When buyers compare spider crane models, one of the most important questions is: how much can a spider crane lift? The answer is not only based on rated lifting capacity. A 3 ton spider crane does not lift 3 tons at every distance, and a 10 ton spider crane does not lift 10 tons at every working radius. The real lifting capacity depends on the load chart, boom length, working radius, boom angle, outrigger position, ground condition, and lifting method.
For construction contractors, glass installation teams, industrial plants, power engineering companies, logistics operators, and equipment rental businesses, understanding the spider crane load chart is essential before choosing a model. A load chart helps buyers confirm whether the crane can safely lift the required load at the required height and distance.
This guide explains how to read a spider crane load chart, what factors affect lifting capacity, and how buyers can choose the right spider crane for real job site conditions.
For available spider crane models, buyers can review STCM’s Spider Crane Category Page: https://www.stcmcrane.com/product-category/spider-crane/
Table of Contents
What Is a Spider Crane Load Chart?
A spider crane load chart is a technical reference that shows the safe lifting capacity of the crane under different working conditions. It usually includes lifting capacity at different boom lengths, working radii, boom angles, and outrigger positions.
The load chart is more important than the rated capacity alone because it shows what the crane can actually lift in real operating conditions.
Why Rated Capacity Is Not Enough
Many buyers focus only on the rated capacity, such as 3 tons or 10 tons. However, the rated capacity is usually measured under specific conditions, often with a short working radius and stable outrigger support.
In actual lifting work, the crane may need to lift farther, higher, or over obstacles. As the working radius increases, the safe lifting capacity decreases.
Simple Example
If a spider crane is rated for 3 tons, it may lift 3 tons only when the load is close to the crane. If the boom extends farther, the crane may only lift a lower weight safely.
This is why buyers should never select a crane based only on the model name or rated capacity.
Key Terms in a Spider Crane Load Chart
Before reading a load chart, buyers should understand several important terms.
Rated Lifting Capacity
Rated lifting capacity refers to the maximum lifting capacity of the crane under specific working conditions. It is not the same as capacity at every radius or boom position.
Buyer Reminder
Rated capacity is useful for basic comparison, but it should always be checked together with working radius and boom length.
Working Radius
Working radius is the horizontal distance between the crane’s rotation center and the load. It is one of the most important factors affecting lifting capacity.
Why Working Radius Matters
The farther the load is from the crane, the greater the overturning force becomes. This reduces the safe lifting capacity.
For example, a crane may lift a heavy load at a 2-meter radius, but it may not lift the same load at an 8-meter radius.
Boom Length
Boom length refers to how far the crane boom extends. A longer boom helps reach higher or farther positions, but it also reduces lifting capacity.
Practical Meaning
Longer boom length is useful for building facades, elevated platforms, equipment installation, and construction sites with obstacles. However, buyers must check whether the crane still has enough capacity at that boom length.
Boom Angle
Boom angle affects lifting height and working radius. A higher boom angle usually gives more vertical height, while a lower boom angle gives more horizontal reach.
Selection Point
Buyers should check whether the crane can lift the required load at the required height and radius, not just whether the boom is long enough.
Outrigger Position
Spider cranes rely on outriggers for stable lifting. The outrigger extension position can affect the crane’s safe capacity.
Why Full Outrigger Support Is Important
If the outriggers cannot be fully extended because of limited space, the crane’s safe lifting capacity may be reduced. Buyers should always check available outrigger space before selecting a model.
How to Read a Spider Crane Load Chart
A spider crane load chart may look technical at first, but buyers can read it step by step.
Step 1: Confirm the Load Weight
Start by confirming the actual weight of the object to be lifted. Do not forget to include lifting accessories.
Items to Include
Buyers should include:
- Main load weight
- Hook weight
- Slings
- Clamps
- Spreader bars
- Vacuum lifters
- Any lifting attachments
If the load is close to the crane’s limit, buyers should choose a larger model or leave a stronger safety margin.
Step 2: Measure the Working Radius
Measure the horizontal distance from the crane’s rotation center to the load position. This is the working radius.
Site Questions to Ask
Before confirming the working radius, check:
- Can the crane get close to the load?
- Are there walls, machines, trenches, or structures nearby?
- Does the crane need to lift over obstacles?
- Is there enough room for the crane body and outriggers?
- Will the load be moved to another position after lifting?
Step 3: Check the Required Lifting Height
The lifting height is the vertical height from the ground to the final placement point. Buyers should confirm whether the crane can reach the required height while maintaining enough lifting capacity.
Height-Related Applications
Lifting height is especially important for:
- Glass curtain wall installation
- Steel structure assembly
- Indoor atrium work
- Power equipment installation
- Industrial machinery placement
- Elevated platform projects
Step 4: Compare the Load Chart
After confirming load weight, working radius, and lifting height, compare these values with the crane’s load chart.
What to Confirm
Check whether the crane can safely lift the load at:
- The required working radius
- The required boom length
- The required boom angle
- The required outrigger condition
- The actual site ground condition
If the load chart does not provide enough safety margin, choose a larger crane model.
Step 5: Confirm with the Manufacturer
Before purchasing, send your lifting data to the supplier. A professional supplier can help confirm whether the model is suitable.
Information to Send
Provide:
- Load weight
- Load size
- Lifting height
- Working radius
- Site access size
- Ground condition
- Outrigger space
- Indoor or outdoor use
- Power requirements
- Destination country
For project-based selection, buyers can contact STCM Crane directly: https://www.stcmcrane.com/contact-us/
Factors That Affect Spider Crane Lifting Capacity
A spider crane’s lifting capacity can change depending on several job site and machine factors.
Load Weight and Load Shape
The total load weight is important, but the load shape also matters. Long, uneven, fragile, or off-center loads may require special lifting planning.
Center of Gravity
If the load’s center of gravity is not balanced, the crane may need extra stability and more careful operation.
Working Radius
Working radius is one of the biggest factors affecting capacity. A longer radius reduces lifting ability.
Practical Buyer Tip
When possible, position the crane closer to the load. Reducing the working radius can improve lifting capacity and safety.
Boom Extension
A fully extended boom provides more reach but lowers lifting capacity. Buyers should compare boom extension with the load chart before operation.
Ground Condition
The ground must be strong enough to support the crane, outriggers, and load pressure.
Ground Conditions to Check
Buyers should check:
- Soil strength
- Concrete floor capacity
- Slope
- Soft ground
- Underground structures
- Drainage covers
- Floor load limit
- Site leveling condition
Outrigger Deployment
Spider cranes use outriggers to create a stable lifting base. If the outriggers cannot be fully deployed, lifting capacity may be reduced.
Confined-Space Limitation
In narrow spaces, the crane may enter the site successfully, but there may not be enough room to extend the outriggers. This should be checked before choosing a crane.
Wind and Environmental Conditions
Wind can affect lifting safety, especially when lifting large panels, glass, signs, or lightweight structures with a large surface area.
High-Risk Loads
Wind impact is especially important for:
- Glass panels
- Steel sheets
- Signboards
- Large flat materials
- Lightweight prefabricated panels
For general lifting safety reference, buyers and operators can review OSHA crane, derrick and hoist safety guidance: https://www.osha.gov/cranes-derricks/
3 Ton Spider Crane Capacity: When Is It Suitable?
A 3 ton spider crane is suitable for light to medium-duty lifting tasks, especially in confined spaces or indoor environments.
Typical Applications
A 3 ton spider crane is commonly used for:
- Glass installation
- Indoor construction
- Factory maintenance
- Small machinery lifting
- Building material handling
- Curtain wall projects
- Warehouse equipment handling
- Municipal facility installation
Best-Fit Buyer Needs
A 3 ton model is usually suitable when the buyer needs:
- Compact machine size
- Better access in narrow areas
- Stable lifting for light to medium loads
- Lower operating cost
- Indoor or building-side operation
- Flexible movement in restricted spaces
For more details, buyers can review STCM’s 3 Ton Spider Crane product page: https://www.stcmcrane.com/product/3-ton-spider-crane/
When a 3 Ton Spider Crane May Not Be Enough
A 3 ton model may not be enough when:
- The load is close to or above 3 tons
- The working radius is long
- The lifting height is high
- The load is large and affected by wind
- The project requires a larger safety margin
In these cases, a larger spider crane may be more suitable.
10 Ton Spider Crane Capacity: When Is It Suitable?
A 10 ton spider crane is suitable for heavier lifting tasks while still maintaining compact site access.
Typical Applications
A 10 ton spider crane is commonly used for:
- Industrial equipment installation
- Power facility maintenance
- Steel component lifting
- Construction material handling
- Machinery replacement
- Infrastructure support
- Heavy indoor installation
- Confined-space heavy lifting
Best-Fit Buyer Needs
A 10 ton model is usually suitable when the buyer needs:
- Stronger lifting capacity
- Longer working radius
- Higher lifting height
- Wider application range
- Better lifting margin
- Compact operation in complex sites
For heavier lifting requirements, buyers can review STCM’s 10 Ton Spider Crane product page: https://www.stcmcrane.com/product/10-ton-spider-crane/
When a 10 Ton Spider Crane Is a Better Choice
A 10 ton spider crane is a better choice when the project involves machinery, power equipment, steel structures, or heavier components that cannot be safely handled by smaller models.
Spider Crane Capacity Comparison
The right spider crane model depends on the relationship between load weight, working radius, lifting height, and job site access.
Capacity Comparison Table
| Selection Factor | 3 Ton Spider Crane | 10 Ton Spider Crane |
|---|---|---|
| Best For | Light to medium lifting | Medium to heavy lifting |
| Typical Loads | Glass panels, small machines, light steel parts | Machinery, steel components, power equipment |
| Site Access | More compact | Compact but larger |
| Lifting Margin | Lower | Higher |
| Working Range | Suitable for smaller jobs | Suitable for more demanding tasks |
| Common Users | Glass installers, indoor contractors, maintenance teams | Construction, industrial, power, infrastructure teams |
How Buyers Should Compare Models
Buyers should not simply choose the largest model. A larger crane may cost more and require more working space. The best model is the one that matches the real project conditions.
Choose a 3 Ton Spider Crane If
- The load is light to medium
- Site access is very narrow
- The project is mainly indoor or glass installation
- The working radius is moderate
- Cost control is important
Choose a 10 Ton Spider Crane If
- The load is heavier
- The working radius is longer
- The lifting height is higher
- The project involves machinery or steel components
- A stronger safety margin is required
Common Load Chart Mistakes Buyers Should Avoid
Many crane selection problems come from misunderstanding the load chart.
Mistake 1: Only Looking at Rated Capacity
Rated capacity alone does not show actual performance at different working radii. Buyers should always check the full load chart.
Mistake 2: Ignoring Working Radius
A load that seems suitable by weight may become unsafe if it must be lifted far away from the crane.
Mistake 3: Forgetting Lifting Accessories
Hooks, slings, clamps, and other lifting tools add weight. This additional weight should be included in the total load.
Mistake 4: Not Measuring Outrigger Space
A spider crane needs enough outrigger space for stable lifting. Limited outrigger deployment may reduce safe capacity.
Mistake 5: Ignoring Ground Conditions
Even if the crane has enough lifting capacity, weak ground may create safety risks.
Mistake 6: Choosing Without Manufacturer Confirmation
If the project is complex, buyers should ask the supplier to review the lifting requirements before ordering.
Safety Planning Before Spider Crane Operation
Spider crane operation should be planned carefully, especially in confined or indoor environments.
Pre-Operation Checklist
Before lifting, check:
- Load weight
- Working radius
- Boom length
- Lifting height
- Ground condition
- Outrigger position
- Hook and wire rope
- Hydraulic system
- Wind condition
- Nearby obstacles
- Operator communication
During Operation
Operators should lift slowly, avoid sudden movement, keep the load stable, and follow the safe working range shown in the load chart.
After Operation
After lifting, the boom should be retracted properly, the crane should be parked safely, and key components should be inspected.
For broader crane safety standards, ASME B30.5 is a useful external reference for mobile and locomotive cranes: https://www.asme.org/codes-standards/find-codes-standards/b30-5-mobile-locomotive-cranes
How to Choose the Right Spider Crane Based on Capacity
Choosing the right spider crane starts with matching the load chart to the project.
Step-by-Step Selection Method
Step 1: Confirm the Heaviest Load
Identify the maximum object weight, including lifting accessories.
Step 2: Measure the Working Radius
Confirm how far the load is from the crane’s rotation center.
Step 3: Confirm the Lifting Height
Check whether the boom can reach the required height safely.
Step 4: Check Site Access
Measure entrance width, working area, turning space, and outrigger deployment area.
Step 5: Compare the Load Chart
Check whether the selected model has enough safe capacity under the real conditions.
Step 6: Contact the Supplier
Send the project data to the supplier for final model confirmation.
Recommended STCM Internal Links
Spider Crane Category Page: https://www.stcmcrane.com/product-category/spider-crane/
3 Ton Spider Crane: https://www.stcmcrane.com/product/3-ton-spider-crane/
10 Ton Spider Crane: https://www.stcmcrane.com/product/10-ton-spider-crane/
Construction & Infrastructure Solutions: https://www.stcmcrane.com/construction-infrastructure-solutions/
Manufacturing and Industrial Facility Solutions: https://www.stcmcrane.com/manufacturing-and-industrial-facility-solutions/
Power and Energy Facility Solutions: https://www.stcmcrane.com/power-and-energy-facility-solutions/
Contact STCM Crane: https://www.stcmcrane.com/contact-us/
FAQ About Spider Crane Load Charts
What is a spider crane load chart?
A spider crane load chart shows the crane’s safe lifting capacity at different working radii, boom lengths, boom angles, and outrigger conditions.
Can a spider crane lift its rated capacity at any distance?
No. Rated capacity usually applies under specific conditions. As working radius increases, safe lifting capacity decreases.
How much can a 3 ton spider crane lift?
A 3 ton spider crane can lift up to its rated capacity only under specific conditions. Actual capacity depends on working radius, boom length, outrigger position, and site conditions.
How much can a 10 ton spider crane lift?
A 10 ton spider crane can provide stronger lifting performance than smaller models, but it still must be operated according to its load chart. It cannot lift 10 tons at every radius.
Why does lifting capacity decrease with distance?
As the load moves farther from the crane, the overturning force increases. This reduces safe lifting capacity.
What information should I provide before choosing a spider crane?
You should provide load weight, lifting height, working radius, site access size, outrigger space, ground condition, power requirements, and application scenario.
Is a bigger spider crane always better?
Not always. A larger crane may provide more capacity, but it may also require more space and higher investment. The best model should match the project’s real lifting requirements.
Conclusion
A spider crane load chart is one of the most important tools for choosing the right crane model. Rated capacity alone is not enough. Buyers must also consider working radius, boom length, lifting height, outrigger space, ground condition, and actual job site requirements.
A 3 ton spider crane is suitable for compact lifting, glass installation, indoor projects, and light to medium-duty jobs. A 10 ton spider crane is better for heavier loads, longer reach, industrial installation, construction, and power projects.
Before purchasing, buyers should prepare complete lifting information and compare it with the crane’s load chart. For project-based selection, contact STCM Crane with your load weight, lifting height, working radius, and site conditions. The team can help recommend a suitable spider crane model for your application: https://www.stcmcrane.com/contact-us/