Picture of How to Securely Seal your Shipping Containers

How to Securely Seal your Shipping Containers

A Guide to Shipping Container Security

One of the worst nightmares for any shipper or receiver of a shipping container: your vessel arrives as expected to port, but on unloading the shipping container it becomes apparent that the security seal used to seal the container is not in the condition expected, and cargo has been interfered with, stolen or otherwise compromised.

In this article we provide some helpful explanations and examples of how you can make sure you select a suitable shipping container seal capable of protecting your cargo; how to apply security seals properly, and other considerations to look out for to ensure security seals provide maximum protection to your goods.


The Rise of Shipping Containers

Containerisation emerged as the standard for global sea freight in the 1970s, revolutionising how sea cargo was handled and transported. Its chief innovation was to simplify the handling of endlessly varied types of cargos – by first packing cargo into discrete, standardised shipping containers suddenly freight could be handled and stacked with ease, regardless of its contents. This helped to greatly increase the efficiency of the global shipping industry and led to a huge increase in global trade. Today, shipping containers make approximately 200million trips per year, and shipping container security has become crucial in protecting global supply chains against fraud, theft, drug trafficking, counterfeiting and terrorism.

But the shipping container introduced new problems… for instance, how could shipping lines keep track of what was in each shipping container? And how could governments and customs authorities be sure that what was in a container was safe and properly declared? How could customers be sure that what they had paid for had actually arrived in tact, and without loss, theft or other mishandling? Record keeping and security had to keep up with the innovation, and the Universeal Group were involved in the design of some of the first generation of shipping container security seals to assist in this aim.


What are Container Security Seals?

Simply put, a container seal is a one-use tamper-evident ‘lock’ for a shipping container door, made to withstand the rigours and harsh conditions experienced during global sea freight, and safeguard the container on its journey. Each security seal has a unique security identification number, and once sealed can only be opened by breaking the seal permanently, making reinstatement or re-use impossible.

Today, security seals are required by customs authorities and shipping lines all over the world as a pre-requisite for the movement of shipping containers. The security seal is a crucial part of shipping container security, and it is for this reason that every shipping container has at least one seal applied before shipping. Container security seals alerts stakeholders to potential theft of goods, reduces fraud and counterfeiting, and minimises the risk of unauthorised access. For this reason, Universeal Group continues to evolve our range of bolt and other container barrier seals to meet modern security concerns and produce hundreds of thousands of barrier seals every year.


Which Types of Security Seals Should be Used?

Shipping containers should only be sealed for international freight movements using "barrier seals": security seals designed to provide tamper-evident security and act as a physically strong one-time ‘barrier’ to entry, delaying intrusion to opportunists who might try to access shipping containers. Barrier seals should be ‘high-security’ classification, as certified to ISO17712:2013 standards. ISO17712 High Security Seals are manufactured to an internationally recognised standard which sets out the tamper-evident and physical strength properties which seals should conform to; for example, they should withstand a tensile strength of over 10kN, amongst other requirements.

It is also important to note that certain shipping lines (Maersk Line, CMA-CGM, MSC etc) have their own particular security policies in place, and when in doubt it is best to check with a representative of the respective shipping line as regards suitability of certain types of seals. Further regulations are laid out in the International Ship and Port Facility Security Code (ISPS) and the US Customs-Trade Partnership Against Terrorism (C-TPAT) program, and the security sealing requirements under these regulations have widespread international adoption.


The Bolt Seal – the Container Seal

Different types of barrier security seals can be used in different scenarios on containers, and we have a guide for this also. However, by far the most popular form of seal is the bolt seal, a barrier seal of pin and barrel type construction, and in this article we focus on this type of barrier seal for international shipping.

Bolt seals are made up of two separate parts which include the bolt pin and the barrel. Both parts should be supplied together and have counterpart seal numbers engraved on both parts of the seal…

bolt seal bin and barrel

counter duplicate bolt seal numbering

                        Bolt Seal - pin and barrel

                                 Counterpart duplicate numbering

You should check that your supplier of security seals marks the serial number on the top of the pin head as shown in the images above… certain suppliers only supply less secure bolt security seals with markings down the length of the pin… this is obscured once sealed… (as below image). If the seal number is obscured, how can you be sure the serial number on the pin actually matches the barrel of the seal, and hasn’t been cut and replaced?

obscured markings on shipping container bolt seal
An example of a bolt seal with sequential numbering duplicated along the length of pin - obscured by the locking hasp when sealed in place. If the seal number is obscured, how can you be sure the serial number on the pin actually matches the barrel of the seal, and hasn’t been cut and replaced? Always make sure you use bolt seals engraved with security numbering located on the pin head instead!


Should I Customise my Bolt Seal?

Customised bolt seals

One particular option you may wish to consider is the option to have your bolt seals custom-marked, with a bespoke marking such as your company logo along with custom barcoding or serial number ranges. You can also consider using particular seal colours on rotation, or pre-fix codes for certain kinds of shipments – these types of measures can reduce the ability of fraudsters to replicate seal numbers from blank seals.


How do you Seal a Shipping Container?


Engaging the Seal

Container bolt seals are locked by pushing the pin into the barrel – the barrel has a self-locking system, and once sealed cannot be opened again; a bolt cutter must be used to open the seal, which permanently destroys the seal and makes reinstatement impossible. Slide the bolt through the hole in the locking aperture and insert it into the barrel from beneath the hole. You’ll hear a ‘click’ sound as the bolt fixes itself into the barrel and is secured to the container. Check the seal by trying to pull apart the two pieces – it is not possible to re-open the seal with your hands so you can check the seal is closed by trying to pull the pin and barrel apart again.

sealing a bolt seal

A standard container has two doors, each fitted with locking bars with cams which lock into keepers located at the bottom of the container. The locking bars have handles with holes through which a seal can be attached to. The left door of the container is closed first, followed by the right door, so seals should be placed on the right-hand door for security.

Please note also, that you should be careful to only use barrier seals which have an anti-spin design. One of the known methods of defeating supposedly ‘tamper-evident’ bolt seals is by taking advantage of the free play of the pin available in inferior bolt seals – the pin is spun out of the barrel using a drill, allowing the seal to be opened and then re-sealed without signs of tampering. Our anti-spin designs prevent these kinds of attacks, as the pin cannot move completely freely.


Correct Location for Sealing Containers with Security Seals

The best location to seal the container is at the bottom of the right-hand door, where a security cam with a hole through engages into a special locking keeper. This is the most tamper-resistant location for placing of a security seal, and is the preferred location where available on containers with this anti-theft locking device. However, not every shipping container has this type of modification on the cam/keeper arrangement, and if not then the only other location where bolt seals should be placed is on the handle attached to the locking bar nearest to the door edge (i.e. the leftmost locking handle on the righthand door). It is not acceptable to seal the handles on the left-hand door, as the righthand door opens first.

correct location for sealing shipping containers


Should I use More than One Container Seal?

There is no fixed rule on how many seals you should put on a shipping container, but every shipping container must have at least one seal located in one of the appropriate places. Technically there could be up to six places where seals can be sealed on a shipping container… It should be noted however, that seals do not actually prevent theft and pilferage – a committed thief with the appropriate tools can cut six seals just as easily as one!


Sealing and Recording Security Seal Use

If you are the sender of finished cargo loaded into FCL containers, and you are in a position to do so, we would always recommend that an authorised member of your team is present when the container doors are locked and the seal is applied – an image with time/date stamp can be really valuable in the event of discrepancies. Sending this image to the consignee is always good practice. Additionally, and particularly for LCL shipments, we would suggest that you ask your freight forwarders to send pictures of the seal (with seal number visible) on the container once sealed, again affixed with a date/time stamp. Such images can become very important in the event of loss or damage to cargo, as they can demonstrate to surveyors and insurance companies of the best practice of the parties to the insurance contract, and help them to determine the veracity of the claim.


Port and Customs Requirements for container seals


Shipping Lines and Bills of Lading

Shipping lines will only accept shipping containers for freight movements passing through customs borders with at least one container seal. The corresponding seal should be clearly noted on all road manifests, waybills and/or Bills of Lading to minimise the risk that shipments are delayed through the customs process. Bills of Lading provide key information about each shipping container movement, including shipping line, third parties, container ID number, weights/ classifications of contents, and also the seal number. As an interesting aside, it is thought that the very first Bills of Lading appeared for the first time in Spain, as early as 1544! An example Bill of Lading is shown below for illustration...

Bill of Lading to include security seal number


Customs Agencies and Security Container Checks

The Customs Department of respective national governments have the authority to conduct checks and random inspections on shipping containers passing through their jurisdiction at any time. During an inspection, any trader or freight forwarder security seal previously applied will be broken, so that the container and its contents can be checked against lodged customs paperwork and any discrepancies.

Once inspection is finished, it is likely that a prescribed ‘customs seal’ will be placed to re-secure the shipping container and to keep the contents safe on its ongoing journey. If you see an official customs seal applied to your container you know that your shipping container has been checked by customs authorities, rather than providing an indication that tampering has taken place.

If discrepancies or other issues with the shipping container has been discovered by customs authorities, they may apply one of a number of remedial steps in order to address the situation, which will depend precisely on the nature of the breach. It is important at this stage to take on board all of the customs authorities’ demands or requests, which may include deviating freight to onward freight handling terminals for further investigation, requests for additional customs duties, or other remedial action.


How Do You Remove a Container Seal?

It is suggested that the following steps are taken on receipt of a shipping container to ensure that no tampering has taken place:-

1Before removing the seal, check for any signs of damage or wear or tear. In particular, check seal number engravings – are all characters uniform in size; are they are any signs of abrasion to the plastic on which markings are engraved; does the seal number on the pin of the seal correspond exactly to the barrel seal number?
2The seal number on the container should obviously correspond to the bill of lading number and any other shipping documents presented by shipping lines or freight forwarders. If not, this discrepancy should be immediately raised and investigated with the shipping line.
3If there is any evidence of tampering whatsoever, it is recommended that the seal should only be opened once the shipping line, freight forwarder and/or insurance representatives are present so that agreement is reached by all parties on the appropriate course of action.
4If you see a customs seal on your container, you know that it has been opened by customs representatives, which is within their authority. You should follow any remedial steps that are requested in full to be compliant with local relevant regulations.
5Container seals should be opened using bolt cutters of appropriate strength and size – the seal should be cut across the length of the pin. It is recommended that protective eyewear is worn for this operation, as the forces applied on cutting a seal are large and debris from the seal can be released at high velocity, causing potential injury to vulnerable parts of the body.


What Should I do if My Container Seal is Broken or Missing?

A broken container seal indicates that cargo and goods inside the container may have been tampered or interfered with. If your container arrives with a broken or no seal, you should immediately contact the shipping line and their insurance company, for further investigation and a potential claim for compensation due to loss or damages pursuant to the any breach of contract.

If you do believe that you have been victim of a potential unauthorised tampering or interference attack, the best course of action is to act thoroughly and promptly:-

1Take photos of the seal (if any) and the shipping container.
2Immediately contact the shipping company, your freight forwarder and the company with which you have contracted your maritime transport insurance immediately.
3Do not open the container until a representative of the shipping company is present.
4Once the container has been opened, be sure to continue taking photos of the contents. This is very important in case you want to file a claim against the shipping company.

If you found this article useful, please share with your colleagues and members of the shipping industry. You can also view all Container Security Seals in our range here, including our High-Security Locktainer 2020 Bolt Seals.