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Posted By Gordon Thelwell
QUOTE: "Is it a legal requirement that the Maximum permitted load be displayed, in writting, on all storage racking used for pallets etc within a warehouse??"
YES it most certainly is.
I am a Pallet Racking Safety Inspector of 15 years experience working for a pallet racking servicing company established for almost 40 years. Please do not mistake SEMA (Storage Equipment Manufacturers Association) 'Guidance' with the over arching HASAWA & relevant statutory provisions, MWR, PUWER, WWSR, etc, etc.
Why is it a legal requirement?
The SWL Sign conveys critical Health & Safety 'Information' and in the event of a racking collapse (of which i have experienced several horrifying events) a prosecution under Section 2 would be included under 'Information', instruction, supervision and training amongst others.
Secondly,
The Health and Safety (Safety Signs and Signals) Regulations 1996 will be applicable due to the required Warning and Prohibition Signs displayed upon a correct SWL Sign;
example here:
http://hometown.aol.co.uk/PalletRacking/swl.PNG
"signboard" means a sign which provides information or instructions by a combination of geometric shape, colour and a symbol or pictogram and which is rendered visible by lighting of sufficient intensity;
PALLET RACKING SAFE LOAD SIGNS minimum requirements:
MAXIMUM SAFE WORKING LOAD
UDL (Uniformly Distributed Load)
Competent Specifier
Conspicuous Locations
Corrosion-Resistant
Mechanically Secured
2.0 m Above Floor
Suppliers Name & Trademark
Safe Working UNIT Load
Safe Working Beam Level
Safe Working Bay Load
Reference Number
Height to First Beam Level & Beam Pitch
Before i expand a little on this subject and perhaps lose a few due to boredom (how boring is racking anyway?!) i wish to make a very important point based upon my experiences as a racking inspector.
Yes SWL Signs are important and it is easy to mistake a correct SWL with the notion that a good sign makes your racking safe. I have often seen perfect SWL Signs on racking that has not been installed correctly, not inspected, not repaired and in some instances down right dangerous.
SWL Signs are the 'easy' bit of pallet racking, if you don't know but want to, ask me. All too often i see companies selling guidance and information for ridiculous amounts of money when, after some digging, the information is freely available on the web. I have done the digging for you, i am committed to this IOSH Forum and will give it freely to anyone who asks for it. Please, please inspect your racking.
Now for the science bit;
Other factors to consider for that effect the SWL.
These points are produced after having made some very “critical” ASSUMPTIONS. In order to better understand them, we must first be aware of one main assumption. THE POST, BEAMS, BRACING & all relevant components and environmental factors are 100% PERFECT IN SHAPE, FORM and DESIGNATED FUNCTION!
Non uniform loads
The possibility of a non-uniformly loaded pallet should be considered. Also the most unfavourable condition must always be taken into account. The non-uniformity of unit load or asymmetrical
placement may be ignored if the effect of the loading compared to the uniform situation is not more than 10%. If not otherwise specified it will be assumed that the pallet or accessory is uniformly loaded and the unit load is placed symmetrically onto its supports.
Variation in range and magnitude of unit loads Where several different magnitudes of unit loads are to be accommodated, it is allowed to define different allowable loads for different aspects of the storage equipment. The specifier may define allowable loads for the upright frame and for overall stability (total rack load) loads that are lower than those based upon the maximum unit load. This variation in allowable loads for different aspects of design is only permitted when a management system is used in an installation to ensure that the lower allowable frame and stability loads specified are never exceeded.
The specifier (the company supplying or manufacturer of the pallet racking), is required to give the maximum unit load per rack configuration and not, for instance, the
average pallet load that may be present in a fully loaded rack. Safe design requires that the rack should be designed
for the maximum possible unit load or load combination that can be encountered. This is because it is possible, at some time in the life of the rack for all of the loading to consist of pallets only of the maximum weight. Also individual components such as beams will be regularly subjected to loading consisting of pallets only of the maximum weight.
Only in specific cases is it allowed to use differentiated design loads as a starting point for designing the individual racking components or design of compartment, bay or rack run. When racks with varying load carrying capacities occur in the same storage area, it is important, for safety considerations, for the maximum permitted load to be clearly indicated for each type of rack design by a load notice.
A pallet with unevenly distributed loading results in racking components such as beams, being unequally loaded.
If a fork lift truck does not place a pallet in a controlled and “normal” way, a larger than normal horizontal force will be exerted on the storage equipment during loading.
A larger than normal horizontal force will be exerted on the storage equipment during loading if either of the following types of misuse occur.
(a) When a pallet is pushed to the back over and in contact with, pallet support bars, thereby creating a large horizontal frictional force (e.g. in the case of a steel stillage when it is tilted forward or backward and two of the four legs are sliding on the pallet foot supports).
(b) When a pallet safety backstop is deliberately used as a pallet buffer backstop to position a pallet load (i.e. the truck driver continues driving until the pallet impacts the pallet stop). In practice this often happens when pallet backstops are provided. The deliberate use of the backstops creates very large impact forces with consequential damage to the backstops and the supporting rack structure. It is therefore strongly recommended always to have sufficient horizontal clearance to minimise the possibility of large impact forces and to use only trained truck drivers who can place the unit loads accurately without the provision of pallet back stops.
If buffering back stops are specified, much larger horizontal loads due to impact forces should be taken into account. e.g;
the design force on a safety backstop should be a minimum of 25% of the maximum unit load.
The actual value of the buffering force for the design however can exceed 100% of the maximum unit load. The requirement for any type of pallet backstop should be carefully considered and clearly specified bearing these points in mind.
I could go on, but by now i'm sure you're losing the will to live. If you wish to learn more, please feel welcome to get in touch.
Gordon Thelwell.
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