“The repairs took a long time because we had to change 800 metres of catenary in a segment”, said a spokesperson for Eurotunnel, noting that working in a confined space meant that the repair work was slow.
The spokesperson said extra shuttles would be operating in a bid to absorb delays so that normal timetabling could be resumed by Wednesday.
Some Eurostar trains on Monday and early Tuesday were cancelled or delayed by up to one hour.
Transporting cargo between France and Britain, which usually takes 90 minutes, in some cases took five hours, from leaving the motorway in France to driving on to the motorway in Britain.
The situation led to severe traffic jams at the entrance to the port of Calais.
Some migrants hoping to reach Britain took advantage of the slow traffic to try to climb aboard lorries, provoking angry reactions from some lorry drivers.