The Basics - Forklift 101

In Its Simplest Form, a Forklift…

• Drives / Travels• Lifts / Other Hydraulic Functions• Utilizes Basic Hydraulics to Accomplish

Work

Basic Hydraulics

• Liquids cannot be compressed• Liquids can assume any shape and be

bi-directional in free flow movement• Pascal’s Law states that when a

confined liquid is placed under pressure, that pressure is transmitted, without change in intensity equally in all directions

Basic Diagrams

Multiplied Forces Do More Work

• Principles of basic hydraulics allow forklifts to lift heavy loads

Pressure / Flow Must Be Created

• Hydraulic pump – Usually gear type are utilized to create flow

Basic Hydraulic Diagram• Various Components Work Together to

Accomplish the Work

Forklift Hydraulic Components• Hydraulic Reservoir (Tank)• Gear Pump ( Creates Flow / Pressure)• Control Valves (To Direst Flow)• Control Valve Levers (Direct Manual)

– Electronically Controlled (Joystick, Fingertip controls)• Connectors – Steel tubing / hosing / fittings• Cylinders (To Do the Work!!) Single Acting / Double Acting

– Lift cylinders– Tilt cylinders– Steer cylinders– Sideshift cylinders

Various Power SourcesEngine Powered Forklifts

Fuel Advantages DisadvantagesGasoline Readily available, good power & performance,

can run continuously, small & medium forklifts, high power to weight ratio, starts well in cold

Emissions, should not be used indoors, volatile costs, storage and refueling regulations

LPG Readily available, easy refueling & tank storage, small & medium forklifts, cleaner burning, good power & performance, can be used indoors, can run continuously, usually costs less than gas

Tank change-outs might be difficult for some, volatile costs

Diesel More durable engine designs, medium, large and extra large forklifts, sometimes better performance & power than gas and LPG, can run continuously

More pollutants, cannot be used indoors, volatile costs, storage and refueling regulations, might not start well in cold environment

Dual Fuel An engine that runs on either gas or LPG, better flexibility and good for rental fleet trucks, can run continuously

Possibly more maintenance, volatile costs, possible refueling issues

Various Power SourcesBattery Powered Forklifts

Fuel Advantages DisadvantagesLead Acid Battery

Readily available, various sizes and capacities, utilized as part of the counterweight, zero emissions & no noise, lower maintenance costs

Purchasing fuel upfront, higher initial cost, replacement usually necessary, disposal complications

Fuel Cell Old technology just making its way to forklifts, water is by-product of process, quick refueling for long running times, zero emissions

Durability concerns, very high acquisition costs & refueling station costs, not yet mainstream, not as efficient as “hybrid” noted below

Hybrid Emerging technology, Komatsu the world’s first electric hybrid utilizing battery & capacitor for power, extended run times, zero emissions & noise, no hefty investments needed

Higher costs than normal lead acid battery, must recharge overnight at least weekly, battery replacement necessary after 4 yrs., paying for fuel upfront, possible disposal complications

Forklift Terminology Acronyms Etc.

• Mast• Upright• MFH• OAHL• FL• LBR• OHG• QD

• OSHA• CARB• EPA• FPM• TOPS• kW• kN• dB

• IHR• MPH• FPM• PSI• Ah• HP• ITA• ANSI

• Nm• WB• RPM• U.L.• NFPA• Towmotor

Lift Truck Main Components

• Chassis

• Counterweight

• Mast

Counterbalanced Forklifts

• 99.9% are front wheel drive and rear wheel steering

• Why?– In a loaded condition all of the weight is over the

drive axle for maximum traction and braking power!!

• In a turning situation, the rear end of the truck swings while the front end stays stationary

Hydraulic pump

Engine Powered Forklift

PS motor

Battery Powered Forklift

Mast Specifications• OALH – Overall Lowered Height

– The distance measured from the floor to the top of the mast when it is fully lowered and vertical

– Critical for entering low clearance areas & doorways• MFH – Maximum Fork Height

– Distance measured from the floor to the top of the forks in the full raised position

– Critical to achieve the desired height to put-away a load• FL – Free Lift

– Distance the forks can be raised without the overall lowered height of the mast increasing

– Critical when working inside of a trailer or other low clearance areas• Ratio of OALH to MFH

– Usually the same, but may vary based upon mast overlap / retention

Mast TypesOAHL - overall height lowered

FL - free lift

MFH - maximum fork height

OAHL

FL

Mast Types

2 Stage Free View Mast

• Large open visibility window

• 2 Main Cylinder design – typically mounted behind rails.

• Limited free-lift. 0 ~ 6”

Mast Types

2 Stage Full Free View

• 3 cylinder design• 2 Main rear cylinders• 1 Center cylinder is for freelift• Full free-lift capability

Mast Types3-Stage Full Free View

• New UltraVizion Mast System (BX50)

• 3 cylinder design• 2 main cylinders• 1 center cylinder for free-lift

• Full free-lift capability

4-Stage Full Free ViewAvailable on some models

Carriage Types4 Roller Carriage

AX50 standard

• Ok with forks or SS. & normal load widths

• Option of 6 roller for all other attachments, long load centers or wide loads

Carriage Types

6 Roller Carriage

AX optional

BX standard

CX standard

How do we classify carriages?

Class II – 16” – Up to 5,500 lbs.

Class III – 20” – 6,000 to 10,000 lbs.

Class IV – 25” – 11,000 lbs. Plus

Carriage Types

Carriage Types

Increased roller span.

Reduced roller load & roller surface pressure

CarriagesWhat are the advantages of 6 roller?

Lower surface pressure on load roller face and mast channel

Force

Lower Moment

Higher Moment

Forks

Hook type forks

• Most common style

• 3 typical sizes

Dimensions

Class II – 16”

Class III – 20”

Class IV – 25”

Pin or Shaft Type Carriage•Generally used on larger applications and larger capacity trucks such as EX models

Forks

Forks

ForksStandard taper pallet fork -Typically a fork that has other than a full taper; commonly thisis one-third of the fork blade length. Fork length shouldtypically cover a minimum of 75% of the load length

ForksFully polished & tapered Fully tapered bottom (from heel to tip) with a polished topsurface

Other Fork TypesBlock fork Generally a narrow, almost square stock that will easily fitmost concrete block.

Gypsum or Sheetrock forksGenerally common to the lumber fork with a rounded or bevel side edge and/or a padded vertical back to prevent product damage.

Lumber fork Typically thin, wide fork fully tapered and polished with a chisel tip IE: 1.5” x 10”. The increased width is necessary to maintain fork capacity.

ForksFork Extensions

What is the rule of thumb on fork extensions vs standard fork length?150% of the standard fork length. IE: 48” fork can support up to a 72” fork extension.

Stability

Stability of Forklifts

• Forklifts can and will tip over if overloaded, or if they raise a full load higher than permitted

• As a Sales Professional you should fully understand the static and dynamic principals of forklift trucks in order to recognize and assure safe operation

Load

Fulcrum is drive tire

Counterweight

Stability of a Counterbalanced

Forklift

• The fulcrum point of a counterbalanced forklift is the center of the drive axle

• Forklifts work on the principle of a teeter totter. You have a pivot point (drive axle center) and counterweight (CW) at one end to offset the load weight (W).

• Too much weight will cause it to tip over. (or) if you move the weight further out from the pivot or fulcrum point it will also cause tip over.

Teeter Totter Principle

CW

Counterweight Makes All The Difference

Load Capacity• The load capacity of the forklift truck is a measure to indicate the maximum weight load that can be handled as a “load” on the forks at a given “load center” with the mast held in a vertical position

•The load capacity rating is expressed in pounds (or kilograms) at the load center in inches (or millimeters) The chart of the load capacity is referenced from the operator’s seat on the truck’s data plate

50004400

39002800

2400

24 30 36 40 48

500PG

Load CenterThe load center is specified as the distance between the center of gravity of the load on the forks and the vertical front face of the forks.

Weight Distribution

• Wheel loadings / weight distribution can be very important in applications where there are floor loading limitations– Elevators / multiple floor buildings / trailers

• Empty forklifts have most of their weight in the rear of the truck when unloaded

• A forklift undergoes the greatest change in weight distribution when a load is placed on the forks– As much as 90% of the weight is shifted to the drive axle

when the truck is fully loaded

Front Rear

3,740 lbs 3,300 lbs.

Total weight = 7,040 lbs.

Front Rear

10,340 lbs. 1,100 lbs.

Total weight = 11,440 lbs.

Example of Wheel Loading of 400PG

Unloaded (Empty) Loaded

3,740 3,300 10,340 1,100

Load Center

The horizontal distance between the face of the forks and the center of gravity of the load it is carrying is called the load center

Be Cautious of Long Load Centers!

• Long load centers have a very detrimental effect on the forklift– It transfers more weight off of the rear axle causing

truck instability and possibly tipover!!• It is like placing an overload at the normal load

center of the forks!!• Consult the factory for capacity ratings at

extended load centers• Anything greater than a 24” load center will

reduce truck capacity and have an effect on truck stability!!

Long Load Centers

Truck Center of GravityThe Center of Gravity of a forklift changes as the mast is tilted or raised. This is important since all forklift capacities are based upon the location of the C of G. This also changes the wheel loading on drive and steer tires.

The illustration show the effect on the C of G as the mast is tilted forward or backward.

HCG = Horizontal Center of Gravity

The illustration shows the effect on the C of G as the mast is raised or lowered.

As you can see as the load weight moves up or down the VCG (vertical center of gravity) also changes.

Truck Vertical Center of Gravity

Combined Center of Gravity

• An empty forklift has a center of gravity and the load has a weight and its own center of gravity

• When the truck picks up the load, the center of gravity of the truck shifts forward

• As longs as the combined center of gravity of the truck and the load is located between the front and rear axles, the truck will remain stable

• If the combined center of gravity of the truck and load is beyond the centerline of the front axle, the truck will tip over

Combined Center of Gravity

Dynamic vs Static Stability

• Static stability is measured when the forklift is standing still

• Dynamic stability is the transfer and shifting of the CG due to dynamic forces such as:– Traveling / braking / turning / lifting / lowering

The Stability Triangle

The Stability Triangle• Stability is the result of many

factors– Wheelbase / overall width at

the front axle / weight distribution / lifting height

• Stability refers to longitudinal and lateral stability, the stability triangle, and dynamic vs. static stability

The Stability Triangle

• Point “A” = Center pivot point of the rear steer axle

• Point “B” and “C” = Straight line between centerline of each drive axle

The Stability Triangle• When a load is

placed on the forks, the center of gravity of the forklift moves forward

• Ideally the CG must always stay within the stability triangle

The Stability Triangle

• This diagram shows the effect of having the mast vertical and using a sideshifter

• The load causes the CG to shift forward and sideshifting from side to sideshifts the CG to the right or left

The Stability Triangle

• DANGER!!– Load is too heavy and too

far out on the forks and the CG has shifted outside of the stability triangle!!

The Stability Triangle

• Danger!!– The load is not stable and

the heaviest part is out in front of the CG creating an unstable situation!!

The Stability Triangle

• Danger!!– The load is not stable and the

heaviest part to one side! When turning the momentum will shift further to the side creating a dangerous situation!! The truck could tip over laterally!!

Stability of Elevated Loads

• Tilt table tests determine at what point the truck becomes unstable and downratesthe truck accordingly to maintain stability with elevated loads

To Maintain Truck Stability

• Always use caution when– Lifting– Tilting– Turning– Braking– Traveling with an elevated load– Traveling over uneven floor conditions

• Always keep the CG within the stability triangle!!

Tilt Table Testing

• The rated capacity and stability factors of a forklift are determined by tilt table tests with criteria established by the ISO (International Organization for Standardization) and ANSI/ITSDF B56.1

• The static center of gravity is definitely not the final determinant of forklift stability

Capacity Ratings and the Data Plate

Data Plate

Truck Model

Tire size

Service Weight Electric

Attachment

Serial Number

UL Type

Tilt Angles

Load center

Attachment 2

Attachment 3

Attachment

Vertical CGLift Height

Service Weight IC

Capacity

Battery Weight max.

Battery Weight min.

Battery capacity

Importance of the Data Plate

• Every truck must have an accurate, legible data plate• Any approved modifications to the truck must be reflected on the

data plate• Data plates show both English measurements and metric• No changes or modifications can be made to the truck without

written approval from the manufacturer– Any change that effects truck stability i.e.an attachment, longer forks,

etc.– Critical to meet OSHA regulations– A truck without an accurate data plate can be removed from service

Capacity of a Forklift

• Is determined by two factors– Weight of the load– Distance of the load’s center of gravity from the face of the forks

• Almost all manufacturers of forklift trucks have standardized onrated capacities at 24” (600 mm) load centers for models up to about 30,000 lb capacity

• The load center is the horizontal distance between the vertical front face of the forks and the center of gravity of the load

• Therefore a 5,000 lb. capacity truck rated at a 24” load center can lift a load that weighs 5,000 lbs. that is 48” long provided the load weight is evenly distributed

Understanding Metrics

Metric Standard

1500 kg @ 500 mm L.C. = 3,300 lbs @ 19.7 in L.C.

= 1,360 kg @ 610 mm L.C.

US Standard

3,000 lb @ 24 in L.C.

A typical load capacity chart shows a forklift truck’scapacities at many load centers. These ratings take intoaccount all dynamic and static stability factors.

50004400

39002800

2400

24 30 36 40 48

500PG

Inch-pound Ratings

Lift Truck Performance & Specifications

Key Measurements

• Discriminating buyers look closely at truck specs to compare competitors

• How do we “measure-up” vs. the competition?• Key specifications:

– Overall width / Overall length / Overall height / Head length / Under clearance / Wheelbase / Outside turning radius / Right angle stacking width / Travel speed / Lift speed / Lower speed

• Key individual specifications represent the forklift’s work capability and suitability for your customer’s application

Truck Dimensions

• Truck width is a critical measurement because it effects the truck’s ability to work in specific areas such as:

Go through doorways / Work in drive-thru / drive-in racking / bulk stack

If the truck is wider than the load, bulk stacking more than one pallet deep could be a problem

The wider the truck, the greater the turning radius will be

Truck Width

• Overall height is critical for working inside of trailers, box cars, and containers

• Overall height is also critical for getting through facility doorways

• Highest point could be OHG or mast – OHG height is usually fixed, mast could be variable

Overall Height

Wheelbase• The wheelbase does not relate directly to maneuvering dimensions (except grade under clearance), but it does affect truck behavior

• A long wheelbase requires a greater angle of wheel steering and results in less efficient steering operation

• The shorter the wheelbase the easier to steer

• This dimension is important when figuring right angle stacking and dimensions for a working stacking aisle

Length to Face of Forks

• The turning radius is the radius of the smallest possible circle in which the forklift truck can turn

• Turning radius is effected by overall truck width and steer angle

Turning Radius

• The under clearances of the truck frame, mast, drive, and steering axles can be significant if there are surface irregularities or obstacles.

• Not all under clearances are indicated on specification sheets. The mast clearance is generally the lowest point and, therefore, most often listed.

• In backing up over bumps or obstacles, the rear (steer) axle clearance is important. Pneumatic-tire trucks have higher under clearances because they are intended for poor surface conditions

Under Clearances

• The operator must know the truck’s grade angle capability for operating on ramps or over dock boards and dock plates

• The incline (in terms of percent) on which the center of the frame under clearance will just touch when the truck is going down from the level to the ramp or when the truck is going down from the level to the ramp or when the truck is going up from the ramp to the level is important

• And the so called departure angle (from the wheel arc to the truck edge) of the counterweight is also essential. But, in most sales literature, gradeability is substituted for the grade angle

Grade Angle Clearance

Grades and GradeabilityHow do we calculate grades and gradeability??

Note: Always drive backwards up a ramp

GradeabilityHow to Calculate A Grade

Percent of Grade = vertical ramp rise / horizontal ramp length0.20 = 20% Ramp Grade

20 4.0

Conversion Percent to Degrees

Percent Degree of of Grade Ramp Angle

25% 14.0320% 11.3115% 8.5314% 7.9613% 7.4012% 6.8511% 6.2810% 5.719% 5.158% 4.587% 4.006% 3.435% 2.864% 2.303% 1.712% 1.151% 0.56

20 ft

4 ft Calculating a Grade and Gradeability

Operator Restraints• Operator restraint systems are designed

to keep an operator within the confines of the operator compartment in the event of a truck tip-over

• Systems include:– Seat belts / Seats with hip or shoulder

restraints / Hood latches / Battery restraints / Decals / Operator manual instructions

Industry Organizations

Industry Organizations

ANSI B56.1 > American National Standards InstituteASME B56.1 2000 > The American Society of Mechanical EngineersANSI/ITSDF B56.1 > Industrial Truck Standards Development Foundation• B56.1 is specifically for Powered and Non Powered Industrial Trucks• Develops Safety codes related to Powered Industrial Trucks

– For Manufacturers– For End Users

Industry Organizations

OSHA > Occupational Safety & Health Administration• Governmental Based

OSHA's mission is to prevent work-related injuries, illnesses and deaths. Since the agency was created in 1971, occupational deaths have been cut in half and injuries have declined by 40 percent.

Your Responsibilities…

• As a material handling professional you are obligated to point out any usage of our equipment that does not comply with OSHA to the company’s contact person…..safety is everyone’s responsibility

• Offer your dealership’s services to provide required operator training

Your Customers Must Properly Train Their Operators

• Required by OSHA• Promotes safe working environment• A well trained operator

– Is far more efficient and productive– Puts safety first!!

Operator Training

• OSHA Regulation:29 CFR 1910.178• Regulation essentials

– Training (Classroom & Hand-On)– Evaluation– Certification

• Regulation topics– Fundamentals– Forklift specific – Workplace specific

Operator Training Is the Law!

• The employer must:– Train– Evaluate– Certify– Must re-train when:

• There is an accident• Near miss• Observed unsafe behavior

– Operators must be re-certified every three years– No exemption for temporary workers

Industry Organizations

ITA > Industrial Truck Association• Comprised of Manufacturers & Associate Manufactures• Board, Statistical, Engineering & Product Liability groups • Develops common standards as guidelines• Reviews legislation that impacts group members • Gathers Statistical Data.

Classifications of Forklift Trucks in the U.S. Market

Class I3-Wheel, 4-Wheel Sit-down Riders, Stand-Up Counterbalance Riders

Used for trailer loading/unloading, indoors in plants & warehouses where good maneueverability is needed

Class IINarrow Aisle Reach Trucks, Order Selectors, Turret Trucks

Used in warehousing & distribution for high level storage and high level orderpicking in narrow aisles

Class III Walkie & Walkie/Rider & Center Control Pallet Trucks,Tow Tractors, Walkie Stackers

Walkie trucks are utilized in a wide variety of manufacturing & warehousing applications

Classifications of Forklift Trucks in the U.S. Market (cont.)

Class IVEngine Powered, Cushion Tire, Sit-down Rider Forklifts

Indoor use on loading docks in plants & warehouses where power & continuous usage are expected & good maneuverability is important

Class VEngine Powered, Pneumatic Tire, Sit-down Rider Forklifts

Outdoor use for load handling in retail, lumber, shipping & stevedoring where power and continuous usage is expected

Industry Organizations

UL > Underwriters LaboratoryUnderwriters Laboratories Inc. (UL) is an independent, not-

for-profit product safety testing and certification organization.

Each year, more than 17 billion UL Marks are applied to products worldwide.

Generally electrical and fuel related validation..Trucks must be manufactured in compliance with U.L.U.L. 558 applies to internal combustion engine forkliftsU.L. 583 applies to battery powered electric forklifts

Industry Organizations

NFPA > National Fire Prevention AgencyNFPA 505 – 2006• NFPA distinguishes forklift types in accordance with their suitability for

use in special environments which present the risk of fire or explosions• NFPA regulations cover designations, areas of use, maintenance and

operation• Electric Forklift Classifications:

– Type “E” / Type “ES” / Type “EE” / Type “EX”• Engine Forklift Classifications:

– Type “G” / Type “GS” / Type “LP” / Type “LPS” / Type “D” / Type “DS” / Type “G/LP” / Type “GS/LPS” / Type “DX” Diesel explosion proof

Industry Organizations

NFPA > National Fire Prevention AgencyNFPA 505 – 2006• NFPA states that hazardous work areas must be properly marked

showing the type of truck classification that must be used in that special area

• It is the customer’s responsibility to communicate these special application needs and need to operate the forklift within a hazardous area

Industry Organizations

MHEDA >Material Handling Equipment Distributors Assoc.• Dealer based Organization• The Material Handling Equipment Distributors Association

is the only trade association dedicated solely to improving the proficiency of the independent material handling equipment distributor.

• MHEDA is your direct connection to the Material Handling Industry's hottest trends, newest products and best management training workshops. MHEDA represents a wealth of resources for all material handling businesses.