Video report by ITV News Correspondent Rupert Evelyn
The second rail worker who died after being hit by a passenger train has been named as Michael Lewis.
In a statement given to British Transport Police (BTP), the 58-year-old's family said: "He was known by everyone, and loved by everyone.
"We would like to thank everyone so much for their support during this difficult time and ask that we are now given the space we need to grieve.”
Friends and family have also paid tribute to Mr Delbridge, 64, who was described as a "genuinely lovely guy".
Gary Chappell, treasurer of the local rugby club where Mr Delbridge had been a fixture for years, said they had known each other for more than 50 years.
He said he was "absolutely devastated" and "numb" to learn of his friend's death.
Mr Chappell added: "I'm absolutely devastated, to be honest with you.
"I've known Gareth for over 50 years, his brother Colin is a very good friend of mine as well.
"He was a genuinely, genuinely lovely guy.
"People say that when someone dies, but he was, he always had a 'hello' for everybody, he always had a beaming smile.
"He was a bit of a joker, if he could take the mickey out of you he would. But he would never ever pass you without saying hello."
Mr Delbridge had been a major part of social life at Kenfig Hill Rugby Club for many years, said Mr Chappell.
He said: "It's going to be a massive, massive, massive loss to the club.
"He was a real loyal, staunch member of this club.... People can't believe he's gone."
He added that Mr Delbridge and his brother were inseparable.
The other victim of Wednesday's accident has yet to be identified, but he is believed to be 58 years old and from North Cornelly, another village south of Port Talbot.
A third person was treated for shock at the scene but was uninjured.
Network Rail is facing demands for answers after their deaths and Transport Secretary Chris Grayling has said there will be an investigation.
ITV News understands that the driver of the train sounded the horn when they saw the workers, but the two men failed to respond, and due to the speed of the train there was not enough time and distance for the driver to bring the train to a halt.
Superintendent Andy Morgan, from BTP, said: “Shortly before 10am, we received a report of a train striking multiple persons on the tracks here in Port Talbot.
“Our units were very quickly on scene, alongside the Welsh Ambulance Service.
“Very sadly, a 58-year-old man from North Cornelly and a 64-year-old man from Kenfig Hill were pronounced dead at the scene by paramedics.
“Following a number of urgent inquiries into this tragic incident, it has been established that the three people were railway workers who were working on the lines at the time.
“The initial stages of the investigation suggest that the two men who died had been wearing ear defenders at the time, tragically, could not hear the passenger train approaching.”
Witnesses at the scene and on board the train will also receive trauma support, Supt Morgan added.
Union bosses have called for a full investigation into the deaths, which involved the 9.29am service from Swansea to London Paddington, a 10-carriage GWR Intercity Express Train, and one of 93 in the fleet.
Manuel Cortes, Transport Salaried Staffs’ Association general secretary, said: “It’s too early to speculate about what has happened here but clearly something has gone badly wrong.
“There must now be a full investigation because it is simply not acceptable that in the 21st century people go out to work and end up losing their lives.”
Network Rail Wales route director Bill Kelly said the railway network owner was “shocked and distressed” by the “dreadful accident”, and added that it was “fully co-operating” with investigators.
He added: “Our thoughts are with the families of our colleagues and our members of staff who will be affected by this tragic loss, and we will provide all the support we can.”
The incident resulted in cancelled trains, with replacement buses being put on for rail passengers.
Investigators from the Rail Accident Investigation Branch (RAIB) and the Office of Rail and Road (ORR) have also attended.
It comes after the RAIB report for 2018 warned in recent years “there have been too many near misses in which workers have had to jump for their lives at the last moment”.