Introduction

As a part of my bachelor's thesis, I have come up with a new and innovative design for a pedal boat. This design is set to revolutionize the traditional pedal boats of today, with its unique appearance, design language, and ecological properties. The main objective of this design is to promote water tourism on inland waterways.

Research

The first pedal boat was presumably invented in 1810 by Joseph von Baader (1763 – 1835), a German engineer and physician. The boat, known as a "water sled," featured a design with two long runners and allowed movement on water through the use of pedals. Constructed from oak, copper, and steel, this pedal boat served as a customizable recreational device, popular in the aristocratic waters of Bavaria.

Baader's propulsion system, considered bionics, drew inspiration from the natural motion of waterfowl's feet. This innovative system mirrored the functionality of waterfowl feet. At the time, it was a contemporary propulsion method, as the modern form of the ship propeller was still unknown.

Analysis of actual condition

The variety of pedal boat models is mainly reflected in their shape and color, while the basic functionality remains largely the same. Modern pedal boats tend to look massive and hull-like despite new designs, as the shape is adapted to the functionality.

The inefficient shape of the hulls and the paddle wheel slow the boat down too much and do not make efficient use of muscle power. Sometimes the impression is created that the boat rental station is still close by after turning around, despite the effort made with leg power. Classic paddlewheel pedal boats have the advantage that they can be used in shallow inland waters without getting caught up in algae as with a propeller. However, the loud paddlewheel generates disturbing noises when moving and stirs up the water, which disturbs fish and other aquatic life.

The design of the boats needs to be reconsidered in order to motivate customers to hire them. The market offers many playful models that are primarily intended to appeal to children, while often only boxy standard models are available for adults.

Some pedal boats show innovative approaches with a distinctive catamaran design, but these solutions are often not developed further. Although they move forward with a propeller instead of a paddle wheel, these models appear pragmatic and often not comfortable for longer boat trips.

Competetive audit

Pedal boats with additional electric drive:

In 2011, the company BionX developed the "SeaScape 12", a pedal boat that is equipped with an electric motor and allows the rider to decide for themselves whether they want to ride under their own power or with the help of the motor. The way it works is very similar to an e-bike, as the different levels of assistance can also be set very easily using the gears.

There are few pedal boats on the market that are propelled by a propeller instead of a crankshaft. Nevertheless, there are some manufacturers of conventional pedal boats that offer the option of integrating a motor in addition to the paddle wheel.

The following pages present some pedal boat models that are equipped with a pedal propeller and are therefore not tied to the standard pedal boat shape.

Pedal boats with propeller drive:

This masterpiece by Hamburg master boat builder Sven Küntzel. With his pedal boat, he attracts everyone's attention when he takes a short boat trip on the Alster. The boat is made of solid mahogany wood glued with epoxy resin.

With its simple lines and no-frills construction, the "Renovatio" pedal boat christened by Küntzel stands out from other pedal boats.However, this pedal boat is still a one-off and is intended more as a showpiece, as the sum of just under 60,000 euros means that there are no great expectations from buyers.

Inspiration from Catamarans:

The term "Katamaran" comes from the Tamil word "Kuttumaran," where "kattu" means "connect" and "maram" means "tree trunk." Catamarans, or "Kats," are watercraft with two hulls connected by crossbeams or a trampoline deck, known for their stability and safety. They can be powered by sails or an engine.

Motorized catamarans, popular as ferry vessels, use the stability of two hulls to minimize seasickness. Workboats and floating platforms often adopt the twin-hull design for enhanced stability.

Sailing catamarans are fast, smaller vessels used for sports or cruising, relying on wind energy for propulsion. Notable models include the "Tornado," "Nacra 17," and "Hobie Cat."

NACRA catamarans, initially developed in the USA and now widespread, impress with design and speed, catering to club regattas and recreational sailors. Their voluminous hulls effortlessly navigate waves, influenced by the teardrop shape. The trampoline provides space, forming a sturdy platform between the hulls.

Design process

After extensive research and analysis of the current situation, the concept and design phase could begin.

The first step was to break away from conventional pedal boat shapes and consider new approaches. During the research, some interesting ideas emerged that could now be examined and, if necessary, implemented.

To make the design process manageable, the pedal boat was divided into six elements:

1. Hulls 2. Connecting level 3. Seats 4. Deck net 5. Pedals + propeller + steering 6. Sun canopy

Then details such as backrests, storage space, cup holders etc. are added.

Sketches

After some initial drawings and simple CAD models, consisting of simplified rectangular shapes, it seemed reasonable to attach the trapeze at the stern and the connecting plane at the rear of the pedal boat. This decision was influenced by several advantages, such as preventing the pedal boat from being slowed down by bow waves since the mesh net is positioned high enough. The trampoline at the back does not obstruct the view during the ride, and if someone relaxes on the net while others continue pedaling, it allows for better conversation compared to having the net at the rear.

A well-designed hull is crucial for a pedal boat. It should have a bow that slopes backwards to cut through waves, instead of riding up and down them. This will reduce drag and provide a faster and more stable ride. This type of hull is called a wave cutter hull. The front of the hull should be tapered and the rear should be more voluminous to balance the weight distribution. Weights should be added to the stern to ensure proper balance. During the design phase, it was discovered that the volume of the hulls was unclear. As a result, several variations were built to determine buoyancy and to find the optimal shape.

Proportions were then determined to ensure passengers have sufficient space to comfortably pedal without feeling confined. The seat backrests are designed to be adjustable, allowing individuals to choose between a reclined or seated position. The trampoline, on the other hand, serves as a comfortable lying area and accordingly provides ample space.

Using masking tape, the necessary dimensions were applied to the floor at a 1:1 scale to precisely establish the proportions based on the given requirements.

The pedal boat will be considerably longer than initially assumed, as it is crucial for even tall individuals to sit, lie, and pedal comfortably without experiencing back pain or discomfort after a short period.

Sketches

The design of the boat seats was inspired by ergonomic office chairs and conventional boat seats, some of which already had features similar to a car seat. During the design process, it was crucial to strike the right balance between functionality and aesthetics. The seat should not appear too bulky or out of place, but rather blend in harmoniously with the other boat components without immediately catching the eye.

Concept / Design Description

The pedal boat has been created to meet the requirements specified in the brief. It boasts a modern and sleek appearance and a harmonious interplay of individual elements. The pedal boat is spacious enough to accommodate four people, with two responsible for the drive and steering while the other two can sit on the large trampoline or relax in the sun. Pedaling is assisted while driving, making for faster and more efficient travel. Passengers can decide whether to focus on sporting activity or enjoy a leisurely boat ride. The boat has been designed to offer a recreational experience close to nature, providing an escape from the stresses of everyday life. The catamaran-like design of the boat ensures safety, as it is practically unsinkable with its two hulls.

Two torque jet propellers with integrated motor are mounted at the rear of each hull and enable steering without an additional rudder. They are easy to turn and highly efficient, enabling fast progress.

The ergonomic seats have a sleek design that features part of the backrest and seat surface highlighted in color. The backrest has two elongated openings arranged parallel to the outer contours of the seat, which not only serve as a visual eye-catcher but also provide a pleasant breeze on the water and prevent the back area from overheating on very warm days. Passengers can quickly and easily adjust the seats with a span of ---- to pedal comfortably. To move the seat, simply push the lever under the seat upwards, and the seat will slide along the rail.

The pedal boat comes in three different color options. All the models have a combination of white and anthracite, but the third color varies depending on the model. This color is displayed on the seats, backrest, turbines, and roof. The colors chosen are classic and timeless, and the different options available are:

- White, anthracite, blue

-White, anthracite, red

- White, anthracite, petrol

Materials

The hulls, connecting plane, and seats are made of Vulcan fiber. Vulcanized fibers have many advantages and are ideal for use in the nautical sector. They have several positive properties that make them a potential replacement for many water sports equipment made of glass fibers. The raw material for Vulcan Fever is cotton, whereby the cotton fibers it contains are processed to create cellulose. Vulcanized fibers are hydrophobic, acid-resistant, temperature-resistant, and dermatologically well-tolerated. One of the biggest advantages is that vulcanized fibers are virtually inexhaustible and 100% recyclable.

The volcanic fibers are compressed and reinforced with honeycomb core ecological sandwich panels for incredible stability. Honeycomb panels have low weight per unit area and high load-bearing capacity.

Mechanism

The pedal boat is powered by a hybrid drive, as two different technologies are combined. On the one hand, the person's own muscle power acts as the combustion engine. The electric motor is activated and provides propulsion as soon as the pedals are pressed. By pedaling, the pulse generator sends information about the direction of travel and speed to the speed controller, which in turn sends this information to the drive. The faster you pedal, the more impulses are given and the speed is increased.

Model construction

1:5 scale model

Conclusion

The goal was to design a pedal boat that appeals to a wider audience. Extensive research showed that previous models wouldn't be relevant for my design. Hulls and the propulsion system were the real challenges, but intense modelling helped me optimize the streamlined design for buoyancy efficiency. In summary, the final design is unique and timeless, meeting customer needs with ergonomic and comfortable features.