GROSSETO, Italy -- The captain of the capsized Costa Concordia on Thursday asked the judge at his manslaughter trial to order tests on the cruise liner's wreckage to determine why electrical and other systems failed after the vessel struck a reef off an Italian island in 2012, killing 32 people.

The outcome of the request from Francesco Schettino, the sole defendant, won't be known until at least September. After only two full days of hearings, Judge Giovanni Puliatti on Thursday adjourned the trial until Sept. 23 for summer's break.

Schettino is also charged with causing the shipwreck and abandoning ship before all aboard had been evacuated. His defence claims that no one died in the collision itself, but that the failure of a backup generator and supposedly water-tight compartments that were flooded created problems during the evacuation, when the deaths occurred.

The court needs "to understand what happened after the collision," Domenico Pepe, one of Schettino's lawyers, said outside the trial, which is being held in a theatre in Grosseto to accommodate all the survivors or victims' families who might want to attend.

As one example, Pepe cited the failure of an emergency generator to work. Had it functioned after the cruise ship's hull was pierced by the rocky reef, "there would have been power to run elevators" to facilitate the evacuation of the 4,200 passengers and crew members who were aboard, Pepe told reporters.

Salvage crews working on an ambitious project to try to right the ship, which is lying on one side just outside Giglio's port, and then float it to the Italian mainland for demolition, hope to pull up the Concordia in mid-September. But if Italian authorities decide to wait until Judge Puliatti rules on the defence request for experts to expert the ship, that timetable be delayed.

Engineers have said the ship might not survive another winter of stormy seas intact enough to be righted and then floated away. They said earlier this week that the ship is slowing compressing under its own weight atop a granite ledge of seabed where it came to rest. However, extensive monitoring indicates the Concordia hasn't budged from its perch.

Just off the rock ledge is a steep drop into the sea. If the Concordia starts sliding off the ledge, it could plunge too deeply to be removed.

Survivors described a chaotic and delayed evacuation and were shocked to see Schettino safely reach the Tuscan island of Giglio before many others made it to shore.

Seawater rushed through the 70-meter (230-foot) long gash in the hull, invading what was supposed to be water-tight compartments, including one housing the engine room. The ship started listing badly almost immediately, and many lifeboats on one side of the ship couldn't be launched.

Schettino claimed the tilt of the ship made him fall off, ending up in a launched lifeboat, and contends he is a scapegoat since five other defendants were allowed to plea bargain for relatively lenient sentences. If convicted, Schettino could receive up to 20 years in prison.

Those five defendants face a hearing in Grosseto that could bring a verdict in their case.

Some survivors have expressed anger or puzzlement that only Schettino was left to stand trial.

Coming to court Thursday was Robert Feher, whose brother, a Hungarian violinist among the crew members, was among the 32 who died.

"There is a responsibility by Costa" Crociere SpA, the Italian cruise company, Feher said.

The cruise company was given an administration fine of 1 million euros ($1.3 million) earlier this year, under a law in which companies whose employees commit crimes can be sanctioned. It has put the blame for the collision on Schettino.