Irish bobsleigh team: Seán Kennysays forget Cool Runningsand all that stuff about loveable losers - these two sisters, Aoife and Siobháin, have won championship medals and have twice only just missed out on Olympic qualification

'Cool Runnings!' Aoife or Siobháin Hoey will be talking about their sport, and some genius is bound to say it, thinking they are the first to formulate this brilliant witticism. "You're like the wans in that film, you know it, sure it's been on the telly, the wan where the Jamaicans start up a bobsleigh team."

They know. They listen with sighing forbearance as their interlocutor continues to derive a tediously disproportionate level of mirth from the image.

"That film; it ruined us! It was actually on TV a few weeks ago. I was thinking, 'oh my God, I can't even watch this'. It's so bad."

Cool Runnings, on which Aoife Hoey has just delivered her verdict, was a Walt Disney production, a pleasant, sentimental film about hope and failure, a psychologically crude caricature. It is moral victory territory, the stamping ground of loveable losers. It is Disneyland.

The Hoey sisters are not loveable losers. In a European Cup race last December, Aoife and Siobháin Hoey of Portarlington, Co Laois, beat teams from Switzerland, Austria, and Italy among others to finish seventh of 23.

Siobháin continues the Disney metaphor. "Teams from other nations, like Britain, have been very supportive of us. People help because they see you're competing with the world. You're not a Mickey Mouse team. You're not there to waste time."

To further purge preconceptions arising from Cool Runnings, here are some facts - the Hoey sisters have won bronze medals in Americas Cup and European Push Championships events. With two Swedish bobsledders, they hold the world record for the fastest four-woman start in a sled. They have twice missed out on Olympic qualification by sickeningly tiny margins.

This, now, is their sporting life. It has been a richly variegated experience. They have attained minor celebrity at a training camp in Germany (Kuhl Runnings, ja?). Eurosport has beamed their Alpine exploits into homes in the flat, temperate county of Laois ("My aunts are on TV again," their young niece will say, with the easy shrugging acceptance of a child). They have been granted an audience with Dustin the turkey.

Bones have been broken. There has been trauma and joy and hair-tearing frustration, sacrifice and vindication and fear and exhilaration.

What they do is unusual only to those on the outside. They see no incongruity; they are athletes, simply pursuing their sport. They have long been athletes. Only the sport has been different in recent years.

It started with the long jump. Then it was the triple jump. Siobháin's father Joe was her coach and she in turn trained Aoife, 13 years her junior. By 2000, Siobháin had won eight successive national triple jump titles. At Morton Stadium in Santry, a curious, intriguing notice appeared one day - trials for establishment of Irish women's bobsleigh team. They tried out. They finished one and two and it all began.

Lillehammer, winter 2000 - learning to drive. If it were possible for bobsleigh to be gentle, this is how neophytes would be introduced to the sport. But it is not, so you go in headlong (not literally; that would be the skeleton). The first time is a vivid palette of novel sensation. There is the cold smell of fibreglass sleds. There is dazzling white, icy brightness. Most of all, there is the violent, reckless whooshing of the sled.

Siobháin recalls her first run with crisp clarity. "I remember arriving at Lillehammer and seeing the height of the corners on the track and crying quietly, not realising, maybe, what was involved. I remember the sensation of driving. I remember the corners of my mouth reaching my ears, as I was screaming. You can't really explain what it's like."

They settled into roles. Aoife became the driver. Siobháin is the brakewoman: "The brake athlete's primary job is the start. The start is explosive. It involves power and speed. The start is crucial, because for every one-hundredth of a second gained at the top, that's one-tenth of a second by the time you reach the bottom, with the momentum generated. If you're not competitive at the start, it's over."

Driving is done with two bungee cords. "I participate in the start, but when you get in the bob you've to forget about everything that happened at the start. You take a deep breath and get ready for the first bend, which might be 10 metres after the start. Mentally, it's very challenging. You've to think ahead of the bob all the time. Your reactions have to be very, very fast."

Adrenalin and fear play counterpoint on the way down. Your thoughts can go hurtling off into an abyss of dire possibility. They have had their share of Hail Mary, heart-in-mouth moments. Out on the icy white blur of the bob track, the soft, sandy landings of the long jump pit are an impossible luxury. The margin of error in a sled travelling at 80 mph on those slick, vertiginous rollercoasters is precisely zero.

Bobsleighs that crash will pendulum wildly until the momentum they have generated is fully spent. It is washing-machine time, while the horrible flailing continues and desperate invocations are sent skywards. If you are lucky, you will escape with only bruising, perhaps a few cuts. Some are unlucky.

Bobsleigh is not netball. People have died.

"Of course, it worries you," says Siobháin. "A few years ago a German girl was killed on a track in Germany we've slid many times. The potential to be hurt is there, but you can't focus on that. Even a good run down on a sled is rough anyway. The transition from one corner to another is quite abrupt. But you can't come out of a track any more."

Any more. The words are laden darkly with the image of sleds, at one time, making an occasional leap beyond their icy confinements. But this is not possible any more. Right?

"No. Well, it's not supposed to be."

She laughs a short nervous laugh.

They must tightly harmonise their performances in the sled. How important is their sisterly relationship? "It's a huge factor. Aoife's my sister and I have all the concerns an older sister would have, but I have to see her as an athlete. And she's a very strong and powerful athlete. She's mentally so powerful.

"Two years ago in Lake Placid, one of the most dangerous tracks in the world, we were getting ready to slide. The five sleds in front of us had crashed. I'm just looking at Aoife, a baby as far as I'm concerned. But she was the first person safely down the track that day. That mental strength is incredible."

They trust one another implicitly. Sliding together, there can be no other way. Their closeness does not preclude rivalry, though. It might even enhance it. They are sisters after all. Both have been drawn inexorably to competition almost all their lives.

"I suppose everything turns into a competition. I've been competing since I was seven, in under-eight Community Games, Siobháin too. Even when you're doing weights training, I'm pushing myself, thinking: 'I can't let her be better than me' or 'I can't let her down'. It's a good thing."

They face into another season on the European circuit. By financial necessity, it will be truncated. Both have full-time day jobs. They receive funding from the Olympic Council and the Sports Council. Some businesses in Portarlington have sponsored them, family have helped out. But Mammon does not chase bobsleigh. It can cut much more lucrative deals elsewhere.

The sport is expensive. Its hard financial exigencies are forcing them to sell their personal sled, bought with the help of the people of Portarlington. It cost €26,000 and its sale will help them see the season out. There are always odds to be defied. Siobháin bears the brunt as president of the Irish Bobsleigh and Skeleton Association.

"It becomes very frustrating, very upsetting, but you can't focus on that. You could become consumed by frustration and those worries, but we work to the maximum of our ability within the situation we're in."

Sometimes they laugh about it. On a bad day on some freezing, desolate mountainside somewhere, they wonder. But they found themselves on this strange slippery slope and the habit has become fixed. Aoife elaborates.

"I do get excited talking about it. I love explaining the sport to people. But when I'm out there I think: 'I hate this.' Siobháin says to me: 'You know you don't have to do this?' But there's something inside me, maybe I just can't be defeated. I want to succeed. I want to make an Olympic Games.

"It's like the triple jump. You want that 2cms more. So on the track you think: 'I did that wrong. I need to go back up and fix that.' I suppose it's a competitiveness in me, in us."

So forget Cool Runnings. Slide safe, Hoey sisters.

•Sisters Aoife and Siobháin Hoey - aged 24 and 37 respectively - are from Portarlington and both have a background in the long jump and triple jump. Siobháin was Irish women's triple jump champion for eight successive years between 1993 and 2000. Aoife has also competed for Ireland in the triple jump. Siobháin became the first Irish woman to drive a bobsled in Lillehammer, Norway, in 2000. She now operates as brakewoman in the two-person bob driven by Aoife. The sisters finished third in the 2002 European Push Championships, which measures the bob's starting speed over a short distance. They also took bronze in an Americas Cup race in the same season. They were 16th in line for qualification for the Turin Winter Olympics in 2006 with 15 places available. Siobháin is a secondary school teacher, while Aoife works as an administrator for Athletics Ireland.