English to Spanish Tech/Engineering Petroleum Eng/Sci Cranes on oil rigs

Hello, I'm translating a document on an oil platform, and when talking about the Crane and Monorrail systems, they refer to "gable length".

It is one of the parameters and dimensions that is specified for the Main Crane, and also for the Drilling Crane.

I haven't been able to find which part of the crane it is referring to, and it does not seem to be a typo (i.e. "cable" length), because it appears up to three times in the document.

I'd much appreciate any help on the matter :).

Thank you!