Structural Characteristics of Single-hull Bulk Carriers And Double-hull Bulk Carriers

Bulk carriers are characterized by large tonnage, large openings, single deck and concentrated loading of bulk dry bulk cargoes. In order to improve loading and unloading efficiency, large hatches are usually used.Depending on the ship structure, they can be categorized into single-hull bulk carriers and double-hull bulk carriers.In this article, we will take you to analyze the structural characteristics of single-hull bulk carriers and double-hull bulk carriers.

▍Forms of Hull Construction for Bulk Carriers:

The hull of a bulk carrier consists of three parts: the bow, the stern and the hull. The bow is usually pointed and tapered to reduce water resistance and increase sailing speed. The stern is usually wider, which helps to improve the stability of the ship. The hull is the main part of the bulk carrier, which is generally a long and wide rectangular structure that can accommodate a large amount of bulk cargo.

▍1. Single Hull Bulk Carrier Structure

Single-hull bulk carriers have only one full-access deck and a double bottom, with two topside compartments below deck against the sides and upward-sloping bottom compartments at the bilge of the double bottom.This reduces the need for leveling work and prevents the ship's stability from being jeopardized by excessive transverse rocking while underway.Meanwhile the triangular water tanks at the corners of the cargo hold are ballast tanks that can be used to regulate draft and stabilize altitude.

▍2. Double Hull Bulk Carrier Structure

Double-hull bulk carriers are based on single-hull bulk carriers. The outboard double-hull structure can be transverse skeleton type or longitudinal skeleton type.

Transverse Skeleton

Longitudinal Skeleton

The structure of double-hull bulk carriers is characterized by the addition of side tanks and the integration of the bottom and top side tanks, which increases strength and rigidity. And the side is flat to facilitate painting and reduce cargo corrosion, but also easy to load and unload. There are watertight or non-watertight platforms inside the double shell, and there are platforms where the inner shell intersects the bottom-side compartments and the top-side compartments.

▍Conclusion

Based on these structural analyses, single-hull bulk carriers and double-hull bulk carriers have their own advantages and disadvantages. Single-hull bulk carriers have advantages in terms of loading and unloading efficiency, but are slightly less safe; Double hull bulk carriers are better in terms of hull strength, cargo transportation safety and stability. In practical application, shipowners can choose the right type of bulk carrier according to their own transportation needs and budget.