Cable jetting

[1] It is commonly used to install cables with optical fibers in underground polyethylene ducts and is an alternative to pulling.

Every time the fibre passes a bend or undulation in the duct, the pulling force is multiplied by a friction-dependent factor (which can be reduced by using lubricant[2]).

The high speed air propels the cable due to drag forces and pressure drop.

Thus, re-using ducts occupied with one cable, leaving some space, is a tempting and often possible and cost-effective alternative.

The technique of installing flexible and lightweight fibre optic units using compressed air was developed during the 1980s by British Telecom.

True cable jetting was invented by Willem Griffioen of KPN Research in the late 1980s.