Eve Johnston from TfI Marine presented at FOWT 2018, outlining the benefits of TfI polymer mooring components for floating wind platform developers.

1. 1
Developing polymer mooring
components for load reduction.
TfI Marine
Mooring load management

2. 2
Polymer Mooring Components :
• Mooring Springs for FOWT,
Marine Renewables, Oil & Gas,
Aquaculture
TfI Marine
TfI Marine develop polymer components for Marine floating structures.
Under development:
• Power Take off
• Flexible structures

3. 3
The polymer mooring component:
Cut view under tensionExploded view
As shown in the video, the component under tension
causing the spring convolutes to compress.
An exploded view of the component showing the
separate shell convolutes, spacers, bars and end plates.

4. 4
The FOWT challenge:
Wave induced motion will result in high peak loads as
background wind loading/thrust stiffens the mooring response.
Background Thrust
High Thrust
stiffness
Normal
stiffness
dx
wave induced
dF

5. 5
The polymer mooring spring solution:
A non-linear polymer component can change the response, allowing low stiffness
response at the thrust loads. Wave induced motion now causes very low load variation.
Background Thrust
dx
wave induced
High Thrust
stiffness
Normal
stiffness
dF

6. 6
Implementation:
FOWT systems were modelled to determine desired
polymer component response (semi-sub shown)
 Response tailored to site and equipment
 Optimised to maximise performance or cost benefit
Polymer Spring designed and fabricated to required
standards
 Simple metal assembly
 Injection moulded polymer material
Inserted and shackled directly into mooring line
 Works with chain, or fibre rope
 Ease of deployment

7. 7
Performance
Load Reduction – Reduces peak, shock and
cyclic loads;
Impact – Smaller anchors, chain, rope and
connectors; Reduced wear on all components
Benefit - Deployability; Enhanced
Survivability; Reduced costs;
Operational
Survival

8. 8
Capex & Opex Benefits
Shock Loading Risk Reduction
Eliminated
• Risk of failures reduced
• Assets protected from rough sea states
• Associated savings from repairs, insurance premiums etc
Peak Loading Significant Capex Saving
30-70% Lower
• Smaller Chains, Anchors, & Mooring Connections
• Less structural steel across entire platforms
• Can use smaller components => Cheaper Deployment
Fatigue Loading Significant Opex Saving
50-90% Lower
• << Lower Maintenance Requirement, Labour, Vessel, Components etc
• >> Greater Life Expectancy Of Infrastructure

9. 9
Where we are with the spring:
Scale – Currently manufacturing 200kN components for extensive
testing and verification. MN scale components being delivered to
customers from Q1 2019.
Certification – Process is beginning in Q3 2018 with 200kN
components. Future full scale products will be certified.
Implementation– Springs designed for application in
different target applications; FOWT, aquaculture, marine
renewables, oil & gas.

10. 10
Some ongoing projects:

11. 11
Mooring Load
Management
Dr. Paul McEvoy
CTO
noel@tfimarine.com
www.tfimarine.com
paul@tfimarine.com
+353 (0)1 905 2190
Noel Halloran
CEO
eve@tfimarine.comEve Johnston
Ocean Engineer