The oil tanker emerges
The oil tanker emerges
The tanker develops
Oil for heating and lighting and for lubricating machinery has long been carried in ships, but usually in containers such as pottery jars or, more recently, barrels. With the serious exploitation of oil fields in the mid-nineteenth century, large quantities of oil began to be carried at sea. A more efficient way of carrying it than in barrels was sought, as the barrel not only cost money, but also wasted space in the ship’s hold. So in the 1860s ships began to be built with large tanks built into their hulls. At first, the tanks were filled and emptied by pumps onshore, but soon tankers had their own pumps and pump room.
It was important to install a number of tanks as just filling the entire hold with oil would allow the cargo to surge dangerously in heavy seas. In fact, the oil tanker was soon designed so that its hull was effectively a series of oil-tight tanks, making it suitable only for liquid cargoes. The tanks have to be capable of being tightly closed as the gas given off by oil is very inflammable when mixed with air. Some allowance has to be made for the cargo to expand as the ship sails into warmer waters. The cargo tanks often have narrow expansion trunks at the top into which the oil can expand.
The first tank steamers
As with other bulk cargoes oil could be carried economically only in sailing ships until the marine steam engine became really efficient in the 1870s. The first ocean-going tank steamer was built in 1872, the Tyne-built Vaderland. However, the pioneer modern tanker is generally agreed to be the Gluckauf of 1886, also built on the Tyne. Gluckauf had a bulkhead along her centreline, and further transverse bulkheads to divide her cargo space into eight tanks. Above the tanks was a trunk to allow cargo to expand. A pump room separated her tanks from the engine room. The engines were placed right aft and she had a navigational bridge almost amidships. Tankers like Gluckauf loaded deeply, and at sea waves would often wash right across their decks. To connect the accommodation aft, the bridge amidships and the forecastle, a walkway was provided a few feet above the deck, and this has remained a feature of most tankers. Apart from increased size, tanker design has largely followed that of Gluckauf ever since.