A BP vice president told a panel of federal investigators Wednesday that critical time was lost after the Gulf of Mexico oil rig explosion because documents that could have led to a faster response weren’t available.

In the end, it didn’t matter, because the blowout preventer — a device designed to prevent oil from spilling after a blowout — failed, Harry Thierens, BP’s vice president for drilling and completions testified.

After the April 20 explosion that killed 11 people, some 206 million gallons of oil spewed into the Gulf until mid-July, when a temporary cap stopped the flow. A permanent fix is expected to be put in place after Labor Day.

Within days of the explosion, it became clear that changes had been made to a locking system on the blowout preventer, Thierens said, but rig-owner Transocean did not immediately have drawings available explaining the changes. It took between 12 hours and 24 hours just to get those documents, he said. There were other changes and questions about the five-story device.

“If that time had not been necessary a faster response” could have been possible, Thierens said.

During this time, Thierens kept copious handwritten notes in a logbook. Before each item he wrote the hour in military time, then noted key moments from conversations he had with personnel from BP, the operator of the well, and with people from other companies, including rig-owner Transocean.

Transocean was ultimately responsible for the maintenance and operation of the blowout preventer. Thierens worked closely with Transocean employees to try to activate the preventer with undersea robots beginning four days after the explosion and until it became clear — sometime in early May — that the device was not going to work.

On April 25, at 2:15 p.m. Thierens wrote: “Some confusion in TEO (Transocean), regarding details around the control system. No Transocean approved drawing available.”

At some point in his log notes, Thierens questions whether Transocean personnel had made changes according to their own protocols. “My concern right now is that Transocean made an … uncontrolled change on the rig.”

Transocean was also aware that a change had been made in a control system, he said, and at 3 p.m. wrote: “TEO trying to establish what they got.”

It later became apparent that there were a variety of other problems with the device, including pipes being run to different places. Thierens and the other workers trying to shut in the device suddenly learned that after hours of working to build up pressure to one area they were actually doing the work to another part of the device that was of no use to them.

“I spoke frankly about the seriousness of this issue and quite frankly was astonished that this could have happened,” Thierens wrote. Billy Stringfellow, a Transocean cementer, was “clearly emotional. Told me ’this stack is plumbed wrong,”’ Thierens added.

“When I heard this news, I lost all faith in this BOP stack plumbing,” Thierens said, referring to the blowout preventer by its acronym.

When pressed, however, Thierens admitted none of it mattered because the blowout preventer didn’t work, even when all the other problems were addressed.

Retired Coast Guard Adm. Thad Allen, the government’s point man on the spill response, suggested Wednesday that the blowout preventer could be raised from the seafloor in the next couple of days, but he was hesitant to give a specific timeline. The blowout preventer is a key piece of evidence to determining what caused the disaster.

Meanwhile, the chairmen of the presidential panel investigating the spill expressed surprise and disappointment Wednesday that the Obama administration didn’t consult senior U.S. environmental officials before announcing plans to expand offshore drilling before the accident.

Nancy Sutley, chairwoman of the Council on Environmental Quality and Jane Lubchenco, head of the National Oceanic and Atmospheric Administration, admitted after repeated questions that neither played a direct role in the March decision to open up more of the Gulf and Atlantic Ocean to oil and gas drilling.

The exchange suggests that a focus of the federal investigation will be the degree to which federal scientists were consulted in oil and gas decisions before the explosion. Federal law leaves the decision on where and when to drill to the Interior Department Secretary, who releases plans every five years.

Also Wednesday, BP said it was deploying new technology that it believes will provide a steady stream of data about water quality in the Gulf.

There has been criticism of the government’s and BP’s statements downplaying the amount of oil still in the water.

The new technology is said to allow for more efficient detection of any emulsified, dissolved and dispersed oil in water and weather and water temperature data, among other benefits.