Supporting the evolution of safe efficient containership operations

Owners are responding to fleet and market dynamics with efforts to maximise cargo capacity for flexible operations, writes Christoph Rasewsky, Global Container Sector Lead, ABS Europe

The containership market is evolving as the focus intensifies on maximising volume capacity for safe transport of cargo on ships whose characteristics are also responding to changes in market dynamics.

In general, the design and operation of ships reflects pressure to operate at maximum efficiency and flexibility. 

General Trends

Consolidation of both freight rates and vessel charter rates reflect the high number of deliveries this year and in upcoming years, leading to pressure in a market which has been supported by the re-routeing of vessels via the Cape of Good Hope.

The profile of the existing fleet is bifurcating, with units smaller than 1,000 TEU capacity having the highest average age at 19.9 years. The orderbook for the 1,000–3,000 TEU units and 3,000–6,000 TEU units is comparatively small but existing ships below 9,000 TEU capacity have a relatively high average age.

In the larger size classes, vessels of 12,000 TEU and upwards have a very low average age but significant fleet growth is observable for 12,000–17,000 TEU units.

The high demand for ships caused by diversions from the Red Sea crisis has resulted in only a moderate number of ships slated for recycling this year. However. the very high number of deliveries will sooner or later create enough pressure on the market increase the number of ships to be scrapped. Data from Clarksons indicates that scrapping in 2027 could be the second highest for a decade, at 605,000 TEU.

An analysis of the container ship fleet illustrates a clear trend from higher to lower maximum speeds. While older ships have top speeds of up to 27 knots, newer designs rarely exceed 22.0 knots and can be closer to 18.0 knots for larger units and even lower for smaller units. 

At the same time, there is a clear tendency for shorter and more compact ships in line with the reduction of the ship’s top speeds. This trend is quite significant for 3,000 to 12,000 TEU vessels and less pronounced for larger ones.

The only exception is the Maxi-NPX class which maintains its beam at the size of the Panama Canal locks. 

Creating Opportunities

ABS supports clients in the containership market in multiple channels, and according to the specific requirements of their vessels. 

Support on fuel strategy can include CII rating analysis and the cost impacts of Fuel EU Maritime, EU ETS and Greenhouse Gas Fuel Intensity regulations.

Operational profile analysis includes insights into vessel operational parameters and support on development of a hull optimisation matrix. ABS can also undertake vessel specification and General Arrangement Plan review, drawing on subject matter experience from within ABS to tailor the ship towards the owner’s needs. 

ABS can also support the owner identify areas of cargo boosting potential to improve their potential commercial opportunity and to future proof their assets.

In an example case, ABS has studied the potential to boost the container carrying capacity of an 9,000 TEU container vessel. By applying latest trends, techniques and technologies, it is possible to raise the nominal container capacity from 8,914 TEU to 9,860 TEU, a 10.6% increase.

Full stowage height +72 TEU: Utilising maximum container stowage height on deck can improve container loading capabilities and increase operational flexibility. 

In some cases, stowage height (in tiers of containers) is the same for containers stowed in hatches as it is for those stowed on deck, leading to a stepped pattern between the bays. It is recommended to utilise the maximum stowage height for all bays. 

ABS can support this process with lashing benchmark studies and provide advisory on the correct lashing bridge design to utilise maximum stowage height.

Additional 12th Tier on deck +412 TEU: If the arrangement of the lashing bridges is designed for higher stowage, a 12th tier on deck allows greater operational flexibility for mixed stowage of high cubes and standard containers.

Raised deck house +68 TEU: The position of the deck house on a twin island vessel impacts the container loading capabilities in two ways, container stowage below the line of sight and stowage below deck in the middle of the ship. 

Early-stage support will focus on finding the right balance between container loading capabilities and tank space requirements below the deck house.

Castle stowage +20 TEU: Using castle stowage, containers can be loaded within an allowable blind spot as per SOLAS regulations.

Bay above mooring deck +80 TEU: Placing an additional bay of containers above the mooring deck has been successfully carried out on some new ships. Challenges to safety include impact on bending moment and structural integration of foundation. This configuration requires a windshield with wave breaker to be installed.

Moving the vessel deck house forward by as little as two bays results in a potential loading gain of +222 TEU.

Slam-B notation +72 TEU: As container vessels have become larger over time, the bow design has become increasingly susceptible to higher slamming loads on the bow flare. Owners can apply the ABS SLAM-B notation for ships with a large bow flare angle and improve loading capabilities on most forward bays.

The SLAM-B notation draws on ABS’ high degree of experience with various bow hull designs for conventional and novel designs. Operators can benefit from lower operational costs reduced risk of damage from wave impacts on the ship’s bow.

Energy Efficiency

In terms of popular energy efficiency measures, sail-assisted propulsion has become an increasingly interesting measure for containership owners seeking to reduce fuel consumption and improve their vessel’s carbon emission footprint.

Several systems are available in the market, each with corresponding advantages and drawbacks.

ABS can provide support in helping owners to identify system that best fits their needs, including undertaking economic feasibility studies, identification of regulatory compliance requirements and shipyard support for structural system integration.

In the example of a 4,000 TEU containership, the application of the correct sail propulsion system could potentially deliver fuel consumption savings of up to 20% on average depending on its specific characteristics, with a payback time of about three years for the sail system.

Editorial Standards · Corrections · About gCaptain