Underwater inspection of port and offshore facilities
Operating conditions of use of the marine, river, port and other port and offshore facilities are basically of the same type, as originally the designs of the port and shore facilities correspond to the same technical rules.
However there are differences – it is a value of the operational load. Certainly the greater load the greater risk of the different underwater damages and hence accidents. That' s why today the survey of the port and offshore facilities became an integral part of the general operating process of any mentioned above facility.
Safety of the span port and offshore facilities (POF) involves a regular inspection, survey of POF, survey of ports and survey of piers. The purpose of such measures is estimation of the service safety for prevention of the different hydro-technical damages, preparing for scheduled or extraordinary repair or for re-construction.
The marine port and offshore facilities which need the underwater inspection more often are mooring quays, piers, protective jetties, groynes and breakwaters, sea defense walls.
The river port and offshore facilities, which need such procedure as the underwater inspection, are water storage concrete and non-overflow dams as well as dikes.
The underwater inspection, survey involve a range of measures including:
- General check of the port and shore facilities design;
- Detailed check of the structures, its elements for compliance with the requirements of the design documentation;
- Estimation of the technical state, detection of possible defects and damages;
- Check and estimation of state of the material of which the structures of the port and shore facilities have been made.
The underwater inspection of the port and offshore facilities, if necessary, testing of the facilities, monitoring of the structure state under influence of the dynamic and other loads.
The diving survey of the port and offshore facilities includes a thorough inspection of the underwater part of the facilities in complete with examination of the variable horizon zone of the water environment and strip of ground being before it. The specificity and content of the inspection program depends on the fact whether the underwater inspection will be scheduled, that is previously provided, or an extraordinary one. Before starting the inspection and survey, a company carrying out the diving survey compiles a package of the technical documentation including the drawings. The group of specialists-divers is provided with special equipment by means of which the underwater parts of the port and offshore facilities are surveyed:
- The measuring instrument such a tape measure, sounding lead, sounding rod (tube consisting of four links with centimeter division), ruler with slider fixed by a screw, torsos and slats, inclinometer (with fixing the pendulum), depth gauge.
- Tools and outfitting for stripping of the underwater surfaces – scrapers, metal brushes, files.
- Special equipment for record, storage and transmitting the information – photo and video-equipment, if necessary - CCTV.
Besides if the underwater inspection is carried out in rather muddy water or in shaded closed places and facilities, the divers are provided with lighting equipment.
The survey of the underwater parts of the port and offshore facilities also includes the underwater inspection on the surrounding water area and bottom at the pier, under the bridges and in other zones of the ship traffic. So littering, sunken objects, gullies, underminings are detected. The profiles and charts of the bottom are made-up according to the results of such inspection.
All information obtained in process of the underwater survey is made in a form of the acts, documents describing the state of the structural facilities, graphs. Photo and video-materials are attached to the reports. In some cases a Client is provided with a preliminary information on the basis of which the additional works are carried out – tests and more detailed inspection of the underwater parts of the port and offshore facilities.