Sympathy might be in order for U.S. District Judge Carl Barbier of New Orleans, who is presiding over the mammoth multidistrict litigation over the Gulf of Mexico oil spill.

As of March, the MDL already had featured about 350 suits against BP PLC and others involving a dizzying array of tort and maritime law claims. And due to a deadline in a potentially crucial case set for trial next year, the number of claims in the MDL has suddenly ballooned by more than 70,000.

The biggest new filer was BP itself, which lodged about $100 billion in claims and cross-claims against rig owner Transocean Ltd., contractor Halliburton Co. and blowout-preventer manufacturer Cameron International Corp., accusing them of causing or contributing to the spill. Halliburton and Cameron filed their own cross-claims against BP and others, as did Anadarko Petroleum Corp. and Moex Offshore LLC, which partly owned the Macondo oil well beneath the Gulf.

BP is represented by Kirkland & Ellis; Covington & Burling; and Liskow & Lewis of New Orleans.

“But for Transocean’s improper conduct, errors, omissions, and violations of maritime law, there would not have been any blowout of the exploratory well,” BP’s lawyers alleged in their $40 billion complaint against Transocean. “Nor, but for Transocean’s misconduct, would there have been any explosion and fire on the Deepwater Horizon, or any deaths and personal injuries, or an oil spill in the Gulf of Mexico.”

April 20 — the one-year anniversary of the disaster — was the deadline for spill victims and defendants alike to file claims in an action Transocean brought last year in hopes of limiting its damages. Transocean invoked an 1851 maritime law called the Limitation of Liability Act to assert that its total liability for the spill should be capped at $27 million — the value of its lost freight when the Deepwater Horizon rig exploded. Earlier this year, the company named BP and dozens of others as defendants.

Barbier set a February 2012 trial date in the Transocean case, which could serve to apportion liability among spill defendants, and plaintiffs’ and defense lawyers were already deposing witnesses at a rapid pace.

The pace of filings on deadline day — which reportedly were overflowing from buckets in the New Orleans courthouse — amounted to a vindication of sorts for the MDL plaintiffs’ steering committee. The committee, over strenuous objections from other plaintiffs’ lawyers, has fought hard to entice spill victims away from the claims process overseen by Gulf Coast Claims Facility administrator Kenneth Feinberg and into the New Orleans litigation.

“The numbers [of claims filed on April 20] indicate that spill victims are fed up with BP trying to buy off claims through the GCCF’s quick pay option,” plaintiffs’ steering committee member Stephen Herman of New Orleans-based Herman Herman Katz & Cotlar said in an e-mail.

FLORIDA’S STANCE

Steering committee members previously said that joining the Transocean limitation case was the only way spill victims could be absolutely sure to preserve their rights against all defendants in the litigation. But some major plaintiffs decided not to join the action. The states of Louisiana and Mississippi, which have filed separate suits in the MDL, let the deadline slide. Florida, which still hasn’t sued any defendants in the MDL, also decided not to join the Transocean case.

A spokeswoman for Florida Attorney General Pam Bondi said the state planned to petition BP for damages under the Oil Pollution Act in hopes of avoiding litigation. In any case, she said, Florida could still sue spill defendants without joining the Transocean case.

Kirkland’s Richard Godfrey didn’t respond to a call seeking comment.

Contact David Bario at dbario@alm.com.