Officials in Sydney have admitted the city’s 10 new ferries don’t fit under some of its bridges, with passengers sitting on its viewing deck having either to vacate the area or duck and cover.

The vessels, which have been built in Singapore and Indonesia and are set to serve Sydney Harbour from later this year, boast a top deck from which passengers can enjoy views of Australia’s largest city – but they will need to take cover twice on their journey, as the ferries can only just fit underneath two bridges on the Parramatta River.

“While customers are able to enjoy the upper deck during their commute, they will need to move to the lower deck when passing the Camellia Railway Bridge and Gasworks Bridge,” a Transport for New South Wales (NSW) spokesperson told CNN.

The new River Class ferries, operated by transport company Transdev, will join the fleet of passenger boats that circle Sydney’s famous harbor and the surrounding areas every day.

The tight squeeze has been seized upon by opposition politicians, who have criticized New South Wales transport minister Andrew Constance for buying foreign-made vessels “off the shelf” and failing to tailor the designs to the city.

“The government is admitting that commuters will have to jump off the top deck, or duck, in order to avoid a bridge coming their way,” shadow transport minister Chris Minns told CNN affiliate 9News. “They’ve been told, time and again, build these things domestically… they insist on building them overseas and we see a debacle like we have seen with the ferries today.”

“This fiasco shows exactly why we should build these ferries in Australia,” the state’s Labor party added.

Graeme Taylor, from Action for Public Transport campaign group, told 9News: “They’ve ordered the wrong vessels and these vessels should really be used elsewhere on the harbor, they’re just not suitable for the Parramatta River.”

The city’s transport department insisted it was aware of the problems with fitting tall ferries under the two bridges, but took the decision to order the new ferries anyway.

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“The clearance requirements of the Camellia Railway Bridge and Gasworks Bridge has always been known and considered as part of the ferry design,” a Transport for NSW spokesperson said.

They added that no two-deck ferry design could fit under the two bridges in question, and that the portion of the Parramatta River is particularly difficult terrain for boats.

The development comes just days after 9News reported that some of the ferries in the same fleet were found to have asbestos.

Boat trips around Sydney Harbour are popular among tourists, though the city’s usual influx of visitors has been hampered by the coronavirus pandemic in recent months.