What is Material Handling Equipments(MHE)?
Material Handling Equipments (MHE) are actually equipments that facilitate the handling of materials, which refers to the movement and storage of materials in the facility.
For better understanding, the video below shows the material handling equipment- Forklift trucks by Hyundai. Forklift truck is one of the many material handling equipments.
Sunday, January 13, 2008
Transport Equipment (l) - Conveyors
The first material handling equipment(MHE) we are going to touch on is Conveyors, which
facilitates transportation in material handling.
What is conveyors?
By looking at the following video, I'm sure you will know what it is immediately.
facilitates transportation in material handling.What is conveyors?
By looking at the following video, I'm sure you will know what it is immediately.
Transport Equipment (ll) - Cranes
The next handling equipment that facilitates transportation we are going to touch on is Cranes.
What is cranes?
In definition, Crane is a machine for hoisting and moving heavy objects by means of cables attached to a movable boom.
Jib crane, bridge crane, gantry cane, stacker crane are the different types of cranes available in the industry and they all have different uses. It is very important to understand the types of lifting systems available and how they differ from each other when deciding on what types of cranes to use.
Therefore we need to ask questions like:
Last updated October 19, 2007 9:33 p.m. PT
L&I looks to public on new crane safety law
Comments can help agency work out the detail
By ANDREA JAMESP-I REPORTER
A tough new law passed earlier this year is designed to give some peace of mind to people who live and work near the looming construction tower cranes dotting Western Washington's skylines.
But the specifics -- just how the safety law will be carried out -- are still being written by the state Department of Labor and Industries.
By the end of this month, L&I plans to have completed its first draft of the rule, spokeswoman Elaine Fischer said. The department will gather comments on the draft in a series of meetings statewide from Oct. 29 through Nov. 5.
The construction industry already voiced its concerns and opinions in a round of meetings in July.
"The biggest issue for discussion was probably the number of operator hours that should be required for operator certification on different types of cranes," Fischer said.
To be considered qualified, according to the law, a crane operator must have up to 2,000 hours of experience -- a maximum that has been challenged by many in the industry as unworkable.
Legislators enacted the law in the wake of several alarming crane incidents late last year. After a 210-foot-high crane collapsed in downtown Bellevue, killing a man in his nearby apartment and severely damaging three buildings, structural problems were found in several more cranes operating in the Seattle area.
A six-month L&I investigation found that the collapsed crane's steel base was to blame. Tower cranes, which are used for construction on skyscrapers, are normally installed in concrete. The Seattle engineering firm that designed the foundation, Magnusson Klemencic Associates, was fined $5,600.
Lease Crutcher Lewis, the general contractor at the Tower 333 site, where the crane fell, was fined $9,200. Both firms are named in a lawsuit filed by the family of the deceased.
Under the new law, which takes effect Jan. 1, 2010, the state will play a much bigger role in ensuring that tower cranes are being operated properly and are secure in their foundations. Under the old rules -- criticized for being lax -- responsibility for safety fell mostly to construction companies.
In the upcoming meetings, L&I will take suggestions in two areas: how crane inspectors should be certified, and what qualifications should be needed to become a crane operator.
"There's a lot of different kinds of cranes and a lot of people that want to weigh in on that," Fischer said. "We're starting from scratch here in our state developing rules in this industry. We have to involve people in the industry that know how things operate."
Developers will have to contract with a certified crane inspector to certify their cranes. That means that the cranes, its inspectors and its operators must all be certified.
The crane inspector rule will likely operate similar to sister rules regarding amusement ride inspectors and maritime crane inspectors, she said.
The law also requires that an independent professional engineer stamp approval on any "non-standard" tower crane base.
P-I reporter Andrea James can be reached at 206-448-8124 or andreajames@seattlepi.com.
Therefore, we can see that general safety rules is also taken into serious considerations. Some of the rules operators shall comply when operating cranes and even hoist are:
What is cranes?
In definition, Crane is a machine for hoisting and moving heavy objects by means of cables attached to a movable boom.
Jib crane, bridge crane, gantry cane, stacker crane are the different types of cranes available in the industry and they all have different uses. It is very important to understand the types of lifting systems available and how they differ from each other when deciding on what types of cranes to use.
Therefore we need to ask questions like:
- What am I actually doing with the system? For example, will it be used to move expensive tools into/out of a molding machine or to load/unload steel from trucks?
- How can a crane increase the safety of the loads being lifted?
- How can a crane improve my workers' safety in handling the loads?
- How frequently will it be used each shift?
- How will the load need to be moved and located?
- How easy is it to move the system to a new location in my factory?
- Do I really need three axes of hook movement (e.g., up/down, left/right, and forward/back) or will only two be sufficient?
- How heavy are the loads to be lifted?
- How much money should I invest in a system?
Crane Safety
Construction crane safety is also a very important issue to take into consideration. The Division of Occupational Safety and Health (DOSH) held a share holder meetings on October 29th through November 5th to gather feedback on the Construction Crane Certification and Operator Qualifications and Experience drafts.
The following article is on new crane safety law in US:Last updated October 19, 2007 9:33 p.m. PT
L&I looks to public on new crane safety law
Comments can help agency work out the detail
By ANDREA JAMESP-I REPORTER
A tough new law passed earlier this year is designed to give some peace of mind to people who live and work near the looming construction tower cranes dotting Western Washington's skylines.
But the specifics -- just how the safety law will be carried out -- are still being written by the state Department of Labor and Industries.
By the end of this month, L&I plans to have completed its first draft of the rule, spokeswoman Elaine Fischer said. The department will gather comments on the draft in a series of meetings statewide from Oct. 29 through Nov. 5.
The construction industry already voiced its concerns and opinions in a round of meetings in July.
"The biggest issue for discussion was probably the number of operator hours that should be required for operator certification on different types of cranes," Fischer said.
To be considered qualified, according to the law, a crane operator must have up to 2,000 hours of experience -- a maximum that has been challenged by many in the industry as unworkable.
Legislators enacted the law in the wake of several alarming crane incidents late last year. After a 210-foot-high crane collapsed in downtown Bellevue, killing a man in his nearby apartment and severely damaging three buildings, structural problems were found in several more cranes operating in the Seattle area.
A six-month L&I investigation found that the collapsed crane's steel base was to blame. Tower cranes, which are used for construction on skyscrapers, are normally installed in concrete. The Seattle engineering firm that designed the foundation, Magnusson Klemencic Associates, was fined $5,600.
Lease Crutcher Lewis, the general contractor at the Tower 333 site, where the crane fell, was fined $9,200. Both firms are named in a lawsuit filed by the family of the deceased.
Under the new law, which takes effect Jan. 1, 2010, the state will play a much bigger role in ensuring that tower cranes are being operated properly and are secure in their foundations. Under the old rules -- criticized for being lax -- responsibility for safety fell mostly to construction companies.
In the upcoming meetings, L&I will take suggestions in two areas: how crane inspectors should be certified, and what qualifications should be needed to become a crane operator.
"There's a lot of different kinds of cranes and a lot of people that want to weigh in on that," Fischer said. "We're starting from scratch here in our state developing rules in this industry. We have to involve people in the industry that know how things operate."
Developers will have to contract with a certified crane inspector to certify their cranes. That means that the cranes, its inspectors and its operators must all be certified.
The crane inspector rule will likely operate similar to sister rules regarding amusement ride inspectors and maritime crane inspectors, she said.
The law also requires that an independent professional engineer stamp approval on any "non-standard" tower crane base.
P-I reporter Andrea James can be reached at 206-448-8124 or andreajames@seattlepi.com.
Therefore, we can see that general safety rules is also taken into serious considerations. Some of the rules operators shall comply when operating cranes and even hoist are:
- Do not engage in any practice that will divert your attention while operating the crane.
- Respond to signals only from the person who is directing the lift, or any appointed signal person. Obey a stop signal at all times, no matter who gives it.
- Do not move a load over people. People shall not be placed in jeopardy by being under a suspended load. Also, do not work under a suspended load unless the load is supported by blocks, jacks, or a solid footing that will safely support the entire weight. Have a crane or hoist operator remain at the controls or lock open and tag the main electrical disconnect switch.
- Ensure that the rated load capacity of a crane's bridge, individual hoist, or any sling or fitting is not exceeded. Know the weight of the object being lifted or use a dynamometer or load cell to determine the weight.
- Check that all controls are in the OFF position before closing the main-line disconnect switch.
- If spring-loaded reels are provided to lift pendants clear off the work area, ease the pendant up into the stop to prevent damaging the wire.
- Avoid side pulls. These can cause the hoist rope to slip out of the drum groove, damaging the rope or destabilizing the crane.
- To prevent shock loading, avoid sudden stops or starts. Shock loading can occur when a suspended load is accelerated or decelerated, and can overload the crane or hoist. When completing an upward or downward motion, ease the load slowly to a stop.
Jib crane, Bridge crane, Gantry crane, Stacker crane are some of the different types of crane available.
Jib Cranes
Jib crane is a crane having an arm guyed at a fixed angle to the head of a rotating mast and it consists of a pivoting head and boom assembly which carries a hoist and trolley unit. The pivoting head is supported either by a floor-mounted mast providing 360 degree boom rotation or by an existing building column which provides 180 degrees of boom rotation.
Advantages of Jib cranes :
The advantage is the strength, stability and flexibility of the device. It is ideal for lifting a product to or from one material handling system to a work station or machine. It should be a repetitive process.Another advantage is that jib crane is commonly used for workstation and simple loading / unloading operations where it is not necessary to spot a load precisely. Also, Jib cranes most often handle lighter loads at lower duty cycles than their bridge and gantry crane counterparts.
Disadvantages of Jib crane :
The major disadvantage is that it is stationary and cannot be moved easily from one work area to another. It is designed for positioning a work piece or tool, rather than for moving a product along in the work flow like an overhead crane.
It is also unsuitable to use when there is a need for precise locating of heavy loads, a large area of hook coverage, or frequent use for heavy loads. Another disadvantage is that the hook coverage is limited to the boom length (typically a maximum of 20 ft). The hook operates along a boom which rotates about a fixed point.
Bridge Crane
A bridge crane runs on an elevated runway system along the length of a factory and provides three axis of hook motion (X, Y, and Z). The hoist moves the load up and down, the trolley moves the load right and left, and the bridge of the crane moves the load forward and backward. Both single and double girder overhead traveling bridge crane designs allow very precise hook positioning and gentle load placement.
Advantages of bridge crane :
- greatest flexibility for hook coverage and control over the load fewest number of physical obstructions on your factory floor
- no interference with the work on the floor
- reduced aisle space requirements, easy access to most areas within the lifting bay
- extension to areas outside the building.
Disadvantages of bridge crane :
Problems encountered like:
- Crane travelling too far before stopping.
It is likely that it uses electric motor brakes and that, like most cranes, the brake pads haven't been replaced (they require replacing or adjusting every 3 months).
- Bearings wearing out too soon.
- Contactor problems.
- Broken push button pendant or cable.
- Parts availability problems.
- Brakes wearing out or not working properly.
Please enjoy the following video from North American Industries
Positioning equipment (l) - Hoist
The first positioning equipment we are going to touch on is hoist.What is hoist?
A hoist is a device used for lifting or lowering a load by means of a drum or lift-wheel around which rope or chain wraps. It may be manually operated, electrically or pneumatically driven and may use chain, fiber or wire rope as its lifting medium.
Advantages of hoist
- It can be placed in tight spaces such as between benches
- Flexible
Disadvantage of hoist
- There is a need take the weight usage into consideration. For example, package hoist is most suitable for light to moderate usage. When handling with heavy usage, we must use built-up hoist. (It will be covered in later part of this post) There is also a need to minimise ratio of dead-weight to payload of the handling equipment.
It usually consists of a block and tackle—a combination of one or more fixed pulleys, a moving pulley with a hook or other similar means of attaching loads, and a rope (or cable) between them.
Characteristic of hoist
The basic hoist has two important characteristics to define it: Lifting medium and power type.
- The lifting medium is either wire rope, wrapped around a drum, or load-chain, raised by a pulley with a special profile to engage the chain. Both the wire rope hoist and chain hoist have been in common use since the 1800s.
- The power type can be either electric motor or air motor.
It must be noted that a hoist can be built as one integral-package unit, designed for cost-effective purchasing and moderate use, or it can be built as a built-up custom unit, designed for durability and performance.
Package Hoist:
The term “package” refers to the fact that the hoist is an “integrated package”. In other words, the hoist is made up of a series of “proprietary” parts, designed specifically for the purpose of that hoist and all electric chain hoist and most wire rope hoists are “package type” hoists.
Therefore, package hoist is most suitable for light to moderate usage, standard speed and normal lifting lengths. If any service that does not have the norms listed, there would be increase in down time, higher maintenance cost and a drastically reduced service life. The farther out of the norms, the worse the performance. Package hoist is normally being used is in a machine shop or fabricating shop.
Built- up Hoist:
When the needs exceed the norms listed above (package hoist), it would be most suitable to use a built- up hoist. It should be noted that built up hoists can be as low as 3 ton capacity, when special speeds, duty cycles or long lifts are required, but normally heavy usage applications, high production, maintenance intensive applications. Even though built-up hoist is more expensive, it is easier to repair and more durable. Built-up hoist on the other hand is used for heavy to sever service like Steel Mill or NASA due to its durability, performance, and reparability requirements.
Hoist Safety
Only qualified and licensed individual can operate both cranes and hoists, and there is a list of safety rules and responsibilities whereby all personnel which came in contact with the equipment must obey to maintain a safe workplace for all personnel.
The following PDF file shows a list of safety rules when handling hoist:www.state.ar.us/labor/pdf/program_crane_safety.pdf
Types of hoist
When deciding which type of hoist should be used, so as to provide extended service and efficiently matches the requirements of the job; we should also ask questions like:
- Is a manual or power hoist needed?
- Is power hoist which is an electric or pneumatic (compressed air) type the better choice?
- What load capacity is required?
- How fast and how high must the hoist work?
- Is a chain or wire rope required?
- What headroom is available for hanging the hoist?
- Manual or Power?
Construction hoist:
Although there are many types of hoist, construction hoist is what most of us haven seen before as it is part of our daily life.
It known as a Man-Lift, or construction elevator, this type of hoist is commonly used on large scale construction projects, such as high-rise buildings or major hospitals.
The purpose being is to carry personnel and materials quickly between the ground and higher floors, or between upper floors.
The construction hoist is made up of either one or two metallic cages which travel vertically along stacked mast tower sections. For controlled travel along the mast sections, most modern construction hoists utilize a motorized rack-and-pinion system mounted onto the mast sections, while some older hoists still utilize a system of counterweights.
Positioning Equipment (ll) - Rotary Index Table
The next positioning equipment is Rotary Index Table. 
What is Rotary Index Table?
Rotary Index Table is a precision work positioning device used in metalworking. It enables the operator to drill or cut work at exact intervals around a fixed (usually horizontal or vertical) axis. Some rotary tables allow the use of index plates for indexing operations, and some can also be fitted with dividing plates that enable regular work positioning at divisions for which indexing plates are not available.
Rotary Index Table is a precision work positioning device used in metalworking. It enables the operator to drill or cut work at exact intervals around a fixed (usually horizontal or vertical) axis. Some rotary tables allow the use of index plates for indexing operations, and some can also be fitted with dividing plates that enable regular work positioning at divisions for which indexing plates are not available.
Examples of how it can be used:
Machine spanner flats on a bolt
Rotary tables are made with a solid base, which has provision for clamping onto another table or fixture. The actual table is a precision-machined disc to which the work piece is clamped (T slots are generally provided for this purpose). This disc can rotate freely, for indexing, or under the control of a worm (handwheel), with the worm wheel portion being made part of the actual table.
Unit Load Formation Equipment (l) - Pallets
A pallet is a low, portable platform constructed of wood, metal, or fiberboard, built to specified dimensions, on which supplies are loaded, transported, or stored in units. Pallets are the most common form of unitizing device.
Some of the primary pallet material choices are wood pallet (most common), steel pallet, paper pallet, metal pallet, plastic pallet.
Pallets may afford two- or four-way entry. The two-way entry pallet is so constructed that the forks of a forklift truck may be inserted from either the front or rear of the pallets. The four-way pallet is so constructed that the forks of a forklift truck may be inserted from any of the four sides.
Various types of pallets are two-way double wing, two-way flush, two-way reversible flush, two-way single wing, four way nonreversible flush, block type, foam padded plywood pallet, single face pallet.
Advantages of using pallets:
Some of the primary pallet material choices are wood pallet (most common), steel pallet, paper pallet, metal pallet, plastic pallet.
Pallets may afford two- or four-way entry. The two-way entry pallet is so constructed that the forks of a forklift truck may be inserted from either the front or rear of the pallets. The four-way pallet is so constructed that the forks of a forklift truck may be inserted from any of the four sides.
Various types of pallets are two-way double wing, two-way flush, two-way reversible flush, two-way single wing, four way nonreversible flush, block type, foam padded plywood pallet, single face pallet.
Advantages of using pallets:
- Handles more items at a time
- Reduces the number of trips
- Reduces the handling costs
- Reduces the loading and unloading times
- Reduces the product damage
Disadvantages of using pallets:
Operators can’t use either option in areas with rocks or other firm high spots. You may need a forklift to install and remove pallets.
Different types of pallet material will have its own pros and cons.
The majority of pallets are made from wood.
Advantages:
- Lower cost than most other materials
- Can be repaired/renovated
- Can be painted and easily printed on
- Stickers can be easily removed
- Their popularity allows them to be used universally
Disadvantages:
- The dimensions can vary slightly
- Can be distorted through rough handling
- Contain metal parts (nails) which could interfere with metal detection (some now are made without nails)
- Need to be maintained
- Can become contaminated with unwanted bacteria or pests. Export pallets need to be heat treated.
- Weight can fluctuate due to wood variations and level of absorbed moisture
- They can be prone to splintering or have loose nails
- Wooden pallets are not fully washable
- They cannot be nested in each other when empty
Plastic 
Advantages:
- Precise and consistent specifications
- Do not absorb humidity
- Some can be moulded so that that can be nested when empty
- No sharp edges, loose nails or splinters
- Can be cleaned effectively
- Very low maintenance required
- Can be manufactured from recovered material
- Can be lightweight (depending on density)
- Long life if handled correctly
- Washable and not prone to infection or infestation
Disadvantages:
- High purchase cost
- Cannot be repainted
- Stickers may not be easily removed, leaving bug harbouring and unsightly residue
- There are no universal standards, reducing the possibility of pooling and swapping
Metal
Advantages:
- No loose splinter/nails
- Long life if handled correctly - can withstand rough treatment
- High load bearing capacity (depending on specification)
- Washable and not prone to infection or infestation
- Low maintenance requirement
Disadvantages:
- Can be warped through mis-use
- Heavy
- Stickers may not be easily removed, leaving bug harbouring and unsightly residue
- Very high purchase cost
- There are no universal standards, reducing the possibility of pooling and swapping
Paper 
- Lighter weight
- Disposable
- Recyclable
- Very flexible to adapt to special transport needs
- Meet IPPC requirements
- Meet international regulations on trade (ISPM)
- No fumigation
- Environmental Friendly
- Clean and dust free
Disadvantages:
- Susceptible to moisture
- Lack stiffness compared to most other pallet materials
Unit Load Formation Equipment (ll) - Inter-modal Container
Since the 1960s major efforts have been made to integrate separate transport systems through intermodalism, which took place are several stages. This involves the use of at least two different modes in a trip from origin to destination through an inter-modal transport chain. Inter-modal transportation is the movements of passengers or freight from one mode of transport to another, commonly taking place at a terminal specifically designed for such a purpose.
The container is a large standard size metal box into which cargo is packed for shipment aboard specially configured oceangoing vessels and designed to be moved with common handling equipment enabling high-speed inter-modal transfers in economically large units between ships, railcars, truck chassis, and barges using a minimum of labor. The container, therefore, serves as the load unit rather than the cargo contained therein, making it the foremost expression of inter-modal transportation.
Diamond uses 65 leased owner-operator trucks and 25 company-owned trucks. About 20 office personnel are employed in the company's Birmingham headquarters, and at terminals in Atlanta and Chattanooga.
Hauling the phone books
One of the company's biggest jobs is delivering BellSouth phone books in nine Southern states. Last year, Diamond Express was rated the best delivery company by supervisors at 514 drop-off sites, scoring a 3.85 out of 4.0 (similar to a college grading scale) in quality of service, professionalism, courtesy, condition of the books, on-time performance and other criteria.
The container is a large standard size metal box into which cargo is packed for shipment aboard specially configured oceangoing vessels and designed to be moved with common handling equipment enabling high-speed inter-modal transfers in economically large units between ships, railcars, truck chassis, and barges using a minimum of labor. The container, therefore, serves as the load unit rather than the cargo contained therein, making it the foremost expression of inter-modal transportation.
Advantages:
- Flexibility of usage. It can transport a wide variety of goods ranging from raw materials (coal, wheat), manufactured goods, and cars to frozen products.
- Costs. Relatively to bulk, container transportation reduces transport costs considerably, about 20 times less than bulk transport.
- More items can be handled at the same time, thereby reducing the number of trips required and, potentially, reducing handling costs, loading and unloading times, and product damage.
- Enables the use of standardized material handling equipment.
Disadvantages:
- Time spent forming and breaking down the unit load.
- Cost of containers/pallets and other load restraining materials used in the unit load.
- Empty containers /pallets may need to be returned to their point of origin.
The article below will illustrate real world application of inter-modal transportation:
Containers from around the world can be found at Diamond Express Inc., a trucking company tucked away between First Avenue North and the airport.
"We're the largest inland container depot around the Birmingham area," says veteran trucking executive Tom Brown, owner of Diamond Express.
The company has developed a niche doing what used to be called "piggybacking," delivering truck trailers to and from flatbed railcars. The process is more modern these days, with containers lifted off trailer chassis and loaded, two-high, minus their cumbersome wheels.
Diamond Express, with $8 million in sales revenue last year, transports and stores containers from around the globe. One of its top customers is Maersk-Sealand, the world's largest steamship company. Intermodal freight, mostly containers from the Far East coming through ports in California, includes clothing, lumber, paper and electronics.
But Brown says his company, spread across three lots totaling 15 acres, doesn't rely solely on international export/imports to and from companies in the South, or the rail-dependent intermodal business as a whole.
"With Norfolk Southern closing its Birmingham intermodal ramp, and Burlington Northern (Santa Fe) moving its California freight through Atlanta (instead of Birmingham), we started focusing four or five years ago on van freight in the South," he says. Industries served include paper products, cooking oil containers and fire extinguisher equipment, to name a few. Local clients include Pepsi bottler and snack food vendor Buffalo Rock, Stevens Graphics, Amerex, Cook Publications and Ventura Foods.
Brown says the ratio of intermodal containers to van freight business is 60/40.
Diamond uses 65 leased owner-operator trucks and 25 company-owned trucks. About 20 office personnel are employed in the company's Birmingham headquarters, and at terminals in Atlanta and Chattanooga.
Hauling the phone books
One of the company's biggest jobs is delivering BellSouth phone books in nine Southern states. Last year, Diamond Express was rated the best delivery company by supervisors at 514 drop-off sites, scoring a 3.85 out of 4.0 (similar to a college grading scale) in quality of service, professionalism, courtesy, condition of the books, on-time performance and other criteria.
Below are some pictures that illustrate inter-modal containers.
Storage Equipment (I) - Pallet Racking
Basically, racking is one of the equipments that contributes to the storage system of the distribution centre, ensuring it to be well-designed by making use of the volume available, providing proper access to the stored goods through facilitating the throughput of goods as well as minimizing the distance traveled. Furthermore, the use of this equipment will also minimize the risk of insecurities towards damage and deterioration of goods.
There are several choices of racking medium depending on the physical characteristics; risks of hazard, deterioration and hazard; values of the goods. Furthermore, the capital availability of users, characteristics of the available storage methods and equipment as well as the stock and throughput levels must be taken into consideration.
Below are elaborations of several types of racking used by most warehouses and distribution centres throughout the world.
Selective Pallet Racking
This pallet racking is most generally used. This is due to it easy access to every load and flexible choice providing 100% selectivity to every load. This equipment is mainly for the best access and high-demand product. Although it delivers maximum access to stored pallets, it requires numerous aisles and aisle space, resulting in lower storage density than other form of racking.
A type of a selective pallet racking is the boltless selective pallet, which in-demand due to its tool-free assembly, fast and affordable price. However, initial savings can be offset by high replacement and maintenance costs as it is found that the open-back roll formed columns don’t withstand the impacts of fork truck.
Drive-through Pallet Racking
This type of pallet racking is used for storing pallets of a similar stock-keeping unit (SKU) or goods. In this racking, loads are supported by rails attached to vertical frames, and lift trucks are driven between the frames to enter the rack from either side to pick up or pull out pallets as pallets can slide backwards on a continuous rail, open at both ends, which thus, allowing ‘first-in, first-out’ storage.
Drive-through pallet racking is used when there are seasonal items moving quickly out of the inventory and when there are large amount of similar items that can be stored in a single pallet position. It is not encouraged using this equipment when storing a wide variety of loads in the rack. Although selectivity is forgone, storage density is improved due to the ability to store a large amount of similar loads in a smaller area.
Push-back Pallet Racking
The objective of the push-back pallet racking is to minimize empty pick faces or honeycombing. The ideal appliance of the racking will be where all loads in a row are alike and not critically in a ‘first-in, first-out’ stock rotation.
This racking has the same storage density as the drive-through racks and up to 90% more product storage than selective pallet racking systems, but with greater selectivity of 4 times more than the drive-in pallet racking. Due to these factors, it improves the speed of pick rates. Besides offering a large target for loading and unloading, it also maximizes space through storing a range of SKUs on different levels of lanes for convenient access of goods.
Here’s how it operates:
There are several choices of racking medium depending on the physical characteristics; risks of hazard, deterioration and hazard; values of the goods. Furthermore, the capital availability of users, characteristics of the available storage methods and equipment as well as the stock and throughput levels must be taken into consideration.
Below are elaborations of several types of racking used by most warehouses and distribution centres throughout the world.
Selective Pallet Racking
This pallet racking is most generally used. This is due to it easy access to every load and flexible choice providing 100% selectivity to every load. This equipment is mainly for the best access and high-demand product. Although it delivers maximum access to stored pallets, it requires numerous aisles and aisle space, resulting in lower storage density than other form of racking.A type of a selective pallet racking is the boltless selective pallet, which in-demand due to its tool-free assembly, fast and affordable price. However, initial savings can be offset by high replacement and maintenance costs as it is found that the open-back roll formed columns don’t withstand the impacts of fork truck.
Drive-through Pallet Racking
This type of pallet racking is used for storing pallets of a similar stock-keeping unit (SKU) or goods. In this racking, loads are supported by rails attached to vertical frames, and lift trucks are driven between the frames to enter the rack from either side to pick up or pull out pallets as pallets can slide backwards on a continuous rail, open at both ends, which thus, allowing ‘first-in, first-out’ storage.
Drive-through pallet racking is used when there are seasonal items moving quickly out of the inventory and when there are large amount of similar items that can be stored in a single pallet position. It is not encouraged using this equipment when storing a wide variety of loads in the rack. Although selectivity is forgone, storage density is improved due to the ability to store a large amount of similar loads in a smaller area.
Push-back Pallet Racking
The objective of the push-back pallet racking is to minimize empty pick faces or honeycombing. The ideal appliance of the racking will be where all loads in a row are alike and not critically in a ‘first-in, first-out’ stock rotation.
This racking has the same storage density as the drive-through racks and up to 90% more product storage than selective pallet racking systems, but with greater selectivity of 4 times more than the drive-in pallet racking. Due to these factors, it improves the speed of pick rates. Besides offering a large target for loading and unloading, it also maximizes space through storing a range of SKUs on different levels of lanes for convenient access of goods.
Here’s how it operates:
Loads in each row lie on a cart by forklift on an inclined rail sloping gently toward the front. When a new load is deposited into a lane, it ‘pushes back’ the loads already at the face and those behind. When the load is picked, the forklift takes out the front pallet, allowing the pallets on carts behind it to roll gently to the front of the rack, showing a "push back" momentum. The nested carts of the racking make position and retrieval of loads convenient.
Storage Equipment (II) - Automated Storage and Retrieval Systems (AS/RS)
AS/RS is an array of computerized routines for automatically receiving and shipping materials from defined storage locations without manual labor, generally used in distribution centers and warehouses all over the world. It generally include machines moving up and down one or multiple parallel storage aisles, receiving and shipping products and materials for distribution to internal and external locations.
It's advantages:
- Grant users with increased tracking and inventory control, plus greater flexibility having room for changing business conditions.
- Specialized construction and installation systems, providing seismic and rack supported buildings.
- Feed-in and feed-out systems, very high tolerance racking, automatic fire protection strictly controlled weight checking and load sizing.
- Systems comprising modular subsystems easily substituted reducing downtime and expanding the life of the whole system.
- Produces key reserves in inventory storage costs, as greatly improved both vertically and horizontally warehouse space utilization creating larger storage density.
- Reduces labor costs, lowering essential labor force necessities, improving workplace safety, and eliminating staff from complex operational conditions.
However, there are the disadvantages of it as well;
- Requires significant investments of a company's capital; Particularly for maintenance and updating of different subsystems. Also, capital expenses can tempt some business owners to cut financial corners, buying "bargain" systems that are ill-equipped for extensive, long-term use à end up costing far more in the long run
- Not without occasional frustrations for maintaining highly integrated systems; Requires knowledge, skills and experience.
However, interrupted AS/RS service extends from the measurable such as lost in manufacture and delivery revenue, increased labor costs for repair, to the intangible such as the shrinking workforce confidence in the company's operations as well as the client’ confidence.
Identification and Control Equipment (I) - Bar Code
Series of vertical bars and spaces representing numbers and other symbols; it is affixed to postal mail, retail store items and identification cards in order to identify a particular location, person or product number. The symbol usually consists of five parts: a quiet zone, a start character, data characters which include an optional check character, a stop character, and another quiet zone. Although there is no particular standard bar code, there are several different bar code standards (symbologies) serving different industries, geographic needs or uses. The most common bar code standards are; Code 39 (Code 3 of 9), serving in Identification, inventory, and tracking shipments; Interleaved 2 of 5, serving the shipping and warehouse industries; and Uniform Product Code (UPC) serving the Retail stores in sales checkout, inventory and such.History traces back to its first patent for a bar code type product (US Patent #2,612,994), which was issued to inventors Joseph Woodland and Bernard Silver on October 7, 1952. This bar code was made up of a series of concentric circles described as a "bull's eye" symbol, and over time, has converted into today’s UPC bar code.
Bar code consists of information, called barcode data, or also point-of-sale (POS) data. It is automatically gathered as a consumer's purchases and place through a check-out. Massive volumes of such data is gathered every day by the POS terminals and processed before being very useful for marketing purposes, such as planning on pricing a particular product, or initiation of sales campaigns.
Barcode Reader
Bar code is read by a barcode reader, which is a stationary or hand-held input gadget used in capturing and reading information contained in it. Also called a price scanner or POS scanner, a barcode reader uses a laser beam sensitive to the reflections from the line and space thickness and variation before translating the reflected light into digital data transferred to a computer for immediate action or storage. A barcode reader consists of a scanner, a built-in or external decoder and a cable which is used to connect the reader with a computer.
Consisting of five basic types, the simplest barcode reader is the pen wand, which contains no moving parts. It is known for its durability and low cost. On the other hand, it can be challenging to the user, as it has to stay in direct contact with the bar code, held at a certain angle, and moved over the bar code at a certain speed. 
Another type is the slot scanner which remains stationary when the item with the bar code on it is pulled by hand through the slot. It is normally used to scan bar codes on identification cards.
Also, there is the type of bar code reader, the CCD scanner, having a better read-range than the pen wand and is often used in retail stores. Normally, a CCD scanner has a "pistol" type interface and has to be held at most 2.5cm from the bar code. Although several readings are taken to reduce the possibility of errors every time the bar code is scanned, it cannot translate a bar code that is wider than its input face. 
Furthermore, there is another type called the camera reader, or image scanner. It uses a small video camera capturing an image of the bar code before using sophisticated digital image processing techniques to translate the bar code. The camera reader can read a bar code from about 7.5cm to 23cm away and commonly costs less than a laser scanner.
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Lastly, a laser scanner, either stationary or hand-held, does not have to be close to the bar code to do translate it. Regardless of orientation, it uses a system of mirrors and lenses allowing the scanner to translate the bar code, and can easily translate a bar code up to 61cm away. A laser scanning may perform up to 500 scans per second to reduce the possibility of errors. A specialized long-range laser scanner is capable of reading a bar code up to 0.9m away.
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