Case Study 2857 Deflector sheave

Subsea 7 Deflector Sheave

Rig Type: Lay Vessel
Work Location: UKCS
Pertinent code: AISC 9th edition
Client: Subsea 7



Model 3D
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Project description
Rig Engineering in alliance cooperation with Enterprise Engineering Services, has been tasked by leading underwater engineering services provider, SUBSEA 7 to assist with deflector sheave project on one of their lay vessels. This assignment relates to design of deflector sheave foundation to accommodate free issued 25 Te sheave assembly. This follows with drawings package to destruct existing sheave housing assembly, new fabrication drawings to allow for the system to be shop built and ready to be shipped offshore for final bolting connection to the deck of the vessel.

Photographs taken on site


FEA Phase


R.E. Scope of work
The assignment consists of designing and detailing of a new structural foundation to house the deflector sheave free issued by SUBSEA 7. Functional layout, operational loads and scantlings are fully briefed by SUBSEA 7. This also includes the basic geometry and dimensional layout of the bolting patterns and fleet angle of the wire rope. From this basic information, RE constructs structural Finite Element Assessment (FEA) Model and corresponding operation loads prescribed by SUBSEA 7, has been applied. Iteration was done using off the shelf steel available for this project, which has to be concluded in short design / fabrication life cycle. Further iteration with RE alliance, results in EES obtaining AFC status
Engagement Condition
Upload your problem to us and give us relevant input to allow us toresolve your problem, we will need:
1. Geometry instruction
2. Required payload
3. Wire rope tension, sheave angle.
4. Code and standards
5. DAF factor of the unit / system
6. Time frame from conception to AFC status
Key word: Rig Engineering, Alliance, Scottish Rig Repairers, Enterprise Engineering Services, Deflector sheave and foundation, Subsea 7