'You never pass the spot without reliving it. If I shut my eyes, I see it again."
Thomas Hughes was just nine months into his training when it happened. An elderly woman jumped in front of the train he was driving while accompanied by his instructor. One life lost, another altered. She was just one of about 200 people a year who kill themselves in this particularly horrific manner.
"Because of the way she dived, it felt like a glancing blow," he says.
As drivers are instructed, after following the emergency procedures required of him Hughes got out of the cab and walked back along the track, not knowing what scene would confront him. The injuries were horrific.
Six weeks previously, Hughes, 40, a ScotRail driver, had suffered the death of his father.
"It's an occupational hazard," he says quietly, but it is a heavy price to pay for doing a job.
Details of the suicides referenced in this article are minimal. The Press Complaints Commission's code of practice seeks to keep details of such deaths to a bare minimum in order to respect bereaved relatives. ScotRail – which, for the first time, has given a newspaper exclusive access to train drivers who have been involved in suicides – also asked that details such as locations are not revealed. One of the risks for any newspaper reporting suicide is triggering copycat events.
ScotRail drivers are trained to deal with suicides but nothing prepares them for the reality, which is quick and horrific. There have been cases where the body has come through the driver's cab. The trauma can be exacerbated if drivers have to wait alone with the body before help arrives, often for up to an hour depending on the location of the incident.
They may be forced to relive the experience at an inquest in front of family members, who may even challenge the cause of death.
Most drivers will pass the spot again and again after the incident. The first time they do so a manager will drive with them.
Suicide by train, though an inherently public act is, in many ways, a taboo subject, rarely reported in the media and seldom discussed openly. Reports of such incidents will state, "killed by a train", with the impact on the man behind the machine rarely acknowledged.
For Hughes, who has been driving for seven years and is married with children, having his instructor with him helped to share the burden.
He returned to work after two days because, he says: "I didn't want to sit at home and relive it."
ScotRail says experience shows drivers can find it harder to return after long periods away so they aim to get employees back as soon as possible. While some return the next day, many take up to six months, and one in 20 will never get back in the cab and are redeployed to another role.
Steven Hunter, 45, a driver for 19 years, knows of one man who experienced it five times. He now works in a rail depot.
Hunter himself has experienced two suicides, the first eight years ago. The man was lying on the tracks as Hunter drove his train around a corner.
"I put my brake on and blew the horn, but obviously there was nothing I could do. It is something that is so surreal. I didn't feel anything. His injuries were very, very horrific.
"If you were to hit someone straight on and you knew they were dead, I personally wouldn't go back. But if you don't know they are dead, you feel duty-bound to see how this person is. It wasn't just a horrific sight for me but the conductor, too.
"We had to stay with the gentleman for nearly an hour."
The aftermath for drivers and their families can be severe, he says. "The biggest problem is that it's the thing at the forefront of your mind, and it stays at the forefront of your mind for the next few months.
"You don't sleep. If you are tired all the time you don't function well, you are irritable. Your whole family has to deal with you being more foul-tempered than usual."
The first time it happened, Hunter was off work for almost three months. He used the railway's counselling service and saw a psychologist.
"I can only praise them for that," he says. "They are very good under these circumstances. There is no pressure to come back.
"There is also the brotherhood of the railway. The men who have been through this, they will phone you. You get a lot of support."
If the fatality happens in England all drivers must attend an inquest. In Scotland it is only required if there is a question mark over the cause of death.
"That is something that fills me with dread," Hunter says. "I would never want to come face-to-face with the person's mother or wife or children or sister.
"I know it's not my fault, I didn't cause this to happen. But you do still have pangs of guilt."
Understandably, Hunter says drivers go through a range of emotions, from shock to guilt and even anger towards the fatality.
"There is a slight level of resentment," he says. "Why are you involving me in your problems? What have I done to be involved in your problems? They don't see what you and your family have to go through for the next few months. Your life is put on hold. But these people don't see you at the front of the train."
The second incident, which happened earlier this year, involved a man who had jumped off a bridge into his path.
"I only saw him for two or three seconds," he says. "It wasn't horrific like the first one. Unbeknown to me, he was under the train.
"Once again I went out. The guy was lying in the middle of the two rails. He looked pretty peaceful but I knew he was gone. It's a long, hard hour sitting there yourself waiting for the emergency services."
The modern trend for laying floral tributes can exacerbate the trauma for drivers returning to work.
"Imagine how the driver involved feels seeing that," says Hunter.
Drivers may also face a mistaken belief from the public, or relatives, that they were at fault in some way. That they could have stopped, or given a warning. A train travelling at 100mph can take up to one-and-a-quarter miles to come to a full stop.
Hunter says: "I think the public know that you don't steer a train. It's a very helpless feeling. It's a long few seconds waiting for a train to stop."
Kevin Lindsay, Scottish secretary of rail union ASLEF, was a driver for 15 years and has direct experience of the trauma. His job now is to support others through it.
He says: "I know the feeling myself. It is very traumatic. Each individual deals with it in a different way. You get drivers who take it in their stride. With others, it can take up to a year for them to return to work. Over the years support has improved significantly. Most companies are very good."
As well as the impact on rail staff, rail suicides can prove a logistic nightmare for rail companies, causing significant disruption.
The Rail Safety and Standards Board estimates the total cost of suicides to the industry is more than £11 million or £61,000 per suicide. This includes delays to trains, lost working time a result of trauma suffered by staff.
Last year, Top Gear presenter Jeremy Clarkson provoked outrage and was forced to apologise when he branded those who jump under trains "selfish" – a view not shared by the majority of passengers, according to Hunter.
He says: "There have been incidents where passengers on the train might say, 'I've got a meeting' when the guard explains what has happened. But on the whole, they are usually sympathetic."
He adds: "I do think it changes your perspective on things. It takes the shine off the job. It's very, very sad. I don't think any of us appreciate it if you have never been there. I don't know what it's like to be in such a bad place."
On average, there is one death from suicide every 90 minutes across the UK and Ireland.
Around 200 people each year in Britain take their own lives on railway lines.
Since March 2010 there have been 40 fatalities involving ScotRail trains.
Suicide is three times more common among men – 17 per 100,000 population over 14 – than women, five per 100,000.
The Samaritans say more research is needed into why people choose this method.
Psychologists say in some cases it may involve a fantasy of revenge on society.
In September, the Samaritans will begin the second phase of a campaign aimed at cutting rail suicides. It was launched in 2010 and has had a measured effect.
Figures show that the number dropped by 11% from 233 in 2009-10 to 207 in 2010-11.
Around £5 million has been invested in measures including training railway staff how to spot people on platforms who may be contemplating suicide.