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Ten Things to Know Before Purchasing an Overhead Crane
There are many things to know and understand before purchasing an overhead crane. Your purchase is typical to improve productivity and safety within your facility. Therefore you need to take several things into account before your purchase. The lowest bid does not work in the crane industry. There are too many crane variations, safety requirements, and technological features available today that you will miss the boat on if you go with the lowest bid. Not only that, you may get a crane that is not even suitable for your application. In the end, you will overspend on a crane with specifications that are not needed for your application. I have seen way too many times bids on overhead cranes that have specs way over what the application requires. These specs cause them to pay sometimes double the amount for a crane that does not even fit their application. Before you invest your money into a new overhead crane, take into account these ten items that will not only save you money but will invest in the best crane for your application. A local crane advisor could help you with acquiring the information below.
1.Environment
The environment is one of the key elements with your crane requirements that often does not get discussed. The environment can change many of the deciding factors on what kind of crane you will need. For example, certain chemicals can make plastic brittle or accelerate metal corrosion. Cutting oils can make neoprene and PVC brittle. Heat and moisture can cause your motors to overheat. You will not pick the right crane without the crane company knowing what the environment is existing. Your crane will need to have special components depending on its application and environment. To know your application you will need to know what you’re picking up, and the site in which the crane operates. Added components will be necessary for specific areas. Particularly conditions with heavy dust, humidity, high or low temperatures, outdoor, indoor, chemical exposure, Light, and even altitude can affect the crane. Outside of the standard range, additional components will be required.
Look out for these items on your application.
a. Standard Altitude is Below 3280ft (Altitude can affect cooling of electronic components and not allow heat dissipation)
b. Standard Temperature Range is 32˚F to 104˚F
c. Standard Humidity is below 90%
d. Outdoor Applications will require features to prevent damage during rain, snow, ice, heat, wind, and ultraviolet radiation.
e. Corrosive or Explosive Chemicals/ Fumes will require added features
f. Heavy dust environments from cutting will require protective added features
g. Heat can liquefy lubricants, and affect motors, and electrical components
h. Cold can freeze lubricants, crack plastic components, and electrical parts
i. Drastic temperature changes can cause condensation and short out electrical components and cause corrosion
2. Duty Cycle
The crane’s duty cycle is going to depend partly on the application. If the crane is a production crane it will probably need a heavy duty cycle. If it is a maintenance crane or a crane used for shipping then the cycle may be shorter. You will need to ask yourself how often will this crane get used every hour and how often will it be lifting near full capacity? Depending on this, different components will be used to make your crane. Electric motors have duty cycles therefore, you want to make sure that your crane has the right motor for the job. Picking a severe duty motor for a light-duty application will cause you to spend well over what is necessary for the application.
There are two standards crane manufacturers go by when picking out the right duty cycle. FEM and CMAA. CMAA is the Crane Manufacturers Association of America and FEM is Federal European De La Manutention. This is the standards for design and manufacturing internationally of overhead traveling cranes. Both specifications are written based on the input from the larger crane companies. The difference is that FEM is worldwide while CMAA is for America. FEM will also separate each main part of the crane (hoist, trolley, and bridge) while CMAA specs classify the crane as a whole. To understand these classifications you will also need to understand what a lift or work cycle is. A work cycle is lifting the load, having a rest period where the trolley or bridge is moving, lowering the load, having a rest period again where the trolley or bridge may be moving, and then returning the hook to the starting position.
3. Capacity
Picking the right capacity is very important to extending the life of your crane. Also, it reduces unwanted wear and tear. Capacity requirements will help in deciding your Duty Cycle as well. For example, you may have a product that weighs 10 tons. However, do you have another component that the crane will be picking up that weighs less than 10 tons? It may be ideal to raise the capacity of the crane to 15 tons. Doing so keeps a Class C rating instead of going to a Class D rating. A ten-ton crane maybe your best option as well if most of what you are picking up on weighs five tons. It all depends on the loads they need to take into account. These are not just the maximum weight requirements. You need to also think about any below-the-hook requirements that may be essential to pick up your product. Sometimes the below the hook device can weigh several tons. That could have a substantial impact on the crane requirements.
4. Speed
I would say that out of these ten things to consider, the speeds are what gets missed the most. Typically the standard speeds will work for most applications, there still are some applications where you will need faster or slower speeds. Depending on the capacity, the hoist speed will vary. A typical bridge speed is around 100 fpm, a trolley speed is about 70 fpm, and the hoist is between 30-60 fpm depending on capacity. There is also adaptive speed range which is specific to the weight and the most ideal for many different crane applications. Depending on the utilization you may need higher speeds. If you have a crane that feeds your facility with raw material or loading the finished product such as rebar you may need a high-speed crane in which you can not get with standard features. The last thing you want is to purchase a crane to increase production and find out that the crane operates too slowly. You may also have an application where you need to utilize the crane for assembling a product; this often requires precise lifting and extremely slow speeds. If you purchase a standard crane the speeds will be too fast for this application making the load jerky and you will not be able to assemble your product using the crane. Take the time to discuss the required speeds with your crane company.
5. Safety Issues
You will also need to know any safety issues for the application that may exist for the crane operator. Is there anything your operators will be exposed to? Can the operator keep up with the trolley and bridge speeds safely by walking? Perhaps radio control will be required, or a cab, even a remote station. Many smart features can be added to increase safety, productivity, and save on ownership cost. Is there anything in the bay your crane could get snagged on during the lifting process? Do you need to flip the load? Is there any area in the bay that you want to protect from the crane accessing? These questions can be answered using Smart Technology. Smart features can drastically increase your production and are well worth the investment. Unlike the automotive industry or any other for that matter, you can still purchase cranes today with decade-old technology. This older technology would be the worst investment you could make for your company. With the latest technology available you can increase your production and at the same time make your facility safer for your employees. There is specific technology you should never purchase a crane without. Always ensure your crane comes with a variable frequency drive for the crane and trolley motions.VFD's ensures the safe operation of your crane and will help in reducing load swings. Hoist variable drives are also highly recommended. Radio Control help keep your operators away from the load. The cost to add this on a new crane is minimal and well worth the extra cost. Another crucial consideration to think about when reviewing your crane’s safety is a real-time analysis of your crane’s operation. This is currently limited in the crane industry but is readily available with certain manufacturers. Many other features can be added to your crane today. All are designed to improve your productivity or make your crane safer to operate. Features such as sway control, inching, micro speed, slack rope prevention, load floating, hook centering, follow me, hoist synchronization, extended and adaptive speed ranges, and shock load prevention, are available and may greatly benefit your application. Talk to a consultant or your crane provider for these options.
Lighting may also be something you need to think about. If your crane is a large double girder it may cover much of the overhead lighting. Often lights will be provided on the crane to help the operator and workers see when it is blocking the overhead lights.
Catwalks may be required if there is no access for maintenance personnel from the floor. Catwalks will allow your cranes to be repaired even if it is over machinery or a pit.
6. Area Coverage
Another factor to consider is where in the working crane area do you need to reach with the load hook? This is called your hook approach. The hook approach end is the minimum horizontal distance that is parallel to the runway and goes from the centerline of the hook to the centerline of the runway. The hook approach side is the minimum horizontal distance, perpendicular to the runway between the centerline of a hook and the centerline of the runway rail. You will need to know how much coverage your process or application will be required before getting crane pricing. Don't think you have to acquire this information yourself. A crane consultant can help with getting this information for you.
Dimensions Needed to Properly Size the Crane for an Existing Runway
a. Center of runway rail to face of building column or side obstruction
b. Approximate length of runway
c. Number of Cranes on runway
e. Runway conductor location
f. Below the hook dimensions
7. Lift Height Requirements
Depending on whether you are installing a new system or a new crane on an existing system you will need various information. Your lifting requirements will be restricted based on the height and design of your existing building. If you have an existing runway you will have even greater restrictions. To get crane pricing you will need some preliminary information.
Building Clearances for existing runway
a. Floor to Top of Runway Rail
b. Top of runway rail to lowest overhead obstruction
c. Runway rail size
d. Below the hook dimensions
Building Clearances for new system
a. Available dimension from floor to nearest ceiling obstruction
b. Height of product being lifted
c. Below the hook equipment dimensions
8. Power Supply
Your overhead crane is going to run off of 480V or 230V. You will need to verify you have three phase and one of these voltages available. Your crane needs to be on a dedicated circuit and typically a 20AMP breaker but of course that is dependent upon the size of the crane, and and electric below the hook devices. You also have to figure out how many cranes are on the same runway. This will increase your amperage requirements. Typically your power source on the runway will be a enclosed conductor bar. Building power must be installed in the middle of the runway unless it is a short runway with low amperage requirements. In this case it would be at the end.
You will also require a runway disconnect that is not provided by the crane manufacturer. This disconnect must be readily accessible from the floor and arranged to be locked in the open position. It also must be labeled for its purpose.
9. Warranty
When reviewing your quotes you want to take into consideration your warranty. Not all warranties are created equal. Key things to look for with your crane’s warranty is the following.
a. How long is your warranty?
b. Does it include labor, parts, and shipping?
c. What doesn’t it cover?
d. Is there a local service group that can deal with warranty issues?
10. Service
Your crane purchase does not end with the crane installation. During the life of the crane it will require servicing and possibly warranty issues. There will also be a need for crane inspections to meet local regulations and ensure your crane is operating safely and efficiently. You will also be in the need of training your operators on your new equipment. When reviewing crane proposals ask about their service to ensure they have someone local and the resources to meet your needs.
a. Ensure that whoever you’re purchasing your crane from they are a turn key supplier. They will provide everything needed to get your crane installed and up and running, including crane commissioning by the manufacturer, and even shipping of the crane.
b. Are you purchasing from the manufacturer or a distributor? If it is a manufacturer your are getting it straight from the source. If it is a distributor the manufacturer of those crane components does not have any kind of quality control on the crane itself so you will need to do more thorough research to ensure you are getting a good quality product.
c. Who will be handling any warranty issues? The manufacturer or distributor? Are they local?
d. Is there a local manufacturer representative that can provide training on my new equipment? What type of training do they offer? Can they train my trainer?
e. Can the manufacturer of my crane provide periodic inspections on my new equipment?
f. Is the crane company registered members of CMAA (Crane Manufacturers Association of America) and HMI (Hoist Manufacturers Institute)?
h. Can I easily purchase parts?
i. What kind of consulting is available to me free of charge?
If you review these 10 items prior to purchasing or getting a quote for your next overhead crane you will be one step ahead and on the right track to making the best decision for your company. A crane advisor can help you with additional questions to help ensure that you are purchasing the best crane for your application. Don't go it alone. You can always send me an email or give me a call and I would be happy to consult with you on your next overhead crane project. If you are not in my area I can still help and then get you to the right person.
1.Environment
The environment is one of the key elements with your crane requirements that often does not get discussed. The environment can change many of the deciding factors on what kind of crane you will need. For example, certain chemicals can make plastic brittle or accelerate metal corrosion. Cutting oils can make neoprene and PVC brittle. Heat and moisture can cause your motors to overheat. You will not pick the right crane without the crane company knowing what the environment is existing. Your crane will need to have special components depending on its application and environment. To know your application you will need to know what you’re picking up, and the site in which the crane operates. Added components will be necessary for specific areas. Particularly conditions with heavy dust, humidity, high or low temperatures, outdoor, indoor, chemical exposure, Light, and even altitude can affect the crane. Outside of the standard range, additional components will be required.
Look out for these items on your application.
a. Standard Altitude is Below 3280ft (Altitude can affect cooling of electronic components and not allow heat dissipation)
b. Standard Temperature Range is 32˚F to 104˚F
c. Standard Humidity is below 90%
d. Outdoor Applications will require features to prevent damage during rain, snow, ice, heat, wind, and ultraviolet radiation.
e. Corrosive or Explosive Chemicals/ Fumes will require added features
f. Heavy dust environments from cutting will require protective added features
g. Heat can liquefy lubricants, and affect motors, and electrical components
h. Cold can freeze lubricants, crack plastic components, and electrical parts
i. Drastic temperature changes can cause condensation and short out electrical components and cause corrosion
2. Duty Cycle
| Classification | Use | Shift operation | Load Spectrum | ||
| FEM | HMI | CMAA | |||
| 1Cm | H1 | Class A | Light duty | Single shaft | Very light |
| 1Bm | H1 | Class B | Light duty | Single shaft | Maxmum load lifted occasionally |
| 1Am | H3 | Class C | Light to mudium duty | Single shaft | Maxmum load lifted occasionally |
| 2m | H4 | Class D | Medium to heavy duty | One or two shaft | Medium to heavy loads |
| 3m | H4 | Class D | Heavy duty | Two shaft | Heavy loads lifted regularly |
| 4m | H4 | Class D or E | Exrremely heavy duty | Two to three shaft | Heavy loads lifted regularly |
The crane’s duty cycle is going to depend partly on the application. If the crane is a production crane it will probably need a heavy duty cycle. If it is a maintenance crane or a crane used for shipping then the cycle may be shorter. You will need to ask yourself how often will this crane get used every hour and how often will it be lifting near full capacity? Depending on this, different components will be used to make your crane. Electric motors have duty cycles therefore, you want to make sure that your crane has the right motor for the job. Picking a severe duty motor for a light-duty application will cause you to spend well over what is necessary for the application.
There are two standards crane manufacturers go by when picking out the right duty cycle. FEM and CMAA. CMAA is the Crane Manufacturers Association of America and FEM is Federal European De La Manutention. This is the standards for design and manufacturing internationally of overhead traveling cranes. Both specifications are written based on the input from the larger crane companies. The difference is that FEM is worldwide while CMAA is for America. FEM will also separate each main part of the crane (hoist, trolley, and bridge) while CMAA specs classify the crane as a whole. To understand these classifications you will also need to understand what a lift or work cycle is. A work cycle is lifting the load, having a rest period where the trolley or bridge is moving, lowering the load, having a rest period again where the trolley or bridge may be moving, and then returning the hook to the starting position.
3. Capacity
Picking the right capacity is very important to extending the life of your crane. Also, it reduces unwanted wear and tear. Capacity requirements will help in deciding your Duty Cycle as well. For example, you may have a product that weighs 10 tons. However, do you have another component that the crane will be picking up that weighs less than 10 tons? It may be ideal to raise the capacity of the crane to 15 tons. Doing so keeps a Class C rating instead of going to a Class D rating. A ten-ton crane maybe your best option as well if most of what you are picking up on weighs five tons. It all depends on the loads they need to take into account. These are not just the maximum weight requirements. You need to also think about any below-the-hook requirements that may be essential to pick up your product. Sometimes the below the hook device can weigh several tons. That could have a substantial impact on the crane requirements.
4. Speed
I would say that out of these ten things to consider, the speeds are what gets missed the most. Typically the standard speeds will work for most applications, there still are some applications where you will need faster or slower speeds. Depending on the capacity, the hoist speed will vary. A typical bridge speed is around 100 fpm, a trolley speed is about 70 fpm, and the hoist is between 30-60 fpm depending on capacity. There is also adaptive speed range which is specific to the weight and the most ideal for many different crane applications. Depending on the utilization you may need higher speeds. If you have a crane that feeds your facility with raw material or loading the finished product such as rebar you may need a high-speed crane in which you can not get with standard features. The last thing you want is to purchase a crane to increase production and find out that the crane operates too slowly. You may also have an application where you need to utilize the crane for assembling a product; this often requires precise lifting and extremely slow speeds. If you purchase a standard crane the speeds will be too fast for this application making the load jerky and you will not be able to assemble your product using the crane. Take the time to discuss the required speeds with your crane company.
5. Safety Issues
You will also need to know any safety issues for the application that may exist for the crane operator. Is there anything your operators will be exposed to? Can the operator keep up with the trolley and bridge speeds safely by walking? Perhaps radio control will be required, or a cab, even a remote station. Many smart features can be added to increase safety, productivity, and save on ownership cost. Is there anything in the bay your crane could get snagged on during the lifting process? Do you need to flip the load? Is there any area in the bay that you want to protect from the crane accessing? These questions can be answered using Smart Technology. Smart features can drastically increase your production and are well worth the investment. Unlike the automotive industry or any other for that matter, you can still purchase cranes today with decade-old technology. This older technology would be the worst investment you could make for your company. With the latest technology available you can increase your production and at the same time make your facility safer for your employees. There is specific technology you should never purchase a crane without. Always ensure your crane comes with a variable frequency drive for the crane and trolley motions.VFD's ensures the safe operation of your crane and will help in reducing load swings. Hoist variable drives are also highly recommended. Radio Control help keep your operators away from the load. The cost to add this on a new crane is minimal and well worth the extra cost. Another crucial consideration to think about when reviewing your crane’s safety is a real-time analysis of your crane’s operation. This is currently limited in the crane industry but is readily available with certain manufacturers. Many other features can be added to your crane today. All are designed to improve your productivity or make your crane safer to operate. Features such as sway control, inching, micro speed, slack rope prevention, load floating, hook centering, follow me, hoist synchronization, extended and adaptive speed ranges, and shock load prevention, are available and may greatly benefit your application. Talk to a consultant or your crane provider for these options.
Lighting may also be something you need to think about. If your crane is a large double girder it may cover much of the overhead lighting. Often lights will be provided on the crane to help the operator and workers see when it is blocking the overhead lights.
Catwalks may be required if there is no access for maintenance personnel from the floor. Catwalks will allow your cranes to be repaired even if it is over machinery or a pit.
6. Area Coverage
Another factor to consider is where in the working crane area do you need to reach with the load hook? This is called your hook approach. The hook approach end is the minimum horizontal distance that is parallel to the runway and goes from the centerline of the hook to the centerline of the runway. The hook approach side is the minimum horizontal distance, perpendicular to the runway between the centerline of a hook and the centerline of the runway rail. You will need to know how much coverage your process or application will be required before getting crane pricing. Don't think you have to acquire this information yourself. A crane consultant can help with getting this information for you.
Dimensions Needed to Properly Size the Crane for an Existing Runway
a. Center of runway rail to face of building column or side obstruction
b. Approximate length of runway
c. Number of Cranes on runway
e. Runway conductor location
f. Below the hook dimensions
7. Lift Height Requirements
Depending on whether you are installing a new system or a new crane on an existing system you will need various information. Your lifting requirements will be restricted based on the height and design of your existing building. If you have an existing runway you will have even greater restrictions. To get crane pricing you will need some preliminary information.
Building Clearances for existing runway
a. Floor to Top of Runway Rail
b. Top of runway rail to lowest overhead obstruction
c. Runway rail size
d. Below the hook dimensions
Building Clearances for new system
a. Available dimension from floor to nearest ceiling obstruction
b. Height of product being lifted
c. Below the hook equipment dimensions
8. Power Supply
Your overhead crane is going to run off of 480V or 230V. You will need to verify you have three phase and one of these voltages available. Your crane needs to be on a dedicated circuit and typically a 20AMP breaker but of course that is dependent upon the size of the crane, and and electric below the hook devices. You also have to figure out how many cranes are on the same runway. This will increase your amperage requirements. Typically your power source on the runway will be a enclosed conductor bar. Building power must be installed in the middle of the runway unless it is a short runway with low amperage requirements. In this case it would be at the end.
You will also require a runway disconnect that is not provided by the crane manufacturer. This disconnect must be readily accessible from the floor and arranged to be locked in the open position. It also must be labeled for its purpose.
9. Warranty
When reviewing your quotes you want to take into consideration your warranty. Not all warranties are created equal. Key things to look for with your crane’s warranty is the following.
a. How long is your warranty?
b. Does it include labor, parts, and shipping?
c. What doesn’t it cover?
d. Is there a local service group that can deal with warranty issues?
10. Service
Your crane purchase does not end with the crane installation. During the life of the crane it will require servicing and possibly warranty issues. There will also be a need for crane inspections to meet local regulations and ensure your crane is operating safely and efficiently. You will also be in the need of training your operators on your new equipment. When reviewing crane proposals ask about their service to ensure they have someone local and the resources to meet your needs.
a. Ensure that whoever you’re purchasing your crane from they are a turn key supplier. They will provide everything needed to get your crane installed and up and running, including crane commissioning by the manufacturer, and even shipping of the crane.
b. Are you purchasing from the manufacturer or a distributor? If it is a manufacturer your are getting it straight from the source. If it is a distributor the manufacturer of those crane components does not have any kind of quality control on the crane itself so you will need to do more thorough research to ensure you are getting a good quality product.
c. Who will be handling any warranty issues? The manufacturer or distributor? Are they local?
d. Is there a local manufacturer representative that can provide training on my new equipment? What type of training do they offer? Can they train my trainer?
e. Can the manufacturer of my crane provide periodic inspections on my new equipment?
f. Is the crane company registered members of CMAA (Crane Manufacturers Association of America) and HMI (Hoist Manufacturers Institute)?
h. Can I easily purchase parts?
i. What kind of consulting is available to me free of charge?
If you review these 10 items prior to purchasing or getting a quote for your next overhead crane you will be one step ahead and on the right track to making the best decision for your company. A crane advisor can help you with additional questions to help ensure that you are purchasing the best crane for your application. Don't go it alone. You can always send me an email or give me a call and I would be happy to consult with you on your next overhead crane project. If you are not in my area I can still help and then get you to the right person.
0086-371-5532 8269
Ext. 1039
