The £1.5 billion deal will also see new fleet rolled out across the network.
68 Found In Container At Harwich Port
Four Polish nationals have been arrested after the discovery of 15 children and 53 adults on lorries during a port search in East Anglia.
The lorry drivers were arrested on suspicion of facilitating illegal immigration, after the vehicles arrived from Holland.
The stowaways - 35 Afghan nationals, 22 Chinese nationals, 10 people from Vietnam and one Russian - were discovered at Harwich International Port after a search by Border Force officials.
A Home Office spokesperson said: "We can confirm Border Force officers discovered 53 adults and 15 children during a proactive search of four lorries which had arrived at Harwich port from Holland on Thursday evening.
"Seven of those discovered were taken to hospital as a precaution, before being released. All 68 individuals are now in the care of Border Force.
"Four Polish nationals, who were driving the vehicles, have been arrested on suspicion of facilitating illegal immigration. They have been taken to separate police stations and will now be questioned by the Home Office's criminal investigations team while inquiries continue.''
Two pregnant women were among those taken to Colchester General Hospital after the discovery at the Essex port at around 10pm on Thursday.
An ambulance spokesman said: "The patients who were taken to hospital were suffering from abdominal and chest pains and were feeling faint. None are in a life-threatening or serious condition.''
Essex Police said it had been contacted by the ambulance service to reports that 68 people had been discovered in four lorries on a ferry from the Hook of Holland.
"Essex Police made contact with staff at Border Force, who were already in attendance, and they are taking the lead as the incident relates to immigration offences.
"We are continuing to liaise with Border Force while their inquiries continue,'' said a spokesman.
A spokesman for the port said the stowaways were discovered on vehicles that had arrived on the Stena Hollandica.
A spokeswoman for Stena Line said: "We can confirm that four different lorries carrying 68 clandestines were stopped by Border Force at Harwich International Port last night as they disembarked from the Stena Hollandica.''
She added that the ship left the Hook of Holland at 2.15pm and arrived in Harwich at 7.45pm on Thursday - a five-and-a-half-hour journey.
Could Addenbrookes Paedophile Doctor And Essex Teacher Been Stopped Earlier?
The world's first out of hours service supporting veterans across Norfolk and Waveney has launched.
It's Thought Missing Mobile May Be In Bin Lorry - Not Found By Police Yet
Recently Played Tracks
To listen live, choose your preferred location:
Deposit £10 to get a £40 Welcome Bonus - That's £50 to play bingo, slots and more!*
Over 50 tracks to make you feel-good. New album out now...
Find your local four day weather report here.
Make Heart the soundtrack to your day and you could be a winner with great prizes up for grabs throughout the day.