A hydraulic clamp, which prevents the arms of the wheel moving while the gondola is docked, is removed, allowing the wheel to turn.

液压夹具可防止贡多拉停靠时轮子的臂部移动，移除这个液压夹具可以让轮子转动起来。

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Installation of a working wheel of the hydraulic turbine.

安装水轮机工作轮。

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In addition, the company's hydraulic motors will drive 32 special tires that contact the 648-foot diameter wheel, making it rotate at a constant speed of three times an hour.

此外，该公司的液压马达将带动32条特制轮箍，而这些轮箍连接到这个直径为648英尺高的摩天轮，使其以每小时旋转三次的匀速旋转。

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Controlling steering using electric motors also helps to reduce fuel consumption and hence carbon-dioxide emissions. (Electric motors require power only when the steering wheel is turned, whereas a hydraulic pump drains power from the engine all the time.) Ford reckons 90% of its cars will have electronic steering within three years.

ECONOMIST: Rational consumer

Before landing, the flight crew were not aware the nose wheel steering system was not working, as the hydraulic fluid level was low.

BBC: NEWS | Europe | Isle of Man | Air crew criticised for fire risk