Gazb
I was just highlighting the fact that its not possible to use the "ROT" method for this calculation.

I was also interested to find out how many variations we as instructors/examiners are using to caculate an increased load centre SWL

I worked your problem out to 615lbs @ 78" LC

Try this Fomula as used by BT Rolatruc

Rated Capacity X by LC then divide by what you actual got.

works the same as Sean in Co Antrim

Star,

I do not think that anyone is denying the fact that when an attachment is mounted onto the carriage, the data plate reads the new rated capacity, and the number should never be toyed with. However, when an odd-sized load arrives at the loading dock, whether the truck has an attachment or not, the capacity will be reduced based upon the new load center of the incoming pallet, or whether the load is fully engaged, or unevenly distributed.

Not sure about the rest of the world but in the U.S. when we are going to be using an attachment on a lift truck on a regular basis the machine is supposed to have a data plate reflecting the capacities of the machine with that attachment.

I have some customers that have two or three data plates on their machines because they own multiple attachments.

Yes it is great to know how to make the calculations yourself, but for liability issues. It is best to go to your dealer with your lifts model, serial number and mast numbers. Give them the info from the attachment and they can submit it to the factory and the engineers can do the calculations.

That way you and your company have minimal liability and all of the operators can know at a glance what the limits are.

In Europe, forklifts rated <5000kg @ 600mm have to be able to lift the rated load on a gradient of 4% up to 3.25m without tipping. ANSI states that the forklift be rated to whatever height it can lift the base capacity to when on a gradient also. If the operator lifts a load until the back wheels lift off, they are lifting way too much & should be aware of why they shouldn't do so. Besides the tyres, forks, fork carriage & mast might not be rated to handle such a load.

Regarding the post above asking if a forklift can lift more @ a smaller load centre than its rated at? Probably not. in most cases the mast will only have a lifting force equal to the rated capacity. ie a forklift rated to lift 4000kg @ 600mm LC can only lift 4000kg @ 100mm LC.
You could however increase the lifting pressure to override this but it wouldn't be recommended at all.

I think the simplest method for an operator to rate the forklift would be to use the linear rating formula (weight x Load Centre / New Load Centre). It's simple, should cause less confusion & its a bit more conservative than the moments formula that uses the distance from the fork face to the drive axle.

Hi Snowman

It's not that simple. Firstly the forks themselves have a rating that has to be checked - it varies in its own right in respect of distance from the forkface.
Secondly the carriage and its support chains have a rating - you will appreciate that the chains have a safe working limit which relates to the weight of the carriage and forks plus the rated load of the forklift. The rating of those chains may only allow 5000 lb to be lifted safely ever - any increase above 5000 lb could lead to premature failure of the chains. Note that these chains are subjected to high loads in travel with bounce, and an off-centre load could mean one chain is supporting the whole load.
Finally, there is the issue of forward stability - tip-over. A much heavier load means that under braking there is greater force trying to tip the forklift over - for most small forklifts a load equal to 40% of the rated load carried with its centre of mass 800 mm above the floor may cause it to tip over under full braking. A 200% load would cause it to tipover at a fraction of full braking!

Question: Can my 5000 lb lift truck lift 9 or 10000 lb at a 12" center. You say we double the load center we cut in half the load roughly. I think we have increased capacity closer. We don't agree at our shop. To me if the machine remains stable and it does not go on relief valve then it works. No more strain on chains or forks etc. in my opinion.

As I have mentioned several times throughout this board, the problem lies with the enforcers. I am not sure what occurs in other countries however I do find a lack of dedication on the part of government. As long as they allow things as John mentioned to go on, then why should management care whether they have readable plates, propely trained staff, and so on.

When it snowstorms here in Ottawa (Canada, for that matter) no one is thinking about forklift training. When it is too hot, too cold, too snowy, too rainy, too windy, shortened weeks, weeks before shortened weeks, weeks after shortened weeks, hunting season, summer season, Christmas and so on, companies find a reason to procrastinate. Whether they are extremely busy or extremely quiet, it is all the same. Why? Because labour ministries do not enforce the law, and companies figure that they can get away with it.

So misinformed plates, clipboards covering plates, rusted plates, missing plates, lousy trainers, CD and online courses, all rest with the responsibility of government, and as long as they sit in their offices because it is too hot, too cold and so on, and not out in the field enforcing what they should be enforcing, we can talk til we are blue in the face, and companies will continue to procrastinate.

I said what I have to say.

Hi all

Those responsible for a workplace are required to provide the training, knowledge, skills, equipment, protective gear, procedures and culture to ensure the workplace is safe.

Those providing training are required to assist in the achievement of the goal of a safe workplace by being very careful in the information and training they provide.

THe two most basic points in forklift training are for the operator to check/determine the rating of his forklift in respect of the load to be lifted and for the operator to check the weight of the load to make sure it does not exceed the forklift rating. And as all of us invovled in training and retraining know very few operators, experienced or not, can tell you the actual ratings of their forklifts or the weight of the heaviest loads they lift.

By implication all of us trainers and all of the workplace managers and supervisors have totally failed in the most basic task of ensuring forklift operators do not overload their forklifts.

And along with that goes all the things we see to regularly - forklifts with missing rating plates, forklifts with unreadable rating plates, forklifts where the rating plates do not have ratings for the attachments used on them, forklifts where a clipboard had been installed over the rating plate (Simple solution to this problem - don't have the rating plate where a clipboard will be installed - in fact you should never have a rating plate on an engine cover because in sites with lots of forklifts you may have the same forklift with different ratings because of mast and/or attachment differences - if the engine covers on both are removed they may be reinstalled on the wrong forklift) et cetera.

And we have charts on some forklifts showing the loss in capacity with increased distance - but many forklift drivers cannot read graphs - if communication was to be maximised you'd have a table with distances and ratings for the forklift as fitted with its normal attachment. this would require load tables to be customised to each forklift.

And of course every site should have at least one forklift with a weighing scale (one of the larger ones) so that if there is a query it can be used to check the weight before it is moved off a truck.

So perhaps we need to put our efforts into this area rather than the nuance of a "rule of thumb"

Not wanting to start a war here.

As an OEM rep, just had to put that legal stuff in.

I agree, multiple load centers should be stated on Capacity charts when other than non standard forks are employed.

When the manufacture is notified, in written form, from a dealer of fork lengths that are unusual, meaning over 48", a capacity chart will be issued for that unit.

Never should an ooperator exceed the capacity or design of equipment.

Employ the proper equipment to perform the required task,

However my point was it should never be the position of an instructor to even hint that an operator can calculate or derated capacities other than stated on load charts, etc.

.

As instructors we have a responsibility to our students and employers to teach teh fundamentials and principals of safe operation.

Should have read 5000 pounds, not 500, but I figured you knew that already.

Should have read 5000 pounds, not 500, but I figured you knew that already.

Drlifttruck you have finaly put some common sense in the response.

Having said that Dan has a point and as trainers we realy need to unite so we can pressure the engineers to supply charts that can be referenced when that 60" pallet arrives at the dock.

Why Fight lets unite to make our industry safer!!!!

DrL

500lb forklift, 24" load center, 48" forks.

A 60" pallet arrives on a trailer.

Sorry Mr. Truck Driver, I cannot unload this pallet until I contact my manuafacturer to determine whether I can unload this pallet. Oh, I'm sorry. My manufacturer is in Korea and their office is closed. I'll ask my manager whether we can hire a mechanical engineer to determine whether I can unload your truck.

Yeah, right!!!!

Gentelmen,

Your math is flawed. 1 inch = 100lbs!!!!!

Contact the OEM to determine capacity of any given machine, equipted with any number of MFH available, with any given attachment.

ANSI B56.1 and OSHA 1910 29 CFR specifically require that capacity ratings be done by the manufacture or a competent Mechanical engineer.

As trainers it is our responsibility ,and required by ANSI, OSHA, ASME, ETC to train operators about the stability triangle and load capacities.

Not to calucalate load capacites beyond that which is stated on the capacity chart on the lift truck!

Think more speak less.

Regards