The Hells Gate bridge came first then the Tyne Bridge followed by the Sydney Harbour Bridge

All similar being Arch bridges but the steelwork at the abutments different. That no doubt because of greater loading as The Tyne bridge does not carry rail traffic unlike the other two.

Why Arch bridges and not suspension bridges. Possibly to do with the ground that they were built on apart from the technology at the time. I have no idea.

Allan C.