For the last couple of columns, I’ve focused on learning new things and techniques. Last month, I wrote about high fiber count cables—1,728, 3,456 and 6,912 fibers—and the need to use ribbon or mass fusion splicing with them. Without ribbon splicing, the splicing or terminating of these cables would take weeks instead of days and cost much, much more.
Once a contractor commits to ribbon splicing and purchases a ribbon-splicing machine, it may prove to be an even better investment than they thought. Ribbon splicing can be used on regular loose tube cables, too, providing similar savings in time and money when splicing cables with even 144 fibers. That’s why many cables with 144 or more fibers use ribbon construction.
Most splicing is done with single fibers in loose tube cables. Two or more cables are prepared, and their buffer tube fibers are attached to splice trays. Individual fibers are stripped, cleaned, cleaved and spliced, and the splice protectors are shrunk over the splice. The completed unit is placed in a splice tray. An experienced tech can splice two fibers in about four minutes.
The ribbon splicing process is similar, but most ribbon cables have stiff ribbons of 12 fibers each. A single splice tray typically accommodates 12 ribbons for 144 fibers. Each ribbon is stripped and cleaved with special tools provided with the ribbon splicer, cleaned and fusion spliced to another similar ribbon. A single splice protector covers all 12 fibers in the ribbon splice.
Then the ribbons are carefully arranged into the tray to snap the splice in place. The ribbons are solid and flex only in one direction, which makes arranging ribbons in a splice tray somewhat more complicated than single fibers. Splicing a dozen fibers at once is fast. Most installers say it takes about eight minutes per ribbon—only about twice as much time as splicing a single fiber—making ribbon splicing six times faster. That makes a ribbon splicer a “labor-saving device” if I ever heard of one.
Some cable manufacturers are now making flexible ribbons that can be bent in all directions and even rolled up to save space. That saves time arranging fibers in a splice tray, but it may cost time when preparing cables because the ribbons have to be carefully arranged to ensure the color-coded fibers stay in their proper location. So splicing 12 fiber flexible ribbons is maybe four times faster than single fibers. That’s still a big savings.
You can also use ribbon splicing on regular loose tube cable by “ribbonizing” the fibers. (That’s what it’s called—the fiber industry is always good at creating new words.) I visited a contractor that used this technique in the field by installing backbone and drop cables for a fiber-to-the-home (FTTH) network. He was splicing 144 fiber loose tube cables using a ribbon splicer. His splicers were separating the 12 fibers in a single tube of the loose tube cable, aligning them to the standard color code, then placing them in a simple gadget that glued them into a ribbon. The process of ribbonizing took less than a minute, then the splicing worked just like a regular ribbon splicing process. Again, saving a lot of time.
A simple internet search for “ribbonizing fiber” will lead you to some interesting videos, gadgets and instructions. Many cable and splicer manufacturers offer these tools. They vary from simple, molded plastic parts you hold in your hand to arrange the fibers while gluing them to more complex machines that sit on a desk and flip, slide and glue fibers into ribbons. It all looks easy.
The advantages of ribbon splicing and ribbonizing fibers in loose tube cables only apply to higher fiber count cables. At 144 fibers, it makes sense if you are doing a lot of splicing. But with 288 fibers or more, it really starts to make sense. And with those new high fiber count cables, that are showing up in metro networks and data centers, it’s a necessity.
If you are the person signing the purchase orders or checks, you may have second thoughts. Fusion-splicing machines are expensive, and they require some personnel training to get started. They need constant cleaning and periodic service to keep them operating properly. But if you have crews doing a lot of splicing of high fiber count cables, calculate the payback—it should pay for itself quickly.
About The Author
HAYES is a VDV writer and educator and the president of the Fiber Optic Association. Find him at www.JimHayes.com.