An electrical fault in a hot press is “a likely cause” of the Stardust fire that killed 48 people, an expert witness has told an inquest jury, confirming that “it is difficult to see” how the fire would have got out of control without the presence of carpet tiles on the walls of the nightclub.
Dr Will Hutchinson, who has 23 years of experience as a fire investigator, told the Dublin District Coroner’s Court on Monday that the combustible carpet tiles on the walls under a low ceiling contributed to the rapid spread of the fire that swept through the nightclub in Artane in the early hours of Valentine’s Day, 1981.
Defects
Dr Hutchinson confirmed to Séan Guerin SC, representing a number of the families of the victims, that expert electrical reports identified defects in the electrical installation in the Stardust.
Mr Guerin said that there were issues identified with the overloading of circuits, particularly in the stage area.
He said that backstage there had been a bank of additional sockets put in, and the jury had heard evidence from people who performed in the Stardust that they were powering multiple lighting units through a system of sockets.
Dr Hutchinson agreed that this potentially could be a serious issue.
Concerning the possibility of lighting the seats in the Stardust with a match, cigarette, or other materials, Mr Guerin said that a lot of initial scientific tests were focused on how the PVC-covered seats could be ignited by a small flame.
He said that a test had been conducted on thin PVC sheeting, in which a strip of just over half a metre was stretched over a frame and one end was subjected to flame from ethanol, with the strip ignited and allowed to burn out.
He said the material continued to flame for approximately 50 seconds and the alcohol burned for around 23 seconds, with the average distance of burning 23cm. In three of these tests, flaming material fell from the strip and continued to burn.
Dr Hutchinson said that this showed that PVC material could be ignited from an absolute alcohol source.
Flaming material
Mr Guerin said that a non-standard test was also carried out in relation to flaming material, in which it was attempted to burn a seat by igniting a carpet tile that was held over the seat, and burning material fell and caused the seat to ignite.
Taking those two tests together, Mr Guerin said that both showed that these seats were capable of being ignited relatively easily if molten and burning plastic material were dropped onto them. Dr Hutchinson confirmed this.
“If you do have flaming droplets falling onto that seat material, it will form a pool which will continue to burn, so that heat is then sufficient to ignite the PVC coating on the bench,” he said, adding that once the fire gets down to the polyurethane under the PVC, that will sustain flaming combustion.
Mr Guerin said that there were a number of distinct issues with the upper immersion unit in the hot press in the main bar of the Stardust, which produced excess heat.
He said there was only a small portion of the total strands of wiring properly connected, which forced the current through copper wiring that was not sufficient to take that current, and this would produce heat.
He said that there was also corrosion at the connections that would have increased the resistance at the point of the connection and generated excess heat.
Mr Guerin said that the round plastic cover that was meant to be in place on the upper unit in the hot press had been removed before the fire, and the consequences of removing the cover was that it would affect the operation of the thermostat. Dr Hutchinson confirmed this.
Mr Guerin said that with the cap removed, the thermostat is exposed to the air around the unit, which could lead to the thermostat not switching off.
He said if the thermostat does not switch off, the current will be forced through the bad wiring and forced through the area of corrosion, generating heat.
He said that the insulation jacket around the hot press could then be ignited.
Dr Hutchinson confirmed that defects in the wiring of the upper immersion unit could have caused a fire, which could, through escaping into the roof space and then the west alcove, have caused the events of that night.
Electrical fault
Dr Hutchinson said he had not seen any other evidence for a cause of the fire, and he said that an electrical fault in the hot press was one of two options he had identified, the other being that there was an accidental or deliberate ignition of a seat in the west alcove.
“Isn’t the electrical fault in the hot press the likely cause of the fire in the Stardust?” asked Mr Guerin.
“Yes, it is a likely cause,” replied Dr Hutchinson.
Mr Guerin said that a key issue is the speed with which the fire developed into something that was “completely out of control and engulfed the whole building”.
He said that two features of the premises were absolutely crucial to this, namely the low ceiling in the west alcove and the carpet tiles on the walls.
Dr Hutchinson confirmed that the ignition of the carpet tiles on the walls led to a considerable increase in the rate of heat output, as did the presence of flaming droplets.
He went on to confirm that the radiating heat in the presence of the low ceiling along with the flaming walls and the burning of hot gases were enough to cause the spontaneous ignition of seats, and then the situation got completely out of control.
He confirmed to Mr Guerin that the combustible carpet tiles on the walls under a low ceiling and over a sufficient quantity of seating to provide the fuel contributed to the rapid spread of the fire.
“It is difficult to see how this fire would have got out of control the way it did without the carpet tiles on the wall,” said Mr Guerin.
“Yes, I agree,” said Dr Hutchinson.
The inquest continues on Tuesday in the Pillar Room of the Rotunda Hospital.
