IRISH Rail has come under fire from train users for its continued problems with 'shaking' carriages on its flagship Dublin to Cork fleet, dubbed the 'vomit comets'.

The train authority has been accused of running carriages that make passengers physically ill and which have still not been put right some three years after their introduction.

The Rail Users Ireland (RUI) pressure group has criticised the company after it emerged it had gone to tender for further works on suspension to the trains which, they claim, have been dogged with problems since their introduction in 2006.

A tender published last month by the company referring to 67 coaches in all, noted: "The fleet is three years old and the ride-comfort of the vehicles requires improvement".

In a statement, Irish Rail said the issue had arisen from customer feedback and stressed that is "is purely a passenger comfort issue and has no operational consequences".

But according to RUI – a group claiming to have over 100 members – which has researched and travelled on trains throughout Europe, these have been ongoing problems.

"Trains are second only to aircraft in terms of being complicated at this stage," explained spokesman Mark Gleeson.

"It takes years to put them into service and they have to be certified. But all these problems occurred when the trains were put in service. There is a quality issue here."

The group has claimed that the shaking on the carriages had become so bad that management ordered the removal of curtains because their constant movement was causing motion sickness.

Referring to the launch of the trains in 2006, Gleeson said: "They shook and flopped from side to side, some people nicknamed it the 'vomit comet' because they couldn't physically walk up the car without being thrown from side to side.

"A lot of people were falling over as they were walking around. I was actually thrown across the coach once.

"On the day, the train shook violently and they said yes, we will fix it and tweak it but that was a long time ago; that was 2006 and the problems are still there."

The group maintains that central to the problem was the condition of the Dublin to Cork line itself and that in certain places temporary speed restrictions have been put in place.

Irish Rail says it maintains its tracks according to appropriate technical standards, in common with all major European railways.

The MK 4 fleet is the country's flagship service, and its busiest, operating from Dublin to Cork with some three million passengers using the service last year alone.

A statement from the company said: "Each train set has exceptionally high utilisation, clocking up at least 300,000km per year."