The Rinspeed sQuba: Pioneering Amphibious Electric Innovation Inspired by James Bond

Introduction

The Rinspeed sQuba, inspired by the Lotus Esprit from James Bond's "The Spy Who Loved Me," is a concept vehicle marking a significant advancement in automotive design. This car stands out for its amphibious capability, operating on land and underwater, exemplifying a perfect symbiosis between terrestrial and aquatic domains. Notably, the sQuba employs electric motors, aligning with the rising trend of electrification in the automotive industry and emphasizing the importance of sustainability. This propulsion choice minimizes carbon emissions and underscores the ongoing pursuit of cleaner transport technologies. The sQuba's design addresses specific challenges of operating in aquatic environments, such as resistance to salinity and underwater pressure. From an academic perspective, the sQuba manifests human dreams and aspirations, proving that seemingly insurmountable challenges can be met and overcome in engineering, turning audacious ideas into tangible realities.

The Company

Rinspeed is a Swiss company specializing in groundbreaking vehicle concepts. Founded and envisioned by the visionary Mr. Frank M. Rinderknecht, Rinspeed is a testament to daring automotive dreams and forward-thinking. Known for its relentless pursuit of innovation, the company has showcased concept cars, like the "sQuba", that challenge and redefine the traditional paradigms of the automotive industry. Apart from the "sQuba", Rinspeed has also brought to life other unique vehicles such as "CitySnap", "MetroSnap", and "MicroSnap", each embodying distinctive characteristics and cutting-edge innovations. Nevertheless, Rinspeed's ambition does not end at car design; they constantly venture into uncharted territories of technology, exploring novel solutions that foreshadow the future of mobility. This bold approach cements Rinspeed's position as a beacon of automotive innovation.

Lotus Elise Chassis

The sQuba vehicle was constructed using the Lotus Elise chassis, a sports car known for its lightness and agility. The Elise's chassis, made of aluminum and steel, provides strength and durability, standing out for its excellent driving dynamics, essential features for the sQuba's amphibious functionality. This specific chassis gave the sQuba a solid and adaptable base for operations on land and underwater.

Technical Specifications

Application Type: Luxury Sports (Conceptual).

Vehicle Type: BEV (Battery Electric Vehicle).

Engine: Three electric motors, one for land operation and two for water operation.

Dimensions

Length: 3'785 mm

Width: 1'940 mm

Height: 1'117 mm

Wheelbase: 2’300 mm

Front Track: 1’470 mm

Rear Track: 1’520 mm

Ground Clearance: 130 mm

Empty Weight: Approximately 920kg

Distribution and Functionality of Electric Motors in the Rinspeed sQuba

The vehicle contains a total of 5 electric motors, whose arrangement is described below:

• Electric Motor for Land Displacement

Location: This engine is strategically positioned to optimize traction on the vehicle's rear wheels. 

Power: It has a maximum power of 54 kW. Rotation: The rotation to achieve maximum power is 4,500 rpm, while the maximum torque of 160 NM is reached at 1,500 rpm. 

Battery: Powered by Lithium-Ion batteries with a combined voltage of 6 x 48 Volt. These batteries are designed to provide sustainable and efficient power for land displacement. Function: This engine is responsible for moving the sQuba on land, allowing it to reach speeds exceeding 120 km/h.

• Electric Motors for Aquatic Propulsion

Location: These engines are located at the vehicle's rear, enabling propulsion on the water's surface. 

Power: Each motor has a power of 800 watts, totaling 1.6 kW for both. 

Battery: They use the same Lithium-Ion battery that powers the land motor, ensuring a smooth transition between land and aquatic modes. Function: These engines allow the sQuba to move on the water's surface at speed exceeding 6 km/h.

• Electric Motors for Underwater Diving (Directional)

Location: These engines are positioned at the front of the vehicle, facilitating underwater movement. 

Power: Each motor has a power of 3.6 kW, supplied by the Rotinor brand. 

Battery: Like the aquatic propulsion engines, these engines are powered by the same Lithium-Ion battery. 

Function: These engines are essential for the sQuba's diving capability, allowing it to move underwater at a speed exceeding 3 km/h and reach a maximum depth of 10 meters.

A flowchart of the aforementioned distribution can be viewed below.

Topology of Batteries and Electric Motors

The Rinspeed sQuba uses a unique configuration of batteries and electric motors to meet its specific performance needs.

The vehicle is equipped with six lithium-ion batteries, each operating at 48 volts. These batteries are crucial for powering the various electric motors of the sQuba. On the road, the batteries are set up in series, which increases the total voltage supplied to the main electric motor. This series configuration allows the vehicle to achieve optimized efficiency and adequate power for on-land driving.

When the sQuba moves to the aquatic environment, the batteries' configuration switches to a parallel arrangement. This parallel topology is crucial for providing the necessary current to power multiple components simultaneously, including the two rear thrusters for water movement and the two front thrusters for diving.

The sQuba uses a water jet propulsion system when submerged. Water is pulled through an opening at the bottom of the vehicle, passes through an impeller, and is expelled backward through a steerable nozzle. This technique provides effective and safe propulsion with no exposed rotating parts. Additionally, the vehicle has two propellers at the rear that assist in aquatic propulsion and two thrusters behind the front wheels for underwater direction.

In summary, the topology of the batteries and electric motors of the Rinspeed sQuba is carefully designed to adapt to the vehicle's different operating conditions, whether on land or underwater, ensuring optimal performance and safety in both environments.

Power (5 electric motors):

Engine for land: Maximum of 54 kW.

Motors for water (Heckpropeller): 2 x 800 Watt.

Motors for diving (Bug Jetantriebe): 2 x 3.6 kW.

Performance:

Maximum speed on land: > 120 km/h.

Acceleration from 0-80 km/h: 7.1 seconds.

Maximum speed in water: > 6 km/h.

Maximum underwater speed: > 3 km/h.

Maximum diving depth: 10 meters.

Batteries:

Type: Lithium-Ion.

Voltage: 6 x 48 Volt.

sQuba's Drive and Propulsion Dynamics

The sQuba, as a pioneering amphibious electric vehicle, boasts a unique drive system tailored for terrestrial and aquatic environments. Its seemingly automatic transmission is designed to toggle between modes efficiently, ensuring a seamless transition and optimal performance. Key features of this system include:

• Transmission: R - N - F.
• Traction Type: Rear-wheel drive, alternating underwater propulsion methods (propellers and directional thrusters).

Likely Specifications of the Energy Storage System

During my research, I found that specific details regarding sQuba's energy storage system weren't openly available to the public. I had the privilege of contacting Mr. Frank M. Rinderknecht for further insights. He kindly clarified that certain specifications aren't accessible due to the car's status as a concept vehicle. It's paramount to recognize the distinction of the Rinspeed brand in pioneering such an innovative vehicle, and it's essential to describe it in a manner that underscores its groundbreaking nature.

That said, the specifications listed below are presented as "likely" based on the Lotus Elise model, which served as the foundation for the sQuba.

Storage Technology: Lithium-ion (Li-Ion).

Cell Voltage and Arrangement: Specific details regarding voltage and cell arrangement (such as 10s-6p, 20s-8p, etc.) were not provided.

Operational Parameters:

Maximum and Minimum Voltage: Data not specified.

Maximum Current: Not specified.

Operating Temperature: The operating temperature range was not detailed.

Cooling System: The type of cooling (active, passive, air, or other cooling agents) was not mentioned.

Energetic Capacity:

Total Stored Energy: kWh value not provided.

Maximum Discharge and Charge Power: Data not specified.

Recharge:

Charger Type: High-efficiency charger specific for Li-Ion batteries.

Socket Type: Standard J1772 socket (North America) or Type 2 (Europe) for AC charging.

Charging Voltages: Standard AC charging between 110V to 240V. Fast DC charging can vary from 200V to over 600V.

Physical Characteristics:

Weight: Estimated between 200kg to 600kg, depending on capacity.

Vehicle Distribution: Possibly in a single package or multiple packages for space optimization.

Durability and Cost:

Expected Lifespan: Between 8 to 15 years, depending on usage and maintenance.

Warranty: Common warranties for electric vehicle batteries typically last 8 years or more.

Replacement Cost: Estimated between 5,000 to 20,000 dollars, varying with capacity and manufacturer.

Rinspeed sQuba's Underwater Propulsion and Steering

The Rinspeed sQuba, in addition to its notable amphibious capability, showcases a unique underwater propulsion and steering system. In its aquatic mode, the vehicle employs a water jet propulsion system, where water is drawn through an inlet at the bottom of the hull and forced to pass through an impeller, subsequently being ejected rearward through a steerable nozzle. This method ensures effective propulsion and offers added safety due to the absence of exposed rotating parts beneath the hull. Moreover, the sQuba is fitted with two propellers at the rear for water propulsion and two thrusters behind the front wheels to control direction when submerged. These technical features highlight Rinspeed's dedication to crafting a vehicle that efficiently operates on land and delivers an unparalleled underwater experience.

Autonomous Driving

The sQuba was conceptualized with a visionary outlook on the future of mobility, integrating autonomous driving technologies. Even in 2008, the vehicle was already equipped with advanced systems, such as the Ibeo LUX laser scanner, which enabled obstacle detection and autonomous navigation on land and offered a range of Advanced Driver Assistance Systems (ADAS) functionalities.

The reliability and effectiveness of the Ibeo LUX laser scanner were further demonstrated at the Darpa Urban Challenge, where it was used in the top three winning driverless cars.

Suspension

The sQuba's suspension is constructed from stainless steel, merging durability with corrosion resistance, essential attributes for an aquatic-operating vehicle. The suspension design, termed "Doppeldreiecklenker" or "Double wishbone," guarantees a smooth and stable ride irrespective of the terrain or water conditions.

Instrumentation and Control Unit

The sQuba's dashboard and instrumentation, crafted by VDO, are waterproof and pressure-resistant.

Sustainable Design and Ecology

Efficient LED Lighting: The sQuba incorporates LED illumination, known for its energy efficiency and long lifespan. By utilizing LEDs, the vehicle not only ensures optimal battery usage but also emphasizes the eco-friendly essence of its design.

Recyclable Materials: The sQuba is built using a variety of recyclable materials. This reduces the vehicle's environmental impact and demonstrates Rinspeed's commitment to sustainable manufacturing practices.

Biodegradable Lubricant: The vehicle uses biodegradable grease for all its lubrication functions, demonstrating the company's commitment to minimizing environmental impact.

Zero Emission: The car is powered by electricity, so it does not emit harmful environmental pollutants. This makes it an eco-friendly choice for those concerned about reducing their carbon footprint.

sQuba Project Partners

The sQuba project stands as a testament to collaboration and innovation achieved through the joint efforts of several specialized partners. Each contributed their unique expertise, turning this underwater vehicle dream into reality. Key partners and their respective roles include:

Esoro: Specialized in engineering and production and was instrumental in materializing the sQuba concept.

KW automotive GmbH: Renowned for suspension systems, they guaranteed the sQuba's impeccable ride quality.

Strähle+Hess: Supplied premium materials for the vehicle's interiors, ensuring comfort and longevity.

Weidplas GmbH: Experts in advanced plastic components, they sculpted and infused functionality into sQuba's design.

AEZ Leichtmetallräder AG: Providers of alloy wheels, they married aesthetics with performance.

Harman: Pioneers in audio systems and infotainment, they elevated the auditory and connectivity experience within the sQuba.

VDO: Entrusted with precise instrumentation, ensuring drivers are always informed.

Seabob: Specialists in underwater propulsion, their expertise was pivotal for sQuba's diving capabilities.

Linde: Innovators in fuel cell technology instilled a green approach to the vehicle's operations.

Pirelli: A global leader in tires, Pirelli provided specialized traction solutions, ensuring sQuba's performance across various terrains.

HS Genion GmbH: HS Genion applied its expertise in movable modules and components with a focus on aerodynamics and cargo management. They adapted innovations to meet the sQuba's standards, including cooling systems and storage mechanisms.

Foliatec: Specialized in automotive customization, Foliatec likely contributed unique finishes and aesthetic details to the sQuba.

LeasePlan (Switzerland) AG: As leaders in fleet management and leasing, LeasePlan endorsed the innovative sQuba concept, emphasizing its forward-looking vision.

Each partner's innovation and expertise made the sQuba a milestone in automotive history.

Additional Information

Suspension:

Front and Rear: Doppeldreiecklenker (Double wishbone).

Tires:

Front: Pirelli P Zero 205/40 R17.

Rear: Pirelli P Zero 225/40 R18.

Other Features:

Diving air supply: 1 x 15 liters + 1 x 18 liters from ScubaPro.

Laser scanner: Ibeo (Autonomous Mode).

Lubricants: Motorex (Biodegradable).

Number of Seats: 2.

Range:

On Land: It is estimated that the sQuba can travel between 100 to 144 km, based on an estimated consumption of 44 kWh.

Underwater: The vehicle can operate for over 3 hours underwater. However, it's important to note that the oxygen tanks provide supply for approximately 2 hours.

Price: $1.5 million.

Internal Combustion Engines (ICE): The vehicle has no internal combustion engine; it's entirely electric.

Demonstrative Video

Author

Student: Marcus Vinícius Leal de Carvalho (Ph.D. in Electronic Systems Engineering)

Advisor: Prof. Leopoldo Rideki Yoshioka

References

Websites and Online Articles:

1. Rinspeed. (n.d.). sQuba - Technical Data. Retrieved from https://www.rinspeed.com/upload/conceptfiles/technical_data_squba.pdf
2. Rinspeed. (n.d.). sQuba. Retrieved from https://www.rinspeed.com/en/sQuba_30_concept-car.html#mehrlesen
3. Wikipedia. (n.d.). Rinspeed sQuba. Retrieved from https://en.wikipedia.org/wiki/Rinspeed_sQuba
4. Tuningblog.eu. (n.d.). Unterwasserfahrzeug. Retrieved from https://www.tuningblog.eu/kategorien/tuning-wiki/unterwasserfahrzeug-284722/
5. Graphic News. (n.d.). sQuba Amphibious Car. Retrieved from https://www.graphicnews.com/en/pages/22223/motoring-squba-amphibious-car
6. MotorBiscuit. (n.d.). The sQuba Car Can Go Underwater. Retrieved from https://www.motorbiscuit.com/the-squba-car-can-go-underwater/
7. NetCarShow. (n.d.). Rinspeed 2008 sQuba Concept. Retrieved from https://www.netcarshow.com/rinspeed/2008-squba_concept/#8
8. Car Magazine. (2009). Rinspeed sQuba (2009) Review. Retrieved from https://www.carmagazine.co.uk/car-reviews/rinspeed/rinspeed-squba-2009-review/
9. The Sands Mechanical Museum. (n.d.). Lotus Elise - Strategic Review. Retrieved from http://sandsmuseum.com/cars/elise/information/misc/strategic/strategic.html

Research Papers:

1. Amaya Solís, J. M. (2018). DISEÑO DE LOS MÓDULOS DE ELECTRÓNICA DE POTENCIA PARA UN PROTOTIPO DE VEHÍCULO ANFIBIO. Universidad Nacional Mayor de San Marcos.
2. Zhang, Y., et al. (2019). Research Overview of Amphibious Platform Driving Device. IOP Conf. Ser.: Earth Environ. Sci. 252 032152.
3. Li, F. (2011). International City Traffic Congestion Based Analysis and Countermeasures Research. Zhangjiakou City, Hebei Province, China.

Image and Primary Information Credits:

All images and primary information for the sQuba vehicle are credited to Rinspeed's official website.