I-C. Industrial Trucks

Industrial trucks are used to move materials over variable paths, with no restrictions on the area covered by the movement. The major types of industrial trucks are:

Industrial trucks:

• Used to move materials over variable (horizontal) paths with no restrictions on the area covered (i.e., unrestricted area)
• Provide vertical movement if the truck has lifting capabilities
• Used when there is insufficient (or intermittent) flow volume such that the use of a conveyor cannot be justified
• Provide more flexibility in movement than conveyors and cranes
• Not licensed to travel on public roads—"commercial trucks" are licensed to travel on public roads

Characteristics:

• Pallet/Non-Pallet: Does the truck have forks for handling pallets, or does the truck have a flat surface on which to place loads. Non-Pallet => (usually) other means required to load truck.

• Manual/Powered: Does the truck have manual or powered vertical (lifting) and/or horizontal (travel) movement capabilities. Manual => walk => operator provides the force needed for lifting loads and/or pushing the vehicle. Powered => on-board power source (e.g., batteries) used for lifting and/or travel.

• Walk/Ride: For non-automated trucks, can the operator ride on the truck (in either a standing or sitting position) or is the operator required to walk with the truck during travel. Walk => manual or powered travel possible => powered travel speed limited to a normal walking pace. Ride => powered => travel speed can be faster than a walking pace.

• Stack/No Stack: Can the truck be used to lift loads for stacking purposes. Stack => can also be used as no stack => more expensive to add stacking capability. No Stack may lift a load a few inches to clear the floor for subsequent travel (e.g., pallet jack), but the loads cannot be stacked on top of each other or on shelves.

• Narrow Aisle: Is the lift truck designed to have a small turning radius or does it not have to turn at all in an aisle when loading/unloading. Narrow Aisle => greater cost and (usually) standing operator => less aisle space required. Counterbalance and/or straddle used for load support. Small turning radius => load support via straddle or reaching capabilities. No turning required => even narrower aisle => only one-side loading (sideloaders) or the capability to rotate the load (turret truck).

• Automated: Is the truck automated so that it can transport loads without requiring an operator. Non-Automated => direct labor cost of operator is by far the largest cost to operate a non-automated truck. Semi-Automated => operator used to control loading/unloading, but automated transport control (e.g., the S/R machine of a Man-on-board AS/RS). Automated => Automated Guided Vehicle (AGV) => no direct labor cost, but higher equipment costs.

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1. Hand Truck

Non-pallet + manual + no stack

1(a) Two-Wheeled Hand Truck

Load tilted during travel

1(b) Dolly

Three or more wheeled hand truck with a flat platform in which, since it has no handles, the load is used for pushing

1(c) Floor Hand Truck

Four or more wheeled hand truck with handles for pushing or hitches for pulling

Sometimes referred to as a "cart" or "(manual) platform truck"

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2. Pallet Jack

Pallet + walk + no stack

Front wheels are mounted inside the end of the forks and extend to the floor as the pallet is only lifted enough to clear the floor for subsequent travel

Pallet restrictions: reversible pallets cannot be used, double-faced nonreversible pallets cannot have deckboards where the front wheels extend to the floor, and enables only two-way entry into a four-way notched-stringer pallet because the forks cannot be inserted into the notches

2(a) Manual Pallet Jack

Pallet + walk + no stack + manual

Manual lifting and/or travel

2(b) Powered Pallet Jack

Pallet + walk + no stack + powered

Powered lifting and/or travel

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3. Walkie Stacker

Pallet + walk + stack

3(a) Manual Walkie Stacker

Pallet + walk + stack + manual

Manual lifting and/or travel (and straddle load support)

3(b) Powered Walkie Stacker

Pallet + walk + stack + powered

Powered lifting and/or travel (and either counterbalance or straddle load support)

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4. Pallet Truck

Pallet + ride + no stack

Same pallet restrictions as a pallet jack

Control handle typically tilts to allow operator to walk during loading/unloading

Powered pallet jack is sometimes referred to as a "(walkie) pallet truck"

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5. Platform Truck

Non-pallet + powered + no stack

Platform used to provide support for nonpalletized loads

Used for skid handling; platform can lift skid several inches to allow it to clear the floor

Greater lifting capacity compared to fork trucks because the platform provides a greater lifting surface to support a load

5(a) Walkie Platform Truck

Non-pallet + powered + no stack + walk

Operator walks next to truck

Floor hand truck is sometimes referred to as a "(manual) platform truck"

5(b) Rider Platform Truck

Non-pallet + powered + no stack + ride

Operator can ride on truck

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6. Counterbalanced (CB) Lift Truck

Pallet + ride + stack

Also referred to as fork truck.

Weight of vehicle (and operator) behind the front wheels of truck counterbalances weight of the load (and weight of vehicle beyond front wheels); front wheels act as fulcrum or pivot point.

Rated capacity reduced for load centers greater than 24 in. and lift heights greater than 13 ft.

Workhorses of material handling because of their flexibility: indoor/outdoor operation over a variety of different surfaces; variety of load capacities available; and variety of attachments available—fork attachments can replace the forks (e.g., carton clamps) or enhance the capabilities of the forks (e.g., blades for slipsheets).

6(a) Sit-Down Counterbalanced Lift Truck

Operator sits down

12-13 ft. minimum aisle width requirement

6(b) Stand-Up Counterbalanced Lift Truck

Operator stands up, giving vehicle narrow-aisle capability

9-11 ft. minimum aisle width requirement

Faster loading/unloading time compared to NA straddle and reach trucks

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7. Narrow-Aisle (NA) Straddle Truck

Similar to stand-up CB lift truck, except outrigger arms straddle a load and are used to support the load instead of the counterbalance of the truck

7-8 ft. minimum aisle width requirement

Less expensive than stand-up CB lift truck and NA reach truck

Since the load is straddled during stacking, clearance between loads must be provided for the outrigger arms

Arm clearance typically provided through the use of load-on-beam rack storage or single-wing pallets for load-on-floor storage

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8. Narrow-Aisle (NA) Reach Truck

Similar to both stand-up CB lift truck and NA straddle truck

8-10 ft. minimum aisle width requirement

Load rests on the outrigger arms during transport, but a pantograph (scissors) mechanism is used for reaching, thereby eliminating the need to straddle the load during stacking

Reaching capability enables the use of shorter outrigger arms (arms > 1/2 load depth) as compared to NA straddle truck (arms = load depth)

Counterbalance of the truck used to support the load when it extends beyond the outrigger arms

Although the NA reach truck requires slightly wider aisles than a NA straddle truck since its outrigger arms do not enter a rack during storage, it does not require arm clearance between loads (arm clearance is still required when the truck must enter a storage lane when block stacking or drive-in or -through racks are used)

Extended reaching mechanisms are available to enable double-deep storage

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9. Turret Truck

Greater stacking height compared to other narrow-aisle trucks (40 ft. vs. 25 ft.), but greater investment cost

Forks rotate to allow for side loading and, since truck itself does not rotate during stacking, the body of the truck can be longer to increase its counterbalance capability and to allow the operator to sit

Can function like a sideloader for transporting greater-than-pallet-size load

9(a) Operator-Down Turret Truck

Operator not lifted with the load

5-6 ft. minimum aisle width requirement

Termed a swingmast truck (picture shown) when, instead of just the forks, the entire mast rotates (thus can store on only one side of a aisle while in aisle)

9(b) Operator-Up Turret Truck

Operator lifted with the load to allow precise stacking and picking

5-7 ft. minimum aisle width requirement

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10. Order Picker

Similar to NA straddle truck, except operator lifted with the load to allow for less-than-unit-load picking

Typically has forks to allow the truck to be used for pallet stacking and to support a pallet during less-than-pallet-load picking

"Belly switch" used for operator safety during picking

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11. Sideloader

Forks mounted perpendicular to direction of travel to allow for side loading and straddle load support

5-6 ft. minimum aisle width requirement

Can be used to handle greater-than-pallet-size loads (e.g., bar stock)

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12. Tractor-Trailer

Non-load-carrying tractor used to pull a train of trailers (i.e., dollies or floor hand trucks)

Extends the transporting capacity of floor hand trucks

Typically used at airports for baggage handling

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13. Personnel and Burden Carrier

Non-load-carrying vehicle used to transport personnel within a facility (e.g., golf cart, bicycle, etc.)

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14. Automatic Guided Vehicle (AGV)

AGVs do not require an operator

Good for high labor cost, hazardous, or environmentally sensitive conditions (e.g., clean-room)

Also termed "automated" guided vehicle

AGVs good for low-to-medium volume medium-to-long distance random material flow operations (e.g., transport between work cells in a flexible manufacturing system (FMS) environment)

Two means of guidance can be used for AGV systems:

Fixed path: Physical guidepath (e.g., wire, tape, paint) on the floor used for guidance

Free-ranging: No physical guidepath, thus easier to change vehicle path (in software), but absolute position estimates (from, e.g., lasers) are needed to correct dead-reckoning error

14(a) Tow AGV

Used to pull a train of trailers

Automated version of a tractor trailer

Trailers usually loaded manually (early type of AGV, not much used today)

14(b) Unit Load AGV

Have decks that can be loaded manually or automatically

Deck can include conveyor or lift/lower mechanism for automatic loading

Typically 4 by 4 feet and can carry 1–2,000 lb. loads

Typically less than 10 vehicles in AGV system

14(c) Assembly AGV

Used as assembly platforms (e.g., car chassis, engines, appliances)

Greatest development activity during the 1980s (alternative to AEMs)

Typically 50–100 vehicles in AGV system

14(d) Light Load AGV

Used for small loads (< 500 lbs), e.g., components, tools

Typically used in electronics assembly and office environments (as mail and snack carriers)

14(e) Fork AGV

Counterbalanced, narrow-aisle straddle, and sideloading versions available

Typically have sensors on forks (e.g., infrared sensors) for pallet interfacing

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Last modified: September 30, 1999