TABLE OF CONTENTS Ships designed specifically to carry bulk liquid cargoes are generally referred as tankers. Tankers are commonly associated with the carriage of oil, but a wide variety of liquids are carried in smaller tank vessels and there are a considerable number of larger tank vessels dedicated to carrying chemicals in bulk.
Small tankers not exceeding 75 metres in length, involved principally in the coastal trade have a single longitudinal bulkhead on the centre line providing two athwartships tanks. The machinery is aft, and an expansion trunk, if fitted, is on the centre line in way of the tank spaces (see Figure 22.1).
This chapter is concerned with the construction of the larger ocean-going type, which may be considered in two classes. There are those ships which carry refined oil products, and perhaps some other cargoes like molasses, which tend to be in the smaller 12 000 tonnes to 50 000 tonnes deadweight range. Then there are the crude oil carriers which extend to the 500 000 tonnes deadweight range. The former vessels, the smaller of which may have a single centre line longitudinal bulkhead (see Figure 22.4), have a greater number of tanks, and more complicated pumping arrangements which permit the carriage of a number of different products on a single voyage.
Both types of ship have traditionally been single flush deck ships with longitudinal bulkheads and a structure within the tank spaces consisting...
