Precision Under Pressure: Successful Emergency Scrubber Repair at Singapore Anchorage

Executive Summary

Asian Sealand Energy Services (ASES) successfully executed an emergency repair on a DN2300 exhaust gas cleaning system (scrubber) for a bulk carrier at the Singapore Eastern Anchorage. The initial crack report of 800mm had propagated to 1200mm by the time our riding crew boarded the vessel.

Despite limited access and ventilation challenges, our team completed the repair within the operational window using TIG welding, Penetrant Testing (PT) , and post-weld acid pickling and passivation. The vessel returned to service without dry dock diversion.

Key Metrics:

• Mobilization Time: Under 4 hours from emergency call

• Crack Length Repaired: 1200mm

• Material: Super Duplex (DN2300 scrubber system)

• Safety Record: Zero Lost Time Injury (LTI)

• Vessel Downtime: Minimized – no schedule deviation

Why This Matters for Vessel Operators

Scrubber system failures can trigger:

• Regulatory non-compliance with IMO 2020/2025 sulphur emission standards

• Port state detention in Singapore or next port of call

• Costly dry dock diversions adding 5-10 days to voyage schedules

• Environmental risks from unplanned system breaches

ASES eliminates these risks by delivering class-approved, on-voyage repairs at Singapore anchorages – no shipyard required.

The Challenge: Complex Crack in Super Duplex Material

Parameter	Details
Vessel Type	Bulk Carrier
Location	Singapore Eastern Anchorage
Equipment	DN2300 Scrubber System (Exhaust Gas Cleaning)
Material Grade	Super Duplex Stainless Steel (high corrosion resistance, high tensile strength)
Initial Crack Report	800mm
Actual Crack Length	1200mm (propagated while awaiting repair)
Site Constraints	Limited access, poor ventilation, confined space
Time Window	72 hours before next charter commitment

Technical Context: Super Duplex stainless steel is highly sensitive to heat input during welding. Improper technique can cause intermetallic phase formation, reducing corrosion resistance and causing immediate or delayed failure. ASES welders are specifically certified for Super Duplex and similar exotic materials.

Before

Result

Our Solution: Precision Engineering at Anchorage

Phase 1: Rapid Assessment & NDT

Upon boarding, our team:

• Conducted visual inspection to map full crack extent

• Performed Penetrant Testing (PT) to verify crack boundaries and detect micro-fractures

• Confirmed 1200mm repair length – 50% larger than initial estimate

• Assessed access points and ventilation requirements

Phase 2: Engineering & Repair Plan

We developed a phased repair plan prioritizing:

• Complete crack removal – no surface patches

• Verification – PT after each grinding pass

• TIG welding – controlled heat input for Super Duplex

• Specified filler metal – matching parent material properties

• Post-weld treatment – acid pickling and passivation

Phase 3: Execution Under Constraints

Despite confined space and limited airflow:

• Deployed portable ventilation equipment to maintain safe working conditions

• Established confined space entry protocols with vessel crew

• Completed TIG welding in segments to manage heat buildup

• Performed intermediate PT between weld passes

Phase 4: Quality Verification & Close-Out

Post-repair verification included:

• Final PT on all welded areas – no indications

• Visual inspection by vessel superintendent

• Acid pickling to remove heat tint and restore passive layer

• Passivation to enhance corrosion resistance

• Documentation – complete repair report for class surveyor

The Result: Vessel Returned to Service

Outcome	Status
Crack completely removed	✅ Verified by PT
Scrubber system operational	✅ Tested and confirmed
Vessel schedule maintained	✅ No dry dock detour
Safety incidents	✅ Zero LTI
Quality non-conformances	✅ None
Class surveyor approval	✅ Provided

Customer Feedback:

"ASES mobilized fast, worked safely, and delivered a quality repair under difficult conditions. Our vessel met its next charter without delay."— Technical Superintendent, Major Bulk Carrier Operator

Technical Capabilities Demonstrated

This project highlights ASES's core competencies:

Capability	Application in This Project
24/7 Emergency Mobilization	Boarded vessel within 4 hours of call
Super Duplex Welding (TIG)	Repaired 1200mm crack in DN2300 scrubber system
NDT – Penetrant Testing (PT)	Verified crack removal before, during, and after welding
Confined Space Entry	Worked safely in limited-access, low-ventilation areas
Acid Pickling & Passivation	Restored corrosion resistance post-weld
MPA Permit Coordination	Handled all hot work approvals from port authorities
No Dry Dock Required	Complete repair at Singapore Eastern Anchorage

Why ASES for Scrubber & Super Duplex Repairs in Singapore

Certified Exotic Material WeldersASES maintains a team of welders certified for Super Duplex, Duplex, CuNi, GRE, and Stainless Steel. Not every marine repair provider has this capability.

24/7 Emergency ResponseOur emergency hotline is staffed 24/7. Riding crews are on standby for immediate deployment to any Singapore anchorage (Eastern, Western, Jurong, OPL).

MPA-Approved Hot WorkWe coordinate directly with the Maritime and Port Authority of Singapore for hot work permits at anchorage – no delays due to paperwork.

ISO 9001 & BizSafe Level 4Our quality management and safety systems are internationally certified. Zero LTI is not a target – it is a requirement.

500+ Projects CompletedProven track record with vessel owners, ship managers, and classification societies (ABS, BV, DNV, LR).

Strategic Partner NetworkThrough our partnership with CCW (Clean Concept Works), we can coordinate chemical cleaning and hot oil flushing alongside structural repairs.

When to Call ASES for Emergency Scrubber Repair

Call our 24/7 emergency hotline immediately if you observe:

• Cracks in scrubber casing or support structures

• Leaks at welds or flange connections

• Exhaust gas bypass or abnormal pressure readings

• Corrosion or pitting on Super Duplex components

• Any damage following grounding, collision, or heavy weather

Do not wait for the next dry dock. We repair at anchorage – your vessel continues its voyage.

Contact ASES Singapore

📞 24/7 Emergency Hotline: +65 9747 8683 (Oliver)

📧 Email: sales@asenergyservices.com

📍 Office: 18 Boon Lay Way, TradeHub 21, Singapore 609966

🔗 Website: www.asenergyservices.com

🤝 Strategic Partner: Clean Concept Works (CCW) – Chemical Cleaning & Hot Oil Flushing