INITIAL REACTION AND COMPARISON WITH SS WARATAH.

The Argus, Melbourne, Friday 31 March, 1911.

CAPSIZE IMPROBABLE.

BRISBANE, Thursday - In view of the

widespread statements that the Yongala

"turned turtle," Mr. Wareham flatly 

contradicted the possibility, and pointed 

out that the steamer had been running 

on the coast in the interstate trade for 

eight years - five years running between 

Sydney and Fremantle. Consequently she 

crossed the Australian Bight every four weeks, 

often with less than 100 tons of cargo and not 

more than 200 or 300 tons of coal. She never 

gave owners, master, crew, or passengers any

cause for uneasiness on account of her 

behaviour. It was unreasonable to suppose

that the Yongala, which left Brisbane with

2,000 tons weight in her bottom and only 5

tons of cargo on deck, could turn turtle.

This initial reaction from a representative of the owners is interesting. The scene was set for the Inquiry to come; under no circumstances was Yongala to be presented as a tender steamer which could have turned turtle in a cyclone. But the rumours were there as soon as one week after the disaster. Yongala did indeed have a good track record, particularly across the Bight. 

However, Mr. Wareham failed to mention that she carried 164 tons of pig iron ballast to compensate for minimal cargo and coal during these runs. The distance between Fremantle and Adelaide is 1720 n miles. Yongala consumed, on average, 60 tons of coal per day. Cruising at a modest 12 knots she would have taken 6 days = 360 tons of coal. Mr. Wareham already as early as 31 March, was prone to exaggeration in favour of dispelling the rumours and exaggerating Yongala's capabilities. 

He protested too much! 

It is known from the Inquiry that Yongala departed Brisbane with 11 tons on deck. Again, Mr. Wareham attempted to underplay the top heavy component by reducing this figure to 5 tons. It is interesting to note that Yongala had a jerky recovery when steaming in ballast with the 164 tons of pig iron (forward). The pig iron lowered the centre of gravity, raising GM, and with it the righting force recovering from a list. It appears that a concentrated focus of specific gravity lowest down in the ship had a remarkable effect on the righting powers of the steamer.

This reminds me of the Waratah. Captain Ilbery, finally on the last voyage, had sorted out Waratah's inherently tender condition by adding 1,500 tons of lead concentrates in a lower hold at 11 cubic feet to the ton, 8 ft. high. This produced a stable steamer with a GM of 1.9 ft.. However, the increased righting force, as in the case of Yongala, produced a jerky recovery which had passengers falling on the promenade deck during the voyage from Adelaide to Durban.  

Yongala, I believe that the absence of the pig iron had a significant impact on tenderness and being 34% full in terms of cargo dead weight, and a prominent funnel, made Yongala tender and vulnerable to turning turtle in a gale. 

The West Australian, 13 April, 1912.

STABILITY OF SHIPS AND

LAWS OF STORMS. 

- To the Editor.

"Sir, now I that the missing Koombana

may certainly be listed as lost, like the

Waratah and Yongala, the travelling public

might very well be interested in studying

for themselves the simple proposition of 

stability in ships. This proposition lies buried

in scientific jargon as far as the man in the

Street is concerned, and can easily be 

demonstrated in ordinary language. 

It is a long time since Archimedes proved. 

that a floating body is exactly the same 

weight as the water it displaces. A steamer, 

with whatever cargo or ballast she may 

have in her, is exactly the same weight as 

the water she displaces. The water she 

displaces is what would fill the cavity her 

weight and shape impose below the water 

line or surface of the water. Exactly in the 

centre of this cavity, in which the floating 

ship fits lies the vessel's centre of buoyancy, 

and through this centre there acts an upward 

pressure from the sea in its endeavour to 

become level against the weight of the ship. 

When a steamer is floating upright, this 

centre of buoyancy lies midships in a 

vertical line or plane, dividing the vessel 

in two. If one thinks of  a partition being 

built from stem to stern amidships from 

the keel upward, then in this partition lies 

the centre of buoyancy when the steamer 

stands upright, and it lies nearly half-way 

between the keel. and the water line. 

The water line is a imaginary line or plane 

joining, from side to side through the vessel 

the  surfaces of the surrounding sea. Not any

of the painted lines on the hull often alluded

to as the "water line." When a steamer

heels over; that is lists or rolls from side to

side part of her hull comes out above the

level of the sea on one side and another part

sinks further in on the other side. When

this happens the centre of buoyancy changes

position in the hull while always retaining

its position about the centre of whatever

portion of the hull is immersed. Thus, as

she rolls to starboard, it leaves the assumed

partition amidships, moving to starboard,

returning to partition, and then towards

port as she rolls from starboard, through

upright, and then to port.

As before explained, there is always an

upward pressure from the ocean in a 

straight line perpendicular to its level

surface through this moving centre of 

buoyancy and that line always passes 

through a given point in the midships 

partition above it. This point is termed 

the "meta centre" by experts and it will 

readily be imagined that the centre of 

buoyancy swings from side to side like 

a pendulum suspended from it, when

the vessel is rolling at sea.

There is now the centre of gravity, which

everyone nowadays understands is simply

the centre of weight to be considered as it

must readily be realised that a vessel's

centre of gravity depends upon the amount 

of cargo or ballast she may be carrying and

how such is stowed or disposed in her holds.

But once the cargo or ballast is placed, stowed,

or, disposed in the vessel, the centre of 

gravity remains constant, and does not

shift (unless the cargo shifts), like the centre

of buoyancy. If the vessel be stowed properly 

it will be found somewhere in the assumed 

midships partition and at a point below meta 

centre point. The pressure from the weight of 

the ship is always in the direction of an assumed 

plumb line hanging from the centre of gravity point, 

and as the vessel rolls at sea this plumb line or 

direction of pressure swings from side to side

in harmony with the line of buoyancy, exactly 

coinciding when the vessel is upright, and parallel, 

with an increasing distance between them as the 

vessel rolls to one side. 

The degree of stability- that is safety from capsizing 

- depends on the distance of the meta centre above 

the centre of gravity. This distance is termed the meta 

centric height. (GM). The force downward from the

centre of gravity is exactly equal to the force 

upward exerted by the ocean endeavouring to 

get level; and these two forces tend to right the ship 

when the undulations of the sea swing her away

from the upright. The greater the metacentric 

height which is the same as saying the greater 

the safety from capsizing, the more uncomfortable 

the vessel to travel on. The more leverage the forces 
of buoyancy and gravity have the more quickly 
they can right the vessel swaying on the undulating 
surface. Too great safety from capsizing brings about 
other dangers. Sailing vessels with heavy dead-weight 
cargoes have been known to lose their masts and 
strain their hulls to such an extent, in so rolling, their

masts out, that they have sprung a leak and

foundered. 

Iron and such like heavy cargoes have often to 

be stowed in narrow trunkways or on platforms

especially built in the ship to keep her centre

of gravity higher when loaded. When we hear

people say that such and such a vessel is a 

grand seaboat, etc., etc., such a vessel may 

have been very unsafe on that particular voyage, 

her very unsafety contributing to the comfortable 

travelling. 

It may be taken for granted there is very little

difference in modern cargo vessels when

carrying complete cargoes that nearly fill

them. With like loading they may safely

be expected to behave much the same in

similar storms. The common design for such

vessels provides a breadth equal to about

twice the moulded depth below the main

deck,and as there are no passengers

carried there is very little superstructure

above the main deck. When we consider

passenger steamers, however, the tendency

to build additional decks and keep the 

passengers' accommodation all above the main

deck is most noticeable. Everyone prefers a

nice airy cabin to the stuffy ones which were

once the vogue, and all below the main deck.

Here it is an open question whether we are 

not sacrificing safety for comfort and carrying 

capacity. 

The fact that we have had the Waratah,

Yongala, and Koombana mysteries in these 

latitudes during the last three years is sufficient 

excuse for the public requiring some practical

and expert investigation made on their behalf. 

In the case of the Waratah it seems abundantly 

clear, from the evidence given at the Law Courts 

that this vessel was not considered to have 

sufficient ballasting powers when sailing without 

cargo, to counteract the weight of superstructure

supplying the passenger accommodation. She

was to some extent in the same predicament as 

our famous sailing clippers of last century, which 

needed nearly half a cargo of ballast to go seeking 

for cargoes from one port to another. 

When the Waratah was lost she had nearly a 

full cargo on board and whatever her degree 

of stability was when empty, had surely nothing 

to do with her degree of stability when loaded. 

Yet, as far as  the writer can learn, there was 

little or no evidence forthcoming as to the weight 

and disposal of the cargo she had when lost.

In the case of the Koombana there is

considerable food for reflection. She was

probably carrying less than 500 tons of

cargo and:appears to have been engulfed

in the centre of a "willy-willy." It the opinion 

of the writer that the Koombana in light trim 

was not fit to encounter a hurricane centre.

The writer has been caught near a cyclone 

centre off Mauritius in a sailing vessel, and 

remembering how that vessel, although in 

ideal load and trim was.smothered under 

almost bare poles with bulwarks under water 

and hatch comings awash, he cannot conceive 

it possible for a steamer like the Koombana 

in light trim, exposing such an area of 

superstructure to such a force of wind, to live 

through it.

The question is, 'Is it a legitimate risk to send

such a vessel in such a trim into hurricane

latitudes in hurricane seasons?" 

It must be remembered that the law of

storms is getting on towards being an exact

science, with barometers to provide indications

of approach; and with means to indicate the 

vessel's position from the centre and to show 

from collected data the most probable path of 

the centre, a good steamer with an experienced 

and expert master should easily avoid being 

caught. It is a matter of vigilance and judgment

just as is the case with a pedestrian avoiding

motor cars. These remarks are applicable.

to cyclones, typhoons, and other well

known and studied storms, but have we

done our duty with regard.to the Nor'-West

"willy-willy" ?? Is there a published hand

book with information; instructions; and

suggestions as is the case in other 

hurricane parts of the,world for the

safety of mariners. If not, is it not a work 

worth taking in hand at once?

'Yours; etc.,

LONGSHOREMAN.'

Fremantle, April.

SS Yongala

  

SS Waratah - Port Adelaide.