Hull Structural Integrity · Zeebrugge, Belgium

Checking the Structure of Vehicle Carriers and Ro-Ro Ships While They Work Zeebrugge

Hull structural integrity means knowing how a ship's steel is behaving, not only how thin it has become. At Zeebrugge the interesting structure belongs to ships built to carry wheeled cargo: tiered car decks, ramps, large side doors and ballast tanks that fill and empty with every call. Our technicians travel from India to the ship, record corrosion pattern, deformation and cracking in the places this trade punishes, and report in a form the superintendent can take to the class surveyor or the repair yard.

Request a Quote Talk to an Inspector

Deck damage from wheels and lashings

Car decks take repeated point loads from tyres and from lashing gear. Buckled panels, dished plating between stiffeners and cracked lashing-point doublers show up first in the lanes used most, and a walk-through with a gauge finds them early.

Contact damage at ro-ro berths

Short-sea ships make hundreds of berthings a year against fenders, linkspans and quay faces. Dents in the side shell and distortion at door openings are recorded, measured for depth, and checked for cracks that follow impact.

Ballast tanks that cycle constantly

Vehicle carriers ballast heavily to offset light cargo. The alternation of full and empty tanks accelerates coating failure and bottom pitting, so tank condition is recorded as corrosion patterns, not only as an average thickness.

Where can hull structure be inspected at Zeebrugge?

Zeebrugge is a working port, so structural inspection mostly happens afloat at the berth the ship already occupies. Car terminals give access to empty decks between discharge and loading, ro-ro berths suit main-deck and ramp work on lay days, and the Fluxys terminal allows hull spaces outside the cargo containment to be examined within its safety permit. Ships that wait offshore can sometimes be reached by launch at the Belgian anchorages when the sea allows.

The inner port behind the Pierre Vandamme lock is the calmest option for a thorough structural look. A ship lying there for a charter handover or a pre-purchase examination has idle decks and stable conditions, which suits a combined gauging, visual and crack-detection programme. Where a ship needs the hull itself examined, such as the underwater plating, that work belongs at the yard where it will be docked, and we hand the topside data across to it.

Which Zeebrugge ships need a structural inspection, and why?

Owners of older car carriers that will keep trading on European routes ask the structural question most often. The car trade is changing, with heavier electric vehicles and revised expectations for deck strength and fire protection, and older decks were not designed with those loads in mind. A structural record gives the owner the basis for deciding which decks need strengthening and which can carry on as they are.

Ro-ro freighters on fixed UK and Irish services suffer the daily wear of heavy freight units and repeated berthing. LNG carriers have little deck wear but ageing ballast tanks and exposed deck structure. Buyers and charterers on all three types request structural inspections before purchase, on-hire or off-hire, when an independent view of the steel is worth having before money changes hands.

How is hull structure examined on a ship that stays only a day?

The method is a combination, scaled to the time. Thickness gauging establishes how much steel is left. Close-up visual examination records the shape of corrosion, whether it is general, grooved along stiffener edges or deeply pitted, and whether panels have buckled or distorted. Magnetic particle testing then confirms or rules out cracks at the details where fatigue is most likely, such as ramp hinges and lashing points.

Because the call is short, we agree beforehand where to look and in what order. High-risk details come first, representative gauging of large panels second, and the remainder if time allows. Readings and observations are logged against frame and deck numbers as the work progresses, so a decision can be made while the ship is still alongside, and the superintendent is not waiting for a report to learn whether something needs urgent attention.

Visual survey of decks, ramps and shell with photographs referenced to frame numbers.
Ultrasonic thickness readings on plating, stiffeners and brackets in wasted areas.
Deformation records for buckled or dished panels, measured against adjacent structure.
Magnetic particle testing at hinges, supports and doublers where cracks are suspected.

What does the inspection normally find on these ships?

On car decks, corrosion tends to follow water: the lowest decks and the edges of drainage areas wear fastest, and wasted stiffener flanges show up under apparently sound plating. On ramps, hinge pins, brackets and the structure around lifting arrangements carry cyclic loads and are where cracks begin. On the shell, contact damage at doors and berthing points often hides small cracks behind the dent.

In ballast tanks, the pattern is bottom pitting and edge grooving where coating has broken down, with heavier wastage near suction points. The report separates general wastage from localised loss, because the two lead to different repairs. Findings are ranked by urgency, so that the items that need steel renewal at the next opportunity are not buried among the observations that only need monitoring.

Planning a structural inspection around a Zeebrugge call

Tell us the berth, the time alongside and the cargo operation, and which decks and tanks can be freed. For car carriers the best moment is after discharge and before loading, with decks empty and lighting available. For ro-ro freighters it is a weekend lay-over or any delay in the rotation. For LNG carriers it is the terminal permit window, agreed with the terminal ahead of arrival.

Send previous survey reports, any repair records and the class notes about structure in need of monitoring. If you suspect a particular problem, such as a deck that has dished or a ramp that has been repaired before, say so, because it changes how the time is spent. Access to the terminal is controlled under ISPS, so the agent submits the team's details early, and the technicians' Schengen visas are arranged around the confirmed call rather than an estimate.

Where hull structural integrity sits in the survey cycle

Every renewal survey asks for more thickness measurement than the last, and for oil tankers, chemical tankers and bulk carriers the ESP Code adds close-up survey on top. The table is the usual shape of the work; the class rules and the surveyor set the exact extent, which is why the measurement plan for a job at Zeebrugge is agreed in writing before mobilisation.

Survey	When it falls	What the thickness measurement usually covers
Annual survey	Every year, within three months of the anniversary date	General examination. Gauging where the surveyor finds suspect areas or where substantial corrosion was recorded at an earlier survey.
Intermediate survey	In place of the second or third annual survey	Suspect areas, and on older ships and ESP ships selected ballast and cargo spaces with close-up survey; the extent grows with age.
Renewal survey No. 1	Around 5 years	The first full baseline: suspect areas and selected plating and stiffeners, usually with modest steel renewal.
Renewal survey No. 2	Around 10 years	Wider gauging of deck, bottom and side plating, transverse sections across the cargo area on ESP ships, and more close-up survey.
Renewal survey No. 3	Around 15 years	Extensive gauging of cargo and ballast tank structure and more transverse sections. The survey most likely to turn up steel renewal.
Renewal survey No. 4 and later	Around 20 and 25 years	Gauging extended to most structural members in cargo and ballast spaces. Charterers often add a Condition Assessment Programme.
Docking survey	Twice in each five-year period	Bottom and side shell, sea chests, rudder and stern area while the hull is dry; suspect bottom plating gauged.

How the job runs at Zeebrugge

A gauging job at Zeebrugge runs the same way whatever the ship type. The sequence below is what the superintendent, the attending surveyor and the yard can expect from us.

Send the vessel name or IMO number, ship type, class society, the survey due (annual, intermediate, renewal survey number, CAP or owner's condition survey), the port and dates, and the scope you expect.
We confirm the scope against the class rules for that survey, prepare the thickness measurement plan with frame and section references, and say whether the measurement will be credited to a class survey.
Mobilisation is planned around visa lead times and the vessel's schedule; the ship's agent arranges port access, and the yard or ship arranges staging, lighting, ventilation and gas-free certificates.
Gauging with calibrated ultrasonic thickness gauges: through sound coatings only where the gauge's through-coating mode has been verified on a coated reference, otherwise on cleaned bare steel, with every reading tied to its frame, strake and location on the sketch.
Readings are compared with original thicknesses as work proceeds; substantial and excessive corrosion and any cracks are reported to the attending surveyor and the superintendent the same day.
The final report is issued on the class thickness-measurement formats with sketches, a summary of locations exceeding the allowable margins, piping tables where piping was in scope, and the gauge calibration and technician certificates.

Who does the work, and when class approval applies

Atlantis mobilises its inspection team from India to the vessel, for each job. There is no office or agent at the port; the team travels to the ship, which is why the planning step comes first. Work is planned and supervised by our Responsible NDT Level III, the founder, who holds ASNT NDT Level III in UT, RT, MT, PT and VT and has more than eleven years of international field experience. Technicians are qualified and certified under the company's written practice to ASNT SNT-TC-1A, and Atlantis is certified to ISO 9001 and ISO 14001.

Thickness measurement that a classification society credits to a class survey has to be carried out by a firm approved by that society under IACS UR Z17. Atlantis is in the process of obtaining UR Z17 approval from DNV, Lloyd's Register and ABS. Until a certificate is issued, the readings we take are for the owner's own decisions, not for credit to a class survey, so tell us the vessel's class and the survey due when you enquire and we set the scope for the right purpose. Owner's and charterer's condition gauging, pre-docking steel estimates, pre-purchase and on-hire or off-hire gauging, and scrubber and piping condition checks between surveys do not need class approval.

Governing codes and standards

IACS UR Z7 for hull classification surveys
Class society rules for hull structure, ramps and shell doors
SOLAS chapter II-1 for structure and watertight integrity
IMO PSPC resolution MSC.215(82) for ballast tank coatings
ASTM E797 for manual pulse-echo thickness measurement
ISO 17638 for magnetic particle testing of welds

What you receive

Structural condition report by deck, tank and frame, with photographs
Thickness readings in the areas of wastage, referenced to the previous records
Deformation measurements for buckled, dished or impacted plating
Crack detection records for hinges, supports and lashing doublers
Findings ranked by urgency, with monitoring and repair recommendations
List of areas not reached on the call, for follow-up at the next call or dock

Industries served

Pure car and truck carriers (PCTC)
Ro-ro freight ships
LNG carriers with dual-fuel propulsion
Container ships at the outer port
Ships under pre-purchase or on-hire examination
Cruise ships with a short call

Frequently asked questions

Is hull structural inspection in Zeebrugge more than thickness gauging?

Yes. Gauging tells you how much steel is left, but a structural inspection also records the shape of the corrosion, any buckling or dishing, and cracks at fatigue-prone details. For a car carrier or ro-ro ship, the combination matters because decks, ramps and shell fail in different ways, and each calls for a different repair.

Can car decks be examined while the ship is working cargo at Zeebrugge?

Only the decks that are clear at that moment. Between discharge and loading, a number of decks are empty and can be examined; during loading they are not. We plan for the gap and agree the order with the superintendent, so the decks of most concern are done first.

What do you look for on ro-ro ramps and hinges?

We look for cracking at hinge brackets, wasted plating around lifting arrangements, distortion in cross-members and wear under the surface where freight units travel. Magnetic particle testing is added at hinges and brackets because cracks there start small and can look like dirt or scratches to the eye.

Do electric vehicles change how car decks should be inspected?

They add weight and a different fire risk, so owners of older car carriers increasingly want a structural record of the decks. Our inspection records plate thickness, stiffener condition and any dishing, which gives the owner's technical department data to judge whether a deck needs strengthening for the cargo it will carry.

Can hull structure be inspected at the Fluxys LNG terminal?

Parts of it can, within the terminal's permit: ballast tanks, voids, deck structure away from hazardous zones and the engine room. Cargo containment is not part of a quay inspection. The terminal and the ship define what is accessible, and we agree the equipment list through the agent beforehand.

How are findings reported so the repair yard can use them?

Findings are logged against frame and deck numbers with photographs and sketches, ranked by urgency, and delivered in a structure the yard can read without reinterpretation. Where thickness is near a renewal limit, the plate is marked on a sketch so the yard can quote steel renewals from the same document the superintendent holds.

Can hull structural integrity at Zeebrugge be credited to a class survey?

Planning a survey or a drydock?

Send the vessel name or IMO number, the class, the survey due and the port. We reply with the scope, the mobilisation plan and a quote for that vessel.

Request a Quote

Request a ship gauging quote

Send the vessel name or IMO number, the class society, the survey due and the port. We reply with the scope, the mobilisation plan and a quote for that vessel.

Speak to an ASNT NDT Level III

Atlantis NDT provides ASNT Level III consulting, NDT training to ASNT SNT-TC-1A, inspection management software and independent report validation. Request a free consultation and we will return a tailored quote — affordable, accessible and fully customizable to your programme.