Correct me if I'm wrong but a galley kitchen is just a kitchen of certain dimensions(that is, long and narrow), whereas the Frankfurt kitchen is a complete layout, involving location of drawers, appliances, etc.

From the link:

>"The term galley kitchen is also used to refer to the design of household kitchen wherein the units are fitted into a continuous array with no kitchen table, allowing maximum use of a restricted space, and work with the minimum of required movement between units.

The first mass-produced galley kitchen design was known as the Frankfurt kitchen, designed by Margarete Schütte-Lihotzky."

The Frankfurt Kitchen was a type of galley kitchen.