Mehmet AVCI

TÜRK LOYDU is a Classification Society and a Conformity Assessment Body performing classification and statutory services, inspection, certification and notified body activities.

It has constituted and has been managing its organization to protect independence and impartiality values and maintain the continuity of improvement.

"A Type" Inspection Body activities are performed in accordance with the “ISO/IEC 17020 General Criteria for the Operation of Various Types of Bodies Performing Inspection” standard and accredited by TÜRKAK.

Notified Body activities which are composed of conformity assessment activities are performed in accordance with the relevant directives of EU legislations and the Guide to the Implementation of Directives Based on New Approach and Global Approach.

To reduce the risk and ensure that the project progresses at minimum quality requirements in accordance with the standards and technical specifications, it is of high importance that third-party surveillance companies take part in the projects.

Not only for the safety of construction but also in products with 3rd party inspection, insurance costs are reduced which is the other advantage of 3rd party inspection.

Because bridges are exposed to a wide variety of loads such as wind load and earthquake load and operate under dynamic loads, they are structures of high importance in terms of safety.

Accordingly, after the construction standard of the bridge is selected, the execution class is determined according to EN 1090-2.

Bridge structures are usually built according to the highest execution classes; EXC3 and EXC4. The choice of these execution classes affects the tolerances and extra tests to be applied during the fabrication of the bridge, the documentation requirements, and the traceability requirements.

Türk Loydu provided its services in the 1915 Çanakkale Bridge Project within the scope of main cable fabrication inspection, hanger cable fabrication inspection, pile pipes fabrication inspection, bridge shaft fabrication inspection, and gantry rail winch fabrication inspections.

Main and hanger cables inspections were carried out in accordance with EN 1090-2: 2018, the main standard of the project, and in accordance with the inspection and test plan, which was created according to technical specifications and standards of the project.

In the overseas leg of the project, the main cable fabrication inspections were carried out in Zhejiang, China, the hanger cable fabrication inspections were carried out in Changzhou, China, the Gantry rail crane fabrication inspections were carried out in Shanghai, China, and the fabrication controls of the wrapping and compaction machines were carried out by Türk Loydu personnel in Wuxi, China.

The stages of cable manufacturing were inspected by socket manufacturing controls (casting, heat treatment, machining, dimensional checks), wire stranding and socketing inspections, measurement dimension inspections, witnessed mechanical laboratory tests, witnessed chemical analysis tests, witnessed cable wrapping inspections, visual and non-destructive inspections, and the conformity of the fabrication of cables to the standards was checked and reported to the owner.

At the beginning of fabrication inspection test plan (ITP) was created by the manufacturer, and was agreed by all sides of the project; manufacturer, owner, 3rd party inspection body.

ITP shows the responsibility of each party, and shows which step will be controlled by which party. At ITP perform point, witness point, review point and hold point responsibilities are determined for each party.

At the 1915 Çanakkale Bridge Project, the same process was followed for each fabrication part.

The meanings of responsibilities at ITP are given below;
  • Perform Point: Shows the activity which will be performed. This point is under the manufacturer's responsibility.
  • Hold Point: Parties shall be notified by the manufacturer and the work shall not proceed without the owner and 3rd Party release by letter, e-mail or put on the inspection form.
  • Witness Point: The parties must be notified to witness the inspection and testing of the manufacturing activities. If the owner and 3rd Party are not available at the required inspection time, work can proceed. In that case, the preferred practice is owner and 3rd Party to review of inspection & test results for acceptance.
  • Review Point: Review of quality documents, reports, certificates, inspection & test results for acceptance.
If any non-conformity was detected at inspections, a non-conformance report (NCR) was issued and published by 3rd party to both the owner and the manufacturer. After issuing an NCR, the manufacturer reported to the NCR for a corrective action which was done to close the related NCR issue and the manufacturer should report on what preventive action was taken to avoid the non-conformance again. After confirmation by all parties, the manufacturer took the action to close the NCR.

Review of documentation and certification

Fabrication and quality procedures were submitted by the manufacturer's quality department for review. 3rd party and the owner´s QA/QC department reviewed the documents to check procedures were compliant with standards and project technical specifications and gave comments if necessary.

Certificates such as quality system certificates of the factory, raw material certificates, calibration certificates of measurement and testing devices, welder certificates, welding operator certificates, and non-destructive testing operator´s certificates were reviewed by 3rd party and the owner´s QA/QC department.


Welding inspection
Welding procedure qualification record (WPQR) and welding procedure specifications (WPS) were prepared or performed by the manufacturer before welding processes. The 3rd party body checked whether the weld was made according to the approved WPS, and the qualification of the welder was checked.

Visual inspection and non-destructive inspections after welding were witnessed and monitored. Welding inspection was done with special gauges specially developed for welds, it is called bridge-cam gauge.

Before non-destructive tests (NDT) such as Ultrasonic test, Magnetic Particle test, radiographic test and penetrant test, visual inspection was done by a qualified person.

After the visual test, other NDT methods could also be applied by a certified person according to related standards. 3rd party body witnessed and monitored the tests. All NDT devices should be calibrated according to related international standards.

Heat treatment inspection
If heat treatment was applied, the heat treatment process was checked by 3rd party according to the approved heat treatment procedure. The placement of the parts at the furnace and the heat treatment graphics were examined and their compliance with the procedures was checked.

Dimensional inspection
After all welding and assembling were completed, the parts were dimensionally inspected by the manufacturer´s QC personnel to approve project shop drawings and witnessed by 3rd party.


Dimensional tolerances were given at drawings, standards and project technical specifications. All dimensional inspection tools should be calibrated according to related international standards.

Painting inspection
Painting processes were inspected according to project technical specifications, standards and painting procedures. Environment conditions were checked before and during the painting process; after painting visual and dry film thickness (DFT) inspections were done with DFT ultrasonic test device.

Bridge cable inspection
For Cast Socket forks, each fabrication step such as pouring, molding, sampling and mechanical tests, chemical composition tests and dimensional inspection tests, NDT tests, welding repairs (if needed) and heat treatment checks were done by the manufacturer´s QC personnel and the 3rd party inspector.

Polyethylene, heat shrinkage tube and socketing material certificates were checked. After stranding of galvanized wires, dimensional inspections of wires before socketing, socketing processes, sealing and length checks were done.

During the manufacturing of cables, fabrication tests such as a tensile test of cable strands, socketing procedure test, and fatigue test of cables were performed by the manufacturer and checked by 3rd party according to project technical specifications.

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