The 1998 Esso Longford gas explosion was a catastrophic industrial accident which occurred at the Esso natural gas plant at Longford in the Australian state of Victoria's Gippsland region. On 25 September 1998, an explosion took place at the plant, killing two workers and injuring eight. Gas supplies to the state of Victoria were severely affected for two weeks.
In 1998, the Longford gas plant was owned by a joint partnership
between Esso and BHP. Esso was responsible for the operation of the
plant. Esso was a wholly owned subsidiary of US based company Exxon,
which has since merged with Mobil, becoming Exxon Mobil. BHP has since
merged with UK based Billiton becoming BHP Billiton
Built in 1969, the plant at Longford is the onshore receiving point for
oil and natural gas output from production platforms in Bass Strait.
The Longford Gas Plant Complex consists of three gas processing plants
and one crude oil stabilisation plant. It was the primary provider of
natural gas to Victoria, and provided some supply to New South Wales.
Normal processing procedure
The feed from the Bass Strait platforms consists of liquid and gaseous
hydrocarbons, water (H2O) and hydrogen sulfide (H2S). The water and H2S
are removed before reaching the plant, leaving a hydrocarbon stream to
be the feed to Gas Plant 1. This stream contained both gaseous and
liquid components. The liquid component was known as "condensate". The
LPG is further extracted by means of a shell and tube heat exchanger,
in which heated "lean oil" and cold "rich oil" (oil which has absorbed
LPG) are pumped into the exchanger, cooling the lean oil and heating
the rich oil.
Explosion at Longford
During the morning of Friday 25 September 1998, a pump supplying heated
lean oil to heat exchanger GP905 in Gas Plant No. 1 went offline for
four hours, due to an increase in flow from the Marlin Gas Field which
caused an overflow of condensate in the absorber.
A heat exchanger is a vessel that allows the transfer of heat from a
hot stream to a cold stream, and so does not operate at a single
temperature, but experiences a range of temperatures throughout the
vessel. Temperatures throughout GP905 normally ranged from 60 °C to
230 °C. Investigators estimated that, due to the failure of the lean
oil pump, parts of GP905 experienced temperatures as low as -48 °C. Ice
had formed on the unit, and it was decided to resume pumping heated
lean oil in to thaw it. When the lean oil pump resumed operation, it
pumped oil into the heat exchanger at 230 °C - the temperature
differential caused a brittle fracture in the exchanger (GP905) at
About 10 metric tonnes of hydrocarbon vapour were immediately vented
from the rupture. A vapour cloud formed and drifted downwind. When it
reached a set of heaters 170 metres away, it ignited. This caused a
deflagration (a burning vapour cloud). The flame front burnt its way
through the vapour cloud, without causing an explosion. When the
flamefront reached the rupture in the heat exchanger, a fierce jet fire
developed that lasted for two days.
The rupture of GP905 led to other releases and minor fires. The main
fire was an intense jet fire emanating from GP905. There was no blast
wave - the nearby control room was undamaged. Damage was localised to
the immediate area around and above the GP905 exchanger. Peter Wilson
and John Lowery were killed in the accident and eight others injured.
The fire at the plant was not extinguished until two days later. The
Longford plant was shut down immediately, and the state of Victoria was
left without its primary gas supplier. Within days, the Victorian
Energy Network Corporation shut down the state's entire gas supply. The
sudden crisis was devastating to Victoria's economy, crippling industry
and the commercial sector (in particular, the hospitality industry
which relied on natural gas for cooking). Loss to industry during the
crisis was estimated at around AUD$1.3 billion.
Natural gas is also widely used residentially in Victoria for hot water
and gas heating, and Victorians endured many weeks of cold showers and
Gas supplies to Victoria were resumed on 14 October. Many Victorians
were outraged and upset to discover only minor compensation on their
next gas bill, with the average compensation figure being only around
A Royal Commission was called into the explosion at Longford, headed by
former High Court judge Daryl Dawson. The Commission sat for 53 days,
commencing with a preliminary hearing on 12 November 1998 and
concluding with a closing address by Counsel Assisting the Royal
Commission on 15 April 1999.
Esso initially blamed the accident on worker negligence, in particular
Jim Ward, one of the panel workers on duty on the day of the explosion.
The findings of the Royal Commission, however, cleared Ward of any
negligence or wrong-doing. Instead, the Commission found Esso fully
responsible for the accident:
The causes of the accident on 25 September 1998 amounted to a failure
to provide and maintain so far as practicable a working environment
that was safe and without risks to health. This constituted a breach or
breaches of Section 21 of the Occupational Health and Safety Act 1985.
Other findings of the Royal Commission included:
- the Longford plant was poorly designed, and made isolation of dangerous vapours and materials very difficult;
- inadequate training of personnel in normal operating procedures of a hazardous process;
- excessive alarm and warning systems had caused workers to become desensitised to possible hazardous occurrences;
- the relocation of plant engineers to Melbourne had reduced the quality of supervision at the plant;
- poor communication between shifts meant that the pump shutdown was not communicated to the following shift.
Certain managerial shortcomings were also identified:
- the company had neglected to commission a HAZOP (HAZard and
OPerability) analysis of the heat exchange system, which would almost
certainly have highlighted the risk of tank rupture caused by sudden
- Esso's two-tiered reporting system (from operators to supervisors
to management) meant that certain warning signs such as a previous
similar incident (on 28 August) were not reported to the appropriate
- the company's "safety culture" was more oriented towards
preventing lost time due to accidents or injuries, rather than
protection of workers and their health.
Esso was taken to the Supreme Court of Victoria by the Victorian
WorkCover Authority. The jury found the company guilty of eleven
breaches of the Occupational Health and Safety Act 1985, and Justice
Philip Cummins imposed a record fine of $2 million in July 2001.
In addition, a class action was taken on behalf of businesses,
industries and domestic users who were financially affected by the gas
crisis. The class action went to trial in the Supreme Court between on
4 September 2002, and was eventually settled in December 2004 when Esso
was ordered to pay $32.5million to businesses which suffered property
damage as a result of the incident.
Following the Longford accident, Victoria introduced the Major Hazard
Facilities Regulations to regulate safety at plants that contain major
chemical hazards. These regulations impose a so-called
"non-prescriptive" regime on facility operators, requiring them to
"demonstrate" control of major chemical hazards via the use of a Safety
Management System and a Safety Case.
Other states have also implemented similar regulatory regimes.