Everything you need to know before you join a container vessel.

Bay, Row, and Tier.

The list starts with one of the most basic things, the knowledge of Bay Row and Tier. If you already know this you can skip this paragraph to save time. Ship lengthwise is divided into bays and you can generally find it written on both sides of the hatch cover. So when you are walking on the main deck you can see the Bay number. The image below shows the Bay number marking onboard.

The image shows Bay 33 and Bay 34.
Bay number is also marked on both extreme sides top of hatch covers.

Then we have Rows this is breath wise marking or transverse marking.

The center row is 00. Portside will have even numbers like 02, 04, 06 and so on depending on the width of the vessel, and starboard side will have odd numbers eg. 01, 03, 05.

And now we come to Tier, It is the height where the container is stored. Above the hatch cover, it starts from 72 then 74 then 76, and goes so on. At the bottom of the hold is 00 and just above that will be 02 then 04 and so on.

Example of Tier

The brown container is at Tier 72 and the green one is at Tier 74. in the image below.

In the image below the topmost container is at Tier 78.

With the knowledge of Bay, Row and Tier you can locate any container onboard the vessel.

Knowledge of base lock, Twist-lock and Mid lock.

Base lock

As the name suggests it locks the base of the container to the hatch cover. Always remember to turn the lever right to open and left to lock the container in the base lock. The image below shows 2 baselock. The socket in which base lock is locked is called Base lock.

Mid locks

They are only used in the case of 20 feet container, Mid locks are not required when loading a 40 feet container. As the name suggests it is in the middle of the hatch cover.
The image below shows the mid lock.

Twist lock

Each tier of the container is locked with the other tier of the container with twist locks. If not loaded properly or if the container does not sit properly its because of a twist lock. So while loading the crew keeps a close watch and report if any twist lock problem is noted. The image below shows the use of twist lock.

Container number.

Container marking consist of fallowing –

1. There is a 4 letter code first 3 letters represent Owner code and the last letter represents Equipment category. 
2. The serial number consists of 6 digits followed by 1 number check digit.
3. Below that 4 digit alphanumeric code. (It represents size and type of the container.)
4. Maximum gross – the Maximum combined weight of container and cargo.
5. Tare weight – Weight of empty container without any cargo.
6. Maximum payload – Maximum weight of cargo that can be loaded in a container

Containers also contain CSC certificate image is shown below-