Underground rooms, bunkers, corridors of studios, workspace cupboards, marquees and production trucks… All sorts of temporary specialist headquarters are set up to ensure the efficient running of The Championships.

A hangar-style space, buzzing with an adjacent bank of cables and servers (officially called the Rack Room), houses the automated Electronic Line Calling (ELC) system and its 50-strong team of operators. 

ELC, made by the pioneering Hawk-Eye sports technology company, is being deployed at Wimbledon on all 18 match courts for the first time at the 2025 Championships, bringing to an end the role of the line judge after 147 years in SW19.

“The time is right to take this important step in seeking maximum accuracy in our officiating,” said Sally Bolton, Chief Executive of the All England Club, when the announcement was made last autumn.

“For the players, it will offer the same conditions they have played under at a number of other events on tour.”

The ELC system is an impressive operation. The hub has the feel of an air traffic control tower at a major international airport, which seems fitting for a technical project that is monitoring the flight trajectories and landing spots of every official Slazenger ball struck this Fortnight. 

The technology works by tracking balls using 12 cameras set up discreetly around the court, with bespoke covers made in the very specific shade of All England Club Wimbledon green. 

The courtside cameras capture the ball’s movement as a computer interprets the location in real time, producing an accurate three-dimensional representation of the court and the ball’s trajectory within it. 

Similarly, cameras monitor the feet of a server on the baseline during their service motion. 

If required, a voice mimics that of a line judge, with a loud call of “Out!”, “Fault!” or “Foot fault” released within a tenth of a second. The clarity and tone has prompted people to think there really might be a human, on court, making those calls.

As Andrew Birse, Technical Project Manager, and Rebecca Finch, Programme Manager, explain, this is because there are 24 varieties of Wimbledon-specific voice calls – male and female voices pre-recorded by All England Club staff members and tour guides.

It’s clever stuff. If a ball is very close to the line, the automated call will be a bit louder to mirror the emotions of a tight match and therefore be more audible through a noisier crowd.

Up in Ball Traffic Control, the team of operators work shifts to oversee the technology. One operator works across two courts and every court has a review official, who is in communication with the chair umpire.

The room contains 144 screens. Each court has a dedicated desk with eight screens – two displaying tracking software, two displaying visualisation software, one with a live camera feed of the court and another dedicated to foot faults for the review official.

The laser-like focus required means each ELC operator works to a pattern of two hours on, one hour off.

Hawk-Eye is used by other sports in the form of goal-line tech in football or leg-before-wicket decisions in cricket, but the team at Wimbledon is the specialist tennis unit who travel from tournament to tournament.

It's a serious bit of infrastructure to set up. Installation at Wimbledon took nearly six weeks. A logistics team arrived at the All England Club in the last week of May to start installing the servers, setting up the cameras and network, and then testing, testing, testing to ensure absolute accuracy.

It is human to be resistant to change, but players are positive about the introduction of the electronic system. As Aryna Sabalenka said on Monday, "I think it's easier. Whatever the system is saying, it is what it is."

Where before she said she would be wondering whether to challenge or not, now there is no doubt on that score. "Just to have less struggle in the head, I prefer Hawk-Eye."