NAI Cranes home
Search field lablel Site Map link  

Home About NAI Cranes, Components & Kits Services Engineering Industries Served Parts Picture Gallery Contact Us


What Makes Our Cranes Unique

Gantry Crane for Bridge Repair

What Does Our Affiliation with the CMAA Mean for Our Customers?

The CMAA (Crane Manufacturer’s Association of America) is an independent trade association founded in 1955. Companies striving for admission must undergo a thorough application and review process. Member companies represent leaders in the overhead crane industry.

CMAA member companies are concerned, conscientious manufacturers who meet regularly to review and revise standards for the mechanical, structural and electrical design of overhead cranes. CMAA members also formulate guidelines for the proper use, operation and maintenance of those cranes.

As a member of the CMAA, North American Industries, Inc.:

  • meets high standards in engineering design, production, and related operations
  • maintains a position of technological advancement

North American Industries is a proud member of:
Material Handling Industry of America (MHIA)
Crane Manufacturers Association of America (CMAA)

NAI prevents the problems you could encounter with other cranes:

Crane Travels Too Far Before Stopping?
If your crane coasts more than a few feet, then 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).

We use a mechanical braking system that never needs adjusting or replacing. This provides a gentle, consistent coasting stop that does not vary over time. For cranes that travel over 100 FPM or require quick stopping, we suggest considering the soft-stop feature of a variable speed inverter.

Bearings wearing out too soon?
We use a minimum of 2 bearings per wheel. All of our bearings are Class "D" which means they are designed with a minimum life expectancy of 10,000 hours of actual motor on-time. This is double the Class "C" rating - bearings for Class “C” cranes have a minimum life expectancy of 5,000 hours. Our Class "D" bearings are also sealed-for-life and never need lubricating.

Contactor problems?
Our contactors, rated for 20,000,000 stop / start cycles if used in conjunction with inverters or electronic soft start features, should never need replacing under normal operating conditions. See our Technical Report entitled "Electrical Contactors: How Long Should They Last?"

Broken Push Button Pendant or Cable?
NAI pendants are ergonomically designed to be easily held in one hand, and are constructed of a durable thermoplastic material. The pendant cable has 2 steel wires built into the cable jacket for permanent strain relief.

Parts Availability Problems?
Our components--bearings, contactors, gearboxes, motors and electrical systems--are designed to industry standards, and most are readily available throughout the U.S. All motor name plates and gearbox name plates are clearly labeled with the original manufacturing information. And virtually every spare part for the crane (excluding the hoist) is in stock here at North American and can be shipped immediately.

Brakes wearing out or not working properly?
Our mechanical braking system on the trolley and bridge eliminates the need to adjust brakes on a regular basis (typically every 3 months). There are no brake pads to change or adjust with our mechanical brakes. This will reduce overall maintenance and extend the life of the wheel gears and pinions.

Low Maintenance:

Most North American Industries' cranes also have:

  • Sealed ball bearings, which never need lubricating and keep out dirt and grit – a major cause of bearing failures in cranes.
  • Gearboxes with high-grade synthetic oil that never needs changing.
  • Automatically resetting thermal overloads, instead of fuses, which must be replaced. These overloads are placed inside all 3 motor windings to assure the most accurate measurements.
  • A cable for the push button with 2 steel cords built into the jacket. The cable holding the push button is usually abused, scraped and used as a ladder. Ours are able to handle the strain. The wires in the cable all lay straight, and are never spiral wrapped.
  • No electric brakes on the bridge and trolley. Electric brakes have brake pads that must be continually adjusted and changed every 1–2 years. If they are not changed, the crane rolls 10 to 20 feet before stopping. The operator, in turn, learns to reverse the crane to stop it. This "Reverse Plug" will damage the gearbox. A North American crane uses a mechanical brake (high ratio worm gear reducer) which stops the crane gently. This device has no brake pads to change and lasts 20 years.
  • Approximately 10–20% spare conductors for our bridge electrification cable and our pendant cable. If a wire breaks, you don't have to replace the cable, just connect the spare conductor.
  • Engineered features for easy maintenance. When maintenance is needed, our cranes are designed to allow quick repairs. Our wheels can be removed from above. You do not have to lift the crane off the runway rails. Our electrical panels are not crowded, and the wiring diagram is mounted inside the panel.

Class "D" crane

NAI produces Class “D” heavy duty cranes rather than moderate-duty Class “C” cranes. A Class "D" crane is designed to make twice as many lifts in an hour and lift the full rated load 30% more often than a moderate-duty Class "C" crane. Physically bigger and stronger than a Class "C" crane, Class “D” cranes generally last 30 to 40 years. NAI also offers a two year warranty.

Hoists supplied on our cranes are rated by HMI (Hoist Manufacturers Institute) as H-4 for heavy-duty use. Many competitors supply H-3 average duty hoists, or H-2 infrequent use hoists. See our parts department for further information on hoists.

Motors on the bridge and the trolley of NAI class “D” cranes are 60-minute motors. A Class "C" crane uses 30 minute motors. All motors have Class "F" insulation, which allows the motor to run hot and still work well. Competitors’ cranes often have Class "B" insulation, which would cause the motor to burn out at temperatures that our Class “F” motors can withstand easily.

See our Technical Reports:

| Contact | Site Map |