When a bulk carrier's main engine starts showing signs of wear on its cylinder units, Ship Owners and Chief Engineers need a shiprepair partner who can mobilize fast, work safely at anchorage, and deliver a fully documented, maker-standard overhaul. That is exactly what Bac Viet Shiprepair Company delivered for MV MOUNTAIN LION during a major Main Engine Overhaul project carried out at Cam Pha Anchorage, Vietnam.

This article walks through the full scope of work, the technical challenges our riding engineers overcame, and why Bac Viet Shiprepair is the trusted choice for main engine overhaul, cylinder unit repair, and marine engineering services at all ports and anchorages across Vietnam — including Cam Pha, Hon Gai, Hai Phong, Cai Lan, Vung Tau, Cai Mep, Quy Nhon, and beyond.

Project Overview

• Vessel: MV MOUNTAIN LION
• Location: Cam Pha Inner Anchorage, Quang Ninh, Vietnam
• Scope: Main Engine Overhaul – four (04) cylinder units
• Main Engine Type: MAN B&W 6S60MC-C Mk6, 12,240 kW, built by Doosan Engine Co.
• Contractor: Bac Viet Shiprepair Company
• Service Model: Riding/service engineers attending the vessel at anchorage, with all spare parts and special tools supplied by the vessel

Rather than requiring the ship to divert to a shipyard berth, Bac Viet Shiprepair's team of riding engineers boarded MV MOUNTAIN LION directly at Cam Pha inner anchorage. This is one of the core strengths of our main engine overhaul service in Vietnam: minimizing vessel downtime and avoiding costly deviation by carrying out full overhaul work safely and efficiently while the ship remains at anchor.

Bac Viet Shiprepair engineers lifting and inspecting the cylinder cover of MV MOUNTAIN LION's MAN B&W 6S60MC-C Mk6 main engine.

Detailed Scope of Work: Main Engine Overhaul, 4 Cylinder Units

Our team executed a comprehensive, maker-standard main engine cylinder overhaul covering the following key work items:

1. Disconnection and dismantling of cylinder head assemblies

Our engineers disconnected the fuel oil pipes, cooling water pipes, air pipes, exhaust pipe and all associated connections, then dismantled the cylinder covers and moved them to a clean, dedicated work area for thorough cleaning and inspection.

2. Piston withdrawal and inspection

The engine was turned to Bottom Dead Center (BDC), the combustion space in the liner was cleaned, piston rod bolts were loosened, and the complete piston assemblies were withdrawn for detailed inspection — a critical step in every professional main engine piston overhaul.

3. Cylinder head cooling jacket renewal

Using specially rigged tools, our team dismantled the cylinder head cooling jackets, cleaned and inspected each unit, and renewed the jackets on No.2 and No.5 units while reassembling the jackets for No.4 and No.6.

4. Precision measurement and recording

All clearances and dimensions were measured and recorded strictly in accordance with the maker's (MAN B&W) technical manual, ensuring every component met OEM tolerances before reassembly.

Piston crown, piston skirt, and piston ring renewal work carried out on MV MOUNTAIN LION's main engine units.

5. Cylinder liner renewal — Units No.2, No.4, No.5 and No.6

This was one of the most technically demanding parts of the project. Using rigged special tools, the engineering team withdrew the cylinder liners and carried out full cylinder liner renewal, including new O-rings, for four cylinder units.

6. Cylinder liner cooling jacket renewal

The cylinder liner cooling jackets were dismantled, and new jackets and O-rings were installed on Units No.2, No.4, No.5 and No.6, restoring optimal cooling performance to the liner assembly.

7. Piston crown and piston ring renewal

Piston crowns were cleaned and inspected, with all piston rings renewed. Piston crowns for No.2 and No.5 were fully renewed, while No.4 and No.6 were reassembled after inspection.

8. Piston skirt renewal

Piston skirts were renewed on No.2 and No.5 units and reassembled on No.4 and No.6, restoring correct running clearances within the cylinder liner.

9. Hydraulic testing of piston crowns

Each piston crown underwent hydraulic pressure testing at 7.0 kg/cm² to confirm structural integrity and leak-free performance before reinstallation — a mandatory quality-control step in any certified main engine overhaul procedure.

10. Stuffing box overhaul

The piston rod stuffing boxes were dismantled, cleaned, inspected, and all scraper rings were renewed to maintain proper crankcase sealing.

11. Gasket fabrication and renewal

Our engineers fabricated and renewed gaskets for the fuel oil pipes and cooling water pipes as required, ensuring leak-free reconnection of all engine systems.

12. Final restoration, testing and commissioning

Upon completion, the working areas were thoroughly cleaned, oil spillage wiped down, and crankcase doors closed. The main engine was restored to normal operating condition, with all relevant parts checked, adjusted, tested and commissioned prior to handover to the vessel's Chief Engineer.

Rigging and withdrawal of the cylinder liner assembly — one of the most technically demanding stages of the overhaul.

Overcoming On-Site Challenges

Every main engine overhaul at anchorage brings its own set of challenges, and this project was no exception:

• Seized cylinder liners: All cylinder liners were found extremely tight and seized in place, making standard removal methods insufficient. Our engineers fabricated additional special tools on-site and used dry ice cooling techniques to safely and efficiently loosen and withdraw the liners without damaging the engine block.
• Limited crane availability: The vessel's engine room overhead crane was not functioning properly, requiring careful manual rigging and sequencing to safely handle heavy components such as piston assemblies and cylinder liners.
• Additional spare parts requirements: More components required replacement than initially anticipated, and our team coordinated closely with the vessel and owner to adjust the work schedule while maintaining quality and safety standards.

These challenges highlight why experience matters. Bac Viet Shiprepair's riding engineers are trained to adapt to real-world anchorage conditions, improvise safely, and keep the main engine overhaul schedule on track even when unexpected issues arise.

Engine room overview and final reassembly stage of the main engine cylinder units aboard MV MOUNTAIN LION.

Supporting Services Included

Beyond the core mechanical overhaul, Bac Viet Shiprepair also arranged the full logistics package required for anchorage repair work:

• Transportation and traveling for engineers and equipment between shore base and vessel
• Boat services / boat supply for the full duration of the repair, ensuring safe daily transfer to and from Cam Pha anchorage
• Permits, boarding passes and port authority coordination, handled as a lump-sum service to eliminate administrative delays for the vessel

A Full Range of Ship Repair Services at Cam Pha and Beyond

The MV MOUNTAIN LION project is a clear example of Bac Viet Shiprepair's core specialty, but it is only one part of what we offer to vessels calling at Cam Pha and other anchorages in Vietnam. In addition to main engine overhaul, our team provides a wide range of complementary shipboard repair services, including:

• Overhauling Turbocharger
• Overhauling Auxiliary Engine
• Steel fabrication and repair
• Pipe fabrication and repair
• Workshop in-house fabrication
• Electric motor servicing and rewinding
• Underwater services / lashing services

These services allow us to act as a true one-stop technical partner for vessels at anchorage — covering not just the main engine, but the full range of mechanical, electrical, structural and underwater work a ship may need during a single port call.

Engine Part Reconditioning — A Leading Service in Vietnam

Bac Viet Shiprepair is a leading provider in Vietnam of Engine Part Reconditioning services, restoring critical, high-value engine components to maker-standard condition rather than requiring costly full replacement. Our reconditioning capabilities include:

• Reconditioning of Main Engine / Auxiliary Engine piston crowns
• Reconditioning of exhaust valve spindles and valve seats
• Reconditioning of shaft pumps
• And other critical engine components, as required

This specialized reconditioning capability, combined with our full-service overhaul and repair offering, is a key reason ship owners and Chief Engineers trust Bac Viet Shiprepair for technically demanding work at Cam Pha and other Vietnamese ports and anchorages.

Why Choose Bac Viet Shiprepair for Main Engine Overhaul in Vietnam

Bac Viet Shiprepair Company specializes in main engine overhaul, cylinder unit repair, piston and liner renewal, and full marine engineering services for vessels calling at any port or anchorage in Vietnam. Our riding engineer teams are mobilized to:

• Cam Pha Anchorage and Hon Gai Anchorage (Quang Ninh)
• Hai Phong Port and Hai Phong Anchorage
• Cai Lan Port
• Vung Tau Anchorage and Cai Mep – Thi Vai Port
• Quy Nhon, Da Nang, Nghi Son, Dung Quat, and other major Vietnamese ports and anchorages

Whether your vessel needs a single-unit inspection or a full main engine cylinder overhaul across multiple units, our team brings maker-standard procedures, proper measurement and documentation, and the flexibility to work at anchorage without diverting to a shipyard.

Get in Touch

If your vessel is scheduled to call at any Vietnamese port or anchorage and requires main engine overhaul, cylinder liner renewal, piston overhaul, engine part reconditioning, or general marine repair services, contact Bac Viet Shiprepair Company for a fast technical response and competitive quotation.

Bacviet Commercial & Shiptech JSC (Bacviet Shiprepair)

Available 24/7 – Ship Repair & Marine Services at All Vietnam Ports

Service Areas: Hai Phong | Phu My | Dung Quat | Nghi Son | Cam Pha | Nationwide

1. BACVIET COMMERCIAL AND SHIPTECH JSC -  HEAD OFFICE:

+ No. 25/6/302 Van cao street – Haian District- Haiphong City

+ Mobile/ WhatsApp/ WeChat: +84 904 125 520

+ Email: bacviet@haiphongshiprepair.com

2. SHIP REPAIR SERVICES IN HO CHI MINH CITY (Saigon) - HCM CITY BRANCH:

+ No. 66 Dragon Village Phu Long - Phu Huu Ward, Dictrist 9 - Ho Chi Minh City

+ Mobile/ WhatsApp/ WeChat: +84 904 125 520

+ Email: bacviet@haiphongshiprepair.com. Email: Bacviettechco@gmail.com

3. SHIP REPAIR SERVICES IN DA NANG CITY - DA NANG CITY BRANCH:

No. 1109 AZURA Building, 339B Tran Hung Dao Street- Son Tra District - Da Nang City

Mobile/ WhatsApp/ WeChat: +84 904 125 520

Email: quangtrungpr@gmail.com

Updated: August 2026 by Mr. Le Quang Trung – Bacviet Projects Manager

Copyright of this article belongs to Bacviet Ship Repair Company.