During the course of shipping business, you may have seen or come across the term “Lost Slots”.. In this article I explain what are Lost Slots and possible methods of calculation of lost slots..
I have written quite a few articles about Out of Gauge (OOG) Cargo.. Let me jog your memory a bit..
OOG is cargo that cannot fit inside a General Purpose container and requires special containers such as Open Top containers (OT) or Flat Rack containers (FR) or Platform containers due to the nature and size of the cargo..
The design and carrying capacity of container ships are based on TEU (Twenty-Foot Equivalent Unit) specifications which is 20 x 8 x 8.6 feet or 6 x 2.4 x 2.4 meters.. That is the dimension of a single slot on board a container ship..
These dimensions of the slots are fixed when the ship is designed and fittings are set such that the corner posts of the container sit on it and so that it may be secured to the deck..
In the below image you can see how the deck of a container ship looks like with the securing points for containers to be placed on deck..
Any dimensions above the 6 x 2.4 x 2.4 m will be considered as OOG and containers with such cargo will NOT fit within these dimensions..
For example, if a cargo is loaded on a Flat Rack container (as shown below) and its dimensions are 6 x 3.4 x 3.4 m, the cargo will be over-wide and over-high by 1 meter respectively..
OOG cargoes are (and should be) generally packed in the center of the container for equal weight distribution, so we can assume that this cargo will be protruding over the width of the container by 0.5 meters on each side and 1 meter above the height of the container..
If you look at the below image of a fully loaded ship, you can see how close the containers are loaded and you can see that there is no space for protrusion of any kind as the boxes are tightly stowed..
Therefore if the above OOG container is loaded on deck, no containers can be loaded to the left, right and on top of this container..
If the shipping line has to load this OOG cargo with the above example, they may have to compromise loading a few other containers to the right, left and above this container..
If we take the minimum of say 1 container on each side, it means that the shipping line is losing 3 slots on board the ship in order to accommodate this 1 container..
This loss of space caused to the shipping line by this OOG cargo is called LOST SLOTS..
Because they are losing these 3 slots, naturally the shipping line will have to charge the shipper of this OOG cargo for these lost slots as they are losing revenue..
The calculation of the number of lost slots and the cost for the same will depend on various factors like
- How full the ship is
- How many slots will be lost
- Where would be the most effective and easiest placement of this container to facilitate easy access for loading and discharge
- The port rotation of the ship
- Whether there will be any restows en route or not
A shipping line has to take all of this into account before they advise the client the details of the lost slots and its associated costs..
This is also the reason that the shipping lines sometimes take a while to advise you the costs for OOG cargo, so please be patient..
OOG cargo is not restricted to on-deck loading only and depending on the stowage of the ship, type of cargo, port rotation, OOG cargo may also be loaded below deck where also such lost slots will occur..
In order to assist the line with the exact calculations, when booking OOG cargo, the client must ensure that the exact dimensions and weight of the cargo is advised to the shipping line..
There have been several cases where the client misdeclares the information to the shipping line either out of ignorance or to try and save a few $$$..
But such misdeclarations could end up in extra costs for additional handling, cancellations, vessel delays etc..