Bräuchte mal Hilfe zum Satzbau

[Ellenor18]

Ich verstehe den Satzbau bei folgendem Satz nicht

They decided they would have to go out into the box-room and walk across it taking steps as long as the steps from one rafter to the next.

Der Teil ...and walk across it taking steps as long as the steps...

ich bekomm da wirklich gar nichts gebacken. wieso sagt man das so? Oder ist dort eine Redewendung enthalten???
Kann jemand helfen?

[TDonK]

You missed half of the noun that the steps that are taken are compared to. It's saying:

taking steps - as long as - the steps from one rafter to the next.

The entire last part is one phrase.