Warren, R.I. — Inside a cavernous shed at Blount Boats, a 14-foot-wide chasm has opened between two halves of the R/V Connecticut, now connected only by a single steel beam and a narrow wooden walkway used by work crews.

“Torches,” said Luther Blount, project engineer at the boat-building company, explaining on Wednesday how the 76-foot steel research vessel had been severed in two earlier this month. “We’ve never cut a boat in half before, but we have a lot of knowledge working with steel and we’ve built vessels like this, and certainly some that are bigger.”

Since February, the “floating lab,” which usually is docked at the University of Connecticut's Avery Point campus in Groton when not in use by marine scientists, has been out of the water undergoing a transformation somewhat akin to turning a four-door sedan into a stretch limo. At the boatyard Wednesday, professor James Edson, head of the marine sciences department at UConn, looked at the gap between the bow and stern halves of the boat and envisioned the expanded labs and additional bunks that soon would fill the space.

“This has been a terrific work boat for getting buoys and ROVs (remotely operated underwater vehicles) out, but now it will become a real research boat,” Edson said, as hard-hatted welders sent showers of sparks spraying from the deck. “We’ll be able to go out for a couple of weeks at a time and do experiments.”

The $2.5 million project to extend the 18-year-old vessel to 90 feet will add six bunks to the existing 12, triple the lab space and install larger tanks for fuel, sewage and water so it can travel farther and stay at sea longer. That will give the boat more versatility in the types and duration of research for which it can be used. It also will be better able to accommodate classes of graduate and undergraduate students, Edson said.

“We will now be able to do overnights with undergraduates as a bonding exercise at the beginning of a class, where they go out and collect data and do the analysis,” he said.

In addition to the expanded lab and bunk space, the vessel will be outfitted with new laboratory appliances, new pumps and electrical systems, larger winches and fixed weather measurement equipment, said Edson, who focuses his research on marine meteorology.

Turner Cabaniss, marine and waterfront operations manager at UConn Avery Point, said the boat is expected to be back on the water in July, and there already is interest from groups wanting to use it. In addition to UConn scientists, the vessel — the larger of the campus’ two research boats — and its three-man crew have been rented for $7,000 per day by groups including the U.S. Navy, the Woods Hole Oceanographic Institution, the University of Rhode Island, the National Oceanic and Atmospheric Administration and the U.S. Geological Survey.

“It’s a very popular boat,” Cabaniss said, adding that he expects its use will increase once the project is complete.

A marine engineering firm, which determined that adding 14 feet would actually make it more streamlined, increasing its speed, stability and fuel efficiency, designed the expansion, he said.

“The final product will be worth the wait,” Cabaniss said.

Building a new boat this size, he said, would cost $6 million to $7 million. By expanding the R/V Connecticut instead, UConn extends its life in a way that will quickly pay for itself, as it gets more use from outside groups and UConn scientists are able to attract more grant funding, Cabaniss and Edson said.

Edson said he’s already alerted marine science professors to the upcoming deadline for National Science Foundation Grants, urging they propose projects that will use the larger boat.

Over the next few weeks, the new section will be built and welded onto the two existing halves of the boat, Blount said over the roar of a steel needle gun being used by one of the workmen to remove paint and rust.

Once the work is complete, Blount said crews will conduct sea trials on Narragansett Bay, then invite Cabaniss and his crew to do their own trials before it is taken back to the docks at Avery Point.

“Maybe if you look close, you’ll be able to see the weld beads, but it should look seamless,” Blount said. “There won’t be a hole in the boat.”

j.benson@theday.com