'Emirates Air Line' cable car opens in London

Britain's first urban cable car service opened to the public on Thursday, carrying passengers across the River Thames in London - just in time for the Olympic Games.

The five-minute ride takes visitors from Greenwich in southeast London to the Royal Docks in east London, joining Olympic venues on both sides of the river.

Each car provides 360-degree views taking in the Canary Wharf financial district, Greenwich and its historic maritime and timekeeping sites, the Thames Barrier - one of the world's biggest flood defence systems - and the Olympic Park.

London Mayor Boris Johnson said it was "a must-see destination in its own right", as he opened the service.

"Get on this cable car immediately. It's beautiful, worth every penny and a stunning piece of engineering," he said after a taking a trip on it himself.

The gondola system has been described as the most expensive in the world, with the overall cost of the project hitting £62.6 million ($A96 million).

Construction costs totalling £45 million were offset by a £36 million, 10-year sponsorship deal with Dubai airline Emirates.

The 1.1-kilometre long cable car system, named the "Emirates Air Line", can carry up to 2500 people per hour in each direction - the equivalent of 30 London buses - the British capital's transport authority said.