The MOSE project consists of a system of mobile metal gates designed to safeguard Venice and its lagoon from the high water phenomenon.
In 2012, Tecnocontrol proposed to the company CIMOLAI spa (Company in charge to create the first lot of 23 gates, destined to LIDO-TREPORTI) to replace the planned radiographic controls for the main weldings of the perimeter panels of the gates with advanced ultrasonic tests with Combined technique TOFD + Phased Array.
To this end, Tecnocontrol has undertaken a thorough study on this subject, providing for the design and realization of a series of calibration and validation blocks and prepared a Test Procedure to be submitted to the Works Direction Department for Approval.
After a series of practical tests to demonstrate the actual capacity of detection of discontinuities, in particular in relation to the Acceptable Criteria of radiographic test, the Works Direction jointly with the Italian Institute of Welding has approved the proposed Procedure.
Tecnocontrol subsequently carried out the TOFD-PA controls on the first dozen gates, while tests on the remaining gates were completed by the manufacturer using the procedure developed by Tecnocontrol.
At the beginning of 2015, Tecnocontrol was commissioned by Brodosplit, a shipyard of Split-Croatia mandated to realize the other lots of gates , to perform the same type of control (TOFD + PA) on their gates, in particular at the initial stage of the works, as long as the Brodosplit operators did not obtain authorization to operate in the project by Works Direction.
Given the publication of new European Standards for TOFD and Phased Array, Tecnocontrol has prepared a new Test Procedure by setting up new calibration and validation blocks in accordance with the new Standards.
Also in this case, after a series of practical demonstration, Works Direction, jointly with the Italian Institute of Welding has approved the new Procedure.
During the continuation of controls, Brodosplit, contrary to the provision at the beginning of the work, commissioned Tecnocontrol the TOFD-PA controls on all gates made by Brodosplit in Split until completion work.
Currently (August 2017) the works are in the final phase and are expected to complete the checks at the Brodosplit shipyard for September-October 2017.
The numbers now Tecnocontrol can put forward in reference to the TOFD-PA controls on gates of the MOSE project are briefly listed below:
- Proposed replacement of radiographic control with advanced ultrasonic control with combined TOFD + PA technique.
- Study on the feasibility and results of the system.
- Issue of Test Procedures approved by the Works Direction in conjunction with the Italian Institute of Welding.
- TOFD-PA control on the first 10 gates made by Cimolai spa in Italy.
Note: in addition to TOFD-PA controls, Tecnocontrol was also commissioned to perform radiographic checks on welds that could not be inspected with TOFD-PA, and this has made it possible to gain a lot of experience on the interpretation of the TOFD-images PA (especially dubious ones) by easily comparing them with the radiographic image corresponding to the same stretch.
- TOFD-PA controls on all gates of the remaining lots:
1. bocca di Malamocco (21 gates),
2. bocca di Chioggia (20 gates)
3. bocca Lido San Nicolò (22 gates)
- About 33 km of inspected welds; thickness between 8 and 13 mm ; welding process 136 (FCAW) and 121 (SAW);
- About 8.800 TOFD-PA test reports issued.
- About 600 RX test reports issued.
- About 21.900 data files of scans, for a total size of about 1.7 TB.
