I wholeheartedly agree. Take the revised info (new lowered capacity) off the data plate, and then subtract the approx 1=100lbs.

Pretty obvious, tho'.

Just a bit of food for thought when considering applying (or not applying) the "rules of thumb" in quesstimating the capacity at an extended load centers, it seem every one starts with the base rated capacity of the machine (3000, 4000 (kg or lbs) etc.

In the US 3000 to 6500lb base capacity cushion, pneuamtic or electric forklifts are most commonly (80%+) equipped with a 4.8 meter (188") triple mast and side shifter and typically the net capacity of this machine is 400 - 600 lbs less than the base of the machine. This is the point from which any derating guesstimates needs to start.

Hi Dan

I understand where you're coming from though you do contradict yourself - you state "They will pick up any load and determine whether the back end starts to lift" inferring they have no idea of the weight of the load.

You go on to say "I am sure that many other safety instructors on this board will agree that many of their students are not even aware of the lifting capacities of the trucks they are operating" and then you promote the 1" = 100 lb rule. In the scenario above any rule is irrelevant.

In respect of charts I'm referring to charts prepared by management relating to the actual work forklifts do. If they load items to the centre of trucks the chart would say the maximum load for that movement was X lbs. If because of site layout and product type they have to place goods on the far side of a truck it would give a maximum of Y lbs and so on.

And management is obliged to put systems in place to ensure operators know the weight of loads they lift - otherwise in any fatality or serious injury situation they are wide open to being found negligent.

As trainers, we can take the time to digest all this info and evaluate each situation as it arises. As far as the average forklift operator is concerned, he/she will not take the time to establish the actual weight of the load vs. the capabilities of the forklift. Although they should, in real life, you, I, and a host of others know better. They will pick up any load and determine whether the back end starts to lift.
The 1"=100lbs is a simple, straight forward determination that most can understand so the operators can get a general idea as to whether they are within the lifting capacity of the forklift.
It is best to keep it as simple as possible because if the info goes over the heads of the operators, they will not listen, and worse, not practice what is taught.

And this contiues on to many other topics on this board where the letter of the law is quoted, and this is the way it is. If you understand where many of these operators are coming from, then you will soon learn to realize that they do not want to be in that classroom. They are there only because they HAVE to be there. And if an instructor is going to complicate the issue, the attendees will snooze. They want in/out in the shortest period of time (my students have to be patient) but if the topic is kept light and easy to understand, you may very well win them over. But you cannot complicate matters. We are not dealing with engineers, doctors or scientists. Most of my students have not attended college, and some did not even finish high school. And being too specific on many matters pertaining to forklifts, will definitely confuse them, resulting in the students ignoring what is being taught.

Yea, maybe manufacturers should place some type of chart explaining the capacities based on a variety of circumstances but I am sure that many other safety instructors on this board will agree that many of their students are not even aware of the lifting capacities of the trucks they are operating. Sad, but true. Do you think they even bother to read all the warning decals on the truck?

So, what is required is an easy formula for them to quickly determine the weight of the load they are lifting based on load centers greater than 24", and in most cases, the 1"=100 lbs is the simplest and easiest to remember. It may not always be accurate, but it does fall in close proximity to keep these operators from overloading the forklift, killing themselves, or someone else.

Hi all

Pity you can't put diagrams on here.

There are a limited numbers of concepts trainees need to understand:
Firstly there is the seesaw concept where the seesaw fulcrum is the drive axle of a counterbalance forklift - the relevant distance is the rated distance plus the extra distance to the drive axle - if you double that distance then you have to halve the load. For example if the forklift has a 24" load centre and a 16" distance from the fork face to the drive axle the relevant distance is 40'. Doubling that to 80" halves the rating with the load centre than being 80 - 16 = 64" from the fork face.

Secondly there is consideration of the forks themselves. I have nothing in writing from any fork manufacturer but have evidence to support that forks fitted to forklifts are often, or maybe rated higher than the forklift, and that forklifts rated individually at a certain rating may be downgraded as a pair presumable to allow for the fact that loads are supported offcentre be typically 30 mm on average. Hence a pair of forks individually rated to 4000 kg at 24" may be rated as a pair at 7500 kg at 24" and may be fitted to a forklift rated at 7000 kg at 24" (this is the actual situation in an investigation I am involved with into a case where two forks failed completely and concurrently at the heel after three years use). For forks the allowable load halves as the distance from the fork face doubles. So in the case above the load centre goes from 24" to 64" and hence the allowable load on the forks is reduced to 24/64 = 37.5% of its rating at 24" or a little more than a third of the forks original rating.

Thirdly there is consideration of any attachment being used, its rating with load distance, and the impact its weight and the degree to which it alters the actual load distance affects the forklifts rating. For example fitting a third party side shift adds weight and usually also means the forks are further from the drive axle so the two factors combine to reduce capacity.

Finally there is the serious matter of side stability. No forklift manufacturer I'm aware of provides customers with information as to whether side stability(rollover) or forward stability (tipover) is the controlling factor in rating the forklift. If it is side stability that is the issue then in rare situations all the calculations above may be irrelevant when the forklift is being operated at or close to maximum height.

So my advice is and always will be that the manufacturer should be invovled in determining the capacity of the forklift at different load centres and/or with different attachments. Every forklift should be fitted with a laminated chart that shows the actual capacity versus attachment and load centres for all situations likely to be encountered in the workplace, that all loads have mass estimates shown on them, and that at least one forklift (preferably the largest or one of the larger ones) is fitted with a load measuring device so that where the weight is not known that forklift can weigh the item to determine which forklifts can safely handle that item.

The 1"=100lbs works with most attachments and odd sized pallets and loads, but not with a carpet pin. The force of the load (carpet) is concentrated along a very narrow path, unlike a pallet, which has loads as wide as 48", sometimes wider. Therefore, the formula regarding carpet hauler forklifts is different. and as you can see, doesn't work, or apply in thia instance.

Dan

John Lambert.......You have considered the 78" carpet boom would probably have a 40" LC.

In the UK a normal carpet prong attachment is 4 metres in length.

Therefore 4 metres = 156" so the LC would be at 78"
Once again im having a problem in explaining to my trainees about using this 1"=100lbs reduction.

Truck rated capacity 2000lbs @ 24"
156" prong with a LC at 78"
LC increase of 54"
Reduce capacity by 5400lbs

Perhaps its just me, but you cant possibly use this rule of thumb calculation.

Guys first of let me wish you all a happy new year!

Ive read all your replies and the one thing thats very clear is theres so much confusion regarding this derating calculation.

I appreciate the fact that its a complicated issue when you consider all thats involved.

My reason for starting this topic was to find out how many different variations of the same subject are being used.

I suppose the forklift are no different here in Canada as they are in Australia, Same crap goes on here as well, except it is much colder, and snowier. How about I FEDEX you some?

Actually, I may have some training to do in the next couple of weeks in Iqualuit, Nunavat (?), in the Candian Arctic, about a 3.5 hour flight north of Ottawa. As in the desert, this land is beyond the tree line. Some of these guys are probably Eskimos. But who cares...it is the law there as well, and although I hate the frigid temps, and even shorter days, it shall be an experience that one should not forget.

That's fine Dan

Keep up your passion.

Aussies are a lot like Canadians - both live in big countries with not much population - your country has a very cold "desert" area; and ours has a very hot desert area.

My biggest concerns are that the operators I retrain a) don't know the capacity of their forklift if you ask them b) often have clipboards inslalled over the load plate and/or ilegible load plates and/or load plates that do not show the capacity of the forklift with its attachments, and c) they don't know the weight of what they are lifting because it's not marked with a weight in any way.

Makes one beleive that most training is totally ineffective when they don't follow the most basic rule to check the capacity of the forklift and check the weight of the load before you lift it

And considering that the vast majority of forklifts I train upon are pretty much rated between 4000 and 6500 lbs, 1"=approx 100lbs., sounds good.

I think that if I was brought into litigation, I would have plenty of support from the industry to back up my teachings.

What I am concerned about, though, are students not paying attention, even though they were instructed, when acquiring these lengthy pallets (loads), and end up hurting themselves, or wrecking the forklift.

Knock on wood, all's well!

Dan

Appreciate all you say as I too train operators.

In regard to the steer wheel lift off I explain to operators that if that is happening they are lifting 40% to much - 1400 kg when they should only be lifting 1000 kg. And that the result of overloading is that the forklift will tipover even more readily.

Consider the 78" carpet prong mentioned - would probably have a 40" load centre. The 100 lb per inch rule would say reduce the capacity by 1600 lb.

So for a 2000 lb forklift the predicted capacity would be 400 lb. The actual capacity would be over 1400 lb.

But for a 10000 lb forklift the predicted capacity would be 8400 lb but the actual capacity would be only 7100 lb. At 8400 lb it would be around 20% overloaded.

My suggestion for you if you beleive that you need a "X lb per inch" would be to relate it to truck size say:
2000 lb - 3500 lb 50 lb/in
4000 lb - 6500 lb 100 lb/in
7000 lb - 8000 lb 150 lb/in
9000 lb - 12000 lb 200 lb/in...

You'd have to do your own risk assessment and develop your own values for the rules keeping in mind that if there was a serious incident that resulted from someone using your rules you might be drawn into litigation.

John,

It all depends on which 'people' you are quoting who should have a complete understanding of this concept.

I am not quite sure of the educational levels of the operators you are training in Australia however, many of the operators that I train here in Canada are doing this work for one main reason...they could not tolerate sitting in class all day when they were attending school. Several of them have not even completed high school (secondary), let alone pass their math classes.

When I ask how much is 5000-600=, some cannot even provide the correct answer. This does not apply to all my students, but a fair number of them.

When attempting to deliver this information in the lowest common denominator, the K.I.S.S. principle is mandatory. Adding, multiplying and dividing goes beyond the intelligence level of many. They need a relatively quick and easy means of approximating the weight of a load based upon different load centers. If an instructor is only going to confuse the **** out of them, than what's the point of teaching these materials. As instructors, we are there to teach them forklift dynamics, not math. And I can only vouch for my students, that 7 of 10 would fail to comprehend your formula, thereby, not putting these calcualtions to work when an oversized load is being acquired.

State all the laws and principles you want, and I fully wholeheartedly am a zero tolerance guy when it comes to forklift safety, but try teaching the 'book' to a bunch of guys working in some dumpy warehouse in eastern Kentucky. Chances are, they will pick the load up regardless, and when the rear end starts to lift, then they will put the load down.

I am not in arguement with you at all. I am simply stating that if this forklift safety stuff becomes too complex for them, they will just continue to do their own thing, their way, and the time spent educating thse operators would be for not.

Now, if these 'people' you talk about are on the management level, that is a different story. Management generally possesses a better comprehension for these matters, and math, but how many times do you end up training the operators, and a shirt/suit/tie is nowhere to be found?

So as I said earlier...5000x24/36=HUH?

RPM7 - excellent

Forklift safety demands that people understand the issues completely.

The degradation in capacity of the forklift tynes (forks) is faster than for the forklift because the formula only considers the distance from the fork heel. A fork rated at 2500 kg @ 600 mm will be rated at 2500 * 600/900 = 1670 kg.

However for a counterbalance forklift with a distance of 400 mm from the centre of the drive axle to the fork face of 400 mm, the formula is 2500 * (600+400)/(900+400) = 1920 kg.

For that reason some forklift manufacturers actually fit forks with a higher rating than the forklift. For example if they fit forks rated at 3000 kg @ 600 mm in the case above, then the fork rating at 900 mm is 3000 * 600/900 = 2000 kg which is close to the forklift rating as a whole.

Finally in regard to the 100 lb/in rule that started this discussion. That rule of thumb only applies to forks with ratings of 3000 - 4000 lb (with an error in the range of up to 20%), or coounterbalance forklift trucks with a distance from the centre of the drive axle to the fork face of 16 inches (400 mm) with ratings of 4000 - 5500 lb (with an error in the range of up to 20%). SO MY RECOMMENDATION IS TO NEVER USE SUCH A RULE.

If you want to be conservative you use the fork strength related rule of "rated load" x "rated distance" / "larger centre of mass distance".

BUT ALWAYS KEEP IN MIND THAT AT FULL HEIGHT, ESPECIALLY FOR LIFT HEIGHTS OVER 4500 mm THE SITUATION MAY BE MORE COMPLEX AND YOU SHOULD CONTACT AND GET ADVICE FROM THE MANUFACTURER/ SUPPLIER.

I find that the rating of a forklift has to take three aspects into account.
1st: the strength of the forks
2nd: the strength of the mast & finally the counterweight of the forklift itself.

If the forks are rated for 2500kg @ 600mm (the formula for them will be (2500 x 600)/(new load centre).
The mast is rated similarly.
For the amount the forklift can counterweight using moments the formula is the same as some guys have mentioned above.
For example. A forklift rated at 3000kg @ 600mm Load centre with front overhang (dist of front axle to front of fork) of 200mm. Has to lift @ 1000mm Load centre the formula is.
(3000*(600+200))/(1000+200).

In a nutshell what I'm saying is that the most a forklift can lift will be what the forks are rated to and after that you can use the moments formula as long as it's values are less than the forks.