Special Survey Thickness Measurement · Bremerhaven, Germany

Renewal and Intermediate Survey Gauging for Vehicle Carriers and Boxships at Bremerhaven

Vehicle carriers rarely enter dry dock outside their survey cycle, so the terminal call at Bremerhaven is often the only time their deck steel can be measured between dockings. Special survey thickness measurement here covers renewal and intermediate survey gauging for car carriers, ro-ro ships and container ships, in the floating docks of the Fischereihafen and afloat behind the locks. Each job is carried out by a team mobilised from India to the vessel, planned around the lock schedule, the car terminal's discharge and loading, or the dock slot.

Request a Quote Talk to an Inspector

Deck steel between dockings

A car carrier between discharge and loading has empty decks for a few hours. Fixed and hoistable deck plating, stiffeners and ramps can be measured then, building the renewal picture without waiting for the dock.

Programmes spread over repeat calls

Vehicle carriers on liner-style rotations return to Bremerhaven again and again. A renewal gauging scope can be split across successive calls on the same grid, instead of being forced into one short berth.

In-dock gauging at Bredo

Bredo Dry Docks operates floating docks for container ships, ro-ro ships and offshore vessels. In dock, readings follow the thickness measurement plan and the surveyor's close-up list, with renewal plates marked as work proceeds.

Where does special survey gauging happen at Bremerhaven?

Bremerhaven offers three working environments, and a renewal programme usually uses more than one. Behind the Kaiserschleuse and Nordschleuse locks, the car terminal and the ro-ro and breakbulk berths give the team clear decks on vehicle carriers and staged-loading windows on ro-ro ships. On the open Weser, container ships at the river quay offer a short liner call, enough for deck, coaming and machinery-space readings. In the Fischereihafen, floating docks take ships for the full survey programme.

Lay-by berths in the overseas port are quietly useful. Offshore wind and research vessels often lie idle between campaigns, and their crews can open tanks and voids without cargo pressure, which makes them among the easiest ships to gauge thoroughly. The cruise terminal is the opposite: turnaround days are packed, so renewal-type gauging there is limited to narrow, well-defined scopes such as a specific tank or piping run.

Car terminal inside the locks: fixed and hoistable decks, ramps and door structure.
River container quay: deck, coamings and machinery spaces within the liner call.
Bredo Dry Docks: in-dock renewal gauging and close-up survey support.
Overseas port lay-by berths: tank and void programmes on idle offshore vessels.

How is renewal gauging scoped on a car carrier?

A vehicle carrier is a tall box of decks, not a ship with large tanks. Its structure is the shell, the fixed car decks and their stiffeners, hoistable decks with their suspension and brackets, ramps, and the side and stern doors. Renewal gauging concentrates on the deck plating and stiffener webs, the ramp plating and hinges, the shell plating at the waterline and in the ballast tank boundaries, and the engine room. Because the decks are heavily loaded by wheeled cargo, wear and corrosion appear where moisture collects at drains, deck edges and ramp joints.

Access is the limiting factor. Gauging on a loaded deck is impossible, so the team boards once discharge has cleared a level and works upward as decks empty, finishing before loading starts. The plan names the decks in priority order, so if the loading window shortens, the structurally most important levels have been measured first. Ballast tanks, when included, need the usual emptying and gas-free preparation, which the chief officer has to fit around ballast operations during cargo work.

What differs for ro-ro, heavy-cargo and container ships?

Bremerhaven handles high-and-heavy cargo such as construction machinery, agricultural equipment and rolling stock, so ro-ro and vehicle carriers here often carry concentrated loads on decks and ramps. For renewal gauging that means extra readings on tank-top and main-deck plating in the heavy-cargo areas and on stern-ramp structure, because a thin panel under a point load behaves very differently from the same panel under an even load.

Container ships at the river quay are the other main group. Their renewal scope follows the society's hull survey requirements, with the extent growing at each renewal survey: deck plating and coamings, side shell in the wind-and-water zone, ballast tanks and the double bottom. On scrubber-fitted ships, the wash-water and overboard pipe wall thickness is often added to the programme because the repair decision falls at the same docking.

How does renewal timing work for ships that visit Bremerhaven regularly?

A renewal survey may be started at the fourth annual survey and carried through the following year, and class credits work done early only if the whole survey is completed within the permitted window. For a vehicle carrier on a regular rotation, that gives a natural plan: take deck readings across several Bremerhaven calls in the year before the docking, then use the dock to finish the bottom, the tanks and anything flagged on the way.

This approach also gives the superintendent an early view of what will be asked. If decks show wastage in the first calls, the steel quantity is known months before the yard quotes. If they show little, the dock programme can be kept short. The same grid is used each time, so readings from different calls are directly comparable and a corrosion rate can be seen instead of a single snapshot.

What does planning a Bremerhaven renewal job involve?

Send the ship type, the survey due date, the previous thickness report and the rotation, and tell us whether the ship uses the car terminal, the river quay or a dock. The agent confirms which lock or quay the ship will use and registers the technicians for the ISPS-controlled terminals and yards. Germany is in the Schengen area, so the team from India travels on Schengen visas, which we apply for as soon as the call or docking date is firm.

Bremen Airport has European connections and Hamburg Airport offers wider international routes, and both are linked to Bremerhaven by road and rail. We build the team to match the scope: a short deck programme needs fewer technicians than a full in-dock renewal, and the number is set from the plan, not from habit. After each call we send the readings to the superintendent so that the next call can be adjusted.

Where special survey thickness measurement sits in the survey cycle

Class rules set the survey cycle, and the cycle sets how much gauging a ship needs. A superintendent planning a call at Bremerhaven usually knows which survey is due; the table shows what the thickness measurement for each one typically involves. The exact extent comes from the class rules for the ship type and the surveyor attending, so the thickness measurement programme is agreed with the class before work starts.

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 Bremerhaven

Most of the work on a Bremerhaven job happens before the team boards: scope, plan and access are settled first, so the time on board goes on measurement.

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

The inspection team is mobilised from India for each job; nobody is stationed at the port, so mobilisation is planned against the vessel's schedule and visa lead times. Our founder and Responsible NDT Level III, who holds ASNT NDT Level III in UT, RT, MT, PT and VT and has over eleven years of international field experience, plans and supervises the work. Technicians are certified under the company's written practice to ASNT SNT-TC-1A, and the company holds ISO 9001 and ISO 14001 certification.

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 (hull classification surveys)
IACS UR Z17 (procedural requirements for service suppliers)
SOLAS chapter II-1 (structure of ships)
ASTM E797 (manual pulse-echo ultrasonic thickness measurement)
ISO 16809 (ultrasonic thickness measurement)
ASNT SNT-TC-1A (personnel qualification under the written practice)

What you receive

Thickness readings by deck, frame and member on the class format or your own
Diminution against original thickness and the allowance for each member
Ramp, door and hoistable-deck bracket readings reported separately
Plates marked for renewal for the yard specification
Repeat-call comparison on an identical grid

Industries served

Vehicle carriers (PCTC and car and truck carriers)
Container ships at the river quay
Ro-ro and high-and-heavy ships
General cargo and project cargo ships
Offshore wind installation vessels
Research vessels and fishing vessels
Cruise ships with narrowly scoped tank work

Frequently asked questions

Can a car carrier be gauged for renewal survey between cargoes at Bremerhaven?

Yes, for the parts of the ship that empty decks expose. The team works level by level as discharge clears each deck and finishes before loading starts. Ballast tanks, shell and the engine room can be added where the chief officer can release them, and anything unfinished is carried to the next call or the dock.

Is there a dry dock in Bremerhaven for renewal survey gauging?

Bredo Dry Docks in the Fischereihafen operates floating docks that take container ships, ro-ro ships and offshore vessels. In dock, we gauge to the thickness measurement plan and support the surveyor's close-up survey, marking renewal plates for the yard. Dock availability is agreed between the owner and the yard.

How can gauging be spread over several Bremerhaven calls?

Vehicle carriers and container ships on liner rotations return to Bremerhaven on a known schedule. We take a defined part of the scope on each call using the same grid and reference points, so the readings combine into one dataset. The superintendent sees the findings early and the final dock stay is shorter.

What do you measure on ro-ro ships carrying heavy cargo?

Main-deck and tank-top plating in the heavy-cargo positions, stern-ramp structure and the deck stiffeners beneath concentrated loads, along with shell and tank boundaries. Heavy machinery and rolling stock load panels at points, so these areas get closer readings than an evenly loaded general cargo deck would need.

Do hoistable car decks need crack detection as well as thickness readings?

Often, yes. Hoistable decks hang from brackets and pins that see repeated loading, so we examine brackets and ramp hinges visually and by magnetic particle testing where cleaned, while thickness gauging covers the plating. Those crack records are owner's NDT records and support the class engineer, but they carry no class credit.

How do technicians from India reach Bremerhaven for a renewal job?

They fly to Bremen or Hamburg and continue by road or rail. Germany is in the Schengen area, so they travel on Schengen visas, which we start once the call or docking window is firm. The agent registers them for the terminal or yard gate and confirms which lock or quay the ship will use.

Can special survey thickness measurement at Bremerhaven 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.