I think that they are referring to what amounts to scaffolding+shrinkwrap: https://shrinkwrapcontainments.com/image-gallery/ https://shrinkwrapcontainments.com

I think that they are referring to what amounts to scaffolding+shrinkwrap: https://shrinkwrapcontainments.com/image-gallery/ https://shrinkwrapcontainments.com/image-gallery/ Near the bottom of the page there are a couple photos of the Golden Gate. Most probably they have "traveling scaffolding" for the standard parts and some specific built-on-spot structures for other parts.