The first of our queries this month asks if only pins relative to specific racking should be used and why. Our second query looks at the importance of pallet blocks and their positioning.

Should you use only rack specific pins?

Q. Inspectors often seem to suggest that racking pins should be specific to the racking and if the racking is dislodged the racking will then fold into itself.

I was always of the opinion that the racking pins / bolts were there to help stop racking shelves from jumping out of their uprights if they happened to be dislodged by a lift truck whilst loading stock onto the racking.

They would have no bearing on how the racking collapsed in the event of an impact.

I would be grateful if you could enlighten me on this as I can’t find anything on the type of racking pin required in any of the SEMA guidance.

A. You are correct in stating that the beam safety locks are there to help stop the beams being dislodged by mechanical handling equipment. However, in some instances, they also have a bearing on how a rack may or may not collapse. The SEMA Code only states a minimum uplift force that the beam safety locks should be designed for. The manufacturer designs the safety lock and the connection, including failure modes, to suit the specific requirements of the racking product.

Each manufacturer understands how their beam end connector and safety lock interacts with their uprights and how the connection behaves in certain circumstances. For example, if the locks were replaced by bolts with a higher capacity and the connection was subject to a large rotation, such as failure of the other end of the beam, then the higher capacity lock may induce more movement in the column which may fail the column. This effect may continue along the racking resulting in a more progressive collapse than would have occurred if the correct locks had been used.

There will be times when a non standard lock may be required or allowed to be used, for example, on certain rack configurations with only 1, 2 or 3 bays or dynamic storage systems. However, this decision should be based on the specific requirements of the product and / or the project and should either be specified by the manufacturer or supplier or subject to their approval.

The inspection of the racking should include a check that the correct safety locks have been used and SEMA recommend that the annual inspection is carried out by a SEMA Approved Rack Inspector (SARI) or by someone with a similar level of competence.

In support of pallet blocks

Q. How serious is it to store Euro Pallets on racking that is 800cm deep, such that the 1200cm side overhangs, so that the load bearing blocks on the pallet are not allowed to rest over the beams.

I have a safety concern with this and would like to request SEMA guidance.

A. The SEMA recommendations are that pallet blocks should be supported on the rack beams as without this, pallet quality becomes a serious issue for the safe storage of materials. It is possible to insert pallet support beams into the racking which locate on the front and back beams and support the pallet in the depth between the beams so this problem can be overcome.

If there is a substantial overhang into the aisle it is also necessary to ensure that operating widths of the aisle are still adequate for the equipment being used. From experience it is also difficult to ensure a consistent amount of overhang such that weight is evenly distributed between front and back beams and FLT drivers can operate effectively.

Similarly, care needs to be taken to ensure the space at the rear of the pallet in back to back situations does not result in the pallets touching each other, which in extreme situations can result in product being accidentally dislodged in an adjacent aisle.

Having the correct depth racking for the pallets in use is by far the best solution though in some cases this will not be possible. These situations need to be looked at on a case by case basis with an individual risk assessment and control measures then put in place to reduce the level of risk to the lowest level possible in the circumstances.

SEMA is delighted to be working with WLN on the storage Question and Answer Column which is published in WLN on a monthly basis. On the WLN website is a list of previously published columns which we hope you find useful.

Please note that SEMA Users Club members also have access to a comprehensive range of additional storage related questions and answers.

For more information, please go to

SEMA Annual Safety Conference 2012 – a date for your diary

The 2012 SEMA Safety Conference has been scheduled for Thursday,1 November, the venue will be the National Motorcycle Museum, Solihull.

For full details and a booking form contact SEMA on

SEMA Technical Enquiries

We hope you find the above articles, and those in previous editions, interesting. If you have a query send it to us by fax or email and we will do our best to have it answered by one of our technical experts.

SEMA Rack Safety Awareness and Inspection Courses

SEMA runs a one-day safety course on Rack Safety Awareness and Inspection. These courses are aimed at end users, giving an in-depth look at the need for inspections, how to conduct an assessment and what actions to take when this is completed. These courses are normally held at the SEMA headquarters but arrangements can be made to hold them at the delegates’ premises.

SEMA Approved Rack Inspectors Qualification

This qualification is aimed at professionals who conduct rack surveys as an integral and significant part of their duties. It involves delegates in undertaking an in-depth SEMA Course, together with an examination and practical assessment. CPD will be an important part of the qualification, demonstrating to end users that SEMA Approved Inspectors maintain a high professional standard.

SEMA Publications

SEMA has 26 publications in stock -Codes of Practice, ‘Guides’ and European documents – all of which are available from our Offices. For further information on these documents contact SEMA or visit our website, and click on ‘Codes of Practice’.


SEMA runs a USERS Club designed to be of benefit to purchasers and users of storage equipment. Members receive newsletters, access to specialised events and discounted rates on publications and codes of practice. For further information contact SEMA.

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