Page 34 - Analysis Report of Global Market in the Submarine Cable Field (2017)

Wire and Cable

Challenges in Completing an International Telecom

Cable System Sea Trial

Dr Jerry Brown, XuRendong, Sun Guilin, Sun Xiaohua, HaoChangji,
XuGuoxiang, Jiang Yin, Zhang Chao, Shang Qingliang

1.Introduction: calculations, computer modelling of deployment, operational, overload
China has a rapidly developing submarine cable system manufacturing and repair conditions. The products are also extensively tested onshore
industry which operates in a healthy competitive manner. Subsea cables and undergo a comprehensive Factory Acceptance Test. To meet these
can fall into several different system product streams including relatively extensive requirements Hengtong Marine has invested in a R&D Test
standard products for long haul telecoms projects (the subject of this Centre which has been constructed to match or exceed the capabilities of
paper) and customised products for the Oil & Gas, Scientific Observation other international subsea cable test facilities. This facility is available for
Systems, Defence applications and HV subsea cables. While much of use by other companies.
the Telecoms product has been sold in the domestic market, Hengtong
Marine has broken into the International Market by addressing client 2.3 Customised cable system solutions including specialised cable
concerns over quality and now has a track record for deployed overseas accessories for Scientific Observation Networks. This suite of products
systems. This has been achieved in part by completing an offshore cable is handled in a similar way to Oil & Gas products described in point
system sea trial, which is a requirement of the cable system qualification 2.2 above. The products generally incorporate multiple power cores
to ITU-T G-976 & ITU-T G.972 standards. The requirement for a sea and optical units in a customised design to meet project requirements.
trial is a barrier which every cable system producer has to address to Extensive modelling, design calculations & onshore testing of these
achieve international sales. Hengtong Marine is moving forward to products is required. No sea trial of products is required.
promote and improve the image of “Global Quality from China”.
2.4 Customised system solutions for the Defence Industry.Severe
2.Different Products, Different Standards: restrictions on what can be said regarding these products, but they
At Hengtong Marine Cable Systems, our product portfolio covers the also follow points 2.2&2.3 above. Generally, no sea trial of products is
following – required.
2.1 Subsea Telecoms Systems. These use relatively standard designs 2.5 HV Subsea Power Cables. Products have been developed for
of long haul optical telecom cables (both repeatered & un-repeatered). offshore wind farm array cables and export cables, together with
These products generally cover 5 or 6 cable types (Rock Armour, Double interconnector cables. Cables are designed and qualified by Type Testing
Armour, Single Armour, Single Armour Light, Lightweight Protected and certified by internationally recognised bodies. Generally, no sea trial
& Lightweight Cables) which are manufactured and qualified to ITU-T of products is required.
G-976 & ITU-T G.972 standards. The qualification extends to include
the integration of cable joints, optical amplifier units, branching units As can be seen one of the key differences between relatively standard
and other cable accessories which are required to build cable systems. As subsea telecom products and the other customised industry solutions is
part of this system qualification process, and usually before international the requirement for a comprehensive sea trial.
clients will purchase a cable system, a sea trial deployment & recovery
of the system components is the last step to be performed to verify the 3. Designing an Offshore Sea Trial to meet International Expectations
products are fit for purpose. This last step of the qualification process There are many things to consider when designing a sea trial, as the last
forms the main theme of this paper. stage in the cable system qualification. The following are probably some
of the key points for to be considered when planning the sea trial activity.
Each of these items will now be discussed briefly.

3.1 What marine operations to sea trial: The key marine operations
which should be demonstrated during the sea trial include
3.1.1 armoured cable burial using an industry recognised cable plough.
This will cover the plough launch operation, deploying the plough on
the cable & lowering to the seabed. The grading into the seabed of the
plough share & burial of cable, joints and optical amplifier units. After
completion of burial, the recovery of the plough back to the cable ship
followed by the recovery of the cable system back on-board.

3.1.2 Surface lay (deployment) of lightweight cables, joints and optical
2.2 Customised cable system solutions including specialised cable amplifiers with bottom slack control and cable recovery. This trial
accessories for the Oil & Gas Industry. These types of products are will show that cables can be handled through the linear cable engine
generally designed and manufactured to client specifications, including for deployment and through the Cable Drum Engine for recovery
ISO 13628-5API 17E & DNV standards and can involve power, optical, operations.
copper data cable units together with high & low pressure tubing
lines. As the products are customised to client’s specifications, each 3.1.3 Surface lay (deployment) of a Branching Unit (BU), with three
project requires a unique design solution which is not sea trialled. The cable legs attached.This trial verifies that the single leg cable (Leg A)
products are verified as suitable for operational use by extensive design can be used to support the BU and the two branched cables (Legs B
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