tl;dr how to make helium feasible in heavy-cargo airships

Hey y'all, so I'm writing a story about airships and shit. I've researched the topic a bit and am currently laying down the ground rules for the world I'm building. Here's the bullet points:

>Not Earth, but basically-Earth world
>Airships run the shipping industry, tourism, hobbies, etc. They're everywhere
>Also trains are p prevalent
>Because of its illegality, federal and law-abiding people use helium
>pirates (yeah there's pirates) use hydrogen for its extra lift and low cost and steal the helium from victim ships for that sweet cashflow

So how does make sense that Helium is used for transporting engines and books and other heavy shit? Obviously it's retarded and yeah it's a fantasy adventure story, but I like to keep things at least semi-plausible. Does anyone have any suggestions on ways around the retardedness of using helium as a heavy-lifting agent? Or any other suggestions, I like to hear ideas and discussion.

thanks boo