Bahrain solar catamaran autonomous design

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Looking for a couple of ROS enthusiasts to remote work on an autonomous kite cruise catamaran project.

Below is a tailored design plan for your houseboat, incorporating the specific components you listed while aligning with the previously defined purpose (weekend getaways for 7-14 people in the Gulf of Bahrain for kitesurfing, diving, and snorkeling). The plan integrates the propulsion, solar, electrical, and structural components you provided, ensuring functionality, safety, and compliance for the Gulf’s weather conditions (20 knots)

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# Houseboat Design Plan with Specified Components

## Purpose Recap

- **Use**: Weekend getaways for 7 families (7-14 people) in the Gulf of Bahrain, focused on kitesurfing, diving, and snorkeling.

- **Lifestyle**: 7 individual cabins with bunk beds for 2 people, each with a private composting toilet; easy water access for watersports; large rooftop deck with solar panels and hammock-style beds.

- **Mobility**: Electric propulsion with dual Oceanvolt SD15 Saildrives (15 kW).

- **Power**: Solar-charged battery system with CIGS and mono 710w panels.

## Hull and Structural Design

- **Hull Type**: Catamaran for stability and space, ideal for the Gulf’s calm to moderate waters (shallow areas, occasional chop).

- **Dimensions**: ~60 ft (18 m) long, ~25 ft (7.6 m) wide to accommodate cabins, deck, and equipment.

- **Materials**:

  • **Hull**: Marine-grade aluminum for lightweight strength and corrosion resistance.

  • **Roof Structure**: 2 1/8” tubular aluminum frame, welded in place, supporting fiberglass roof panels (3 layers cloth, ¾” foam core, 3 layers cloth) for durability and insulation.

  • **Deck**: Non-slip composite decking for safety during watersports.

- **Lightning Protection**: Bristle-type lightning arrestors on the roof, wired to Dynaplates at the waterline for grounding, protecting electronics and occupants in Bahrain’s occasional thunderstorms.

## Layout and Accommodations

- **Lower Deck (Interior)**:

  • **7 Cabins**: Each ~8 ft x 6 ft (2.4 m x 1.8 m) with marine-grade bunk beds for 2 people, under-bed storage, private composting toilet, compact sink, and porthole for ventilation/light.

  • **Common Area**: ~15 ft x 10 ft (4.5 m x 3 m) open-plan galley/lounge with a compact kitchen (stove, fridge, sink) and foldable dining table/sofa.

  • **Storage**: Lockers near stern for kitesurfing gear (kites, boards), diving tanks (10-12), and snorkeling equipment.

- **Main Deck**:

  • Wide side decks with railings for safe movement.

  • Stern platform with foldable ladder for easy water access (kitesurfing, diving, snorkeling).

  • **Superwinch 12V Lift**: Mounted at the stern for dinghy retrieval/storage, powered by 12V house batteries.

  • Hammock-style beds (4-6) along deck edges, using weather-resistant netting, collapsible for storage.

- **Rooftop Deck**:

  • ~40 ft x 20 ft (12 m x 6 m) with 20 SunPower E22 solar panels (360W each, 7200W total).

  • Remaining space for leisure (foldable chairs, small table, shade canopy).

  • **Instrument Mast**: Mounted centrally, supporting antennas (VHF, GPS), radar, and navigation lights.

- **Watersport Access**:

  • Stern platform with non-slip surface and gear racks for kites.

  • Rinse station with freshwater hose for post-dive/snorkel cleanup.

  • Low-profile side entry points for easy water re-entry.

## Propulsion System

- **Propulsion**: Dual Oceanvolt SD15 Saildrives (15 kW peak for 30 minutes, 12 kW continuous) per hull, with three-blade propellers for efficient thrust in the Gulf’s shallow waters.

- **Control**:

- **Performance**:

  • Top speed: ~8-10 knots.

  • Cruising speed: ~5 knots for ~50-60 nautical miles range, sufficient for weekend trips.

  • Hydrogeneration recharges batteries while sailing, reducing reliance on solar or generator.

## Power and Electrical System

- **Solar Array**:

  • 20 SunPower E22 panels (360W each, 7200W total) on the rooftop.

  • Wiring: 2 panels in series (5 pairs per hull, 10 pairs total), then parallel to Victron MPPT solar controllers (150V, 30A) for efficient charging.

  • Circuit breaker before MPPTs for safety and maintenance shutoff.

- **Battery System**:

  • **48 VDC Banks**: One per hull, 16 kWh each (32 kWh total), lithium-ion, marine-grade, in ventilated, waterproof compartments.

  • **Daly SmartBMS**: Manages battery health, with disconnect capability for safety.

  • **Victron SmartShunt**: Monitors battery status and communicates with Victron CCGX displays.

  • **Cooling**: Fans in battery compartments to prevent overheating in Bahrain’s hot climate.

- **Inverters**:

  • **Victron Quattro Inverters**: Convert 48 VDC to 120 VAC for appliances, with selector switch (on-off-on) for control.

  • **Inverter Remote Displays/Controllers**: Monitor and manage inverter output.

- **Generator**:

  • **DC Polar 17 kW 48 VDC Generator**: Backup power for extended cloudy periods or high loads, with diesel motor controller and diode bridge for AC-to-DC conversion.

  • **Capacitor Bank**: Absorbs voltage spikes to protect electronics.

  • **Generator Remote Displays**: Monitor status from the helm.

- **House Batteries**:

  • 12 VDC system using 4x 6V golf cart batteries (series/parallel for 12V).

  • **ProMariner Battery Charger**: Converts 120 VAC (from shore power or generator) to 12 VDC for house battery charging.

- **Wiring and Connectivity**:

  • **100mm² Wiring**: Rated for 300A at 48 VDC, connecting motors, batteries, solar, and inverters.

  • **System Busbar**: One per hull, centralizing connections for motors, generator, batteries, solar, and inverters.

  • **Canbus Wiring**: Integrates all systems (motors, batteries, solar, inverters) for centralized monitoring via Victron CCGX displays.

  • **System Main Switch with Key**: Secures the entire electrical system for safety.

## Utilities

- **Water**:

  • Freshwater tank: 500 liters with reverse osmosis purifier.

  • Greywater/blackwater tanks: 300 liters each, with pump-out for marina disposal.

  • Stern shower for rinsing gear post-watersports.

- **Climate Control**:

  • Insulation in roof (fiberglass panels with foam core) and walls for temperature regulation.

  • Ventilation via marine-grade vents and fans in cabins and battery compartments.

- **Safety**:

  • Life jackets (14+), fire extinguishers, bilge pumps, flare kit.

  • Navigation: GPS, depth finder, VHF radio on the instrument mast.

  • Anchoring: Electric windlass with 50m chain for secure mooring.

## Compliance and Mooring

- **Regulations**: Designed to meet Bahrain’s maritime standards (Ministry of Transportation and Telecommunications) for recreational vessels, including waste management and safety equipment.

- **Mooring**: Cleats and fenders for docking at marinas (e.g., Amwaj Islands). Anchor system for open-water stays.

- **Insurance**: Verify coverage for liveaboard use and watersport activities.

## Estimated Costs

- **Hull and Structure**: $80,000-$120,000 (aluminum catamaran, fiberglass roof).

- **Propulsion**: $30,000-$40,000 (Oceanvolt SD15 Saildrives, controllers, throttles, displays).

- **Electrical/Solar**: $50,000-$70,000 (solar panels, batteries, inverters, generator, wiring).

- **Interior and Systems**: $40,000-$60,000 (cabins, plumbing, appliances).

- **Total**: ~$200,000-$290,000 (custom build, excluding labor if DIY).

- **Maintenance**: ~$5,000-$10,000/year (hull cleaning, battery maintenance, marina fees).

## Build and Testing

- **Design**: Use 3D software (e.g., AutoCAD) to integrate the aluminum frame, solar array, and electrical systems. Consult a naval architect for catamaran stability.

- **Construction**: Engage a Bahrain shipyard (e.g., near Manama) or customize a pre-built catamaran hull.

- **Testing**: Conduct sea trials in the Gulf to verify propulsion, stability, and water access for kitesurfing/diving.

## Recommendations

- **Local Expertise**: Work with Bahrain marine engineers for Gulf-specific conditions (high salinity, shallow waters).

- **Solar Optimization**: Consult a Victron specialist to ensure MPPT controllers maximize solar output in Bahrain’s sunny climate.

- **Watersport Integration**: Collaborate with local kitesurfing experts (Gulf Kitesurfing Paradise) to refine stern platform design for kite launching.

Would you like me to dive deeper into any specific component (e.g., electrical system wiring diagram, solar panel layout, or cabin design details)?

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///// Here the design: ////

### Propulsion System Design for 39ft Aluminium Trimaran

Based on your specifications for a 39ft (11.9m LOA) aluminium trimaran with foil assists (2 per side, positioned between the central hull and amas for partial lift and drag reduction), I’ll focus on the inboard electric propulsion setup. I’ll assume a twin-prop configuration with one system in each ama (side hull) for balanced “smooth power out of each hull,” leaving the central hull free for accommodations, batteries, and foil attachments. This avoids cluttering the middle hull while providing redundancy and maneuverability. Total power is targeted at 50-60kW (25-30kW per hull) for cruising speeds of 8-12 knots under electric power, complementing sails for hybrid operation. The foils (e.g., curved or J-shaped assists attached to crossbeams) will reduce drag by 20-30% at speed, lowering power demands.

The system uses electric motors from H3X or Joule Motors (as alternatives), integrated with Python-Drive for vibration isolation. Emphasis is on a “level” (horizontally aligned) motor installation for optimal efficiency and minimal stress, with shaft angles kept low (5-8°) to ensure smooth torque delivery without excessive prop wash or hull interference. Props are selected and positioned to stay within the 1.0m draft, preventing grounding while maintaining efficiency.

#### Key Components

1. **Electric Motors**:

  • **Primary Option: H3X HPDM-30** (one per ama).

    • Rationale: Compact, high power density (up to 12kW/kg continuous), suitable for marine applications like hydrofoiling craft and workboats. At 33kW peak (~25-30kW continuous estimated based on typical derating), it provides ample torque for a 39ft trimaran’s needs without overkill. High RPM (up to 20,000) allows efficient pairing with a reduction gearbox.

    • Specs: 33kW peak power, 4.1kg weight, integrated inverter for seamless control, versatile as motor/generator (useful for regeneration under sail).

    • Suitability: Designed for inboard shaft drives; lightweight aluminium construction complements the hull material. Voltage: 400-800V DC (high-voltage for efficiency, paired with marine-grade batteries like LiFePO4).

    • Alternative: If higher power is needed (e.g., for foiling bursts), scale to HPDM-140 (140kW peak, 11kg), but HPDM-30 balances size for slender amas.

  • **Secondary Option: Joule Motors Custom PM Motor** (from joulemotors.com, high-performance permanent magnet motors with VESC controllers).

    • Rationale: Customizable for marine propulsion, focusing on high-voltage setups with precise control. Similar to H3X but potentially more tailored for EU compliance (as per joulesmotor.eu query). Power: 20-50kW models available, with VESC for smooth, field-oriented control to minimize ripple.

    • Specs: Brushless PM design, 90-95% efficiency, torque up to 100-200Nm, RPM up to 10,000-15,000, weight ~5-10kg. Controllers handle regenerative braking and integration with foil systems for energy recovery.

    • Suitability: Emphasizes custom marine kits, including hybrid sailboat integrations (similar to JOOOL systems for turnkey electric/hybrid yachts).

Both options are electric for silent, zero-emission operation, with instant torque for smooth acceleration. Cooling: Liquid-cooled (glycol or seawater loop) to handle heat in enclosed amas.

2. **Python-Drive Shaft System**:

  • Model: P60-R (6kN thrust capacity, suitable for 25-30kW motors; upgrade to P100-R for heavier loads).

  • How it Works: This is a constant-velocity (CV) joint system with a separate thrust bearing mounted to the hull. The motor connects to the Python-Drive’s input flange via a flexible coupling, which absorbs axial and angular misalignments (up to 8°). The thrust bearing handles prop forces (up to 6kN forward/reverse), decoupling them from the motor to prevent vibration transmission. Output connects to the prop shaft.

  • Benefits for Vibration Reduction: Electric motors produce minimal inherent vibration, but shaft imbalances or hull flex can amplify it—Python-Drive reduces this by 80-90% through its double CV joints and rubber-isolated mounts. Ideal for foiling trimarans where smooth power prevents resonance with foil oscillations.

  • Compatibility with Electric Motors: Fully compatible; no gearbox needed between motor and Python-Drive (gearbox after if RPM reduction required). Installation allows soft motor mounts (rubber or elastomer) for further isolation.

  • Specs: Shaft sizes 25-40mm (1-1.5"), length adaptable (200-500mm unit), weight ~10-15kg. Thrust bearing bolted to reinforced hull bulkhead.

3. **Reduction Gearbox** (if needed):

  • Inline planetary gearbox (e.g., 4:1 or 5:1 ratio) to step down motor RPM (10,000-20,000) to prop-optimal 1,500-2,000 RPM. Integrated with Python-Drive output for compact setup. Efficiency: 95-98%.

4. **Propeller**:

  • Type: 3-blade folding prop (e.g., Gori or Flexofold) for sailing efficiency, bronze or composite to match aluminium hull (with isolation to prevent galvanic corrosion).

  • Size: 16-18" diameter, 12-14" pitch, optimized for 25-30kW at 10 knots (thrust ~2-3kN per prop).

  • Draft Compliance: Prop hub positioned so tips clear the keel by 10-15% of diameter (e.g., 2-3" clearance). With 1.0m draft, shaft exits hull at ~0.7m below waterline, prop radius 0.2-0.23m—total extension <0.3m below keel. This keeps props within draft even at full load, avoiding damage in shallows.

5. **Battery and Power Management**:

  • Central bank in middle hull: 100-200kWh LiFePO4 (e.g., 800V system for H3X efficiency), with BMS for balance. Solar/wind regeneration via motors/generators. Controllers: Integrated with motor (H3X) or VESC (Joule) for throttle response and monitoring.

#### Inboard Setup and Installation (Per Ama Hull)

To achieve “level properly” (horizontal motor alignment for even weight distribution and minimal stress), the setup prioritizes a near-horizontal shaft line with precise alignment:

1. **Layout**:

  • Motor mounted amidships in ama (at ~40-50% LWL for balance), horizontally on soft mounts ~0.5m above keel. Footprint: ~0.3x0.3m, fitting slender 0.95m beam.

  • Python-Drive aft of motor (200-300mm), bolted to reinforced bulkhead. Allows 5-8° shaft angle without strain.

  • Shaft: 1.25" stainless (AISI 316), 2-3m long, through sealed stern tube (dripless packing) exiting hull at stern. Supported by 1-2 cutless bearings.

  • Prop: Aft of shaft exit, in clear flow (away from foils to avoid turbulence).

2. **Alignment Process for Smooth Power**:

  • **Horizontal Leveling**: Mount motor so its output shaft is parallel to waterline (use laser level or inclinometer during dry fit). Python-Drive compensates for any hull curvature, ensuring <0.5° misalignment.

  • **Shaft Angle Optimization**: 5-8° downward angle (industry best practice for trimarans) to direct prop wash under hull without lifting stern. Align using feeler gauges or dial indicators on couplings (target <0.05mm gap). This minimizes vibration and ensures even torque delivery.

  • **Vibration Minimization**: Python-Drive isolates motor; add hull damping (foam insulation). Electric torque curve (flat from 0 RPM) provides smooth starts—program controllers for ramp-up to avoid jolts.

  • **Balancing for Each Hull**: Identical setups in port/starboard amas, synced via central throttle. Differential power for turning, enhancing maneuverability around foils.

  • **Tools/Verification**: Use laser alignment (e.g., from shaft to coupling) post-install. Check in water: Vibration <1mm/s at cruise; adjust mounts if needed.

3. **Integration with Foils and Hull**:

  • Foils (2 per side, e.g., 1 forward/1 aft between central hull and ama) attach to crossbeams, clear of props (~2m separation). Propulsion enhances foil performance by providing thrust during takeoff.

  • Weight: ~50-70kg per system (motor + drive + shaft + prop), keeping amas light for stability.

#### Performance and Practical Notes

- **Efficiency**: 85-90% system-wide; range 50-100nm at 8 knots (depending on batteries). Foils boost by reducing wetted surface.

- **Cost Estimate**: Motors ~$10k-15k each; Python-Drive ~$2k-3k per unit; total propulsion ~$40k-60k (excluding batteries).

- **Build Tips**: Aluminium hulls need isolated mounts to prevent electrolysis. Test alignment dry and wet; consult class society (e.g., ABS) for shaft calcs.

- **Alternatives**: If Joule Motors preferred for custom EU-sourcing, their VESC allows finer tuning for foil-assisted modes.

If you provide more details (e.g., battery capacity, exact foil type, or prefer one motor brand), I can refine further!

Interested? WhatsApp +97332233327

First one, first served basis :wink:

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