When a load is unable to be safely lifted with standard lifting slings and rigging equipment due to the size, shape, or center of gravity of the load; an engineered below the hook lifting device, sometimes referred to as an under the hook lifting device or BTH lifting device, is often the perfect material handling solution. According to the American Society of Mechanical Engineers (ASME), a below the hook lifting device is, “a device used for attaching a load to a hoist. The device may contain components such as slings, hooks, and rigging hardware…” Below the hook lifting devices attach to a crane or hoist hook and allow riggers to safely and efficiently attach to pick points on a load. Below the hook lifting devices are mostly mechanical, but can be controlled electronically, pneumatically or hydraulically to operate hooks, tongs, latches or claws.

The most common reasons for using an engineered below the hook lifting device are to increase worker efficiency, to increase worker safety, and to increase load securement. The time savings from increased efficiency not only cover, but often exceed the cost of a below the hook lifting device, adding value to any industrial operation. Below the hook devices also save you money by avoiding accidents and near misses that would have otherwise happened without the device. In addition to preventing harm to your workers, under the hook lifting devices also prevent harm to the load being lifted. Here at Tri-State Rigging Equipment we believe the best time to install a below the hook lifting device is before an accident happens, not after.

The most common loads that require an engineered lifting device are:

• Pipes or Bars
• Coils
• Drums
• Sheets and Plates

• Pallets
• Concrete Slabs
• Bundles and Rolls

Here at Tri-State Rigging Equipment we can provide you with any standard below the hook lifting device, in a variety of styles and sizes. In addition, we specialize in providing custom designed and fabricated below the hook lifting devices to fit any lifting or rigging application. If a standard under the hook lifting device will not fit your specific application, we will work with you to design and manufacture a completely custom below the hook lifting device from scratch, or in some cases, we can modify an existing below the hook lifting device design to fit your lifting application. We can provide you with any lifting or rigging product on the market, both custom and standard, so if you cannot find what you are looking for, or if you don’t know exactly what you need, give our sales team a call to speak with a below the hook product specialist.

Below the Hook Lifting Device OSHA and ASME Compliance

Just like any other lifting and rigging equipment, all below the hook lifting devices must comply with any and all applicable OSHA and ASME standards. OSHA does not specifically address below the hook lifting devices but in the event of an OSHA inspection, they will enforce the standards put forth by ASME under the OSHA general duty clause:

• Section 5(a)(1) of The Occupational Safety and Health Act of 1970 lays out the General Duty Clause which says that in the absence of specific OSHA standards regarding a hazard, each employer must, “furnish to each of his employees employment and a place of employment which are free from recognized hazards that are causing or are likely to cause death or serious physical harm to his employees.” This means that employers are responsible for protecting their employees from serious recognized hazards. Under the General Duty Clause OSHA considers the guidelines of industry consensus standards, such as those published by the American National Standards Institute (ANSI) and the American Society of Mechanical Engineers (ASME), when evaluating whether there has been an OSHA violation. Below are the ASME standards that would be applicable under the General Duty Clause regarding below the hook lifting devices:
  • ASME B30.20 Below-the-Hook Lifting Devices: This standard addresses mechanical and structural lifting devices, magnet lifting devices, vacuum lifting devices, as well as scrap and material handling grapples. It provides the standards that are to be followed regarding the marking, construction, installation, inspection, testing, maintenance, and operation of under the hook lifting devices.
  • ASME BTH-1 Design of Below-the-Hook Lifting Devices: This standard addresses the minimum mechanical and structural design and electrical component selection for ASME B30.20 below the hook lifting devices.

The most important thing that end users must do to ensure OSHA and ASME below the hook compliance is to review the identification tag for correct information and legibility. Below the hook lifting device ID tags must display the following information:

• Manufacturer’s name (manufacturer website address is acceptable)
• Unique serial number
• Lifter weight if over 100 lbs. (45 kg)
• Rated Load

• Cold current amps (if applicable)
• Rated voltage (if applicable)
• ASME BTH-1 Design Category
• ASME BTH-1 Service Class

Below the Hook Lifting Device Design Categories

According to ASME BTH-1 standards, below the hook lifting devices are divided into two design categories.

Design Category A: “Design Category A should be designated when the magnitude and variation of loads applied to the lifter are predictable, and where the loading and environmental conditions are accurately defined or not severe.”

Design Category A lifting devices are limited to a Service Class of 0 and therefore require a lower design factor than category B lifting devices. These lifters are typically used on paint lines or in rapid manufacturing locations where outside conditions are not acting on the load and the load never changes.

Design Category B: A lifting device is designated as design category B when the magnitude and variation of loads are not predictable, and where loading and environmental conditions are severe or not accurately defined. Most below the hook lifting devices fall under this category. These lifters can fall under service class 0-4 and must have a design factor of 3:1.

Below the Hook Lifting Device Service Classes

The Service Class of a lifter is based on the load cycles that lifter will see in a 24-hour period. The service class 0-4 designation defines the total life cycles a lifter can see based on the specified fatigue life of the lifter.

Service Class
Service Class	Load Cycles
0	0 - 20,000
1	20,001 - 100,000
2	100,001 - 500,000
3	500,001 - 2,000,000
4	Over 2,000,000

Service Class Life
	Desired Life (Years)
Cycles Per Day	1	5	10	20	30
5	0	0	0	1	1
10	0	0	1	1	2
25	0	1	1	2	2
50	0	1	2	2	3
100	1	2	2	3	3
200	1	2	3	3	4
300	2	3	3	4	4
750	2	3	4	4	4
1,000	2	3	4	4	4

Below the Hook Lifting Device Inspection Requirements

The most common reason an under the hook lifting device may not be OSHA and ASME compliant is failure to inspect and maintain proper inspection records for the under the hook lifting devices.

Below-the-Hook lifting devices require three regular inspection frequencies per ASME B30.20:

• Before and during each lift made by the lifter
• Frequent inspection
• Periodic inspection

Prior to and during use - Before and during each lift, the lifter should be visually inspected for anything unusual, especially excessive damage and wear.

Frequent Inspection - Visual examinations are to be made by the operator or other designated person(s). Written records are not required for frequent inspections of below the hook devices.

• Normal Service – Monthly
• Heavy Service – Weekly to Monthly
• Severe Service – Daily to Weekly
• Special or Infrequent Service – As recommended by a qualified person before and after each inspection.

Periodic Inspection - A qualified person must visually inspect all below the hook lifting devices, taking note of external conditions to further inform future inspections. Instead of written records, an external code mark is acceptable identification.

• Normal Service – Yearly
• Heavy Service – Semi-Annually
• Severe Service – Quarterly
• Special or Infrequent Service – As recommended by a qualified person before the first such inspection and as directed by the qualified person for any subsequent inspections.

Engineered Product Warning

Tri-State Rigging Equipment is a custom designer, manufacturer, service provider and distributor for all below the hook lifting devices, serving clients from coast to coast, Canada, Mexico and especially focused in the states of Missouri, Illinois, Indiana, Iowa, Kansas, Nebraska, Arkansas, Mississippi, Tennessee, Kentucky, South Carolina, Florida, and Oklahoma.