Branobel, one of the largest oil companies in the world, is active mostly in the oil-rich region around Baku (now Azerbaijan).

Short for Brothers Nobel, Ludvig and Robert Nobel, brothers of Alfred Nobel, had founded Branobel in the Russian Empire in 1876.

Ludvig is a pioneer in the development of early oil tankers, who had first experimented with carrying oil in bulk on single-hulled barges.

Turning his attention to self-propelled tankships, he faces a number of challenges.

A primary concern is to keep the cargo and fumes well away from the engine room to avoid fires.

Other challenges include allowing for the cargo to expand and contract due to temperature changes, and providing a method to ventilate the tanks.

The world's first successful oil tanker is Nobel's Zoroaster.

He designs this ship in Gothenburg, Sweden, with Sven Almqvist.

The contract to build it is signed in January 1878, and it makes its first run later that year from Baku to Astrakhan.

The Zoroaster design is widely studied and copied, with Nobel refusing to patent any part of it.

In October 1878, he orders two more tankers of the same design: the Buddha and the Nordenskjöld.

Zoroaster carries its 242 long tons of kerosene cargo in two iron tanks joined by pipes.

One tank is forward of the midships engine room and the other is aft.

The ship also features a set of 21 vertical watertight compartments for extra buoyancy.

The ship has a length overall of 184 feet (56 m), a beam of 27 feet (8.2 m), and a draft of 9 feet (2.7 m).

Unlike later Nobel tankers, the Zoroaster design is built small enough to sail from Sweden to the Caspian by way of the Baltic Sea, Lake Ladoga, Lake Onega, the Rybinsk and Mariinsk Canals and the Volga River.