Ships’ upgrade eases noise disruption

Rio de la Plata, one of Maersk’s six Rio-class ships that have been modified with a ‘‘silencer’’, moves towards the Port of Otago.

Before the silencers were fitted, the ships emitted a thumping noise, to the frustration to residents as far as Waverley.

Now ‘‘they’re as quiet as a mouse’’, Port of Otago chief executive Kevin Winders said.

‘‘They’ve gone from the most disliked ship on the coast ... [to] probably the quietest ship in the port.’’

Railings had to be cut out of the inside of the ship to move the silencers into place before installation.

Engineers fitted the pieces while the ships were in transit.

The work has taken a year to complete.