Industrial Storage Racks safety

Industrial Storage Racks safety

Introduction:

Storage racks are the most important storage solutions in an industrial manufacturing facility, as well as warehouses. They are also used in various another commercial, residential, and retail applications. Although most users know about the importance of rack safety, still it is one of the most overlooked areas.

Warehouse is a commercial building used for storing industrial goods. A warehouse houses different types of racks for storing products such as roll dispenser racks, coil racks, movable storage racks, etc. Warehouse is also an accident prone idea due to various reasons. Improper management of racks is one of the main reasons for warehouse accidents. To avoid rack related accidents, it is very important that warehouse owners maintain a safety checklist. The checklist should enlist series of tasks and activities to be undertaken by people using these racks.

Hazard Recognition:

Be aware that the following hazards may exist when using steel storage racks to store materials, equipment, machines and tools at the workplace:

  • worker slips and falls from and around the racking during operations and maintenance
  • overturning of the rack because of incorrect height-to-depth ratio (of the entire rack)
  • failure of the racking structure because of vertical constraints, deflections, beam connections and other stability factors
  • collision of moving equipment with the racking system
  • overloading of the racking system if amount of product stored exceeds capacity of the racking

Hazards may also exist under the following conditions:

  1. improper specifications
  2. poor installation
  3. no inspection or maintenance
  4. improper repairs
  5. unknown capacity

Rack design considerations:

In order to determine the ideal storage solution, there are important safety and design  considerations as follows:

  1. Product and Turnover
  2. Load Capacity
  3. Rack Frame and Beam Material
  4. Existing Facility Features
  5. Production Zones and Work Flow Areas
  6. Material Handling Equipment
  7. Temperature
  8. Code Compliance & Permitting
  9. Plan for Long-Term Success
  10. Environmental Forces

Product and Turnover:

The type of rack as well as the shelf elevations and storage bay width will, to a great degree, be
determined by your product and stock rotation requirements. How many different product will be stored? What type, size, and number of pallets will be used? How often will pallets be accessed? Do you require FIFO (first in, first out) or LIFO (last in, first out)? Will processing / picking operations require the integration of automation into your system?

Load Capacity:

Load capacity takes into account maximum pallet load, average pallet load, as well as maximum
carton load, average carton load and storage utilization factor. 

Rack Frame and Beam Material

The type and configuration of your upright rack frames are determined by both the capacity they need to support and their exposure to potential impact during loading and unloading. Unlike some rack suppliers, Steel King has manufacturing facilities that specialize in both hot-rolled (structural) and roll-formed steel, so it is your racking needs that determine the type of steel that is used.

Existing Facility Features:

In addition to the floor space of your facility, take into account all features of your existing
structure – ceiling height, sprinkler systems, columns, floor drains. Be sure to account for sloping
floors within your facility, as you will be required to ensure that your rack uprights are plumb. Check your slab-on-grade capacity. Can your existing concrete floors accommodate the weight of
the system you plan to install? Do they require any special rack anchoring considerations? You will also need to map out your means-of-egress for both personnel and forklift access to ensure that maximum distances to egress are within code, especially for raised work areas.

Production Zones and Work Flow Areas:

Consider the space needed for your production work to safely occur. This is especially important
in manufacturing, where you have materials movement around equipment. For a stock and ship
operation, adequate space is required for packing, shipping, and receiving areas.

Material Handling Equipment:

The material handling equipment to be employed for the movement of the goods will impact rack
design factors. Some of the items to be considered are the type, size and number of pallets to be
used, as well as the type of fork truck vehicle being used, required aisle width, and the maximum
lift height of the truck.

Temperature:

Build your pallet racking system with temperature considerations in mind and consider the
environment where pallet racking will be used. There may be an advantage of using a particular
product based on whether the environment will be dry, in a cooler, or freezer environment.

Code Compliance & Permitting:

Rack systems may be installed only after all applicable building codes have been satisfied and
a building permit has been issued for a particular system design, geographic location, and a
particular user’s application. In most jurisdictions, the applicable building code is the legislatively adopted edition of the International Building Code (IBC) as developed, updated, and promulgated by the International Codes Council (ICC). Some localities enforce a variant of the IBC. The owner must work with the rack equipment provider to determine which code applies and to assure that their system will be designed, manufactured, and installed to satisfy all applicable requirements.

In addition to local building codes, some industries have specific code compliance requirements,
including rack capacity plaques.

Plan for Long-Term Success:

An integral part of every rack planning project is to recognize the importance of rack inspection
and maintenance.

Plan today’s system with future expansion in mind.

Environmental Forces:

Seismic design categories, along with wind and snow loads must be taken into consideration for
rack-supported structures. For free standing rack structures, adequate seismic separation must be engineered into your rack system.

According to OSHA, all goods, materials and equipment at work sites must be stacked, stored, and secured in such a way that they do not flow, move, roll, or collapse.

Storage racks are considered “building-like, non-building structures.” Therefore, according to
the International Building Code, and as reflected in the Rack Manufacturer’s Institute (RMI) Standard, racks need to be designed to the local seismic requirements, just like a building.

While all U.S. states have some potential for earthquakes, 42 of the 50 states “have a reasonable
chance of experiencing damaging ground shaking from an earthquake in 50 years,” which is
generally considered the lifetime of a building.

Types of storage racks:

Steel storage racks are universal equipment found in many workplaces. In most workplaces, they are loaded and unloaded with powered mobile equipment. Due to the common use of the phrase "storage racks" that describes all types of storage systems, as well as shelving units, this guideline provides further clarification and examples of the types of storage rack.

Types of steel storage racks:

  • Selective Rack
  • Drive-In Rack
  • Cantilever Rack
  • Over dock Storage Rack
  • Die Rack
  • High Capacity Wire Reel Rack
  • A-Frame Vertical Storage Racks

Selective Rack

The most popular type of rack is Selective Rack, so called because it allows easy selection, normally by service (truck) aisles. Selective Rack does not make the most complete use of floor space due to the aisles required, but may be the ideal solution for many companies. These systems can increase storage density with the integration of gravity-flow tracks, pushback carts, or double-reach application, allowing for deeper storage and less aisle space. Selective pallet racking is a popular and effective storage method in warehouses, manufacturing facilities and distribution centers due in large part to its ease of design and implementation.

Drive-In Rack

A Drive-In Rack, on the other hand, increases density and is
often utilized where group pallet selection is more likely than
individual pallet selection. With Drive-in Rack, loading and
unloading within a bay must be done from the same aisle. A
similar system called Drive-Thru Rack permits loading and
unloading from both ends of a bay.

Cantilever Rack

Cantilever Rack is primarily utilized to store bulk items such as
building materials (lumber, pipe, drywall, etc.) and furniture. It
is commonly found in home centers and furniture warehouses.
Cantilever Rack is easily identified by the arms protruding from
the face of the columns.

Over dock Storage Rack

Empty pallets cluttered around loading docks are a common
warehouse problem, which can lead to operational inefficiency
and safety issues. Steel King’s Over dock Storage Rack helps solve
these problems by storing your empty pallets in racking, above your
loading docks. Steel King’s standard SK2000 or SK3000 racking can be
designed and configured to fit around your loading dock doors.

Die Rack

Steel die storage racks are perfect for storing dies, motors, jigs,
fixtures, and other heavy material. Standard Steel die racks
feature a solid metal shelf design allowing die placement anywhere
along the shelf, and can accommodate a variety of die sizes. Shelf
design allows dies to be slid on or off a shelf for easy access and
storage. For optimal storage flexibility, shelves on tubular structural                                         rack can be designed so that they are removable
from the uprights and the heights adjustable in 3” increments across
the entire vertical height of the upright.

High Capacity Wire Reel Rack

High capacity, wire reel racks are custom designed with the
flexibility to accommodate the size and capacity of your spools and
axle brackets.

A-Frame Vertical Storage Racks

Steel King A-Frame storage racks are ideal for storing hand loaded,
long slender shaped material, such as moldings, trims, lumber,
ladders and gutters. These racks incorporate a unique framework,
utilizing  boltless pallet rack columns. Columns are angled
back to create a framework that supports your material evenly and
frequently all along its length.

Rack Terminology



Six-Step Pallet Rack Design:

To determine pallet rack configurations:

1. Find the depth and width of your pallet.

2. Determine the load depth, load width, load height and weight of your largest load. For the overall height, add the height of the load and the height of the pallet together.

3. To determine front-to-back depth of your uprights, subtract 6” from your pallet depth.

Example: Your pallet is 40” Wide x 48” Long (Depth).

Subtract (48” - 6”) = 42” Uprights

4. Determine the beam width (assumes 2 pallets per beam): Multiply the load width x 2 and add 12”.

Example: Your load width is 42”: 2 x 42” = 84”+ 12” = 96” beam length.

If required, round the length up to the next highest beam length.

5. Check the beam capacity to ensure the specified beams will carry the planned load. Do not exceed beam capacity.

6. Calculate your upright height (for a system using 4” beams):

(A) Multiply the number of pallets high stored minus one pallet x 10”.

Example: If storing 4 pallets high:
4 pallets high minus one pallet is 3, then multiply 3 pallets x 10” = 30”

(B) Multiply the number of pallets high stored minus one pallet by the overall load height. Include the pallet height in the overall load height.

Example: If storing 4 pallets high, with an overall load height of 50”:
4 pallets high minus one pallet is 3, then multiply 3 pallets x 50” = 150”.

(C) Add the two numbers you solved for together (30” + 150” = 180” in this case).
This number is your upright height. See table for standard upright sizes.

Notes on Upright Height

  • The vertical space between pallets allows for the beam height, and also vertical clearance to lift and remove the pallet.
  • Be certain there is adequate space left between load height of uppermost pallet and
    sprinkler heads, light fixtures, and other obstructions that may exist overhead.

Storage Utilization Factor(SUF):

Cube utilization is an industry term that refers to the amount of the total available space that is actually utilized, expressed as a percentage. When a space is completely filled with product, the cube utilization is 100 percent. This term is often used to describe a trailer when no more product can fit in it.

However, the reality is that as your utilization nears 100 percent, productivity within that space begins to fall – there is no room to effectively move and arrange product. The goal is to determine the optimal Storage Utilization Factor (SUF) that can provide for both fluctuations in inventory balances and honeycombing. Each type of storage – bulk, select rack, double-deep rack – has a different SUF that must be accounted for in the design of a storage system.

Extra Spaces for Inventory

Part of the SUF allowance is to provide extra storage spaces above the normal or planned inventory levels. A distribution center cannot operate efficiently if 100% of the pallet storage slots are occupied. Lift truck operators lose productivity when they must search for an available slot or consolidate partial pallets of the same stock-keeping unit (SKU) to create an empty storage slot. “Effective Utilization” is the level of storage that can be maintained as a percent of total capacity without degrading productivity and throughput.

Extra Spaces for Honeycombing

The second part of SUF is providing empty spaces for “honeycombing,” the term for partially filled pallet slots. For example, if there is one carton left on a pallet in a particular storage location, that location is not readily available to store other pallet. And while pallets can be consolidated, this takes extra time and reduces productivity. For this reason, leaving a certain percentage of empty positions actually increases efficiency.

Recommended Utilization Factors

For single-deep pallet rack storage, Steel King recommends planning for no more than 90% utilization at peak inventory levels. However, the storage utilization factor varies from one type of rack to another.

The SUF for the most common types of storage is in the chart below.

Storage Utilization Recommendation