SUBMARINE CABLE DESIGN LIFE LESSONS: A Case Study for Operating the Italy Greece-1 Repeaterless Cable System Beyond the Design Life

By Brian Crawford
January 22, 2021

Brian Crawford goes in depth on the cable design life lessons he has learned after years in the industry.

When UNIFI COMMUNICATIONS (UNIFI) completed its acquisition of WIS TELECOM (WIS) during 2016, the transaction included an existing submarine cable between Italy and Greece, known as the Italy Greece-1 (IG-1) fiber cable.  For the past few years, while UNIFI has been restructuring WIS to improve the company’s basic financials, we have also been investigating the history and status of the IG-1 fiber cable.  Unfortunately, due to its unusual origin alongside an undersea electrical power cable as shown below, IG-1 has never been utilized to its full potential.

Both the submarine electrical power cable and the IG-1 submarine fiber optic cable illustrated above were constructed by Pirelli in 1995 for TERNA, the largest independent electricity transmission system operator in Europe.

As a result, the IG-1 fiber cable does not have the traditional arrangements found with most undersea fiber cable systems, such as cable landing licenses issued by national (telecommunications) authorities, purpose-built beach landing facilities, and purpose-built cable stations.  At the time, TERNA’s primary objective was the construction of the power cable from Italy to Greece, and the installation of the IG-1 fiber cable was secondary.  In other words, the IG-1 fiber cable was built at the same time as the power cable to satisfy TERNA’s long-term internal communications needs for the power cable.

However, within the IG-1 cable, TERNA included plenty of extra fiber, which suggests they may have been planning to sell dark fiber to third parties.  As it turned out, TERNA sold the entire IG-1 fiber cable to WIND Italy and retained only a few fibers for their own internal use.  At the time, TERNA made an agreement with WIND Italy to extend some of the fibers to reach WIND’s nearest Point of Presence (PoP) from the TERNA landing site, which primarily serves as TERNA’s electrical substation for the power cable.  Subsequently, WIND Italy transferred the ownership of the IG-1 fiber cable to its subsidiary, WIS Telecom, which UNIFI later acquired.  Unfortunately, as we soon discovered, WIND did not extend all of the spare IG-1 fibers out from the TERNA power substation, leaving many dark fibers stranded and unused at the landing facilities in Otranto, Italy, and Aethos, Greece.  In addition to the aforementioned challenges, which make it difficult to determine the best strategy for unlocking the underlying value of this particular fiber network asset, the IG-1 fiber cable’s original operational end of life has just arrived.  IG-1 is now 25 years old.

As most submarine cable industry veterans know, suppliers have forever been designing the submerged portion of the plant (or “wet plant”) to operate in the harsh marine environment for a duration of at least 25 years.  This traditional 25-year operating duration, which is also known as the “Design Life” of the system, has been an industry standard lifecycle target for as long as anyone can remember.  However, due to significant advances in technology, most cable systems have historically been decommissioned, or forced into retirement, due to market disadvantages or commercial obsolescence long before reaching their Design Life.  As many industry veterans should recall, we once used to ask what cost reductions would be possible if the Design Life were shorter, since we had been installing technologically superior replacements every 10-15 years on similar routes.  It was rare to reach the Design Life.

To continue reading the rest of this article, please read it in Issue 116 of the SubTel Forum Magazine on page 28 or on our archive site here.