A specialist in braking systems has told a jury that the fact that the ABS was not working on a bus involved in an accident that killed five Meath schoolgirls significantly affected the outcome of the crash.
Rod McLellan a chartered engineer and independent technical consultant specialising in the braking systems on heavy good vehicles, was hired by the Health and Safety Authority and inspected the Bus Eireann vehicle that had collided with two cars four miles outside Navan in May 2005.
He was made aware that the foundation braking system on the vehicle was compliant with European braking regulations and the bus had been fitted with "an advanced, category one, ABS system".
Mr McLellan said that because the ABS was not working on the bus that day, the wheels locked and the driver, Mr John Hubble, lost control of the vehicle.
He told Mr Brendan Grehan SC, prosecuting, that when the rear wheels lock it causes a vehicle to swing around and rotate until it effectively goes backwards and said that when ABS fails, it leads to a "very serious situation" making it very difficult for a driver to steer the vehicle.
Mr McLellan said that in his opinion "the lack of ABS significantly affected" the outcome of the accident and had it been working the driver would have been able to steer the bus and the consequences would have been different.
Sergeant James Walsh told Mr Grehan (with Mr Remy Farrell BL), that the ABS warning light had not come on "because the bulb had been removed or not fitted".
Sgt Walsh agreed with Mr Roderick O'Hanlon SC, defence counsel for McArdles Test Centre of Dundalk, the company on trial arising from the investigation into the May 2005 accident, that a bulb could "blow" at any time.
"But, the bulb was missing in this case," Sgt Walsh added at Dublin Circuit Criminal Court.
Mr Joe McArdle, a director, has pleaded not guilty on behalf of McArdles Test Centre Ltd, to two charges of failing to note the ABS warning light on the bus wasn't operational while conducting a vehicle test on March 15, 2005, two months before the tragedy.
A second company, Keltank Ltd of Balbriggan, has pleaded guilty through Sonya Kelly, company secretary, that being aware that ABS sensor leads were disconnected, it failed to ascertain whether a hazard arose as a consequence thereof before returning the bus to the driver, Mr Hubble, on May 5, 2005.
It was day five of the trial in which the jury heard witnesses explain that ABS prevents wheel lock-up in heavy and emergency braking and allows the driver to maintain direction.
Mr Tony Wynn, a senior vehicle tester in the Department of Transport, said that if a vehicle has an ABS system fitted and it is not working it would "100 percent" fail a road worthy test but he added that the ABS should not interfere with the integrity of the vehicle, so if it failed a person could continue to drive safely.
He said that ABS was difficult to maintain because it was electronically controlled and involved various wires and cables. He added that if you drove from Dublin to Galway the ABS mightn't be working by the time you arrived at the destination.
"It's more common than you think for ABS not to be working in vehicles. The ABS warning light is on, looking at the driver and they don't care," said Mr Wynn.
Garda James Egan, a Garda public service vehicle inspector, said the warning light should come on when the ignition is switched on to show the driver the ABS was working.
He told Mr Grehan that when they removed the panel from the dashboard of the fatal bus they found there was no bulb in place. When a bulb was fitted and the ignition turned on again the warning light functioned. A replacement panel was also tried out and it worked as well.
He said he examined the underside of the vehicle and found two ABS cables were disconnected or broken. He regarded the broken cables as "significant" and he also noted a "DIY job" where cable ties had held together the ABS cables.
Gda Egan said he supervised the removal of the bus and the two cars involved in the accident to a garage in Co Louth where all the three vehicles remained in garda custody.
He carried out a detailed examination of the bus two days later and found that the normal brakes were in "excellent condition", the condition of the tyres complied with regulations, and the steering system had no defects and was well maintained.
Sergeant Colm Finn said, in reply to Mr Grehan, he had a Forensic Collision Investigator qualification from De Montfort University in England as well as a M.SC in Economics from TCD, a B.A in Public Administration of Justice and he was currently completing a Bachelor of Engineering (Highway Technology) degree.
Sgt Finn, who is now attached to the Garda College in Templemore, said he attended the accident scene as a forensic collision investigator with An Garda Siochana and attempted to reconstruct what happened.
He said that when he carried out a skid test with a bus which didn't have ABS operating, it began moving in an anti-clockwise direction. If there was ABS working, the bus would continue in its correct direction.
Sgt Finn agreed with Mr O'Hanlon that the driver of the bus supplied to him told him the ABS was working on it and he was unaware that in fact it wasn't working.
Gda Adrian Tucker told Mr Grehan that as a Public Service Vehicle inspector and an accident investigator with the relevant qualifications and at the time of the bus crash he had experience of more than 200 fatalities.
When he examined the bus he found that the ABS system wiring was fractured and disconnected. The ABS light wasn't functioning and the fact that this light didn't come on should have been a concern for the driver.
Gda Tucker told Mr Grehan that he would describe the defect in the ABS system as "dangerous" and added that cable ties had been used to "tidy up loose cables" that would have been hanging down because they were disconnected.
Mr Pat Bebbington, a foreman with Keltank, said the company was responsible for the servicing and maintenance of 30 Bus Eireann buses of various sizes and models.
He said that ABS was never mentioned to him and he did not realise there was an ABS system on the bus. He was also not aware of the presence of an ABS warning light on the bus.
Mr Bebbington agreed with Mr O'Hanlon, for McArdles, that he never worked on the bus himself and could not comment on its condition when it was tested by his client in March 2005.
He further agreed that Bus Eireann never asked Keltank to check the ABS on the bus and the first time he became aware that the vehicle was even fitted with the system was from media reports.
Three mechanics with Keltank - Aidan Callan, Colin Maher and Adrian McManus - detailed maintenance and repairs they had carried out on the bus from November 2004 up to two weeks before the accident.
They each said that they were aware the bus had an ABS system fitted but did not think it ever worked.
"To be honest I can't remember any of them ever working," Mr Callan said in relation to the ABS system on the Bus Eireann vehicles he serviced.
They each denied removing a bulb from the ABS warning light and each confirmed that if there was a problem with the ABS system, Keltank did not have the facilities to repair it and Bus Eireann would have to refer the vehicle to another garage.
They also agreed with Mr O'Hanlon that Bus Eireann was responsible for directing what work should be carried out by the mechanics in Keltank and they were never advised to inspect or repair the ABS system.
Mr Denis Farnan, from Daf Distributors Ireland, who supplied the chassis for the vehicles to Bus Eireann, said that without the ABS system the vehicle could become unstable because the wheels didn't have a good contact with the road surface.
Mr Farnan said that a fault in the ABS system would have to be fixed before a vehicle could successfully pass a road worthiness DOE test.
Mr Farnan agreed with Mr O'Hanlon that it was his belief that if a vehicle failed a DOE test on a few points, it was only these faults that would be checked again in a re-test and if they were repaired, the vehicle would be deemed road worthy.
Mr Bruce Archer, sales director of buses in Daf, told Mr Grehan that the company supplied 20 chassis to Bus Eireann between 1991 and 1993 and the company requested that ABS be fitted to each vehicle.
He said the system was available as an optional extra and explained that it prevented wheels locking during emergency braking by releasing the brakes on the wheel for a fraction of a second, before applying them again and releasing them again.
Mr Archer said that Daf supplied a driver's manual to Bus Eireann and a copy should be kept in each bus.
He agreed with Mr O'Hanlon that if the ABS system was shut off, the foundation brakes would operate efficiently without it.
The trial continues before Judge Patrick McCartan and a jury of five men and seven women.