Closures are the housings which contain and protect the individual joints in any fiber system, as opposed to fiber joining (fusion splicing, connectorization and mechanical splicing), which are covered in this separate blog. Given how fragile fiber is, and the potential need to upgrade cables, good quality closures are vital to a successful installation. But what is a closure and what should you be looking for when choosing one?
Types of closures
At its simplest, a closure joins one length of fiber cable to a different length of the same type of cable. This is sometimes known as in-line closure or track joint. Added functionality is provided by a spur (or branch) joint which divides the cable into two ongoing parts - the main cable and a side or spur cable. There are also end of route closures where the cable is broken out into individual elements for customer or telco connection.