When attacking a fire in a rural area we sometimes find ourselves short of wo/manpower. One technique to free up one or two firefighters is to make a "chicago loop".
This is accomplished by bringing the nozzle and hose around in a loop and passing it underneath itself. The firefighter then sits or lies on top of the crossed hose with his body perpendicular to the upper length of hose. This allows one firefighter to handle a large size line, 2 1/4 in. - 3 in. (66mm - 77 mm), that would usually take two or three bodies to hold.
A drawback is that it's not as mobile as a line worked by than more than one, but is very useful in an exterior attack on a fire scene.
The origin of the term "Chicago Loop" unkown, at least to me. It may just be a method of use that my Uncle saw at a convention in Chicago. If you have any clue let me know or just add it on.
Sources - My father, Uncle and self, who have a combined service with the FD of 90 years.