Two types of emergency optical fiber cable systems and an easy use connector have been developed. The first is a 250 m length of 12-fiber cable which is used when an optical fiber cable is damaged at one point due to construction work as gas, water lines or roads. The second is a 1 km length of 4-fiber cable which is used during large disasters such as typhoons, earthquakes or floods. The easy use connector is capable of being joined in 5 minutes without using a special tool.
"Optical Fiber Cable Systems for Emergency Use", Proc. SPIE 0722, Components for Fiber Optic Applications, (14 January 1987); doi: 10.1117/12.937660; https://doi.org/10.1117/12.937660