More than 20,000 breaches of security by migrants at the Channel Tunnel terminal in France were thwarted in 2016, Eurotunnel has claimed.
Spokesman John Keefe said increased surveillance had reduced "what was a disruption every night, down to no disruption to services for 18 months".
Eurotunnel said it was now spending 20m euros (£17.2m) a year on security.
However, Border Force union officials said staff reported that attempts to breach security remained high.
That figure has doubled from previous years despite the dismantling of the Calais jungle.
In 2015 there were nightly incursions in the tunnel with some migrants able to walk all the way to Kent.
A new security control building, which cost three million euros (£2.5m), is part of a security upgrade at the French end of the tunnel.
In the nerve centre, staff monitor 30km (18 miles) of high security fencing, plus there are 9km (5.5 miles) of infrared barriers, 570 static and mobile cameras and more than 300 security patrols.
The decision to embark on the investment was taken in August 2015 between Theresa May, when she was home secretary, and her then French counterpart Bernard Cazeneuve.
Mr Keefe, director of public affairs at Eurotunnel, said a giant screen enabled staff to focus on up to 30 separate activities across the 650-hectare site at any time.
"That combined with the fences, motion detectors, infrared detection, means we can identify people even before they approach the fences and we can stop them getting near the terminal," he said.
However, Paul Booth, deputy director of Border Force, admitted there were still challenges.
He said: "It could push the problem further out, so people could risk their lives more by being in vehicles, further out for longer."
Kevin Mills, from the PCS union which represents Border Force staff, said his staff were not reporting the number of attempts to get through controls had fallen.
He said: "Everything we are hearing is that the numbers of attempts are high, if not higher than before."
He added it was about "Eurotunnel security not the Border Force operation".
"Although they have broken up the camps, the individuals do not just vaporise," he said.