THE two northern powerhouses of soap are divided by the Pennines. And now the worlds of Coronation Street and Emmerdale have collided, in a special crossover episode featuring characters from both shows.

Soap stars came to Bradford for the red carpet premiere of Corriedale. The event, at the National Science and Media Museum, included a screening of the hour-long episode, to be broadcast on January 5.

The content of Corriedale is under wraps until transmission, but a new trailer previews the chaotic aftermath of a multi-vehicle collision, on a country road, with characters from both ITV soaps calling for help as emergency services arrive.

The preview confirms 13 additional characters in the crossover, joining previously announced characters including Corrie’s David Platt, Tracy Barlow and Lisa Swain and Emmerdale’s Aaron Dingle.

The explosive trailer shows Corrie’s Shona and David Platt being treated at the roadside by Emmerdale trainee doctor Jacob Gallagher. As DC Kit Green takes control, Carla Connor tries to calm someone, with paramedic Asha Alahan helping more casualties alongside Cain Dingle.

Vehicles can be seen on fire, flipped in the road. In Hotten General Hospital, Charity Dingle tries to help a distressed Shona. The trailer ends with Kevin and Abi Webster searching for Debbie Webster at the crash site, while Emmerdale’s Robert Sugden screams out for Aaron.

Without revealing details of the episode – which will launch ITV’s new ‘soap power hour’ schedule – the Emmerdale and Coronation Street stars chatted on the red carpet about filming the dramatic special, and working with ‘rival’ soap casts.

Corriedale premiere. Danny Lawson/PA

Jack P Shepherd, of Pudsey, was a 12-year-old pupil at Idle theatre school Stage 84 when he joined Coronation Street as young David Platt. Having grown up on the show, he’s delighted to be making TV history in the crossover episode. “It’s a one-off and something really special to be in,” said Jack. “Filming took place over five weeks; night shoots, very cold, but what a great experience.

“It’s cool to have the premiere in Bradford. When we were arriving today, with the cast, I was pointing out places like the Alhambra, saying ‘I’ve been on that stage!’”

Julia Goulding, who plays Shona Platt, says the action “unravels like a ball of wool”.

“It’s a privilege to be in action scenes, I did a stunt myself which I’m very proud of,” she smiled. “It was wonderful working with the Emmerdale lot, and their crew.”

“Once we got used the whole concept, it felt like ‘why haven’t they done this before?’” said Isabel Hodgins (Emmerdale’s Victoria Sugden). “It was a brilliant experience. We’re not rivals; we were all in it together with the same goal. In three words, it’s devastating, spectacular, mindblowing.”

As Becky Swain, a police officer who faked her death to escape a criminal gang, Amy Cudden is at the centre of a huge Corrie storyline. “Becky causes trouble but she’s more than just a villain,” said Amy. “She’s very damaged, her wife and daughter mean everything to her and she wants them back. I had to find some vulnerability in her.”

Amy enjoyed filming with the Emmerdale cast: “At first it was difficult to get our heads around, but within 30 seconds of meeting, we were all chatting away. Everyone pulled together. There was no time for rivalry.”

Corriedale premiere. Danny Lawson/PA

Corrie’s Harriet Bibby (Summer Spellman) said: “When we first heard about it we were, like everyone else, wondering what was going to happen and who would be in it. It’s been such an amazing experience.”

“We know the Emmerdale gang so it’s been an incredible process,” added Tanisha Gorey (Asha Alahan). “We’re only soap rivals on paper. It’s like a sister relationship.”

In Corrie, Abi Webster has left husband Kevin for his scheming brother, Carl. Viewers fear Abi’s heart will be broken in coming episodes but Sally Carman-Duttine warns: “Don’t mess with Abi”. Filming Corriedale was “a lovely experience”, she says. “There were no egos, we were all together, all buzzing and all delighted to be part of it.”

With the crossover episode launching a new era of soap scheduling, Sally says the shows will evolve, as they always have: “People watch TV differently now, but the show shifts and shapes and finds its natural position. Coronation Street is such an institution, it will always have its place.”

In the run up to Corriedale, we saw a groundbreaking episode of Coronation Street, with the abusive relationship between Theo Silverton and Todd Grimshaw shown through hidden cameras, CCTV and police bodycams. Over recent weeks, Todd has fallen victim to domestic abuse at the hands of his partner, Theo.

Corriedale premiere. Danny Lawson/PA

“It was eerie to film; the cameras were set up differently and it was just us. It felt quiet, it didn’t feel safe,” said James, who plays Theo. “It’s an important storyline to portray. The danger is in the detail. Theo isn’t a psychopath, it’s crucial not to play him as an archetype villain. He’s a very complex man, with a religious background at odds with his sexuality. He’s confused – and dangerous.”

For Emmerdale veteran Chris Chittell, who plays Eric Pollard, the crossover episode is a full circle moment: “I joined Emmerdale for 12 episodes, I’m now in my 39th year,” he said. “As a young child I lived overseas, when I returned to Britain the first thing I saw on television was a show called Coronation Street. How ironic that we’re now blending our two shows. This is quite an occasion.”

* Corriedale will air on January 5 at 8pm on ITVX following two half-hour episodes of each soap, with Emmerdale on at 7pm and Coronation Street at 7.30pm.