Thanks, John. A very detailed and technical report. I like it.

The basic issue is one of engineering design of forks and forklifts. And i will reference counterbalance fork trucks.

As most of you may be aware, the weight on the axles of a forklift vary dramatically from empty to full. For example a Toyota 7FG25 when empty has loadins of 1470 kg on the drive and 2270 kg on the steer. When loaded the weights are 5480 kg and 750 kg.

The maximum gradeability when fully laden is 30%, and when fully loaded the force being supplied through the drive axle is sufficient to overcome the force back down the 30% slope of around 1790 kg. And this could be in theory sustained continuously.

However the tyres are capable on a good surface of achieving friction factors of 0.6 or more. So the force the drive axles in theory could supply is >= 0.6 x 5480 kg = 3290 kg or 85% greater than the force above. In pushing or pulling something some distance the drive train (gears and trasmission shaft and bearings) would be subject to much higher loads than designed and this could seriously reduce the life of the transmission.

In addition, when initially hitting the object to be pushed, inertia could result in much higher peak forces being applied to the drive train than the design loads.

Even though many forklifts are fitted with what appears to be a towing pin at the rear, this is provided to allow the forklift to be towed onto a tow truck if it has broken down et cetera.

Then there is the issue of traction on say a wet surface when the forklift is empty. The friction factor may only be 0.3 - 0.4 so in the case above the traction force available at the drive axle may be 0.3 x 1460 = 440 kg. So on a 10% slope the maximum weight of the forklift and trailer would be around 4400 kg, and as the empty forklift weighs 3730 kg the maximum trailer plus load weight would be 670 kg. And if traction is lost going up a ramp, the end result could be an uncontrollable slide back down the ramp.

If you want to use a forklift to tow a trailer you need to contact the manufacturer/ supplier and get written advice as to the limits and conditions for safe towing.

Note that when th brakes are applied hard a deceleration of 0.6 is possible so the force at the drive axle can be (5480 + 750) x 0.6 = 3740 kg BUT this force is only applied to those components from the tyre outer surface to the brake drum or disc. Generally none of the drive chain is subjected to high forces when the brakes are applied.

One final note - fork tynes are not a good device for pushing loads as expereinced drivers as well aware - the point loads can cause a lot of damage to pallets etc. I was invovled in one case where hazardous goods were placed on a truck. The forklift operator used a tyne to push 200 litre drums together to ensude they would not move in travel. The drums contained solvent. What he did not notice was that the point load cracked the drum. In travel the truck was passing a school when the leaking solvent caught fire. the resulting toxic fumes from the solvent and the other dangerous goods blew over the school and into its buildings- the end result was that every person in the school had to be decontaminated/ washed down and given full medical checks, the whole school and much of its playground and trees had to be washed down, all items in the school that could not be decontaminated had to be replaced (books and similar educational materials, carpets, curtains...). Very expensive for the company that loaded the dangerous goods, and all because a tyne was used as the pushing device.

Liftman,

You're exactly right. I am selling. I'm selling a solution to a problem. My business is to save customers money. When it comes right down to it, that's how we all try to make a living. If you're not saving a customer money, someone else will. The guy did ask for help. His post seemed to be more focused on application rather than service.

Sound like some one is selling something.
Just stating facts from my 31 years of experience. The Bakers did not do as well, cost more, parts were expensive, and they are harder to work on as are several other brands.
We are a 36 year old service company and the guy asked for help, not a sales pitch.

Bottom line....dont't PUSH loads with a forklift. Use a plow instead. Whether people do it, or not, is not the issue. Should it be done? Nope. Does it happen? Yes. Just because it happens, is it right? Not in my books, nor other trainers on this site, maybe some mechanics as well, and probably the forklift manufacturers.

Liftman,

Why buy a truck such as a TCM just because it's easier to fix when it breaks? The Linde hydrostatic drive will eliminate transmission, differential, torque converter and brake failures. Shuttle applications will also increase the fuel savings that the Linde will provide. The rpm's on the Linde will remain low at travel speeds less than 7-8 mph. The low rpm's not only increase the life of the truck but the service intervals as well. With synthetic oil, service intervals can be extended to 1,000 hrs. Most torque converter brands require 250 hour oil changes.

Buying a truck because it's easier to fix????

The linde does have a hydrostatic transmission which is more for shuttle operations. Check out the parts avability and prices first.
Damage to the mast and carriage rollers, is still an issue not to mention product damage.
Finding a lift truck with a heavy drive train is a plus. I like the TCM which survives the demand of paper recycle operations where bulldozing is a every day event. Repairs when needed are easier and you don't get taken to the cleaners on parts.
Most operations handling freight will at some time push loads. Be prepared to make repairs as a lift truck is designed to "lift", not bulldoze.

Too much agreement here, let me stir things up a bit.
Since you can put attachments like slip-sheet attachments on lift trucks that essentially push and pull loads, I have to assume that there is at least some ability for the front end to handle these types of forces (althought the drive systeme isn't necessarily used for this type of pushing).

Also, in practice there is a lot of pushing/nudging going on with lift trucks. Having spent a fair amount of time as a driver, there are times (especially unloading trailers) where you really have no alternative but to nudge a load into a position where you can then properly get under it and lift it. Also, if you watch drivers in any high volume full-pallet environment, you will see that they frequently drive into the pallet until the load hits the backrest. I say "hits" because they basically have a mild collision with the load. Obviously they could slow down and ease into the load, but that's probably not what they are doing in these very busy operations. I have a hard time beleiveing that the lift truck designs are not built to take these forces.
I'm well aware that this is not the lift truck's "intended purpose" and that pretty much any lift truck safety training will say this is a no-no, and would also agree that there is no valid reason to push a load across any significant distance, but in practice, nudges are a reality and lift trucks better be designed to handle the forces that occur when you nudge a load.

You may want to try a Linde.

If you are pushing load directly on the floor with full load resistance, you will have transmission damages. Like you are driving an automatic vehicle with parking brakes on. Anyway like others had said, forklifts are used for lifting and not pushing loads.

Either way it will be done by the driver '''''''

Or to anyone enforcing the laws!

I don't see a problem with pushing dollys and we all know pallet pushing has always happened!!...just don't mention the practice on a warranty claim!

What if the cargo is on a slave pallet that has wheels? (Sort of like pushing a wheelbarrow)

The intended purpose for a lift truck is to lift. The truck was not designed for pushing things, and since pushing items is not its intended design, pushing items with a forklift is not acceptable!