In schools without lockers, students are sometimes provided with two complete sets of textbooks, one set being kept at school for use in class, and the other being kept at home for referring to for homework, thus limiting the amount of heavy carrying that would otherwise be required without having lockers to store them in between classes. However, research has shown an increase in the incidence of back injuries in some students, which has been directly attributed to the lack of lockers for storing books in, thus forcing students to spend more time carrying heavy loads of books in backpacks.
Laundry lockers are used in places like hospitals and food-processing workplaces where uniforms have to be collected, laundered, then returned to their owners. The locker cabinet contains a number of very narrow lockers, each of whose doors is keyed using a key held by the owner, so that they have access only to their own locker; but the entire array of doors is embedded in a much larger door covering the entire front of the cabinet. Opening this opens all the lockers simultaneously, and requires the use of a master key which is held by whoever collects items deposited in lockers, for laundering, then returned in the same way, after which they items are accessible to owners using their individual small doors.
There is a luggage storage service a short one minute walk from Union Station in downtown Denver - LUGDEN. You can make a reservation online - lugden.com, call - (303) 747-5600, or show up as a walk-in. They offer hourly, day, overnight and weekly bag storage. Great place to store your luggage if you're on a layover from Denver International Airport, or going to a concert, or headed to a Rockies game at Coors field and want to enjoy yourself without having to lug your bags around.