This month we look at the need for safety pins following a minor racking collapse and whether these can be interchanged. The second question looks at High level racking and asks if it should always be bolted to a slab.
The job of the Safety Pin
Q. We had an incident recently with a minor racking collapse and issues were raised with regard to the safety pins, our investigator questioned whether the pin actually did its job in preventing the cross beam from coming away and recommended changing the pins to another type of solid right angled pin. Our supplier said the pins come with the racking and were not interchangeable. What is SEMA’s position on this?
A. If you have had a collapse involving a particular manufacturer’s product and have a concern about the effectiveness of any component we would recommend that you approach that manufacturer immediately and seek their opinion.
From the image supplied it would appear this particular product range has been on the market for over 30 years using the same design of pin. It is likely that if there had been a shortfall in the design it would have been a well-known issue within the trade and we have not heard of similar detrimental comment from other sources.
We have seen some non-original locking pins which look very similar however seem to have an inferior specification for the spring steel clip resulting in the pins not fitting snuggly in the holes when in use. This may or may not be the case in your situation.
As far as substituting a different locking pin is concerned then plainly this can be done, however it will likely be entirely at your own risk unless you obtain the approval of the original manufacturer. Without this it is probable that if there were any further incidents, perhaps involving personal injury, then the original manufacturer would decline to provide any technical support on the grounds that their product had been modified by a customer or was not being used in accordance with their operating instruction and was therefore not covered under their warranty!
Locking pins and the holes into which they fit, are designed specifically to resist an upward force of slightly over 1/2 tonne before shearing.
There is no requirement in the Codes of Practice to resist horizontal forces and indeed most systems are designed to allow the beam to pop out in such horizontally abuse-type situations before imposing a larger force on the upright for which it is not designed. This can cause the upright to fail which results in a much larger accident than a single beam knock out usually only involving a couple of pallet locations or so.
Unable to drill
Q. I have read the SEMA documentation on your webpage and researched other papers with similar information relating to warehouse racking. In this documentation you have said that any high level racking should be bolted to the slab. What would you recommend as a solution if you are unable to drill into a slab?
A. Recommendations for floor fixing of racking and shelving are given in the SEMA codes for static pallet racking, static low-rise shelving and static high-rise shelving http://www.sema.org.uk/guides.asp.
In the case of low-rise shelving it is acceptable that the shelving is not floor fixed if it satisfies the rules given below.
SEMA recommends that all other types of static racking and shelving should be floor fixed. In the case of shelving the floor fixing should be able to carry (at least) 3kN in shear and 2kN in tension, for pallet racking these forces are a little higher at 5kN and 3kN. These rules have been in place for over 30 years and have proved acceptable.
It is not stated in codes but the reason that pallet racking should be fixed to the floor slab when it is used in conjunction with mechanical handling equipment is to resist incidental forces due to the handling process and to make sure that the racking or shelving does not move across the warehouse floor.
As noted above, the floor fixing method is normally some sort of screw or bolt although, in principle, other methods could be used provided that they satisfy the performance criteria. Of course you must ensure that the floor slab is able to resist the specified forces; for example there is little point gluing a baseplate to the floor slab if it is possible that the top layer of concrete can simply de-bond from the main body of the floor slab.
It is very unusual to completely prohibit drilling and in almost all cases it is possible to drill into the slab to some extent; in such situations the embedment must be strictly controlled and is normally limited to a particular value. Most of the anchoring suppliers have fixings that can be successfully used at shallow embedment although there is likely to be a cost consequence.
If an acceptable floor fixing solution cannot be found you may conclude that the floor slab is not suitable for the proposed application and either change the floor slab or move the storage elsewhere.
SEMA Technical Enquiries
If you have a query send it to us and we will do our best to have it answered by one of our experts.
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.
Approved Rack Inspectors Qualification
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.
SEMA Publications
SEMA has 26 publications in stock – Codes of Practice, ‘Guides’ and European documents.
SEMA USERS Club
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.
Comments are closed.