In Short: A container’s stow position is a six-digit code showing where it sits on the ship: Bay (front to back), Row (across the ship), and Tier (bottom to top)..

For example, 120682 means Bay 12, Row 06, Tier 82..

Odd bay numbers are used for 20′ containers and even bay numbers for 40′ containers.. Tiers from 82 upwards (or 72 on the largest ships) are on deck..

Some of the people in the industry can identify where a container has been stowed on board of a ship just by reading the stow position (also known as cell position) and also whether it is a 20′ or a 40′ container that is stowed there..

How do they do this..?? Mainly based on experience in handling stowage plans, but there is a formula to it..

I will explain below..

How do you read a container stow position

090482 is an example of a stow position.. This is basically divided into 3 parts

09 / 04 / 82 – where 09 is the bay, 04 is the row, and 82 is the tier – translated into English, it means :-

Bay, row, and tier numbering explained

Bay = each container vessel is split into compartments, which are termed as Bay.. Depending on the size of the ship, it will proceed from 01 to 40 (for example), where Bay 01 is the bay towards the Bow (the front) of the ship and Bay 40 is the Stern (the back) of the ship.. Odd-numbered bays (1,3,5 etc.) mean that it is a 20′ stow, and Even numbered bay (2,4,6 etc.) mean that it is a 40′ stow..

Confused..?? Look at the picture below.. I have used Bay 09/11 (10) as an example here.. What you are seeing here is the cross-section of the ship both on deck and under deck.. Each of the small square blocks represents a 20′ unit space.. The bold lines represent the hatch covers that separate the deck (the part where containers are loaded, which is visible to us when you see the ship) and under deck (which is not generally visible when you are standing outside the ship)..

Row is the position where the container is placed across the width of the ship.. If you refer to the above diagram, the Row numbers are circled in Red.. It starts in the centre and progresses outwards with odd numbers on the right (starboard) and even numbers on the left (port), looking from the stern towards the bow.. Where a bay has an odd number of rows, the centre row is numbered 00..

Tier denotes at which level the container is placed – basically how high the container is stacked on board.. In the above diagram, the Tier numbers are circled in Blue..

Getting back to our stow position 090482 now – in the above diagram you will see that stow has an alphabet R – which I have used for the port of Rotterdam (each line, ship, or chief officer has their own alphabet for the ports).. So what I am saying here is that in stow position 090482 there is a 20′ container that is stowed for discharge at Rotterdam..

So when you see a stow position as above, you will know

09 = bay number, and the container is a 20′ (because it’s an odd number).. If it shows, for example, 10, then the container is a 40′..

04 = row number

82 = tier number, which denotes that this is a 20′ container that is stowed ON DECK.. Usually, ON DECK tier numbers start from 80 and increase by 2 per tier, so it will be 80, 82, 84, 86, etc.. On the largest ships, which can stack 10 or more tiers on deck, the deck tiers start at 72 instead, so the top tiers stay within two digits. If the tier number shows 02,04,06 etc then it’s stowed UNDER DECK..

Four worked examples from a real bay plan

Let’s look at a couple of scenarios from the above diagram..

• Scenario 1 = 090482 is a 20′ container stowed ON DECK on Bay 09, Row 04 and Tier 82 – container is going to R for Rotterdam..
• Scenario 2 = 110482 is also a 20′ container stowed ON DECK on Bay 11, Row 04 and Tier 82, which is basically the adjacent bay to the Rotterdam container, and this container is going to L for Le Havre..
• Scenario 3 = 090202 – which is a 20′ container stowed UNDER DECK on Bay 09, Row 02 and Tier 02, which is the bottom-most tier, and this container is going to D for Dublin..
• Scenario 4 = 100484 – is a 40′ container stowed ON DECK on Bay 10, Row 04 and Tier 84, and this container is going to F for Felixstowe.. This container is basically sitting on TOP of the Rotterdam and Le Havre containers.. Since this is a 40′ container and is sitting across both bays 9 and 11, this bay is given the number 10.. The container is shown as sitting on 9, but the corresponding slot on 11 is marked with an X, which means that this slot is NOT available for placing another container because there is a 40′ container already there..

For reasons of lashing and securing containers, a 40′ container can sit on top of two 20’s, but two 20’s cannot sit on top of a 40′ (unless under deck and surrounded by other containers or within cell guides)

So this is how a stow position is coined and how you identify whether a container is a 20′ or 40′ and whether it is stowed under deck or on deck just by reading the stow position provided..

How have mega ships changed stow positions

Mega ships have NOT changed the bay, row, and tier logic, but they have stretched every number in it.. A Megamax-24 ship, the class that includes HMM Algeciras, carries 24 rows of containers across the deck, 12 tiers in the hold and up to 12 tiers on deck, according to the Port of Hamburg’s profile of the vessel..

MSC Gülsün became the first container ship with 24 rows across the deck when it was delivered in July 2019.. MSC Irina, delivered on 9 March 2023 with a capacity of 24,346 TEU, still holds the capacity record in October 2026, and the large orders placed in 2026 are for ships of around 24,000 TEU, not bigger ones.. Ship size has levelled off, but the number of ships this size keeps growing..

For anyone reading a stow position, that means row numbers running up to 24, around 24 forty-foot bays on a 400 metre ship, and deck tiers that start at 72 instead of 82..

Why do some ships number deck tiers from 72

Ships that can carry 10 or more tiers on deck start their deck tier numbers at 72, because starting at 82 would push the top tiers past 99.. The SMDG (User Group for Shipping Lines and Container Terminals) raised this in May 2011, when Maersk ships reached 11 tiers on deck, and the 10th and 11th tiers would have been numbered 100 and 102..

The SMDG BAPLIE 3.1.1 guide (June 2015) uses 72 as the first tier on deck for ships allowing 10 or more tiers on deck, and 82 for ships with fewer.. So on a Megamax-24 ship, a box on tier 72 sits on the hatch cover at the bottom of the deck stack, and a box on tier 94 is twelve high..

Check which convention the vessel uses BEFORE you read anything into the tier number..

Why is a stow position sometimes 7 digits

A stow position is sometimes 7 digits because the electronic bay plan, the BAPLIE message, sends every slot with a three-digit bay number.. The SMDG BAPLIE guide requires exactly 7 digits in the format BBBRRTT, so 090482 on a printed plan becomes 0090482 in the EDI message..

When a code looks one digit too long or too short, count from the right.. The last two digits are ALWAYS the tier and the two before them are ALWAYS the row, so whatever is left at the front is the bay..

Can I find out where my container is stowed on the ship..??

Yes, but only by asking the shipping line or its agent, because the stow position does NOT appear on the bill of lading or any other document the shipper or consignee receives.. The shipping line holds it in the vessel’s bay plan, and it is worth asking for whenever cargo arrives damaged by heat, cold, or water..

The stow position tells you whether the box was under deck or on deck, how high it sat in the stack, and whether it was in an outboard row exposed to sun and spray.. For heat-sensitive or high-value cargo, agree stowage requirements such as “under deck” or “away from heat” at the booking stage, rather than finding out the stow position after a claim.

My Take: Most people outside the planning office treat a stow position as trivia, and I think that is a mistake.. When heat-sensitive cargo arrives spoiled, the stow position is the first piece of EVIDENCE anyone should ask for, because it tells you whether that box sat deep in the hold or on the top tier in full sun.. The numbering has also quietly moved on, as Megamax-24 ships stack up to 12 high on deck and the SMDG convention starts those deck tiers at 72, not 82.. If your team still reads tier 72 as a typo, it is time for a refresher.. Do you know where your last container sat..??

Article FAQ

What is the difference between a bay plan and a stowage plan..??

A stowage plan shows where every container sits on the whole ship, while a bay plan is the cross-section of one bay within that stowage plan.. Planners and terminals work bay by bay when loading and discharging, and the full plan moves between the ship, the line and the terminals as an electronic BAPLIE message at each port..

Who decides where a container is stowed on the ship..??

The shipping line’s stowage planners decide where a container is stowed, usually working with the terminal’s planners at each port of call.. The ship’s chief officer then checks the plan for stability, lashing and dangerous goods segregation before loading starts, and can ask for changes if the plan is not safe..

Why can reefer containers only go in certain stow positions..??

Reefer containers can only go in stow positions that have a power socket, because they need electricity throughout the voyage to keep the cargo at the set temperature.. These reefer slots are fixed by the design of the ship, so planners usually place reefers first and build the rest of the plan around them..

Critical Note: Does a container keep the same stow position for the whole voyage..??

A container does NOT always keep the same stow position for the whole voyage, because it can be restowed at a port along the way.. Restows happen when the plan changes, for example to reach a container underneath or to rebalance the ship, so the stow position at discharge may differ from the one at loading..