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Dropped object protection

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In a wide variety of offshore operations, impact loads from dropped objects pose a high potential threat to pipelines on the seabed. To minimise the impact of dropped objects, we offer custom designed culverts or concrete mattresses engineered specifically to protect pipelines.

Hybrid systems comprising rock and mattresses can be deployed over exposed pipelines to provide equivalent depth of cover.


Subcon’s standard mattresses can absorb the energy of a 20Te anchor which is industry standard and is designed in accordance with DNV-OS-F101

The key parameter for DOP design is the expected impact energy of a dropped object, which is influenced by the weight and shape of an object. DOP also needs to be designed for the seabed soil type and to be stable for the design environmental criteria.

Vessel anchors or trawling fishing gear impacts can also be deflected by protective measures. Subcon has a range of overtrawlable structures that can be used for Subsea Isoltation Valves (SSIVs) and well head covers.

Subcon’s DOP structures are always designed for a specific application, and can be scaled to the largest pipelines present on the seabed.

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