I read a series about two years ago about a guy who worked on blimps and in the first book he met a girl who was rich and was trying to go on the route that her grandpa died on and in the end it was because of pirates.
In the last book the main character goes to space on a thing that traveled up a line and in the very end he marries the girl he met in the very beginning (the guy was Canadian).
It sounds like it could be the Airborn trilogy by Kenneth Obel (which I haven't read, but matches the description).
The first novel, Airborn, features young Matt Cruse, a cabin boy for the Aurora, an airship that stays afloat using a gas called "hydrium". He saves an old man called Benjamin Mallory, who dies shortly afterwards. On a later trip, he meets Kate de Vries, the granddaughter of Mallory, and they have adventures involving pirates.
There is no space elevator in this novel, but there is in the third in the series, Starclimber.
