Tuesday, July 28, 2009

The Scheyville Experiment

During the period of two-year military conscription in Australia, between 1965 and 1973, some 2700 young men were selected from each Army National Service intake, representing about 5% of the total number of those called up.

These men had volunteered to be Army Officers, and because they were conscripts, rather than regular soldiers, serious misgivings and some resentment resulted in military circles. This also created a rather strange situation - the men were volunteers yet conscripts at the same time. It also was a contradiction of the very old, tried and true Army maxim - keep your eyes open, your mouth shut and never volunteer. It was determined from the outset that they would have to prove themselves in a harsh testing ground before they could become Officers. The whole concept represented largely unchartered waters for the Australian Army.

The location of this military experiment was Scheyville, (pronounced Sky- ville) on the then outer limits of western Sydney. An ex migrant camp, the facilities were spartan but not uncomfortable and had the advantages of being close to the Air Force base at Richmond and also the Blue Mountains where many of the troop exercises were to be held.

The facility was called the Officer Training Unit (OTU) Scheyville and produced a massive culture shock to the incoming twenty year old conscripts, many of whom had come straight from the universities, farms and offices of civilian life.

The OTU Scheyville coat of arms
(Click on image to enlarge)

This carefully handpicked group then undertook a gruelling 22 weeks course, designed to place as much stress as was legally permissible on each individual, who were continuously evaluated during the period. 14 hour days with no weekends off were the norm, together with periods in the bush on combat rations under full tactical conditions, simulating infantry patrols in Vietnam.

The failure rate was high – eventually only 1801 would pass the course, meaning about one in every three was eliminated. Looking at the broader picture this meant that Scheyville graduates represented less than 3% of the total National Service call up of the period.

There were four intakes every year with a graduation parade held every three months. This graduating group then went on to complete their two year National Service obligation as Second Lieutenants in the various Army Corps, several serving with distinction in Vietnam, where 8 were killed in action.

The first intake of 1969 (Click on image to enlarge)

Two of the three platoon commanders at the iconic Battle of Long Tan were National Service Officers and Scheyville men. Gordon Sharp was killed in action there and Dave Sabben led his men with distinction and was subsequently decorated for gallantry. See

The OTU Graduation Parade held on July 16th 1969
(Click on image to enlarge)

Several Scheyville graduates remained in the Army after their National Service period had expired and became respected senior officers up to and including the level of Major General. However, the majority returned to civilian careers where most were highly successful across a broad spectrum of endeavours.

Scheyville graduates today represent possibly one of the most successful groups of Australian males of their generation. In politics, business, the arts, government and the military, Scheyville graduates form an elite group.

Two of the highest profile graduates are Jeff Kennett (ex-Premier of Victoria) and Tim Fischer (ex Deputy Prime Minister of Australia), but there is also a liberal sprinkling of senior police, chief executive officers, university professors and vice chancellors from within the Scheyville ranks.

The memorial plaque commemorating the Scheyville graduates who fell in battle during the Vietnam War.
(Click to enlarge)

An interesting fact quoted by numerous graduates is that they believed that their Scheyville training had played an important part of their later civilian success. This was due, amongst other things, to their learned ability to cope with stress, think laterally and maintain attention to detail in fast moving situations.

After the demise of National Service in 1973, Scheyville gradually fell into ruin and was finally demolished in the late 1990’s to make way for today’s Scheyville National Park. The concrete slabs that formed the foundations of the huts are still visible beneath the long grass and light forest that has gradually reclaimed the area.

Scheyville camp in ruins 1990.
(Click on image to enlarge)

Scheyville was designed to produce a National Service Officer who was capable of commanding an infantry platoon in Vietnam, and in this it was highly successful. But it achieved far more.

Scheyville proved that provided a suitable selection process is undertaken, an operational junior Army Officer can be produced in six months. It was also demonstrated that contrary to conventional wisdom, conscripts can become effective Army Officers. And finally, the Scheyville graduates themselves learned that military skills and training are of considerable value in the civilian workplace.

Hopefully these lessons will not be forgotten.

Nil bastardum carborundum.

For some very rare vision of the graduation parade of the last class of 1967 go to


For a look at the official OTU Recruitment video shown for all intakes at Puckapunyal and Kapooka Recruit Training Battalions from 1965 to 1972 go to



1. The Scheyville Experience, Roger Donnelly, University of Queensland Press, 2001.

2. The OTU Association website:


Sunday, July 26, 2009

Weather Forecasting - By Numbers

One of the great modern breakthroughs in the study of the weather and climate of our planet has been the developing ability to simulate the behaviour of our atmosphere through mathematics.

The use of mathematics to predict the future is called an “initial value” process - that is if we know the state of a physical system at a particular time, and we know the mathematical equations that govern its motion, then we can predict the future state of the system by “solving” the equations.

A simple example that we are all familiar with is as follows. Let’s say we’re in a car moving down a freeway at 100 kph. We want to know where the car will be after 2 hours. Obviously the answer is 200 km away, but let’s step back and see how we arrived with this solution.

We have, perhaps unknowingly, used a mathematical formula


which in words says “distance travelled equals speed multiplied by time”

In this case S = 100 and T=2, so to obtain our answer we use the process of multiplication.

That is D = 100x2, giving us our answer of 200 km.

We have therefore been able to predict the future position of our car by knowing

(1) The initial conditions – the car is travelling at 100 kph
(2) A mathematical equation that describes the motion - D=SxT
(3) A method of “solving” the equation – in this case the process of multiplication.

In any sort of mathematical prediction of the future, we must be able to meet these conditions – the “Big Three”. The principles involved in numerical weather and climate prediction are just the same, although vastly more complicated. By knowing the three conditions we can predict the future state of the atmosphere and so produce a weather forecast.

The first scientist to suggest that weather forecasting could be considered an initial value problem was the Norwegian Vilhelm Bjerknes whose work in the early 20th century generated great interest in the issue. He developed a set of five mathematical equations (called the primitive equations) that describe atmospheric motion and suggested that if we could accurately describe the state of the atmosphere today, a solution of these equations could tell us how the atmosphere would look tomorrow. This process became known as numerical weather prediction (NWP).

Whilst only specialist mathematicians understand in detail what these equations mean, we can gain at least some insight into the complexities involved just by looking at them and the symbolism used

(1) dV/dt= -fkxV –∆ø +F + g

In words this means that motion in the atmosphere is the result of the spin of the Earth (the coriolis force), air pressure differences, friction and gravity.

The other four equations describe other conditions that must be met, including constraints on heat, moisture and air density. In symbolic form these are written

(2) ∂ø/∂P=0

(3) dµ/dt=-µ∆.v

(4) dT(p)/dt=T(p)Q/TCp

(5) dr/dt=Fr - Ω

This is known as a coupled system of non linear partial differential equations and forms one of the most intractable and difficult of all mathematical problems. It was only centuries of effort by mathematicians from all around the world that eventually produced ways of handling systems of equations of this type.

During the first World War, NWP was taken a great deal further by the English scientist Lewis Fry Richardson, an eccentric genius, who actually devised a system that performed this process. However the computational workload was so great that it took him around 6 weeks to prepare a forecast for the next day – an obviously impractical process!

Lewis Fry Richardson - an eccentric genius and father of numerical weather prediction
Image: Wikipedia Commons
(Click on image to enlarge)

Richardson suggested that to overcome this problem the weather office of the future should consist of a vast amphitheatre that held about 64,000 mathematicians, each responsible for a single calculation that applied to a small area of the Earth’s surface. Working together, and directed like an orchestra with a lead mathematician as conductor, it was thought that a global forecast could then be prepared within a useful time frame.

Incredibly, Richardson performed much of his research not from within the closeted confines of a university, but on the battlefields of World War One. A Quaker, he would not take up arms, but volunteered his support as an ambulance driver, and spent any spare time working on his thesis at night by candlelight within ruined farmhouses amid the mud and carnage of the Western Front.

His ideas were published in 1922 in a book called “Weather Prediction by Numerical Process”, which was really the first textbook ever written on numerical weather prediction. Warmly received in academic circles it was, however, thought to be an impractical way of predicting the weather because of three main problems that were directly related to the “Big Three” conditions.

These were

(1) Tremendous difficulties in rapidly gathering together weather observations from all around the world to describe the current state, or initial conditions, of the atmosphere. This was needed to provide the "starting point" on which all future calculations would be based.

(2) The mathematical equations describing the motion of the atmosphere were known but were highly complicated.

(3) The equations could not be solved directly, necessitating the use of what mathematicians call an “iterative process”, that employs multiple calculation repetitions that converge towards a solution. This produces a colossal computational workload and even Richardson’s idea of a “Forecasting Orchestra” was thought to be inadequate for this problem.

The idea of numerical weather prediction then lay dormant for about the next 20 years, until a surprising turn of events resulted in a rebirth of interest.

During the early 1940’s, the eminent mathematician John von Neumann had been recruited to work on Project Manhattan, the construction and testing of the world’s first atomic explosion, codenamed “Trinity” that finally took place on July 16 1945.

In the lead up to “Trinity”, von Neumann and his co-workers, a galaxy of scientific stars from all around the world, realised that they could not cope with the computational workload required. The scientists of the day used slide rules and mechanical calculators – resembling cash registers – to perform all their mathematical work, and even in the hands of skilled operators, these devices were too slow for the workload required.

To get round this problem they managed to construct one of the very first electronic computers by connecting several IBM business machines, including a tabulator, multiplier, collator and sorter. To von Neumann’s delight, the resulting computational speed was much faster than the slide rules and mechanical calculators, and the scientists realised that this represented almost as big of a breakthrough as the atomic bomb itself.

Von Neumann was well acquainted with Richardson’s attempts at numerical weather prediction and realised that with electronic computers likely to become faster and faster that the computational workload required was going to become manageable.

The other main stumbling block – being able to rapidly communicate weather observations from around the world to a central point at high speed was another problem that was showing signs of becoming increasingly tractable. Great strides in methods of international communication had occurred since the days of Richardson in the early 1920’s.

Soon after the war, in 1946, Von Neumann called a major meeting at the Institute of Advanced Studies at Princeton University to review the concept of numerical weather prediction and Richardson’s work of two decades before was “much discussed”.

ENIAC - an early electronic computer that became operational in 1946.
ENIAC stood for Electronic Numerical Integrator and Computer
Image: Wikipedia Commons
(Click on image to enlarge)

From that point on NWP rapidly expanded into one of the most useful tools at the meteorologist’s disposal. As computers became faster and more powerful, communication speeds increased and more weather observation stations came “online” around the world, weather simulations produced by numerical processing became increasingly accurate and today are an indispensable part of the weather forecasting process.

Massive NASA supercomputer.
Calculating power of this scale is necessary to produce accurate weather forecasts out to week ahead for any location around the world.
Image: Wikipedia Commons
(Click on image to enlarge)

Mathematical “models” as they are called, are now routinely used as part of the forecasting process by national meteorological services around the world, to produce forecasts of useful accuracy that typically run out to 7 days ahead.

Richardson's dream has been fulfilled in the most complete manner and the use of numerical weather prediction now forms one of the cornerstones of meteorology. Well ahead of his time, he received little contemporary recognition for his work but he is now acknowledged as one of the key figures in the history of weather forecasting.

Reference: “Understanding Climate Change”, Richard Whitaker, New Holland Publishers (Australia) 2008.

Sunday, July 19, 2009

Australian Banknotes 1914 to 1966

From about 1820 to 1913 Australian paper currency had been the domain of private banks that issued their own distinctive styles of bank notes.

However, from 1914 onwards, the Australian Government assumed the responsibility of issuing official Commonwealth of Australia banknotes and up until the advent of decimal currency in 1966, a wide variety was produced.

The currency consisted mainly of ten shilling, one pound, five pound and ten pound notes but there were rarer issues between 1914 and 1922 that included amounts for twenty, fifty and one hundred pounds.

1918 ten shilling note signed by Collins and Allen
(Click on image to enlarge)

These pre-decimal Australian banknotes constituted some of the more artistic and finely crafted currency around at the time and are now highly collectable, with well-preserved examples fetching high prices in numismatic trading.

1928 ten shilling note signed by Riddle and Heathershaw(Click on image to enlarge)

1936 ten shilling note signed by Riddle and Sheehan
(Click on image to enlarge)

One of the highest price banknotes from this era is the very rare “Rainbow Pound” which was an emergency World War One issue printed in 1915. So called because of its blue and orange colour scheme it proved to be easily forged and was withdrawn from circulation after little more than a year. Today a specimen in reasonable condition will fetch in excess of $60,000.

1918 pound note signed by Cerutty and Collins
(Click on image to enlarge)

1927 pound note signed by Riddle and Heathershaw(Click on image to enlarge)

1941 five- pound note signed by Armitage and McFarlane
(Click on image to enlarge)

1943 ten- pound note signed by Armitage and McFarlane(Click on image to enlarge)

Decimal currency replaced these distinctive banknotes in 1966, introduced by the cartoon character "Dollar Bill" who sang to the tune "Click Go the Shears"

In come the dollars and in come the cents
to replace the pounds and the shillings and the pence.
Be prepared folks when the coins begin to mix
on the 14th of February 1966.

You can see Dollar Bill advertisement, produced by the Commonwealth Film Unit, here:


An interesting type of currency that was planned for Australia but never instituted was the so called “Japanese Occupation Money” that was printed in Japan and was to be used in all countries captured by Japan during World War Two.

In Australia it was intended to use a Japanese version of pounds and shillings, to mirror the existing currency. In this example, (above) a Centavo was planned for use in the Philippines.

Friday, July 17, 2009

Loss of the Southern Cloud

Though far and wide they sought him, they found not where he fell
For the ranges held him precious, and guarded their treasure well.

" Lost" – by Banjo Patterson

In the early morning of Saturday March 21, 1931, Captain Travis Shortridge, his co-pilot and six passengers boarded their aircraft VH-UMF - the “Southern Cloud”-, for a routine commercial flight from Sydney to Melbourne. The weather was overcast, with a light northerly wind and the temperature was close to 22C. Soon after 8 am, the Avro 10 lifted off from Mascot aerodrome, climbed away to the south-west and set course for Essendon airport in Melbourne. It would not be seen again for another 27 years, and became instead, Australia’s first major civil aviation disaster.

During the late 1920’s and early 1930’s, passenger flights between Sydney Brisbane and Melbourne gradually became more common, as the public was slowly convinced that flying was safe and fast – the modern way to travel.

Australian National Airways (ANA) operated daily services between the eastern capitals using their fleet of five Avro10’s, all named in honour of Sir Charles Kingsford-Smith's legendary Southern Cross. There was the Southern Sky, Southern Star, Southern Moon, Southern Sun and Southern Cloud, all state of the art airliners manufactured by the English company Avro.

By modern day standards, the Avro 10 was a very primitive machine, although, if flown within it’s capabilities, was safe and reliable. It was powered by three ponderous Armstrong Siddeley Lynx 7 cylinder air-cooled radial engines, each generating a modest 240 horsepower. It was not a small aircraft, being 14.25 m in length, with a massive wing-span of over 21 metres, but could only carry a flight crew of two together with a maximum of eight passengers. The cruising speed was 160 kph but it had a top speed of about 185 kph and could reach an altitude of around 3400 m – not a great deal higher than Mount Kosciusko’s 2228 m.

Above: A "sister" aircraft of the "Southern Cloud" - VH-UMH was
an identical Avro 10 tri-motor. The massive undercarriage was not retractable and produced considerable air resistance in flight.
(Click on image to enlarge)
Photo: Wikipedia Commons

The Avro 10 was not equipped with two way radios, which meant that once the flight had commenced, there was no way the aircraft could be contacted, or indeed, no way the aircraft could contact anyone on the ground. Whilst this situation seems incredible from today’s point of view, it was the accepted modus operandi in 1931. However, this shortcoming was to prove of critical importance in the flight of VH- UMF.

Because civil aviation was only in its infancy, meteorological services to the aviation industry were in the early stages of development, and the fast communications required to provide an efficient amendment and update service were yet to be developed. Meteorological observations were transmitted between the various weather offices by hand delivered telegram, and the synoptic charts (or “weather maps”) were only updated once per day using the observations taken at 9am.

When Southern Cloud departed Mascot, it was carrying forecast en route weather conditions prepared the previous day that were based on observations some 12 to 24 hours old. This forecast apparently indicated no extreme conditions, although a wind change, together with some shower and thunderstorm activity, was predicted.

However with the flight barely two hours old, the Assistant State Meteorologist in Sydney, Harold Camm, became concerned when a particularly strong cold front swept across Sydney.

The following cryptic extract from the official Sydney observations recorded in the Bureau of Meteorology’s journal notes the arrival of this front:

“March 21st 1931 – Light n’ly wind till 9am but strong, squally westerly change at 10am with driving rain….”

Camm anxiously awaited the arrival of the 9am weather observations from Victoria, and when they finally reached the Sydney Bureau of Meteorology’s office up on Observatory Hill by telegram delivery at about 1030 am, his worst fears were confirmed. A major cold front had indeed whipped across south- eastern Australia overnight and raging winds from the west and south - west were surging up into NSW from Victoria.

Cold fronts of this nature are more common in the winter months, but can occur at any time of the year, and are sometimes referred to as “cold outbreaks”. They are weather systems that drag cold polar air from the far southern ocean over south-eastern Australia and can produce highland snow, even during the summer months. For aviation, cold outbreaks can generate a whole raft of hazards, including very strong winds, severe turbulence, icing and reduced visibility in low cloud and rain.

In the modern era of lightning-fast communication, radar and satellite photography, it is inconceivable that a major front would ever be “missed”, but in 1931, such rapidly evolving weather events could easily slip through the network of slow reacting observation and communication systems.

Upon seeing the Victorian telegram, Camm immediately telephoned Australian National Airways management and spoke in person to Charles Ulm, who had gained previous fame as Kingsford Smith’s co-pilot during the late 1920’s.

Camm informed Ulm that the weather situation was far worse than originally forecast and that the Southern Cloud was probably encountering cyclonic weather with tremendous headwinds, severe turbulence, rain and even snow. However as the two men talked, they both knew that with the flight now over two hours old and with no way of contacting the aircraft, there was absolutely nothing they could do with this vital information.

At this time, far away to the south-west, across the wild peaks and ravines of the Great Dividing Range, the Southern Cloud would have been bucking into turbulent headwinds, rainsqualls and low cloud in a desperate battle for survival.

A grim wait began to see if the aircraft had landed anywhere, firstly at its scheduled refuelling point near Wangaratta, and then at any other airfield where they might have attempted to take shelter from the raging conditions. The nature of the front indicated extremely strong winds from the south-west were right across the flight path and the Southern Cloud would be struggling directly into these, slowing its ground speed dramatically. So at best, a late arrival was expected, but when the time of fuel exhaustion had well passed, it was realised that something terrible must have happened. A massive land and air search was launched and continued for several weeks afterwards, but no trace of the Southern Cloud was found.

A formal enquiry was convened soon after by the Air Accident Investigation Committee, and the final report contained a significant recommendation with regard to the Bureau of Meteorology. This concerned the necessity for more frequent updates of meteorological observations and synoptic weather charts, as well as the establishment of a forecast amendment service. Just as significantly, the report recommended that all passenger aircraft should be equipped with two-way radios. In addition, ground radio stations should be established to communicate with all passenger aircraft and to monitor progress towards their destinations.

The loss of the Southern Cloud was Australia’s first major civil aviation accident and had a devastating effect on aviation services in general. ANA went out of business later in 1931 and public confidence in air travel fell sharply. It only gradually recovered over a period of several years thereafter.

But remarkably, the story of the Southern Cloud was not over. Twenty seven years later, in 1958, a worker in the Snowy Mountains, Tom Sonter, stumbled across some strange, rusty metallic wreckage in a wild inaccessible part of the Kosciusko National Park. Closer examination revealed the presence of skeletal human remains.

The Southern Cloud had at last been found, and from its position, a more accurate reconstruction of the flight was attempted. An amazing picture emerged.

The aircraft had only managed to cover a distance of 353 km from Sydney, and if the flying time was calculated on a full tank of fuel, that represented an average speed of only 71 kph. As the cruising speed of the Avro was around 160 kph, this pointed to average headwinds of about 90 kph – a vindication of Harold Camm’s telephone warning to Ulm all those years before. In fact, because the early part of the flight had been conducted in far lighter conditions, the strength of the headwinds was probably much greater than this; it was even theorised that the Southern Cloud could have been blown backwards during the final minutes of flight.

A certain amount of speculation still surrounds the direct cause of the crash. Did the aircraft ice up, were they forced down by severe turbulence or did they attempt to descend below the cloud base in the belief that they were nearing Melbourne? This latter scenario is perhaps the most credible, as it is unlikely that Shortridge would have realised the extent of the headwinds opposing the aircraft. Perhaps it was some combination of all these, but the precise answer can never be known.

Today a memorial for the Southern Cloud stands near Cooma, NSW, containing pieces from the three radial engines. It is a reminder of the price that had to be paid in the quest for safety in aviation.

Reference: Australia's Natural Disasters, Richard Whitaker
New Holland Publishers, ISBN 1877069043

Thursday, July 16, 2009

Sydney to Hobart 1998 - Disaster on the Water

“With sloping masts and dipping prow
As who pursued with yell and blow

Still treads the shadow of his foe,

And forward bends his head,

The ship drove fast, loud roar’d the blast

And southward aye we fled”.

The Rime of the Ancient Mariner – Samuel Taylor Coleridge

At 1 pm sharp on 26 December 1998, the starters gun boomed across Sydney Harbour and 115 yachts began the Sydney to Hobart Yacht Race in sparkling summer conditions and a gusty north-east sea-breeze. Followed by a large spectator fleet that traditionally accompanies the racing yachts as far as the Heads, some 1135 sailors began the 1000 km ocean race to Hobart, recognised as one of the world’s blue-water classics.

The race follows the NSW coastline down to the Victorian border near Gabo Island, then out across the notoriously changeable waters of Bass Strait, followed by the run down the east coast of Tasmania and finally the last leg up the Derwent River into Hobart.

The weather at this time of the year across the race area can be highly variable. North-east sea-breezes are common during the afternoon along the NSW coast, and on some occasions these have held for much of the race, allowing for a prolonged fast spinnaker run southwards. But this is also the time of the famous “Southerly Buster” which is a squally southerly change that originates over the east coast of Victoria and then flies northwards up the NSW coastline, often generating winds of around 30 to 40 knots. Busters have played a key role in deciding many past race results, with tactics that best incorporated the timing and intensity of the change often proving decisive. As another quirk, races have sometimes ended with yachts being becalmed in the Derwent River, almost within sight of the finishing line.

The race fleet’s demand for weather forecast information is therefore hardly surprising. Traditionally a close relationship has existed between the Bureau of Meteorology and the Race Organising Committee at the Cruising Yacht Club of Australia (CYCA). For around the previous twenty years or so, a meteorologist from the Bureau would conduct a pre race weather briefing for all the crews around the 24th of December, normally held at the Club’s premises at Rushcutters Bay, Sydney. Special meteorological support was also arranged for the race in which daily or twice daily weather forecasts and warnings were issued and transmitted to the fleet.

This arrangement was still in place on 24th December 1998, when some 250 yachtsmen converged on the CYCA clubrooms at 9 am to hear the latest on the weather. This was not the issue of a formal race forecast as such – the first of these would be prepared two days later, on the morning of race day itself. Rather it was a general “weather outlook” and this indicated that the race should begin Saturday in light conditions, but that a strong southerly change was possible late in the day.

Much of this information was based on what are called numerical weather simulations, and these have been one of the major areas of progress in meteorology over the last 30 years or so. They utilise mathematical equations that describe the motion of the atmosphere and these are combined with thousands of weather observations from around the world and fed into supercomputers to produce a simulation of the weather, normally out to a week in advance. The accuracy of these simulations is normally highest when looking at the period out to 24 hours ahead, but this then tends to drop off out towards seven days.

Many countries have produced their own national weather simulations and these are freely exchanged in the interests of improving weather forecasts on a global basis. The Bureau of Meteorology in Australia has developed its own excellent weather simulation that is routinely used in all weather forecasts, but, in addition, has access to simulations from other international sources that include the US, UK, Japan and Europe. Each simulation has its own biases and individual “quirks” and comparing the output from each is very valuable for the meteorologist. If all the simulations are indicating similar outcomes, then the meteorologist becomes more confident of the forecast. If not, confidence is reduced and forecasts can be constructed to reflect this.

Towards the end of the race briefing, the Bureau spokesman mentioned that one of the simulations operated by the European Centre for Medium Range Weather Forecasts (ECMWF), was indicating the possible development of a low pressure cell to the south-east of Gabo Island sometime on day two of the race. This would be worth watching in the run up to the start.

Race Day dawned, and soon after 9 am, the official race forecast was issued to the fleet. The southerly change mentioned at the briefing two days before was still in the forecast but was now expected to be stronger than initially indicated and was expected to reach Jervis Bay around midnight to 2 am on Sunday morning. A gale warning had been issued for all NSW coastal waters south from Broken Bay, to cover the passage of this change, and it was with this knowledge the fleet finally set to sea.

However, soon after the start, high drama was emerging back at the Bureau Offices in Sydney’s Elizabeth Street. Some of the simulations, including the Bureau’s high-resolution version that became available soon after race start, were now indicating that a strong low-pressure cell was likely to develop to the south over the next 24 hours. In particular the Bureau’s simulation was indicating explosive development of an intense low pressure cell virtually on the race track, just to the east of Bass Strait during Sunday.

Poring over this new data, the race meteorologists became increasingly concerned, and took the unprecedented step of preparing a storm warning, the first time in race history that such an action had been taken. A storm warning is the highest category warning issued for waters in these latitudes and is only surpassed by a hurricane warning, which is used in the event of a strong tropical cyclone. The storm warning was then issued with the race just over an hour old and distributed to a prepared schedule of recipients.

As the yachts moved southwards down the coast the weather progressively deteriorated, with the wind and sea steadily rising. The leading yachts began to encounter storm conditions about 18 hours into the race, with winds averaging around 50 knots and gusting to as high as 75. The conditions peaked across eastern Bass Strait during Sunday, as the low pressure cell predicted by the simulation intensified and tracked right through the fleet, creating incredible havoc and destruction.

Left: The synoptic chart at 3PM on 27th December 1998. An intense low pressure cell had developed explosively right on race track. The low is also plainly visible on the satellite image taken at the same time (below).
Images courtesy of the Bureau of Meteorology

For many competitors, racing was forgotten and it became a straight out fight for survival in the mountainous seas and shrieking tempest. Many yachts were forced to retire and several crewmen were injured after being flung about their vessels.

Ultimately 55 sailors were saved from the mountainous seas through a huge rescue operation involving the Australian Maritime Safety Authority, the Navy and the Air Force. Particularly heroic efforts were performed by helicopter pilots in winching sailors to safety in the incredibly dangerous flying conditions. In the end, five boats had sunk, sixty six retired and only forty four made it to the finish line. Most tragically of all, six crewmen had died in the maelstrom.

A lengthy Coronial Enquiry was held and the findings finally released
in December 2000. The Coroner, John Abernathy was critical of certain aspects of the conduct of the Cruising Yacht Club’s Race Committee and also recommended changes to a range of safety gear to be carried aboard in future races.

As far as the weather services were concerned, he recommended

"That weather forecasts which are specifically provided for yacht fleets contain:-

(a) As well as the average winds expected, the maximum gusts of winds that are likely to occur.

(b) As well as the significant wave heights expected, the maximum wave heights that are likely to be encountered

This increased level of detail is now part of all the forecasts issued by the Bureau in support of the race.

Reference: Australia's Natural Disasters, Richard Whitaker
New Holland Publishers, ISBN 1877069043

Tuesday, July 7, 2009

The Brisbane Floods of 1893

The meandering Brisbane River is believed to be several million years old, and as such, is one of the oldest waterways of the world. It flows from above Lake Wivenhoe, which is nearly 60 km inland, across rural areas and then through the Brisbane metropolis, before emptying into Moreton Bay.

The Brisbane River was once an important trade and transport link, but the old wharves and shipyards have mostly disappeared, and the main parts of the river within the CBD now form a picturesque tourist attraction, lined with parks and walkways.

There are numerous tributaries feeding into the river, including the major waterways of the Stanley and Bremer Rivers, as well as a number of smaller flows, such as the Lockyer, Enoggera and Breakfast Creeks.

This fairly complex catchment reacts in different ways to heavy rain. The creeks tend to rise quickly and then fall just as rapidly when the rain eases, a process which might take less than 24 hours. However, the Brisbane River itself responds in a much slower fashion, and may take two or three days to peak, and then remain in flood mode for a week or so.

Given the right conditions, the river can turn from a tranquil flow into a raging torrent flooding the surrounding countryside, and because of the slow response time, can cause inundation for an extensive period.

Floods in the Brisbane area are certainly not a rare event, with some 37 flood incidents being recorded since 1841. However two of the worst happened in 1893, and more recently, 1974.

In February 1893, a tropical cyclone moving north of Brisbane generated a large cloud band across south eastern Queensland and this produced tremendous rains across the area. As the downpour increased, local reports told of the Aborigines coming in from all round the district and camping at One Tree Hill (now Mt Coot-tha). They warned the local residents of a massive flood developing because “the fish had left the Bay and the ants were climbing high into the trees” – sure signs of big trouble to come. Their advice turned out to be perfectly accurate.

The Brisbane River burst its banks and flooded prodigiously across the city, “covering areas of the town that had never been flooded before.”

Houses were torn off their foundations and were carried off downstream. An eyewitness account in the “Queensland Times” stated that “Debris of all descriptions – houses, haystacks, factories, sheep, ships, snakes, bullocks, timber - all went floating down the river.”

Above: The Victoria Bridge was cut
by the raging floodwaters.
(Click on image to enlarge)
Photo: Wikipedia Commons

Much of the debris piled up against the Victoria Bridge, which eventually buckled under the pressure and broke up. Refugees moved to high ground and huddled together, waiting to be rescued by boat. The “Times” further reported that “Houses on all the rising ground were completely packed with human beings, and an empty building, after Saturday afternoon, was not to be had for love or money”.

The flood eventually reached a height some eighteen feet above the previous record in 1890, before eventually subsiding. But the toll was high; eleven people had drowned, including seven miners when the Eclipse Colliery at Tivoli was flooded.

Above: Flooding along Queen Street
inundated the area to a depth of nearly two metres.
(Click on image to enlarge)
Photo: Wikipedia Commons

Property damage was massive, including hundreds of houses destroyed or damaged, as well as significant loss of livestock. The overall damage bill was estimated to have been in excess of two million pounds (four million dollars), which was a colossal sum in 1893.

Above: Classic brewery advertisement:
"When the great flood wet
great grandpas feet,
Castlemaine XXXX wet his whistle".
(Click on image to enlarge)

Reference: Australia's Natural Disasters, Richard Whitaker, New Holland Publishing

ISBN 1877069043