It is perhaps apt that when asked to pose for a photograph with their mobile phones, Marjorie Edgerley, Joyce Burton, Margo Cavill, Marjorie Bateson and Pat Richardson all admit to not having brought theirs.

In the mobile age, it is easy to forget how telcommunications once operated.

The chances are that 50 years ago anyone wanting to make a phone call in Darlington would have spoken to one of these five women.

Before the advent of speed dials and voice recognition, you dialed '0' and then asked to be connected to the number you wanted.

Now, although their lives have taken them in different directions, they still meet up regularly to reminisce about their time on the exchange.

This year, they met for their annual Christmas lunch at the Chequers Inn, Dalton-on-Tees, near Darlington.

In July 1952, the two Marjories, Joyce and Pat left Darlington Girls' High School and the following week began training for work on the telephone exchange.

Margo was to join them soon afterwards.

"We were just kids really. We were just 16, but not like 16-year-olds are now," said Ms Edgerley. "We had six weeks' training in Newcastle and we used to get the train through every day. We used to sing on the train as we travelled through."

At their get-togethers, they pass round the black and white photographs of their time at the telephone exchange, in Barnard Street.

Along with the pictures of them at their desks, complete with headphones and microphone, are photoghraphs of the regular social functions enjoyed by the staff.

"It was a really good job, I really enjoyed it," said Ms Richardson. "You probably won't get too many people keeping in touch regularly for 50 years like we have.

"Even when I moved abroad, I always tried to get back for when we all got together."

On several occasions, famous people would ring the exchange, including Princess Margaret and the Duke of Kent.

As operators, the women could, in theory, listen in to these conversations.

However, they remain tight-lipped about whether this actually happened or what was ever said.

"I think we're still bound by the official secrets act," came the quick reply.

Such breaches of discipline were monitored by the senior supervisors - and woe betide any operator who broke the rules.

Ms Edgerley said: "We had standard expressions which we had to use and we couldn't say anything different. They used to listen to our conversations.

"There was a dress code and we weren't allowed to chat among ourselves.

"And we certainly weren't allowed to chat to the callers - we all did, mind you."