Design of subsea cables/umbilicals for in-service abrasion - part 1 : case studies
- Authors: Reda, Ahmed , Thiedeman, James , Elgazzar, Mohamed , Shahin, Mohamed , Sultan, Ibrahim , McKee, Kristoffer
- Date: 2021
- Type: Text , Journal article
- Relation: Ocean Engineering Vol. 234, no. (2021), p.
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- Description: Submarine cables play a vital role in a myriad of industries around the globe, including power transmission and communication. Failure of submarine cables can have significant economic and technical implications worldwide. Current design methods for submarine cables focus on the ultimate limit states that address the cables structural integrity and on-bottom stability. However, abrasion of the outer protective layers (i.e. yarn and extruded sheaths) can progressively lead to damage and failure of submarine cables when the integrity of the armour sheathing is compromised. This paper documents several case studies of severe abrasion of submarine cables/umbilicals and undertaken corrective measures. The paper also presents some guidelines to be considered in the design process of submarine cables concerning abrasion. The findings of this paper suggest that abrasion should be considered a limit state that must be addressed in the design process of submarine cables and umbilicals. A detailed analysis of the underlying abrasion failure mechanisms is presented and explained in a companion paper (i.e., Part II: Mechanisms). © 2021 Elsevier Ltd
Design of subsea cables/umbilicals for in-service abrasion - part 2 : mechanisms
- Authors: Reda, Ahmed , Elgazzar, Mohamed , Thiedeman, James , McKee, Kristoffer , Sultan, Ibrahim , Shahin, Mohamed
- Date: 2021
- Type: Text , Journal article
- Relation: Ocean Engineering Vol. 234, no. (2021), p.
- Full Text:
- Reviewed:
- Description: This paper is the second of two companion papers about the design of subsea cables/umbilicals for in-service abrasion. Several case studies of severe abrasion of submarine cables/umbilicals and corrective measures undertaken have been documented and presented in the first paper (Part I: Case Studies). The mechanisms of failure due to abrasion are explained in this paper. The effect of repeated lateral movement on LLDPE (linear low-density polyethylene) extruded outer sheaths of two cable samples was investigated. In the first test, a cable sample was displaced the equivalent of 12 km over a crushed mineral aggregate while in the second test, a cable was subjected to 3 km of displacement under conditions that replicated the touchdown point of a dynamic cable. The results of the first test indicated that the overall abrasion was low and acceptable. In the second test however, the outer sheath was completely worn through. The authors recommend the thickness of the outer sheath be increased for cables where uniform abrasion is expected, and high abrasion protection units be employed where localized abrasion is expected. Empirical data is provided to support these recommendations. © 2021 Elsevier Ltd