Hey Mr Tan, regarding to your question- "the problems and constraints of Cantilever Racks used in warehouse or distribution centre".

> The cantilevel rack is less effective in space usage as it uses many number of
aisles. In a warehouse, it is most ideal to have as minimal number of aisles as
the space used of the aisles could be use to accomodate more products.

> It has low storage density. Products that are heavy in their mass, are not able to
be supported by the cantilever as there is only a limited weight allowance a
cantilever is able to endure.

Although the parallel-flange beam section is being adopted by the art since it is a more economical section for most purposes. However, the parallel flange itself is weaker than the tapered flange which creates problems in the use of the cantilever racks of the indicated type because of the increasing possibility of failure of the column flanges. While this problem is partially overcome by the design shown in U.S. Pat. No. 4,065,089 because the point of load is at the root of the fillet of the flange as compared with the tip of the flange, there are other problems created with the loading at the root fillet such as penetration failures in light flange columns from the point loading of this construction. Also, this construction is undesirable in that it is necessary to mount all the cantilever arms on the column from the top down.

A limitation of the prior art cantilever rack constructions is their capability of carrying very heavy loads. Under these heavy load conditions the prior art devices are subject to the possibility of column flange tip failure and failure of the connector between the horizontal arm and the column flange.

Unlike all the above racks, cantilever rack does not have vertical members or columns in the front of the rack to limit the width of the loads to be stored. As the name implies, the storage levels are cantilevered from a rear vertical support only.

Cantilever rack reduces waste, simplifies handling (Article)

Buffalo Veneer and Plywood, located in Buffalo, Minnesota, is a supplier of specialty plywood using common North American tree species.
By Staff -- Modern Materials Handling, 10/2/2005


Buffalo Veneer and Plywood, located in Buffalo, Minnesota, is a supplier of specialty plywood using common North American tree species. While others in their industry have focused on large lot sales and a few woods, Buffalo Veneer remains true to its roots.

"We supply oak and birch plywood to Menards and Home Depot, but we also deal with fine cabinet makers all over the country," says Paul Erickson, company president. "We still do custom four or five sheet orders. Our reputation was built on quality and our ability to work with a variety of materials."

This kind of craftsmanship can be expensive, but it also means that Buffalo Veneer can get top dollar for the two to three truckloads of product it ships each day. The downside to this high-end market position is the cost of waste, which becomes a significantly more expensive problem as the cost of each unit goes up.

The company was experiencing some costly problems in their finished wood storage and staging area. Sheets were simply stacked on top of each other leading to hazardous lifting and product damage.

The answer to these problems was to install modular cantilever rack storage. The modular nature of the system meant that it could easily fit the available space, including the full building height that so often goes to waste in many storage facilities. Heavy duty enough to handle the heaviest loads, the modular system can be reconfigured or added onto as needed.

Wood sheets now stored individually or in small bundles to reduce abrasion and scratch damage. The product is off the floor and out of traffic lanes, eliminating accidental damage from heavy equipment. Pallets are also eliminated, along with the strap damage that goes with them.

Used Cantilever Rack for Sale in Houston (Video)

We shall now look into Single Sided Cantilever Rack and Structural Cantilever Rack.

Structural Cantilever Rack

Structural cantilever rack is a multi-level high density storage system designed to handle long length materials. Structural I-Beam cantilever rack is the most efficient and affordable way to store lumber, engineered wood products, re-bar, metal roofing, pipe, etc. Structural I-Beam cantilever rack can be used indoors or out, so it is extremely rugged. Plus, it's economical and versatile, whether it's used as stand alone storage unit, or used to support the roof of a shed or building.

Single Sided Cantilever Racks
Single Sided Cantilever Racks are ideal for against-the-wall applications. They are completely adjustable and eliminates storage problems. Long, unwieldy stock is handled quickly and efficiently by forklift; instant accessibility to one piece or a full load.They have a base assembly and arms on one side only. The arms are adjustable up and down the length of the upright wherever there are pre-drilled holes. To adjust align arms with pre-drilled holes and bolt in. All arms feature lips to prevent product from falling off.

Pictures of single sided cantilever rack

Cantilever Sheet Metal Racks

Vertical & Horizontal Sheet Metal Racks
A standard vertical sheet metal rack is designed for the vertical storage of sheet goods. Standard unit comes with four bays. Intermediate floor bracing gives added steel support while keeping material off the floor. Capacity per bay is 1,500 lbs. Unit is supplied with lag down points. Powder coat finish.

Vertical or horizontal sheet storage rack for sheet metal, plastic sheets and plywood. Sheet racks helps organize your shop and allows for easy access and identification. We supply heavy duty roll-out shelf racks, cantilever rack and steel storage racks for bar stock, rods, steel angle, pipe and tube storage.

Horizontal sheet racks are designed for storage of sheet goods and similar materials. The flat storage of our horizontal sheet metal rack reduces warping of thin materials. Five shelf design allow for generous storage of multiple thickness materials. Distance between shelves is 91/2". All welded steel frame allows for 2,000 pound capacity per shelf. Four sided access when using 4' x 8' sheet or smaller. Sheet metal racks are supplied with lag down points.

Lumber Rack (For Home Centers & Lumber Yards)

Upright is 4"x4" lumber appropriate length for building height.
Uprights are spaced so as to hit studs in wall. A 6" lag screw is driven through top of each post and into stud (drill pilot holes).

Shelves are ½" black iron gas pipe (have cut at local supplier to 15"-18"). Shelf bottom plate is pressure treated (if on concrete) and is anchored to floor via anchors. You may also fit PVC pipe over top of black iron piping to prevent marring lumber.

Layout shown is for side wall (wall supporting truss). If this is built on adjacent wall, turn top plate 90° and secure top plate to wall instead of ceiling.

Drill perpendicularly into uprights to receive gas pipe. Suggest a 6" hole spacing pattern for maximum flexibility. Space bottom shelf holes close to floor for maximum storage.

Horizontal shelf behind rack is for plywood storage. it is not necessary to support shelf.

On the uprights, a 10° angle is used to help center load over bottom plate, and to limit stress on wall. The angle was selected because it was center of gravity for a nine foot high shelf.

Shelf can be installed over drywall, or on bare studs.

Eight of these units spaced 16" apart can store 12' lumber. Use more or fewer units as needed. Spacing is then close enough to sticker and stack lumber for drying. Also great for storing dried project lumber.

Recommend uprights are cut to length individually to accommodate uneven floors…while in place, use chalk line to lay out pipe holes.

Heavy Duty Metals Rack

It makes storage of long or awkward materials safe and efficient which saves time and money. Often business warehouses put bulk items like aluminum sheets, flake board, dry wall and steel sheets in piles on the floor creating an unsafe and unorganized working environment for warehouse personnel. Instead of having warehouse staff constantly sort and organize unrelated bulky and awkward material, cantilever racks allow you to segregate and store bulky materials by commodity and size. Over time cantilever racks will pay for it self by reducing injuries to employee, increase worker efficiency and improve employee accuracy in stock selection.

It also offer clear frontal access to the storage levels. Unlike conventional racks, cantilevers have no vertical obstructions in the storage area. That lets you make full use of space from side to side on each level. Store materials of varying lengths without interference or modification to the cantilever rack.

The rules governing how to position heavy duty cantilever rack arms:
Rule 1 - use the correct amount of arms so the divided weight does not exceed arm capacity. So a 6000 pound load would require at least 6 arms with 1000 pound capacity per arm.

Rule 2 - total overhang = (1/#arms) X Product length. For example, a 20 foot run with 4 arms. Total overhang = (1 / 4) X 20 feet = 5 feet. So in this case 2, feet can overhand left and right. This is as complicated as cantilever racks get!! Not exactly rocket science.

Furniture Style Cantilever Rack

Cantilever racks are used by some of the Nation's largest furniture manufacturers and distributors for it gives you clear frontal access to the storage levels. Unlike conventional racks, cantilevers have no vertical obstructions in the storage area. That lets you make full use of space from side to side on each level. Store more items or materials of varying lengths without interference or modification of the rack.

A cantilever rack is ideal for storing items of non-uniform size, items easily susceptible to damage, and items or materials that tend to be in great length.

If your warehouse or factory deals with many big and bulky products such as furniture you should look into investing in a furniture cantilever rack. The investment in a furniture cantilever shelving unit can give you much of the space back that had been previously lost due to bulky parts and products cluttering up the precious space. Furniture cantilever racks are the perfect solution for any large products and parts, and being able to move around freely with forklifts is an advantage. One of the other advantages of these specialty pallet racks is that the forklifts can easily get parts on and off of them while loading and unloading trucks, and having well organized shelving units can make the process of finding what is needed easily and getting at it easily.

Application Examples Include:
Furniture
Merchandise in large boxes
TV's, Stereos and Electronic components.

Double Sided Cantilever Rack

The unobstructed wide span on this heavy-duty cantilever rack makes it ideal for storing bar stock, lumber and pipe. Speeds handling, accommodates bulky items which often present a space problem. Arms are constructed of 7 and 10 gauge steel and adjust on 3" centers. "Pin Keeper" device permits easy adjustment yet ensures arm cannot be worked loose during service. For maximum strength and support, uprights are constructed of 7-gauge steel. Cantilever rack is finished in durable gray enamel. Assembly is quick.

Bar & Tube Storage Stanchion Racks

Another way to store bars and tubes is stanchion racks. Fabricated from structural steel sections. Modular stack racks allow you to build a bar storage rack as you need it - instantly, single units are used to support bar stock without special fittings. Simply place the rack section to suit the load! The rack units nest on top of each other. Four or more units high are possible. They take up little room when not in use. Strong structural steel shapes are used to fabricate rack sections for heavy duty capacities. That's why we say stancion tube storage racks have herculean strength.

Its capacities are unlimited. Bar/tube/plate stanchions offer the best accessibility for bulk material storage. Using a stacker crane or side loader application you can easily pull large quantities of material.

Various types of Cantilever Rack

• Bar & Tube Storage Stanchion Racks
• Double Sided Cantilever Rack (For Storing Bar Stock, Pipe & Tubing)
• Furniture Style Cantilever Rack
• Heavy Duty Metals Rack
• Lumber Rack For Home Centers & Lumber Yards
• Cantilever Sheet Metal Racks
• Single Sided Cantilever Rack
• Structural Cantilever Rack

A close up of how they are being assembled.





Picture of a part of the rack.




This is how Cantilever Rack look like before they are assembled.

This is a picture of Cantilever Rack in a warehouse.

Loads are supported by cantilever "arms".
It is used to store long loads (e.g., bar stock, pipes, lumber).
It is quite similar to pallet racks, except the front upright beams and the front supporting beams are eliminated.

Before showing the different types of Cantilever Racks? Let's take a look at how they are actually design.

How To Design Cantilever Rack
The first step in designing a cantilever racking system is knowing specific characteristics of the product being stored. Knowing these four product characteristics will aid in calculations A through E.

1) What is the length of the product being stored?
2) What is the depth of the product being stored?
3) What is the height of the product being stored?
4) What is the weight of the product being stored?

A) Determine The number and spacing of arms required to support the load without deflection.
The load must be supported by enough arms to prevent load deflection. Deflection may cause damage to the load being stored as well as damage to the arms. To test for potential deflection problems place your load onto two wooden blocks (simulating two cantilever arms). If there is no deflection it is acceptable to use a two arm system as long as there are no capacity problems. If there is deflection use three blocks, keep adding blocks until there is no deflection. Note: It is important to conduct these tests using the arm spacing formula as detailed below.
ARM SPACING FORMULA: The load should overhang the end arms evenly and not be more than one-half the distance from upright centerline to upright centerline.

Adhering to the Arm Spacng Formula will ensure that each arm supports an equal amount of the loads weight. Failure to observe the formula may cause an overloaded condition on the arms

B) Determine the proper length of the arms.
The depth of the load should never exceed the length of the arm. If you are storing a load 48" deep you must use a 48" long arm, if you are storing a load 24" deep you must use a 24" long arm, never us an arm shorter than the depth of your load.

Note: All arm capacities are based on evenly dispersed static loads. Rated arm capacities may be seriously diminished if proper loading techniques are not followed.

C) Determine The Height Of The Upright
When determining the height of the upright it is important to consider the ceiling height, forklift reach, sprinkler system and any other factors, such as local building codes, that might effect the overall height of the upright.
The height of the upright is determined by adding the base height, the total height of the loads to be stored, the total thickness of the arms to be used and a minimum 6" clearance between the top of every load and the arm above.
Considering all of the above factors you should be able to determine your height requirement.
Call and ask sales for the various rack dimensions such as base height and arm thickness.

D) Determine Arm And Upright Capacity
Arm Capacity
If properly designed and properly loaded each arm supports an equal amount of the load's weight. By determining the number of arms required per load and dividing it into the weight per load, the required arm capacity is determined.
The example to the right shows each load weighs 6,000 lbs. and that each load is supported by three arms. Dividing the number of arms (3) into the the load weight (6,000 lbs.) determines the minimum arm capacity (2,000 lbs.).
Upright Capacity
To determine the capacity of each upright, multiply the number of arms per upright (on double sided uprights make sure you count the arms on both sides) by the capacity required per arm.
The example to the right shows (4) arms per upright and each arm has a 2,000 lbs. capacity. Multiplying the 4 arms x 2,000 lbs. capacity per arm = 8,000 lbs minimum required upright capacity.

E) Determine Brace Length
The brace length is the horizontal distance from centerline to centerline of uprights. Refer to the various brace set lengths as shown in the price lists. Match the brace length as closely as possible to the arm spacing determined in step A.

As you can see in the previous post, we have touched about the different types of Storage Equipments. Now, we are focusing on one of the equipment which we thought will be interesting-Cantilever rack.

The advantage to Cantilever Rack is that it gives you a clear frontal access to the storage levels allowing you to store material of greatly varied sizes. This allows you to save time and the effort to locate the items or materials that you need.

Unlike conventional racks, cantilevered arms have no vertical obstrustions in the storage area, that lets you make full use of space from side to side on each level and store items or materials of varying lengths without interferences or modification to the rack.

This will help warehouses to save storage space and allow warehouses to store more inventories of different types. Especially in country like Singapore, land is limited thus, having a good storage system is very important.

A cantilever storage rack is ideal for storing items of non-uniform size, items easily susceptible to damage, and items or materials that tend to be great in length such as furniture, lumber plywood, pipes and tubings.

Pictures of Cantilever Rack shall be posted in the next post. Stay tuned.

Storage Practices- How AmerisourceBergen's distribution centers flow (Article)

The six greenfield sites may resemble each other, but they are unique in the industry for their productivity. At peak, they can process 100,000 lines per night.
By Tom Andel, Editor-In-Chief -- Modern Materials Handling, 1/1/2008

AmerisourceBergen's six new greenfield distribution centers are configured for an L-shaped flow starting at receiving. Forty percent of the facility is dedicated to case and palletized reserve storage. An automated A-frame product dispensing system was set up on a platform above manual picking and in the controlled substances area to process high-volume orders.

The warehouse management system (WMS) allocates inventory by item. More than 100,000 controlled locations exist at each site.=

Triage for incoming
The WMS directs deliveries into a staging area for putaway. When receipts are scanned, the WMS calculates whether the item is new or in stock. If there's room in the active pick shelves, it can go directly there. If active is topped off, it goes to reserve storage (pallet or case). The system will calculate the most efficient path to storage, with the least drive time.

The day has staggered starts at 5 a.m., 6 a.m. and 7 a.m. Receipts can include everything from consumer goods products to high-value pharmaceuticals or vials containing temperature-sensitive biopharmaceuticals.

Controlled substances, as well as refrigerated products, are priority one and scanned and segregated as soon as they arrive. The refrigerated products go by pallet truck to the refrigerator and controlled substances go to secured storage areas. These areas are behind the shipping doors, and access to them is limited to associates who are cleared for entry via RF key card.

The next priority is flammable items and those are scanned and moved to a fire-rated room with a containment pit. Aerosol storage, which is a fire-rated structure with armored walls and automatically closing cutoff doors, is on the other side.

The doors behind the pallet rack are for receiving large bulky items, such as paper goods and nutritionals. Those items are destined for reserve storage as palletized goods.
On the other side of the palletized reserve area is loose-case reserve, where narrow-aisle racks are serviced by wire guided order picker trucks. Over-the-road truck receiving is done at the doors behind this area. Conveyors move less-than-case items across the top of the reserve rack, into a merge and into the manual pick zones or to the A-frame.

Replenishment
The WMS can meter replenishment activity to suit the day's workload. The goal is to have every pick slot topped off before the night pick starts. At tote induction, workers load short stacks of small and large totes into stackers to fill a buffer of 20-high stacks to support four hours of production. De-stackers release individual totes into cleaners. Totes are then scanned and married to specific orders. This information is communicated to WMS and all sub systems.

Picking
In the picking areas, items are scanned and dispensed into totes. In manual picking there are seven pick loops, each with three zones, for a combined 21 manual pick zones. Fast-moving prescription and over-the-counter (OTC) products are automatically picked to totes by an A-frame. It is like a 300-foot-long vending machine with 4,000 channels. The 2,200 SKUs in the A-frame account for up to 50% of all prescription and OTC line picks.

Upon order completion, totes are conveyed to the label, lid and strap area where totes are sealed and addressed before they are routed to shipping, where they are sorted and palletized by delivery route/stop.

AmerisourceBergen, Chesterbrook, Pa.
Products handled: Generic and name brand pharmaceuticals and healthcare products
Customers: Nearly 10,000 chain and independent pharmacies as well as thousands of hospitals, nursing homes and mail-order pharmacies.
Size: 300,000 square feet (expandable to 600,000 square feet)
Employees: About 180 per facility (on staggered shifts)
SKUs: 30-40,000
Shipment capacity per facility: 100,000 lines per night

Latest storage methods, material handling equipment and computerised accounting techniques (Video)

The RAF can't operate effectively without supplies of food, fuel and equipment. As a Supplier, you will be part of a team handling over a million different items, and using the very latest storage methods, material handling equipment and computerised accounting techniques to carry out your work. You could find yourself working in stock control, accounting units and supply depots, as well as outside on fuel installations, specialist storage sites and in the delivery of priority spares to operational units in the field. You could be posted to any area of the RAF, from a main supply unit to a squadron on NATO detachment. You could even serve with the Tactical Supply Wing and work on operations and exercises.

After much discussions, we have decided to focus on Storage Equipments-Cantilever rack.
Now, we shall first look into

1. What are Storage Equipments?
2. Why do we need Storage Equipments?
3. When do we need such equipments?
4. How do we operate such equipments?
5. Who uses such equipments?

1. What are Storage Equipments?
Storage equipment used for holding or buffering materials over a period of time.

2. Why do we need Storage Equipments?
The most common reason for storing a product allows the other elements of production to operate more efficiently on a per-unit basis because the fixed costs associated with utilizing the element can be spread over more products; e.g., storing up to a truckload of product in a facility reduces the per-unit costs of shipping; and buffering or storage of WIP enables batch production which reduces the per-unit setup costs.

Other potential reasons for storage include: time bridging—allows product to be available when it is needed (e.g., storing spare machine parts at the facility); processing—for some products (e.g., wine), storage can be considered as a processing operation because the product undergoes a required change during storage; and securing—e.g., nuclear waste storage.

3. When do we need such equipments?
When it is needed (e.g., storing spare machine parts at the facility); processing—for some products.

4. How do we operate storage equipments?
This competency covers the skills needed to manage a complex storage facility. This requires the operations technician to utilise the storage capacity efficiently, and to ensure particulates are stored in the appropriate containers.

The operations technician would control the conveyor systems transporting particulates into or out of a wide range of storage containers. This means setting up the required routing and starting and stopping conveyors and their feeder systems (if any) to convey materials from one point to another (e.g., between storage units, from or into storage).

During the process the operations technician would monitor the transfer operations, and take appropriate action to keep particulates moving correctly. This could include removing blockages and preventing rat holing or bridging in hoppers/silos.The operations technician would also maintain the cleanliness of the facility, along with carrying out minor maintenance according to procedures, and documenting/reporting maintenance requirements and other issues affecting the operation of the facility.

At this level, the operations technician would also recognise and solve problems with the transfer or storage processes. This includes recognising indications of potential problems and taking appropriate and timely remedial action to ensure minimal loss of production time.

From what we have learnt in our course of studies, there are 5 major categories of MHE. Here is a brief explanation of the various categories:

1) Transport Equipment
Equipment used to move materials from one location to another (e.g., between workplaces, between a loading dock and a storage area, etc.). The major subcategories of transport equipment include conveyors, cranes, and industrial trucks. Materials can also be transported manually without using any equipment.

This photo of a crane was taken outside our project site on our very 1st day of arrival :D


2) Positioning Equipment

Equipment used to handle material at a single location so that it is in the correct position for subsequent handling, machining, transport, or storage. Unlike transport equipment, positioning equipment are usually used for handling at a single workplace. Materials can also be positioned manually without using any equipment. Some examples of positioning equipment are as follows:

Manual (No Equipment)
Lift/tilt/turn table
Dock leveler
Ball transfer table
Rotary index table
Parts feeder
Air film device
Hoist
Balancer
Manipulator
Industrial robot

This is a photo of Mr Jacob, the person-in-charge of showing us around the warehouse. Look at his awkward expression when he demonstrated using a Dock Leveler in his semi-formal wear!
*Evil Laughs*

3) Unit Load Formation Equipment
Equipment used to restrict materials so that they maintain their integrity when handled a single load during transport and for storage. If materials are self-restraining (e.g., a single part or interlocking parts), then they can be formed into a unit load with no equipment. Some examples of unit load formation equipment are as follows:

Self-restraining (no equipment)
Pallets
Skids
Slipsheets
Tote pans
Pallet boxes/skid boxes
Bins/baskets/racks
Cartons
Bags
Bulk load containers
Crates
Intermodal containers
Strapping/tape/glue
Shrink-wrap/stretch-wrap
Palletizers

Tsktsk. I wonder who left this pallet drifting among the sea waves at a nearby beach 1km away from the project site.

4) Storage Equipment

Equipment used for holding or buffering materials over a period of time. Some storage equipment may include the transportation of materials (e.g., the S/R machines of an AS/RS, or storage carousels). If materials are block stacked directly on the floor, then no storage equipment are required. Some examples of storage equipment are as follows:

Block stacking (no equipment)
Selective pallet rack
Drive-through rack
Drive-in rack
Flow-through rack
Push-back rack
Sliding rack
Cantilever rack
Stacking frame
Shelves/bins/drawers
Storage carousel
Automatic storage/retrieval systems (AS/RS)
Split case order picking system
Mezzanine

Cool! We found this vertical storage carousel at a corner of the warehouse.

5) Identification and Control Equipment

Equipment used to collect and communicate the information that is used to coordinate the flow of materials within a facility and between a facility and its suppliers and customers. The identification of materials and associated control can be performed manually with no specialized equipment. Some examples of identification and control equipment are as follows:

Manual (no equipment)
Bar codes
Radio frequency (RF) tag
Magnetic stripe
Machine vision
Portable data terminal
Electronic data interchange (EDI)/Internet

Wow! Take a look at the long list of barcodes for the various stocks!

Hello

Hello readers! This is our new blog and we'll be posting our findings about Materials Handling Equipments (MHE) here. So, stay tuned if you are interested to find out more about this topic. We hope that our findings will give you a better understanding about Materials Handling Equipments and feel free to drop us a comment if you have any queries.