Six Generations of Containerships

The first generation of containerships was composed of modified bulk vessels or tankers that could transport up 1,000 TEUs. The container was at the beginning of the 1960s an unproven transport technology and reconverting existing ships proved out to be the least expensive and risky solution. These ships were carrying onboard cranes since most port terminals were not equipped to handle containers. Once the container began to be massively adopted at the beginning of the 1970s, the construction of the first cellular containerships (second generation) entirely dedicated for handling containers started. All containerships are composed of cells lodging containers in stacks of different height depending on the ship capacity. Cranes were removed from the ship design so that more containers could be carried. The ability of ports to handle containership ceased to be a major concern with the setting of specialized container terminals around the world.

Economies of scale rapidly pushed for the construction of larger containerships in the 1980s. The larger the number of containers being carried the lower the costs per TEU. The process became a virtuous circle compounding larger volumes and lower costs. The size limit of the Panama Canal, which came to be known as the panama standard, was achieved in 1985 with a capacity of about 4,000 TEUs (third generation). Once this limit was achieved, we have to wait about a decade to see a commitment to a new generation of containerships. Going beyond panamax was perceived as a risk in terms of the configuration of the networks, additional handling infrastructure as well as draft limitations at ports. By 1996 the fourth generation of containerships was introduced and capacities reached 6,600 TEUs. Once this threshold was breached, the size limits quickly went to the fifth generation (Post Panamax Plus) with capacities reaching 8,000 TEUs.

Each subsequent generation of containership is facing a shrinking number of harbors able to handle them. Containerships above the third generation require deep water ports (at least 43 feet of draft) and highly efficient, but costly, transshipment infrastructures. Containership speeds have peaked to an average of 20 to 25 knots and it is unlikely that speeds will increase due to energy consumption. The deployment of a class of fast containerships has remained on the drawing boards because the speed advantages they would confer would not compensate for the much higher shipping costs. Supply chains have simply been synchronized with container shipping speeds. Although economies of scale would favor the construction of larger containerships, there are operational limitations to deploy ships bigger than 8,000 TEU. Containerships in the range of 5,500 to 6,500 TEU appear to be the most flexible in terms of number of port calls since using larger ships along trade routes would require fewer calls and thus be less convenient to service specific markets. Still, in 2006 sixth generation containerships came online when the maritime shipper Maersk introduced a new class having a capacity of about 14,500 TEUs. This generation will take the new specifications of the expanded Panama Canal, which is expected to open by 2014, so "New Panamax" can properly define it. It remains to be seen which routes and ports these ships would service, but they are limited.