Underwater Inspection Wharf – Tête à la Baleine and Vieux Fort - Basse Côte Nord

Site 1 – Tête à la Baleine
The Fisheries and Oceans wharf at Tête à la Baleine was built in 1992. It is a wooden cribwork with a 30m frontage and 8.1 m wide, which is set back from the Transport Canada wharf. It is used for mooring fishing boats and unloading catches. The wharf has not been inspected for several years and an update of its condition is required.

Site 2 Vieux Fort

The Vieux Fort wharf is also a wooden cribwork built in 1980. The wharf is 65m long and has 2 docking wharf faces. It is a construction with interrupted cribs and bridges (block and span). There are 3 such bridges at the beginning of the wharf, the first near the shore is open, i.e. the underside of the bridge is accessible from its sides. The other 2 walkways are covered with wooden fenders from the top of the quay down to zero. It will be necessary to access the back of the wooden fenders to inspect the bridges and the interior faces of the cribs.

2 - Purpose

Goal of this inspection is to determine the condition of the cribworks material and hardware. A detailed report is expected that will allow DFO to decide on the safety of the structure and determine its useful life.

This inspection requires experienced divers. Among other things, divers must have a good knowledge of wooden cribworks structures. Similarly, the team leader on the worksite must be familiar with the structures in place so the continuous presence of the Departmental Representative is not required during this inspection.

3 – Scope of works

3.1 Preparatory work before mobilization to the site

Familiarize with plans and terms of reference.

Preparation and transmission of the work schedule to the Departmental Representative.

Transmission of the required documents related to health / safety.

Kick-off meeting

Coordinate access with Departmental Representative.

3.2 Works onsite

3.2.1 – Visual inspection of underwater area

Inspection must be carried out on 100% of the surface of the immersed and emerged wharf faces. The diving firm must proceed with cleaning of the crib surface and the bolted connections of timbers at 4 chaining for Tête à la Baleine and 6 chainings for Vieux Fort, and this, over a width of 1000 mm to cover the bolted connections.

Procede with cleaning using pressure washing to allow proper inspection conditions. In the event that a layer of corrosion is present on the connections, mechanical cleaning is mandatory to determine the residual steel present.

It is requested to carry out the visual inspection of the facades, particularly regarding following elements:

• Determine the presence of rot in the wood by probing with a sharp object over the entire height of the wharf face. At each pressure washed chaining, collect 3 wood samples with a Pressler probe at 3 different elevations = +1m; 0m and -1m. Adjust sample elevations based on timber conditions as needed.

• Evaluate the loss in mm of nuts or bolts diameter depending on what applies. Refer to connections in good condition out of the water to determine the original diameter.
• Perform percussion of the connections with a hammer and nut torque tests with a socket wrench to check the integrity of the hardware for 4 connexions per chaining from +0.5m to -1.5m;
• At each of the sites, a connection must be exposed between the post and the crosspiece (in red), at least 50mm wide to measure the diameter of the bolt (in blue) Provide pneumatic tools to drill and cut the wood at elevation + 0.5m.
• Note the presence of undermining at the base of the cribs.
• Note the presence of accumulation of fill materials at the base of the facade;
• Note the presence of deformation or signs of impact;
• Inspection of the ladders (presence and condition of the rungs);
• Any other relevant observation.

Depending on the visibility conditions, take pictures of defects in submerged area in addition to continuous video. The inspection report must include photos that allow the general condition of the cribwork to be assessed on all elevations and surface.

3.2.2. Visual inspection of underwater area

Perform a visual inspection and a photo montage of emerged portion of wharf. Note damage to cribworks bolts and ladders, if any.

3.3.3 – Biological characterization

A allocation is included for a visual inspection of the seabed at Blanc Sablon. Hours has been scheduled in bid form to carry out video transects. Additional indications from our biologist will be provided for this portion of the mandate.

4 - Reference system

For this wharf, the reference system is based on the chainings on perimeter of cribworks to be implemented by the firm. Use this reference system in the report for the description of the structures.

5-Documentation

Plans in Annex B.

6 – Inspection and additional work

If an additional defect or a safety issue is noted during the inspection, it is expected that the firm will make a precise statement of this problem, if necessary. In the event that this additional survey must be carried out, notify the Departmental Representative before carrying out additional work.

7- Methodology

Identify damage and deffects, taking care to document observations extensively through photos, sketches, videos, measurements, etc. Comments must supplement survey to clarify the causes, particularities or to ensure that the observations are properly understood by the technical staff of DFO.

Clearly link all this information to the reference system requested.

The firm must be able to take underwater videos and photos. The files must be given to the Departmental Representative with the report and the DVD correctly identified with the place, the structure inspected, the date.

8 - Work follow up

Team in charge of inspection must put in place the appropriate means of communication to notify the Ministerial Representative as soon as possible, if he is not already on site, of the particular problems identified during inspection in a that appropriate decisions are made in time. Even if no particular problem arises during the inspection, the Departmental Representative must be contacted daily by the team leader on site.

9 - Additional work

DFO reserves the right to require additional work or inspections to be carried out in order to specify characteristics of the structure to be inspected. This additional work will be carried out within the limits of structure to be inspected.

10 - Presentation Plans

All plans appearing in the inspection report must be produced in CAD (computer-aided drawing) and sent to the Departmental Representative at the same time as report in the form of files fully compatible with Autocad software, version 2012.

11 - Technical report

A copy of a preliminary technical report must be provided in French no later than two weeks after the end of the inspection work. This technical report will include, among other things:

• A location map;
• Description of reference system used during the inspection;
• A detailed description of the inspection work specifying the staff and equipment used, the dates and conditions of the inspection, the different methodologies used during the inspection;

• All the results of the observations made during the inspection grouped by inspected structures, accompanied by explanatory notes allowing deffects to be understood;
  • All the measures taken during the inspection (readings, verticalities, etc.);
  • Descriptive CAD plans of the structures inspected with an indication of the reference points and systems used during the inspection;
  • Detailed plans (plan views, elevations, sections, diagrams, etc.) of the components inspected explaining the phenomena observed (breakage, damage, deformations, deterioration, etc.), indicating the nature and location of the various repair works inspection (taking measurements, photos, etc.) and also illustrating the comments in the narrative part of the report;
  • A high-quality photographic montage of all the aboveground parts of the maritime installation taken from a boat and detailed photos of the submerged structures illustrating their current state and the particularities noted;
  • Where applicable, the recommendations and all the information necessary to define corrective work to be done urgently or within a period of less than one year to ensure that the current level of service is maintained;
  • Any other relevant information necessary to understand the specifics of the structures inspected.

This report will be commented on by the Departmental Representative and corrections or additional explanations must be made for the production of the final report.

Four (4) copies of final report in paper support and two electronic copies on DVD must be submitted one week after the Departmental Representative's comments have been sent.

12 – Schedule

Overall, underwater inspections should be carried out according to the following schedule:

Underwater survey

Not later than August 26^th 2022

Preliminary technical report

September 9^th 2022

Final report

September 23^rd2022