50,000 rubles, Russian citizenship, and Faraday's delight: the story of the world's first "electric boat"

It may take decades between the creation of an invention and its application in practice. The story of the first practically applicable electric motor is a reverse example and a graphic illustration of the fact that scientific and engineering thought knows no boundaries.

Jewish by birth, German by education and Russian by heart, the eminent physicist and electrical engineer Boris Jacobi relied on the discoveries of his English colleagues and predecessors: Faraday, Barlow and Henry.

Before Jacobi's invention there were low power density electrical devices with a reciprocating or oscillating armature motion. The inventor wrote about one of them: "Such a device will be no more than an amusing toy to enrich physics classrooms, it cannot be applied on a large scale with any economic benefit..."

Jacobi wanted to develop a more powerful electric motor with practical applications. In 1834, he created the world's first direct-drive electric motor. Jacobi's motor consisted of two groups of electromagnets. The polarities of the moving electromagnets were alternately reversed using a special commutator. The same principle is used in modern traction commutator electric motors, which are applied, for example, in railway locomotives. 

The Jacobi's motor power was 15 W at a rotor speed of 80-120 rpm. It would lift a weight of 4-5 kg to a height of about 30 cm per second, was powered by galvanic batteries, and was the most advanced electrical device at the time. Within six months, Jacobi's invention became widely known and recognized in the scientific world. 

The following year, the professor was invited to teach in Russia. Soon the tsarist government suggested that he organize a series of experiments to equip marine ships with electric motors. Jacobi received Russian citizenship and became a member of a special commission for building an "electric boat". The state treasury allocated a whopping 50,000 rubles for the project, which was a colossal sum at the time. 

The experiments were conducted on an 8-meter long dinghy, which needed a more powerful motor. Therefore, Jacobi created a second version of his motor - larger in size and with a twin stator. However, the 120W power was still not enough, and he changed the concept, making the motor more compact. Eventually Jacobi assembled forty of these motors on two vertical parallel shafts connected to the propelling wheels of the "electric boat". 

In 1838 the "electric boat" began months of tests on the Neva River. The vehicle would transport 14 passengers against the current for a distance of 7 km at a speed of up to 4 km/h. The motors were powered by 320 galvanic zinc-platinum cells weighing 200 kg, which boosted the propulsion power to 550 watts. 

This is the world's first successfully tested means of transporting people and goods on electric traction. Mass media and scientists provided rave reviews. Michael Faraday himself sent Boris Jacobi a personal letter in which he talked about his dream of installing such electric motors in ocean liners.

However, Jacobi calculated that large ships would require too much power and giant batteries. "Chemical energy is now more expensive than mechanical energy," the professor lamented. Due to its economic inexpediency, in 1842 the work on the "electric boat" was stopped, and Jacobi switched to other, no less important projects, becoming, among other things, the founder of electroplating.

We cannot imagine life in the 21st century without electric motors. Jacobi's invention is one of those that are at the origins of our "electrical civilization". And the "Slavyanka" technology and "Sovelmash" are at the forefront of electric motor development today.