operation is a very efficient ocean transport method for general cargo , and represents a major
component of the systems approach to doing business. Some companies have experimented with
hatchless designs which avoid the labour intensive procedure of clamping containers.
Container ship permits fast vessel turnaround, allowing operators to achieve maximum vessel
utilization. The intermodal aspect of the container is very useful to shippers, and containership
operation suits their requirements for speed, efficiency, security, and low costs.
Since the sole purpose of container ships either for the feeder trades or for use in deep sea
services is to carry containers, their design centres on container dimensions. ISO standards identify
a range of containers, the most widely used sizes being the 20 ft and 40 ft containers.
Container ships are generally designed around the 8 ft 6 ins high module, though this also allows a
mix of 8 ft and 9 ft 6 ins containers to be stowed as well. The ISO also specifies a weight standard,
which is a maximum of 24 tons for 20 ft containers and 30 tons for 40 ft containers. These are well
above the average values likely to be found in practice, which may range between 10 and 15 tons
depending on the trade and the type of cargo.
(1)Container ship’s ‘generation’
Smaller container ships of less than 1,000 TEU, often referred to as 'Feeder' (0-499 TEU) and
'Feedermax' (500-999 TEU) vessels are generally used on short haul operations. They distribute the
containers brought to regional load centres by the deep sea services and carry coastal traffic. The
larger vessels, over 2,000 TEU, are used on long haul trades where they spend up to 80 per cent of
their time at sea. There are three groups of these vessels, referred to as Sub-Panamax (2-3,000
TEU), Panamax (3-4,000 TEU) and post-Panamax (over 4,000 TEU). Between the large and the
small container ships is a sizeable fleet of Handy vessels which are small enough to be used intra-
regionally, but large enough to be used in the North-South trades where port restrictions or cargo
volume do not permit the use of a larger vessel.
(2)Fully cellular containerships
Fully cellular containerships carry containers, but have no provision for carrying any
noncontainers on chassis or for carrying any noncontainerized cargo. The latter is carried on-deck as
breakbulk or on flatracks. Carriage of containers sometimes is referred to as lift-on/lift-off (lo/lo)
when compared to the roll-on/roll-off (ro/ro) system.
In some cases, it is not feasible to containerize cargo. This confronted the shipping industry with the
problem of finding a more efficient way of handling a mix of small bulk and heavy and awkward
cargoes, which had moved in the traditional cargo liners but which could not he containerized. To
combine fast cargo handling with greater cargo flexibility, in the late 1960s 'roll on, roll off' vessels
were introduced into the deep sea trades. The ro-ro is a cargo liner with through decks and roll-on