The USS Zumwalt has suffered another mechanical breakdown, this one requiring that it be towed to a port in the Panama Canal.

The Zumwalt, a first-of-its class “stealth” destroyer built at Bath Iron Works, was transiting the canal when it lost propulsion in one of its two drive shafts and crew members noticed water coming into bearings connecting the shaft with its electric motor, according to reports by USNI News, a publication of the U.S. Naval Institute, and the Navy Times. The Zumwalt also suffered “minor cosmetic damage” when the ship made contact with the canal walls.

Tugboats were required to tow the Zumwalt, and the guided missile destroyer is now undergoing repairs on the eastern side of the canal at the former U.S. Naval Station Rodman, USNI News and Navy Times reported.

This is at least the second mechanical problem with the newly commissioned destroyer, although naval experts say such issues are common for the lead ship in a new class, especially one as packed with new technology as the Zumwalt.

“With the Zumwalt, the whole purpose is to push the limits of technology,” said Eric Wertheim, author of the U.S. Naval Institute’s “Guide to Combat Fleets of the World.”

The more than $4 billion Zumwalt is the largest and most technologically advanced destroyer ever built for the U.S. Navy. It features an electric propulsion system, new types of weapons and a sleek, angled shape and hull design that makes the 610-foot ship appear no larger than a fishing vessel on radar. Although much larger than the Arleigh Burke-class destroyers also built at BIW, the Zumwalt is able to operate with a smaller crew and is designed to get closer to shore to support land operations.

The ship’s 78 megawatt gas turbine generates enough electricity to propel the ship through the water as well as power existing and future weapons systems, including lasers and “rail guns” under development by the Navy. But all of that technology carries costs and risks. After initially planning to build 32 Zumwalt-class destroyers, the Navy reduced the order to just three ships – all built by BIW – and revamped the Arleigh Burke line of warships. Instead, the three Zumwalt destroyers will effectively become floating test platforms for technology that could be incorporated into other Navy ships.

Wertheim said some of this technology “is untested and is going to require time and investment to work things out.” But he expressed confidence that the Navy will work out the bugs over time.

“No one likes to see these (problems) but it is early … and we are pushing the envelope on the technology,” Wertheim said. “So this is the ugly side of technology.”

Named for former Chief of Naval Operations Adm. Elmo R. Zumwalt Jr., the Zumwalt was designed as a multipurpose warship able to fight at sea and bombard targets on land with its missiles and new projectile system. The ship has a large landing pad for helicopters, drones and the new F-35 Joint Strike Fighter jets – another technology plagued with problems and cost-overruns – as well as an enclosed bay for launching the small boats used by Navy SEALs or other special forces.

Construction of the Zumwalt took more than six years and the more than $4 billion price tag significantly exceeded original expectations. The total cost of the three-ship program is estimated at $22 billion.

After departing BIW for the final time in September, the Zumwalt was commissioned during a ceremony in Baltimore on Oct. 15 and was en route to its home port of San Diego when the latest breakdown occurred. Prior to commissioning, the Zumwalt also experienced a leak in a lubrication system for one of the ship’s propeller shafts, requiring repairs at Naval Station Norfolk in Virginia.

But Navy officials praised the performance of the Zumwalt during at-sea trials this spring and summer. The ship’s crew even had a chance to engage in the ship’s first (unofficial) mission by helping to rescue a Maine fishermen suffering a medical emergency.

And not all of the recent complications have been related to the ship’s mechanical functions.

Earlier this month, news broke that the rocket-powered projectiles for the Zumwalt’s 155mm Advanced Gun System – billed as a more affordable alternative to cruise missiles fetching $1 million apiece – would still cost $800,000 each. As a result, the Navy only planned to buy 90 of the projectiles rather than the 600 that were supposed to be on board and was researching less-costly alternatives for the gun system.