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Keel plate renewal in Vietnam drydock: cutting and preparation
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SVC Marine’s drydock steel work includes cutting and removing damaged or wasted keel-plate sections for renewal. This project update records the preparation stage of the bottom-steel work.
The project record describes damaged or wasted keel plate being cut, removed and prepared for renewal in drydock. The wider repair sequence below explains the scope SVC can undertake for an appointed steel-renewal job, from the repair worklist to inspection and handover.
01
Crop the agreed keel-plate area
This update concerns preparation of bottom steel for renewal. The agreed crop boundaries identify which damaged or wasted plate is to be removed and the surrounding structure that must remain. Plate thicknesses, adjacent frames or stiffeners, access and the repair drawing guide that preparation.
Our steel workers cut and remove the appointed defective sections and prepare the renewal area. This preparation-stage record is distinct from a completed welding, NDT, coating or final Surveyor acceptance record. The full job worklist and its inspection results establish which later stages have actually been completed.
02
When keel plate renewal is considered
Keel plate or bottom shell renewal may be required for corrosion wastage, cracking, deformation, damage or plate rejected during an ultrasonic thickness measurement (UTM), class inspection or drydock survey. The renewal limits depend on the measured condition and the applicable repair instructions.
The bottom structure is exposed to corrosion, operational and cargo-loading stresses, ballast conditions and grounding or contact damage. A defect can affect hull strength, watertight integrity and cargo operations, and may result in a class recommendation, repair requirement or port-state comment. Inspect the condition during drydock, damage investigation, pre-purchase inspection or repair planning rather than estimating the scope from a photograph alone.
Early review of measurements, drawings and access makes the steel quantities and inspection stages clearer before docking. It also identifies outstanding technical decisions that could otherwise cause rework, coating delay or late undocking. An actual condition assessment of each vessel determines the work required. Define the scope and renewal quantities early so the owner has a basis for planning repair cost and work timing.
03
Agree the steel renewal scope
For a new renewal job, SVC reviews the repair list, available UTM readings, photographs and class or superintendent comments. Identify the location, plate grade and thickness where documented, proposed renewal dimensions, adjacent structure and the inside condition of tanks or spaces behind the steel.
Agree the repair drawing, crop limits, access provisions and inspection points before removal. The method depends on the damage, steel thickness, internal structure, tank condition and drydock access. Where information is incomplete, state what needs inspection before the material quantities, fabrication and fitting work can be fixed.
04
Typical keel plate renewal sequence
Our steel workers, fitters and welders undertake the stages appointed in the repair worklist. The following is a prospective job sequence, with the inspection and test requirements agreed for the particular vessel:
- Inspect the wasted, damaged or rejected keel plate and record its location.
- Review UTM readings, class comments and the superintendent's repair list.
- Mark the agreed crop and renewal boundaries.
- Remove coating, rust, cement and obstructions around the repair area as required.
- Cut and remove the defective steel plate within the agreed limits.
- Clean and prepare the edges and surrounding structure for fit-up.
- Fabricate and fit the new steel insert to the agreed drawing and material specification.
- Weld the insert through the appointed marine welding work.
- Grind and finish the weld area where required by the repair instructions.
- Carry out the specified dye penetrant, magnetic particle or ultrasonic testing where required.
- Present the work for class, attending Surveyor or owner's representative inspection where required.
- Complete the agreed primer and coating work, then record the repair and outstanding items.
05
Fit-up, welding and NDT
Crop marking, sound edge preparation and controlled fit-up make the repair ready for welding. SVC's welders work to the appointed welding requirements and sequence. The worklist identifies the relevant plate and structural details, the access needed on each side and the inspections required before the area is closed or coated.
NDT is specified according to the repair location, weld type, class instructions, owner requirements and the attending Surveyor's decision. Dye penetrant testing, magnetic particle testing or ultrasonic testing may be selected; they are separate methods rather than interchangeable acceptance labels. Record the method, inspected area, findings and any required remedial work against the repair item.
Inspection attendance and NDT records do not themselves constitute a class certificate or permission to sail. The relevant approving parties decide acceptance under the requirements for the actual job. No particular test, result or final acceptance is claimed for this preparation-stage update.
06
Related steel renewal and fabrication work
A docking worklist can contain several steel items with different locations, material needs and access arrangements. SVC's repair workers and welders undertake the agreed fabrication, fitting, cutting and welding scope. Related enquiries can include:
- Bottom shell plate renewal.
- Keel plate renewal.
- Side shell plate renewal.
- Tank top steel renewal.
- Deck plate renewal.
- Pipe support and foundation steel repair.
- Frame, bracket and stiffener repair.
- Local insert plate repair.
- Steel fabrication and onboard fitting.
07
Drydock progress and completion records
Where SVC is appointed to inspect and supervise the owner's repair worklist, our technical attendants check the defined items and report what has been completed, what requires inspection and what remains outstanding. Keep the scope of that appointment clear alongside the steel work performed by our repair team.
Before docking, review the repair list and clarify steel quantities and boundaries. During the work, check daily progress against each item, retain photographs before, during and after the repair, and record welding and specified NDT status. Attend the required class or Surveyor inspections and identify any rework before the next stage.
The final repair report and completion record should link the renewed area to its drawings, quantities, inspection and test results, accepted items and remaining work. Record changes to the agreed scope rather than treating every additional steel item as already included. These are proposed records for a commissioned job, not an undocumented close-out claim for the project update.
08
Safety and hot-work access
Keel plate renewal involves cutting, grinding, welding and material handling, with lifting and confined-space risks depending on the work area. Confirm the hot-work permission and worksite arrangements before starting the appointed tasks.
The vessel and repair team check safe access, staging, lighting, power supply, ventilation, fire watch and isolation of nearby systems. Gas-free conditions and any required clearances must be established for the actual space and work. A ballast tank, fuel tank, cofferdam or void behind the plate requires its own condition and access checks before cutting or welding.
Drydock access also affects steel removal and installation. Define the staging and handling arrangements and the responsibilities of the vessel, dock and repair team. The safety arrangements apply to the actual repair area, and each new hot-work job needs its own clearance.
09
Steel repair enquiries across Vietnam
Coverage enquiries include Hai Phong, Hon Gai, Cam Pha, Cai Lan, Nghi Son, Cua Lo, Vung Ang, Son Duong, Hon La, Chan May, Da Nang, Dung Quat, Quy Nhon, Nha Trang, Vung Tau, Phu My, Cai Mep, the Ho Chi Minh City area, Long An and Vinh Tan, as well as other selected locations in Vietnam. Specify the actual port, anchorage or shipyard, the repair location and whether drydock access is available.
For a docking or wider steel-work enquiry, see Hai Phong ship repair, Vung Tau ship repair and Cai Mep ship repair. These related port services identify enquiry destinations; they do not mean bottom plate renewal can be performed afloat at every location.
SVC undertakes commissioned steel repair for general cargo vessels, bulk carriers, container vessels, tankers, tugboats, barges, offshore support vessels and other commercial ships. The actual worklist, permissions and access determine the attendance plan. Specify the repair location and docking arrangement so material preparation and attendance can be planned for that job.
10
Send the drydock steel worklist
Email SVC repair department with the drydock location and proposed dates, repair list, available UTM report, photographs, drawing references, documented plate thicknesses, estimated renewal sizes and class or Surveyor requirements. State the tank or space behind the plate, access limitations and which inspection or test records are required.
Use the private enquiry channel for vessel particulars. The quotation defines inspection, steel preparation, fabrication, fitting, welding, specified tests, coating and completion records within the appointed scope. Identify any missing measurements or technical instructions so they can be checked before the quantities and sequence are agreed.
11
Related steel and grounding work
See keel damage after grounding for the separate damage overview and project photo presentation. Send a drydock steel worklist to SVC repair department; steel repair in Vietnam covers the wider commissioned scope.
The grounding damage overview is a separate work record, with its own project photographs. Keep its damage account and photographs separate from this keel-plate preparation update. For the wider appointed service, see drydock supervision in Vietnam alongside the steel renewal scope.
12
Frequently asked questions
Does SVC Marine provide keel plate renewal in drydock?
Yes. SVC Marine carries out appointed keel plate renewal, bottom shell repair, steel insert fitting and marine welding work in Vietnam. The worklist defines the cutting and preparation, fitting, welding, specified NDT, inspection attendance and completion records required for the job. This project update records the preparation stage; a new enquiry has its own agreed repair requirements.
When is keel plate renewal required?
Renewal may be required for plate wastage, cracks, deformation, damage, class rejection or thickness below the applicable acceptance criteria found during UTM or drydock inspection. Use the measured condition, repair drawing and attending Surveyor or class instructions to define the renewal limits. Photographs alone do not determine an acceptable thickness or final repair method.
Can SVC Marine provide steel repair workers and welders?
Yes. Our steel repair workers, fitters and welders undertake the commissioned drydock or onboard work in Vietnam. For bottom plating, identify the docking and access arrangements; other onboard steel work has its own limits, permits and inspection needs. Our technical attendants can inspect and report the work under a separate defined appointment where required.
Is NDT required after keel plate welding?
It depends on the class instructions, repair location, weld type, owner requirements and attending Surveyor decision. Specified methods may include dye penetrant testing, magnetic particle testing or ultrasonic testing. The job worklist must identify the method, inspection stage and required records; neither an inspection photograph nor this preparation-stage update proves a test was performed or accepted.
What information is needed for a keel plate renewal quotation?
Send the drydock location and dates, repair list, UTM readings if available, photographs, relevant drawings, documented steel thickness, estimated renewal dimensions and class or Surveyor requirements. Include access and tank-condition information and the required inspection records. Provide vessel particulars privately through SVC’s repair department so SVC can define the appointed materials, repair stages and tests.
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Please provide your company details and the vessel requirement or work scope. Acceptance is subject to verification and confirmation by SVC Marine.