# Cotre Carantec 62 — construction preparation and build plan

Planning revision: 28 October 2026. Status: preliminary; not a released build specification.

## Entry condition and scope

Construction starts only after [M2 — Reviewed construction package](https://projects.alkemata.com/work_packages/46). Design-stage preparation may cover quotations, workshop measurements, sample joints and supplier availability. Cutting production parts, ordering specification-dependent items and permanent assembly require the relevant released drawings and specifications.

The project wiki currently describes a 6.20 m decked plywood/epoxy cutter, 2.28 m beam, 1.15 m draft, 1,490 kg light displacement, 1,970 kg maximum displacement, 520 kg ballast and 25.5 m² sail area. These are concept inputs, not verified as-built values. This plan was prepared from the wiki and work packages; linked CAD files and calculation reports were not inspected through this connector.

## Release checklist before building

- Requirements, operating load cases, intended category and standards/administrative route agreed.
- Reviewed stability, cockpit drainage, openings and downflooding assessment.
- Coordinated hull, structure, appendage, rig, deck and system drawings with revision index.
- Approved plywood grades/thicknesses, timber sections, adhesive system, reinforcement schedules, joints and fasteners.
- Verified panel development, nesting, datum, units, tolerances and trial assembly.
- Mass budget reconciled with the material take-off, equipment and ballast.
- Reviewer findings closed; owner accepts cost, workshop and handling plan.
- Build inspection plan and commissioning acceptance criteria issued.

M2 is a technical release gate, not evidence of statutory certification.

## Preliminary bill of materials and take-off register

All quantities are TBD unless explicitly identified as concept values. Do not interpret an empty quantity as zero. Sheet thicknesses, glass weights, fastener sizes and attachment arrangements must come from reviewed design, not generic boatbuilding practice.

| ID | Material or assembly | Unit | Quantity / basis | Required release information |
|---|---|---|---|---|
| B01 | Hull plywood, separated by panel and thickness | sheets, m² | TBD from approved nesting | Grade, species, thickness, sheet size, grain direction, certificates |
| B02 | Deck, cockpit and cabin plywood | sheets, m² | TBD from drawings | Thickness, openings, local reinforcement, sealing details |
| B03 | Bulkheads, floors, webs and internal plywood | sheets, m² | TBD from parts list | Structural versus furniture parts, cutouts and edge details |
| B04 | Structural timber, cleats, stringers and laminations | m, m³ | TBD from section/length schedule | Species, grade, section, moisture limits and joints |
| B05 | Resin and matching hardener | kg | TBD from bonded/coated areas and trials | Selected system, mix method, working/cure conditions, shelf life |
| B06 | Structural fillers and fairing fillers | kg | TBD from joint volumes and fairing estimate | Approved filler by operation; do not interchange functions |
| B07 | Glass cloth and tapes | m², m | TBD from laminate and seam schedule | Fibre type, weight, orientation, widths, overlaps and layer count |
| B08 | Ballast and attachment assembly | assembly, kg | 520 kg concept target; final TBD | Material, geometry, actual mass/CG, bolts/foundation and corrosion protection |
| B09 | Keel, rudder, stock, bearings and steering hardware | sets | TBD from appendage drawings | Loads, materials, tolerances, attachments and service access |
| B10 | Mast, boom, gaff, bowsprit and fittings as selected | sets | TBD from rig drawings | Sections, material, foundations, tangs and rigging interfaces |
| B11 | Standing and running rigging, blocks and cleats | m, pieces | TBD from rigging schedule | Loads, sizes, terminals, routing, reefing and replacement access |
| B12 | Mainsail, staysail and jib | set | One concept sail set, 25.5 m² total; final TBD | Sailmaker-approved dimensions, cloth, reefs, attachments |
| B13 | Deck hardware, chainplates, backing plates and fasteners | pieces, sets | TBD from hardware schedule | Rated loads, material compatibility, bedding and backing details |
| B14 | Hatches, ports, seals, cockpit drains, pumps and hoses | pieces, m | TBD from opening/system plans | Locations, closures, water exclusion, hose routing and access |
| B15 | Auxiliary propulsion and energy/fuel installation, if selected | set | TBD; option decision outstanding | Mounts, ventilation, isolation, cabling/fuel and mass allowance |
| B16 | Electrical, navigation and lighting equipment, if selected | pieces, m | TBD from system schematics | Circuit protection, cable sizes, mounting and access |
| B17 | Coatings, primers, UV-protective finish and underwater finish | L | TBD from area, product coverage and coats | Compatible coating system and preparation/cure requirements |
| B18 | Accommodation, ventilation, anchoring, mooring and safety equipment | sets | TBD from agreed use | Equipment list, secure stowage, masses and access |
| B19 | Jig, strongback, temporary moulds, cradles and transport supports | set | TBD from build/handling method | Geometry, loads, support points and lifting/turning method |
| B20 | Consumables and PPE | lots | TBD by operation | Abrasives, mixing pots, brushes, rollers, release materials, gloves, extraction supplies |

For each line record drawing/revision, net quantity, separately justified waste allowance, order quantity, supplier, quotation date, unit price, tax, freight, lead time, required-on-site stage, mass and receipt inspection. No current supplier prices or availability have been obtained.

Take-off method:
1. Export the approved parts list and nested panels, grouping plywood by specification. Count whole sheets from nesting rather than dividing area alone.
2. Derive timber lengths including joints and machining allowances; distinguish permanent structure from temporary tooling.
3. Derive glass by layer/overlap and adhesive by operation using the selected manufacturer's guidance and sample consumption. Keep coating resin, laminating resin and filleting demand distinct.
4. Add hardware, systems, rig and sails from coordinated schedules. Reconcile the resulting mass and CG with WP3.2.
5. Obtain quotations and identify long-lead items. Approve substitutions through design change control.
6. Produce a phased purchasing list. Recheck prices, shelf life, storage and specifications before purchase.

## Procedure and inspection hold points

This is a proposed sequence. The selected build orientation, access, ballast attachment and coating system may change the order. Final work instructions must specify dimensions, tolerances, fastening, layups and curing.

| Stage | Proposed work | Release / inspection before continuing |
|---|---|---|
| C0 | Review released documents; freeze BOM, budget, people and build method | M2 complete; correct revisions at workstation |
| C1 | Prepare workshop, jig/strongback, datums and templates; practise representative joints | Workshop/handling readiness; datum and template scale checked |
| C2 | Receive, identify and store materials; nest, mark and cut first approved parts | Material specification and condition checked; first-off part verified |
| C3 | Prepare joints and dry-assemble hull panels/framing in the approved orientation | Symmetry, fairness, reference dimensions, fit and future access signed off |
| C4 | Bond, fillet and reinforce hull and primary structure per drawings | Joint/laminate records; inspect inaccessible areas before closure |
| C5 | Complete external reinforcement/coating as appropriate, then turn hull when approved | Cure and surface inspection; support and turning plan accepted |
| C6 | Install internal structure, appendage foundations, cockpit and system provisions | Foundations, drainage, backing and service access checked before deck closure |
| C7 | Fit deck/cabin and close structure; fair, seal and finish | Closure inspection; protected edges/penetrations; coating compatibility/cure records |
| C8 | Install ballast/appendages and fit out systems and hardware at the designed stage | Attachment inspection; actual masses; controlled tightening and access records |
| C9 | Install rig and sails; set up steering, reefing and controls | Rig load-path/attachment review and dockside functional checks |
| C10 | Weigh and measure completed boat; verify trim, systems and readiness | Resolve deviation from approved mass/load/stability assumptions |
| C11 | Transport, launch, dockside checks and progressive trials | Launch approval; leak checks and trial plan; close findings before expanded use |

No lifting points, attachment torques, laminate schedules or adhesive recipes are inferred here. The designer, selected product documentation and competent handling contractor must supply them.

## Tools and facilities

| Function | Required capability | Own / hire / outsource decision |
|---|---|---|
| Lofting and measurement | Released CAD/print access, calibrated tape/rules, straightedges, squares, levels or laser, battens, templates and labelled datums | Verify print/DXF scale with reference dimensions |
| Cutting and shaping | Suitable saws, supported cutting bench, router/jigs, planes, drills and bits; CNC cutting if selected | Match equipment and extraction to approved materials |
| Assembly | Rigid strongback/jig, trestles, clamps, temporary fixings, cradles and access platforms | Size and count after build method is chosen |
| Bonding and laminating | Manufacturer-approved metering/mixing equipment, pots, spreaders, filleting tools, brushes/rollers and clean work surfaces | Follow selected system instructions; no generic ratios |
| Finishing | Sanders, longboards, effective dust extraction and compatible coating application equipment | Separate dusty operations from bonding/coating |
| Environment and protection | Temperature/humidity monitoring, suitable ventilation, lighting, clean dry storage, product-specific PPE and waste handling | Use selected product data sheets and workshop assessment |
| Fitting and testing | Appropriate torque tools, basic electrical test equipment if needed, inspection lighting and weighing capability | Calibrate or hire where required |
| Handling and transport | Rated lifting/turning equipment, approved slings/supports, adequate transport and launch service | Use a competent provider with a boat-specific handling plan |

Vacuum bagging, welding, casting and spray finishing are not assumed necessities. Decide whether any are required and outsource specialist work where appropriate.

## Logistics and responsibilities to settle

- **Location and envelope:** confirm workshop address, usable dimensions, circulation and service access around a 6.20 m by 2.28 m hull plus jig, overhangs and working clearance. Check door/exit dimensions, turning space and height for the assembled hull; arrange spars/rigging separately.
- **Loads and handling:** check floor/support loads and the mass at each lift. The 520 kg ballast concept and near-two-tonne maximum displacement are not lifting specifications. Determine actual handled mass, centre of gravity, support points and access for turning, ballast installation and transport.
- **Materials:** rack plywood flat/dry, identify timber and glass, control resin storage/shelf life, segregate contaminants and protect finished parts. Inspect deliveries and quarantine unsuitable material.
- **People:** nominate build lead, naval architect/reviewer, procurement coordinator and inspection sign-off responsibility. Obtain specialist support for ballast/metalwork, rig/sails, lifts and electrical/propulsion work as selected.
- **Procurement:** stage deliveries against need dates; record lead times for ballast, spars, sails, custom metalwork and hatches. Reserve long-lead services only after interfaces are stable.
- **Environment:** plan temperature control, ventilation/extraction, neighbour constraints, access to power, lighting and responsible product-specific waste disposal.
- **Transport and launch:** confirm road/trailer or haulage suitability, actual transport dimensions/mass, securing/cradle design, launch-site capacity, storage/mooring and any applicable local requirements.
- **Budget:** separate permanent materials, outsourced fabrication, tools/hire, workshop, review/inspection, transport/launch, fees and contingency. Amounts remain TBD pending take-off and quotations.

## Schedule and dependencies

Keep the original 16-week design sequence as an indicative relative plan, not a calendar commitment. Construction durations and dates remain unestimated until labour availability, workshop, budget, build method and supplier lead times are known.

Before M2: prepare quotations, workshop survey, representative non-production samples and logistics options.
After M2: C0/C1 → C2 → C3/C4 → C5/C6 → C7/C8 → C9 → C10 → C11. Some operations may overlap only after the build method and access sequence are reviewed.

Dependencies are recorded in task descriptions. The current connector cannot set formal predecessor links, task hierarchy, assignees or dates; these must be entered in OpenProject when agreed.

## Quality records and commissioning

Maintain a revision/drawing index, part labels, material/batch register, bond/laminate and environmental log, inspection photos before closure, actual component mass register, change log and defects list. Reassess mass, trim and stability implications of substitutions or added equipment before accepting them.

Commissioning must cover relevant watertight closures, leaks, cockpit drainage, steering travel, rig attachments, reefing/control operation, anchoring and selected electrical/propulsion systems. Confirm the completed boat matches the approved load model; determine with the reviewer what as-built stability verification is required. Plan progressive dockside and sailing trials with defined conditions, personnel, abort criteria and recorded findings. A successful first launch alone does not close the project.

## Reference guidance

- [Main design wiki](https://projects.alkemata.com/projects/cotre-carantec/wiki/cotre-carantec-62-design-and-project-roadmap)
- [WEST SYSTEM User Manual & Product Guide](https://www.westsystem.com/instruction/user-manual-product-guide/) — reference for epoxy handling and techniques; select the actual system before drafting operation-specific instructions. Listing this source does not select a supplier.
- [WEST SYSTEM surface preparation](https://eu.westsystem.com/instruction/epoxy-basics/surface-preparation/) — manufacturer guidance for bonding preparation.
- [ISO 12215-5:2019](https://www.iso.org/standard/69552.html) — structural design scope; companion parts address rudders, appendages and rig loads.
- [ISO 12217-2:2022](https://www.iso.org/standard/79073.html) — stability assessment scope. Confirm applicable editions and hull-length measurement at design release.