era:

SS Waratah, built 1908

gross tonnage      9339
length                  465 ft.
beam                   59.45 ft.
power                  5 400 ihp
speed                   13 to 13.5 knots


SS Omrah, built 1899

gross tonnage     8130 
length                 490.5 ft. 
beam                   57 ft.
power                  9 000 ihp
speed                   17 knots


SS Wiltshire, built 1912 

gross tonnage      10 390
length                   526.5 ft.
beam                    61.4 ft.
power                   13 000 ihp
speed                    14 knots


SS Hororata, built 1914

gross tonnage       9461
length                   511 ft.
beam                    64.3 ft.
power                   8 493 ihp
speed                    14 knots


RMS Morea, built 1908

gross tonnage       10890
length                    540 ft.
beam                     61.2 ft.
power                    13 000 ihp
speed                     16 knots


SS Indarra, built 1912

gross tonnage        9735
length                    450 ft.
beam                     60 ft.
power                    8 132 ihp
speed                     16 knots


SS Assaye, built 1899

gross tonnage        7396
length                    450 ft.
beam                     54.25 ft.
power                    6 500 ihp
speed                     16 knots


SS Devanha, built 1905

gross tonnage         8092
length                     470 ft.
beam                       56 ft.
power                     8 000 ihp
speed                      15.5 knots


To put this important issue into perspective, let's take a closer look at the famous RMS Baltic:


Tonnage:23,876 GT
Length:729 ft (222.7 m)
Beam:75.6 ft (23.1 m)
Propulsion:Two four-cylinder quadruple expansion engines powering two propellers.
Speed:16 knots (30 km/h; 18 mph)
Capacity:2,875 people

At the time of launch Baltic was the largest steamer afloat (until 1905). On her maiden voyage, she completed the distance between Liverpool and New York (2871 n miles) in 7 days and 13 hours, which matched her registered speed of 16 knots. Despite the excellent crossing time, Baltic was proven to be under powered, her twin quadruple expansion engines being the same capacity as her smaller siblings, Celtic, Cedric and Adriatic. Power output was 14 000 ihp, but for her size, should have been 16 000 ihp. Modifications were made at a later stage to improve the output. It is important to note that being under powered did not affect speed under normal conditions. However, in heavy seas, an under powered steamer would have had difficulty maintaining speed / heading = unsafe. Manoeuvrability would also have been compromised, catastrophic if the vessel was caught broad side in a fierce gale. 

If one uses the Baltic as a frame of reference the Waratah should at the very least have had a power output of 6 226 ihp, not 5 400 ihp.

This casts an intriguing light on circumstances off the Wild Coast, 27 July. The falling barometer and physical signs presaging the approach of a cold front storm of 'exceptional violence' would have alerted Captain Ilbery to potential problems. Waratah was heavily laden and under powered. A decision might have been taken to come about irrespective of whether there was a fire on board or not. Captain Bruce remarked that Waratah was smoking fiercely, which might very well have been due to a fire, but also a sign (excessive, dark smoke from funnel) that the engines of the Waratah were being 'pressed' to outrun the approaching storm. It was mentioned at the Inquiry that 15 additional tons of coal were consumed daily on the final voyage, partly due to 'pressing' under powered engines. 

There might not have been a fire at all !

Mr Grigg summed up Waratah's limitations to perfection:

The Waratah, he said; lurched very badly, 
and in an unusual way, and would breast 
the waves in a wriggling, zigzag manner, 
giving the passengers some misgivings
concerning her.

Case closed.







1 comment:

Mole said...

A very important matter. Thank you for highlighting it.