A mechanical splice is a method of permanently joining two separate fibers together within a fiber optic cable. Fiber optics are used to transmit data in fields such as telecommunications or computer networking. Mechanical splicing provides a quick and effective way of joining fibers so that information can pass uninterrupted between different cables or sources. It is an alternative to fusion splicing, which is a method of fusing fibers together using arc welding. Fusion splicing is fairly complex, however, and requires much more skill than mechanical splicing.
To create a mechanical splice, installers first remove the protective jacket from the fibers using a wire stripper. Once the fibers are exposed, they are cut with a tool known as a "cleaver." The applicable fibers are then fit into a simple alignment tool to create the mechanical splice. This alignment tool stays in place permanently to keep the fibers joined correctly.
There are four basic types of alignment tools used to create a mechanical splice. Capillary tubes are made from glass and ceramic, and are just slightly larger in diameter than the fibers themselves. Each of the fibers is inserted into one end of the tube so that they meet in the middle. A small amount of gel or adhesive is used to hold the fibers in place.
Many installers use a V-groove tool instead of a capillary tube. The V-groove consists of a plastic case divided into two parts. The fibers are placed into the case so that when the two halves of the case fit together, they crimp the fibers tightly together. For more flexibility, installers can choose an elastomeric alignment tool, which consists of a soft, flexible tube that can accommodate fibers with a small variation is size.
The primary benefit of a mechanical splice is the speed and ease with which it can be completed. Using an affordable alignment tool, installers can join fibers without the training or expense of an arc welder. Mechanical splicing is also a quick way to restore damaged communications or networking systems until permanent repairs or modifications can be made.
Compared to the strength and durability of fusion splicing, mechanically-spliced fibers tend to have relatively poor pull-out strength. This means that fibers joined with a mechanical splice are susceptible to damage if they are mishandled or left unprotected. While mechanical splicing is an effective way to join fibers, the level of communication between the joined fibers depends largely on the accuracy of the alignment between them.