The anchor was attached to a length of rope.

铁锚系在一段缆绳上。

《牛津词典》

One of them unwound a length of rope from around his waist.

他们中的一个人解开绕在他腰间的一条绳子。

《柯林斯英汉双解大词典》

To secure (a mountain climber, for example) at the end of a length of rope.

把(人)系在绳端拴(如登山者)在一截绳子的末端。

youdao

And to prepare for any slips, the inexperienced are joined to him by a length of rope.

BBC: The perfect trip: Switzerland

Equipped with nothing more than a length of rope and a carpenter's adze, Shackleton and two crew-members successfully completed the journey in 36 sleepless hours.

ECONOMIST: Antarctic exploration

Mr Kelly told reporters after inspecting it that a length of rope was looped around the piece of steel and that no marks were visible on the walls overhead.

BBC: 'Part of 9/11 plane landing gear' found in New York