Coronation Street producers are set to take unprecedented steps to keep their 50th anniversary storyline under wraps, according to reports.

Although it is known that a tram will crash into the street in the dramatic plot, the BBC News website says that ITV is keen to stop further details – such as which characters will be killed in the disaster and which buildings will be damaged – from leaking out.

“We’re actually being given scripts with just our own parts in it,” said William Roache, who plays Coronation Street in the soap.

“We don’t read the other people’s parts. I’ve never known such secrecy.”

The veteran actor – who is Corrie’s longest-serving character – told the website that he had no idea what would happen in the disaster, or even if Ken would be killed off.

“There’s a great mystery around what’s happening at the 50th anniversary,” he said. “They’re keeping it really close to their chests. So we don’t know. Some of us might make shrewd guesses but I’m not going to talk about those.”

Producer Phil Collinson said that the episodes would entail “tragedy and destruction on a previously unseen scale”.

“The scripts are written, they’re all locked away upstairs in a big cupboard,” he revealed. “Literally under lock and key.

“We know where the storyline’s going and we start filming on Monday.”

And he promised that the episodes – which will enlist the help of special effects company The Mill, known for their work on Doctor Who and the Oscar-winner Gladiator – would be “the biggest, most spectacular episodes ever filmed”.

As well as the crash, special effects will also be used to show the rest of the fictional Manchester borough of Weatherfield for the first time in the soap’s history.

“We’re going to see Coronation Street in the context of the wider world,” Collinson explained.

“So we’re going to have great big wide shots that show you the rest of Weatherfield. Life has begun and ended at the top and bottom of the street, but for the first time we’re going to see the wider world.”

A live episode, which focuses on the aftermath of the tram crash, is also scheduled as part of the 50th anniversary storyline.