Transocean CEO Steven Newman on Tuesday testified before a federal judge that the company’s crew made mistakes on the day its Deepwater Horizon rig blew out on BP‘s Macondo well in 2010.

Newman, however, made it clear that Transocean was not in charge of overall safety on the rig, owned by his company.

During the fourth week of a civil trial to determine blame for the spill, Newman said while being questioned by a Transocean lawyer: "We acknowledge that we should have done more."

Newman was CEO of Transocean for less than two months when the blowout took place in Gulf of Mexico, which killed 11 people and caused the worst-ever offshore oil spill in the history of US.

In the trial, Newman said the rig contractor is compensated by a daily rate paid for providing and operating the rig.

"We get paid for 24 hours’ worth of work, so there’s no incentive to take 24 hours’ worth of work and condense it into 23 hours," Newman was quoted by Reuters as saying in court.

The Transocean chief said the company was responsible for safely performing its own operations on the rig; however, the overall responsibility for safety at the well site was lying with BP. BP executives have accepted the company’s role in the accident, but said that rig owner, Transocean, and cementing service provider Halliburton should also share the blame.

"Newman, however, made it clear that Transocean was not in charge of overall safety on the rig, owned by his company."

In January 2013, Transocean had reached an agreement with the US Department of Justice to pay $1.4bn to settle all civil and criminal claims relating to the Deepwater Horizon accident.

Transocean admitted that members of its crew were negligent in identifying signs that the well was not secure and that oil and gas were flowing into the well. In the second week of the civil court trial, Transocean’s senior toolpusher Randy Ezell testified to BP’s negligence before Judge Carl Barbier.

Ezell said there was some misunderstanding of signs of trouble before the blowout, while Transocean colleagues did everything within their authority to control the well.

A Halliburton mud logger Joseph Keith, who survived the fatal explosion on the Deepwater Horizon, also testified that he had missed signs of trouble because of bustling activity on the drilling rig just before the blowout.

During the trial, BP has to prove before Judge Barbier that its own mistakes do not meet the legal definition of gross negligence, for which it may have to pay as much as $17.6bn in Clean Water Act fines. The company has already spent or committed $37bn on cleanup, restoration, payouts, settlements and fines in relation to the spill.

Image: Deepwater Horizon, prior to explosion. Photo courtesy of FT2.