What is the Advantage and Disadvantage of Crane Outrigger Mats

01 Jul.,2024

 

The Safe Use of Outrigger Pads for Equipment Stability

An outrigger pad is a safety tool that can be used with any equipment that has outriggers, down jacks or stabilizers. It is a must for stability when a piece of equipment &#; such as a crane &#; lifts loads or personnel aloft. This article will provide an overview of outrigger pads, including how to use them safely and what kinds of pads are available on the market today.

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The Basics

Outrigger pads are placed on the ground under the equipment&#;s outrigger, shoe, float or foot. The size and thickness of the outrigger pads to be used should be selected based upon the type of equipment, soil conditions of the work site and type of lift being performed.

When working with outrigger systems, it&#;s important to understand that the point of contact between an outrigger and the ground is quite small. Because of the pressure of the outrigger, the ground underneath may shift, be displaced or collapse if an outrigger pad is not used. If any of those things happen, there is the potential for the equipment to shift or tip the load, which could lead to the equipment toppling over. In fact, approximately half of crane lifting accidents are caused by improper use of outriggers.

Outrigger pads were created to stabilize equipment so that the ground below doesn&#;t shift and equipment doesn&#;t topple over. Stability is dependent upon the equipment&#;s footprint and center of mass. The footprint is the total area enclosed by the support structure of the equipment. The center of mass is the point at which the equipment would balance if it were set on top of a single point to support it. If the center of mass is on the edge of the footprint or outside of it, the equipment will topple. There are two ways to provide extra stability. The first is to use a counterweight to help shift the center of mass back over the footprint. The second is to make the footprint bigger with an extendable outrigger system.

All cranes have counterweights, but there is a limit to how heavy they can be due to transportation and setup considerations. As noted earlier, the ground can only sustain so much pressure before it gets displaced or collapses. Even if you can transport a crane to the work location, there is no guarantee the ground conditions will be stable enough to set up and hold the crane. Because of that, it is essential for the stability of the equipment to use retractable outriggers to extend the crane&#;s footprint. After deploying the outrigger system, installing outrigger pads underneath the outriggers will expand their point of contact with the ground and displace the pressure from the equipment through the outrigger pad to the ground.

Six Important Points

As with any safety tools, outrigger systems and outrigger pads must be used according to the instructions of their manufacturers. In addition, keep the following six points in mind when working with an outrigger system.  

1. Proper setup and leveling are critical to the appropriate function of any style of outrigger system. The operator is required to follow the manufacturer&#;s chart regarding the allowable level and grade percentage when setting up the equipment. If the level is incorrect, the equipment&#;s lifting capacity will be reduced.

2. Prior to setting up, try to acquire recent soil conditions for the work area. Knowing the ground-bearing capacity will help workers determine what type of outrigger pad is the best fit for the equipment that will be used. OSHA 29 CFR ., &#;Ground conditions,&#; states the following in paragraph .(b): &#;The equipment must not be assembled or used unless ground conditions are firm, drained, and graded to a sufficient extent so that, in conjunction (if necessary) with the use of supporting materials, the equipment manufacturer's specifications for adequate support and degree of level of the equipment are met. The requirement for the ground to be drained does not apply to marshes/wetlands.&#; Per .(a)(2), &#;supporting materials&#; refers to blocking, mats, cribbing, marsh buggies, or similar supporting materials or devices.

For those who do not work in construction, ASME B30.5-3.2.1.5(i) regarding mobile and locomotive cranes states that &#;[b]locking under outrigger floats, when required, shall meet the following requirements: (1) sufficient strength to prevent crushing, bending, or shear failure; (2) such thickness, width, and length, as to completely support the float, transmit the load to the supporting surface, and prevent shifting, toppling, or excessive settlement under load &#;&#;

3. Check for current locates and know where utilities are overhead and underground. Maintain proper clearances around overhead power lines. It&#;s an absolute must to find out the known voltage of the overhead power lines and determine the minimum approach distance for qualified and unqualified personnel.

4. Outrigger pads must not be used to bridge any gaps or span any voids.

5. The maximum lift capacity of the equipment must be known, which includes understanding how to follow the load chart. Be sure to factor in not only the load being lifted but the rigging being used to lift the load as well. A key to safe lifting work is employing qualified personnel who know how to read load charts and have been trained to run the equipment. A strong job briefing prior to work also is a must.

6. Understand that different pieces of equipment have different outrigger systems. Workers will need to understand how to set up those systems on each piece of equipment they work with. Following are short descriptions of some common outrigger systems found on today&#;s equipment.

  • An out-and-down or vertical pressure outrigger system is very common on 40-ton cranes and above.
  • A-frame or 45-degree outrigger systems are common with bucket trucks and digger derricks.
  • You will find combination units with both A-frame and out-and-down outrigger systems on many boom cranes, from 30 tons on down.
  • Down jacks typically are found on trailers and heavy-haul equipment.

A Rule of Thumb

A known ground-bearing capacity may not be available for every job site or equipment setup. And in a number of industries &#; including line work, tree trimming and some crane work &#; determining the capacity may not be practical, particularly during storm response work. To address the issue, I suggest following a rule that I learned from my father and have been using for more than 20 years. An outrigger pad should be at least three times the square surface area of the outrigger shoe or float, provided you are working on Grade A soil conditions. As soil conditions worsen, continue to create a bigger footprint using outrigger pads and cribbing. After the equipment is set up and level, or within the manufacturer&#;s grade tolerance, and outrigger pads have been deployed, make a dry run of the boom. Use a spotter to ensure the outrigger pads are not shifting, sliding or sinking into the ground. Then check to see that the equipment is still level or within grade. If any issues are identified, stop and stow the boom. Now is the time to add cribbing, blocking or more outrigger pads. The pads should be built to support the maximum load of the pick or lift; to displace the weight of the equipment while keeping the equipment level; and to help the crew work safely. 

A Variety of Pads

Outrigger pads are built in different lengths, widths, thicknesses and shapes. When it comes to shapes, there are pros and cons depending on what you choose. For example, because large square outrigger pads have a large surface area, they are not as easy to move around on the job site as round outrigger pads, which usually can be rolled into position by one person but have less surface area.

In terms of the materials used to build outrigger pads, I have found only three &#; American custom composite, premium birch and American steel &#; that I believe should be used when personnel are aloft or with any critical pick or lift with a load of 10,000 pounds or more.

American custom composite has 3,000 psi and maintains its value for a lifetime. This material is engineered to perform in the most extreme conditions and typically will outlast the equipment it is being used with.

Used in the field since , premium birch has been battle-tested in the harshest conditions with some of the largest equipment. These outrigger pads have a typical life span of 10 years.

American steel crane mats are built with high-grade steel and will outlast the equipment they are being used with.

Conclusion

As with any tool of the trade for line construction and maintenance, outrigger pads must be inspected before each use or setup. After the setup, perform a dry run with a spotter to inspect the outriggers and outrigger pads. Check the equipment level, and then you&#;re ready to move forward with the job.


Lifting Safety : Crane & Rigging Safety Guidelines

The focus of our discussion today is on safety practices related to Lifting Safety / Crane safety. We will explore the various types of cranes, their different parts, potential lifting hazards, and safety precautions to be taken while operating cranes.

Major Causes of Crane Accidents

Overview of Common Crane-Related Incidents

Crane operations, vital for many construction and industrial projects, pose significant risks if not managed correctly. Understanding the major causes of crane accidents is essential for enhancing safety and preventing hazardous incidents. Here are some of the most common causes:

  1. Contact with Power Lines: Cranes often operate in close proximity to power lines. Accidental contacts are frequent and can lead to severe electrical shocks, fires, and fatalities. Ensuring that cranes operate at a safe distance from power lines is critical.
  2. Overturns: Crane overturns are typically a result of operating beyond the machine&#;s capacity or improper handling by the operator. These incidents can cause significant damage to property and severe or fatal injuries to workers.
  3. Falls: Workers may fall from the crane itself or be struck by objects falling from the crane. These types of accidents can occur due to lack of proper safety measures like guardrails or failure to use personal protective equipment.
  4. Mechanical Failures: These can arise from inadequate maintenance and inspections. Failures may involve the crane&#;s hydraulic system, structural components, or other critical parts essential for safe operation.

Understanding these hazards is the first step toward mitigating risks and ensuring the safety of all personnel involved in crane operations.

How Do Accidents Occur?

Exploring the Underlying Causes of Crane-Related Accidents

Crane accidents often have multifaceted causes, ranging from operational errors to environmental factors. Here&#;s a deeper look into how these incidents occur:

  • Instability:
    • Unsecured Load: An improperly secured load may shift unexpectedly, causing the crane to become unbalanced and possibly tip over.
    • Load Capacity Exceeded: Operating a crane beyond its rated capacity is a common cause of accidents. It is crucial to adhere to the specified load capacities to maintain stability.
    • Ground Not Level or Too Soft: Operating on unstable ground can lead to shifting, sinking, or overturning of the crane. Ensuring that the crane is on a firm, level surface is essential for safe operation.
  • Lack of Communication:
    • Point of Operation Is a Distance from the Crane Operator: When the operator cannot see the load or the target area directly, reliance on clear and effective communication becomes critical. Accidents can occur if signals are misunderstood or not seen.
    • Not in Full View of the Operator: Without a clear line of sight to the load and surrounding area, the operator may inadvertently move the crane into hazardous positions, such as too close to power lines or over personnel.
    • Lack of Training: Operators without proper training may not understand how to handle the crane safely under varying conditions, leading to mistakes that could result in accidents.
    • Inadequate Maintenance or Inspection: Regular maintenance and inspection are critical to identifying potential issues before they lead to mechanical failures. Neglecting these practices can significantly increase the risk of accidents.

By addressing these key issues, crane operations can be made safer, reducing the likelihood of accidents and ensuring the protection of all workers involved.

Crane Safety : Lifting Safety

Essential Safety Practices for Crane Operations

To maintain a safe working environment and minimize the risk of accidents involving cranes, certain safety practices and guidelines must be strictly followed. Below are essential safety measures and protocols for crane operation:

  • Training: Only individuals who have received appropriate training are permitted to operate cranes. This ensures that operators are well-versed in both the functionality of the crane and the safety precautions necessary during its operation.
  • Barricades: When operating a crane in areas where pedestrians or traffic may pass close by, it is crucial to use barricades around the swing area of a revolving cab. This prevents accidental collisions and injuries.
  • Proximity to Power Lines: Never operate cranes closer than 10 feet from power lines. This distance should be increased depending on the voltage of the power lines to avoid the risk of electrocution.
  • Inspection of Rigging Equipment: Before commencing any lifting activity, a thorough inspection of all rigging components&#;slings, hooks, chains, and cables&#;is necessary. This helps identify any potential wear or damage that could lead to failure during operation.
  • Reporting Damages: Any observed damage or defects in the crane or its accessories should be reported immediately to a supervisor. Damaged equipment must be taken out of service until repaired and deemed safe for use.
  • Guidance of Suspended Loads: When it is necessary to guide a suspended load, use tag lines to control the load manually, keeping clear of the load&#;s direct path to prevent accidents.
  • Riding Prohibitions: Workers must never ride the load, ball, or hook of the crane as it poses significant risk of falls or being struck by the load.
  • Safe Work Practice Near Excavations: When working near excavations, be aware of existing underground utilities and ensure that the distance from the edge of the excavation is at least one and a half times the depth, to prevent collapse.
  • Signalman / Rigger: The crane operator should not be distracted during operations, and communication should be maintained through a designated signalman / Rigger. This person directs the crane&#;s movements based on a pre-agreed set of hand or radio signals.
Standard Hand Signals

Source : OSHA

Implementing these safety measures can significantly reduce the risk of accidents and ensure a safe working environment for everyone involved in crane operations.

Crane Hazards

Identifying and Mitigating Potential Risks in Crane Operations

Operating cranes involves various hazards that can lead to serious accidents if not properly managed. Awareness and understanding of these risks are essential for maintaining safe crane operations. Below are some common crane hazards and how they can be mitigated:

  • Improper Load Rating: Using a crane to lift loads that exceed its rated capacity can lead to mechanical failures and potential collapse. Always adhere to the manufacturer&#;s load ratings.
  • Excessive Speeds: Operating a crane at speeds too high for the load or conditions can cause loss of control and increase the risk of accidents. Speed limits should be strictly followed.
  • Lack of Hand Signals: Clear communication between the crane operator and ground personnel is vital. The absence of standard hand signals can lead to miscommunication and accidents. Ensure all team members understand and use proper hand signals.
  • Inadequate Inspection and Maintenance: Regular inspections and maintenance are critical to ensure the crane operates safely. Overlooking these can lead to catastrophic failures. Establish a routine inspection and maintenance schedule.
  • Unguarded Parts: Exposed moving parts can pose serious safety risks to operators and other personnel. Ensure all necessary guards are in place and intact.
  • Working Too Close to Power Lines: As noted earlier, cranes should maintain a safe distance from power lines to prevent electrocution. Follow established safety guidelines regarding the minimum distance required.
  • Improper Exhaust System: Faulty exhaust systems can lead to dangerous accumulations of fumes or gases. Regular checks are necessary to ensure the system is functioning properly.
  • Shattered Windows: Damaged or shattered windows can impair the operator&#;s visibility, leading to errors in operation. Replace broken windows immediately to maintain clear visibility.
  • Lack of Steps/Guardrails on Walkways: Ensure that all walkways on and around the crane are equipped with proper guardrails and steps to prevent falls.
  • No Boom Angle Indicator: Without a boom angle indicator, operators may have difficulty determining the angle of the boom, increasing the risk of overturning. Ensure that this device is installed and functioning.
  • Not Using Outriggers: Outriggers provide additional stability when a crane is lifting heavy loads. Always deploy outriggers as per the operational guidelines to stabilize the crane.

By addressing these hazards, crane operators and construction managers can significantly reduce the risk of accidents and ensure a safer workplace for all employees involved.

Planning Before Start-Up

Steps to Ensure Safety and Efficiency Prior to Crane Operation

Proper planning and preparation are critical to ensuring the safety and efficiency of crane operations. Before starting any lifting operation, there are several steps that must be followed:

  1. Preparation of a Lifting Plan: A competent person must prepare a detailed lifting plan for each critical lifting operation. This plan should include:
    • 1.The area and location of the lifting operation.
    • 2. A copy of the work permit and risk assessment.
    • 3. Details about the load weight and crane capacity.
    • 4. Speed and directions of load movement.
    • 5. A simple drawing of the operation layout.
  2. Leveling the Crane: The crane must be properly leveled to ensure stability during operation. The support surface must also be firm and capable of supporting the load without risk of subsidence.
  3. Consulting Power Line Owners: If power lines are in proximity to the planned operation, contact the owners to determine the necessary precautions to maintain a safe distance.
  4. Understanding Crane Capacities and Limitations: Operators should be thoroughly familiar with the crane&#;s capacities, limitations, and any job site restrictions that might affect operation.
  5. Informing Other Personnel: Make sure all personnel on the job site are aware of the hoisting activities. This helps prevent unintended entry into hazardous zones.
  6. Barricading Swing Radius Areas: Areas within the swing radius of the crane should be barricaded to prevent access by unauthorized personnel.
  7. Ensuring Proper Maintenance and Inspections: The crane should be inspected by a competent person to ensure it is in good working order before operation begins.
  8. Determining Safe Storage Areas: Plan where materials and machinery will be safely stored during the lifting operations to avoid clutter and potential hazards.
  9. Conducting a Trial Lift: Before fully starting any lifting operation, it is recommended to lift the load only one foot to check that everything is working properly and that the crane is stable.

Following these steps meticulously can help prevent accidents and ensure that crane operations are conducted safely and efficiently.

Crane Safety Measures : Lifting Safety

Comprehensive Guidelines to Enhance Safety During Crane Operations

To further ensure the safety of crane operations, specific measures need to be implemented consistently. These safety measures not only protect the crane operators but also all personnel involved in or around the crane operation area. Here&#;s a detailed look at some crucial safety measures:

  • Load Management: Avoid improper loads or speeds that could lead to the tipping or instability of the crane. Always adhere to the crane&#;s operating limits as specified by the manufacturer.
  • Distance from Power Lines: Maintain a minimum clearance of 10 feet from power lines. Increase this distance with higher voltage lines to prevent any risk of electrical hazards.
  • Visibility of Operating Signals: An illustration of the operational signals should be posted visibly at the job site to ensure that all ground personnel can communicate effectively with the crane operator.
  • Operator Visibility: Ensure that the crane operator has clear visibility. Replace any broken windows or remove obstructions that might impair the operator&#;s view of the operation area.
  • Access to Control Cab: Use appropriate ladders and steps to ensure safe access to the upper portion of the crane cab. This helps prevent falls and injuries related to accessing or exiting the cab.
  • Underneath Loads: It is crucial that no personnel stand under suspended loads. This rule must be enforced rigorously to prevent injuries from falling objects.
  • Boom Angle Indicator: Every crane should be equipped with a boom angle indicator to help the operator monitor and control the angle of the boom accurately during operations.
  • Supporting Surface: Cranes must be positioned on a firm supporting surface that is level and stable. Check the surface beforehand to prevent any shifting during operations.
  • Condition of Grooves: Regularly check the grooves on the crane where cables lie. These must be smooth and free from surface defects that could wear down the cables or cause them to snap.

Implementing these safety measures requires diligence and ongoing attention to detail. By adhering to these guidelines, crane operations can be conducted more safely, protecting both the personnel and equipment involved.

Load Rating Chart, Load Capacity, Speed, and Warnings

Crane Load Chart Example &#; Source

Critical Considerations for Safe Crane Operations

Understanding and adhering to the load rating chart and being aware of the crane&#;s load capacity, operating speeds, and any special hazard warnings are crucial for safe crane operations. Here&#;s a breakdown of these important factors:

  • Visibility of Load Rating Chart: Ensure the crane operator can easily see the load rating chart. This chart provides essential information on the rated load capacities, which vary depending on the boom length and the load radius. Keeping this information in plain sight helps prevent overloading and related accidents.
  • Knowing the Weight of the Load: Before lifting, verify the actual weight of the load. Use shipping tickets or other documentation to confirm weight. This helps ensure that the crane&#;s lift calculations are accurate and the load is within safe operating limits.
  • Operating Speeds: Familiarize yourself with the recommended operating speeds for different types of loads and crane configurations. Adhering to these speeds can help prevent mechanical failures and loss of control during operations.
  • Special Hazard Warnings or Instructions: Pay attention to any special hazard warnings or instructions specific to the crane model being used. These may include precautions related to environmental conditions, such as wind speeds, or specific operational restrictions.

By focusing on these aspects, crane operators and site managers can significantly reduce the risk of accidents and ensure that lifting operations are performed safely and efficiently. Understanding and respecting the crane&#;s capabilities and limitations is key to maintaining a safe work environment.

Load Limiting Factors

Understanding Conditions That Affect Crane Capacity and Safety

Load limiting factors play a crucial role in crane operations, affecting the overall safety and effectiveness of lifting activities. Here are several key factors that must be considered to ensure safe crane operation under various conditions:

  • Not Level: Operating a crane on an uneven surface can lead to instability and potential tipping. Always ensure that the crane is level before beginning any lifting operation.
  • Wind: High winds can significantly impact the stability and safe operation of cranes, especially when lifting large or flat objects. It&#;s essential to monitor weather conditions and adjust operations accordingly.
  • Side Loads: Lifting loads that are not vertically aligned can introduce side loading on the crane&#;s boom, which can weaken structural integrity and lead to failures. Always ensure loads are lifted straight up and down.
  • On Its Wheels: Operating a crane while it is on wheels, as opposed to being stationary, can reduce stability and increase the risk of accidents. Secure the crane properly before use.
  • Lifting Over the Side: Lifting loads over the side of a crane, as opposed to the front or rear, can dramatically increase the risk of tipping. Avoid side lifts or use proper counterweight measures to maintain balance.
  • Use of Extensions, Jibs, and Other Attachments: Attachments can alter the dynamics of a crane&#;s operation, including its load capacity and balance. Always refer to the manufacturer&#;s guidelines when using any attachments and adjust the load capacity calculations accordingly.
  • Limits of Wire Rope, Slings, and Lifting Devices: The capacity and condition of lifting devices like slings and wire ropes are critical. Inspect these components regularly for wear and tear, and replace them if they do not meet safety standards.

By carefully considering these load limiting factors, crane operators can ensure that they operate within safe limits, thereby preventing accidents and enhancing overall site safety. These precautions help maintain the integrity of the crane and the safety of all personnel involved.

What to Inspect

Key Areas to Check Before Operating Cranes

Routine inspections are a cornerstone of crane safety, helping to identify potential issues before they lead to accidents. Here&#;s a detailed guide on what to inspect to maintain the integrity and safety of crane operations:

  • Correct Air Pressure and Hydraulic System: Verify that all hydraulic systems are functioning correctly, with no leaks. Ensure that air pressure levels are within specified limits to prevent mechanical failures.
  • LMI (Load Moment Indicator): Check the Load Moment Indicator, which helps prevent overloading by providing real-time data on the crane&#;s load. Ensure that this system is functioning properly.
  • Anti-Two Block Device and Limit Switch for Boom: Inspect these safety devices, which prevent the hook from colliding with the boom. Ensure they are operational to avoid potentially dangerous situations.
  • Tires: Properly inflated and undamaged tires are crucial for the mobility and stability of mobile cranes. Conduct regular inspections to check for excessive wear or damage.
  • Clearance for Tail Swing: Make sure there is sufficient clearance for the crane&#;s tail swing during operation. This prevents collisions with other objects or equipment on site.
  • Wire Rope Wear: Inspect the wire ropes for signs of wear, corrosion, or kinking. Replace worn-out ropes to prevent breakage during lifts.
  • Physical Damage to Crane: Look for any signs of physical damage to structural components like the boom, jib, or other parts of the crane. Damaged components can compromise the crane&#;s stability and safety.
  • Loose or Missing Hardware, Nuts, or Bolts: Check all connections and fastenings. Loose or missing hardware can lead to structural failures or loss of control.
  • Fluid Leaks: Inspect for leaks in hydraulic systems, engines, and other components. Fluid leaks can indicate potential failures and should be addressed immediately.
  • Tire Inspections: Regularly check the crane&#;s tires for signs of excessive wear or damage. Maintaining proper tire condition is essential for safe crane operation.

By diligently performing these inspections, crane operators and maintenance teams can significantly reduce the risk of mechanical failures and ensure that crane operations are conducted safely and efficiently.

Third-party Inspection Certificate, Training & Competent Person

Ensuring Crane Safety Through Certified Inspections and Qualified Personnel

Maintaining crane safety standards requires not just regular inspections by the operators but also detailed evaluations by qualified third parties and continuous training. Here are key components of this multi-layered approach:

  • Third-party Inspection:
    • Annual Inspections: Cranes must be inspected annually by a qualified third party. These inspections are thorough and are designed to catch any issues that regular checks may not.
    • Post-Repair Inspections: Any time a crane undergoes significant repairs or modifications, it should be re-inspected by a third party to ensure all changes adhere to safety standards.
    • Certificate Validity: The inspection certificate from a third party must be valid and readily available at the work site. This certificate is a testament to the crane&#;s operational integrity and compliance with safety regulations.
  • Training:
    • Operator Qualification: Operators must be specifically trained by a reputable third-party organization and qualified on the type of crane they are operating. This specialized training ensures that operators understand the particular capabilities and safety features of their machinery.
    • Rigger / Signal Man Training: Riggers are professionals who play a crucial role in ensuring the safe movement and positioning of heavy loads in construction, manufacturing, and various other industries. To become a qualified rigger, it is essential to undergo training provided by a reputable third-party organization. This training equips individuals with the necessary skills and knowledge to perform their duties effectively and minimize the risk of accidents
    • On-the-Job Training: Hands-on training is crucial for practical understanding. Operators should undergo comprehensive on-the-job training to gain real-world experience under the supervision of experienced personnel.
  • Supervisor / Competent Person:
    • Routine Inspections: A designated competent person should inspect all machinery and equipment before each use to ensure everything is in safe working order.
    • Authority to Halt Operations: If a potential safety issue is identified, the competent person must have the authority to halt operations immediately until the issue is resolved. This helps prevent accidents and ensures that safety is always the priority.

By implementing these protocols&#;rigorous third-party inspections, targeted training programs, and the involvement of competent personnel&#;organizations can significantly enhance the safety of crane operations. These measures not only protect the equipment but more importantly, safeguard the lives of all workers on site.

Multiple Crane Lifting

Coordination and Safety Practices for Complex Lifting Operations

When operations require the simultaneous use of multiple cranes, the complexity and risk associated with lifting activities significantly increase. Proper planning, communication, and execution are essential to ensure the safety and success of these operations. Here are the critical considerations and safety practices for multiple crane lifting:

  • Capacity Suitability: All cranes involved in a multiple lifting operation must have suitable capacities for each designated lifting point. This involves prior design and calculation to ensure each crane can handle its part of the load without risk of overload.
  • Vertical Wire Position: Throughout all stages of the lifting process, ensure that the crane&#;s wire remains vertical. This helps prevent lateral stress on the crane structures and load, which can lead to instability or structural failure.
  • Proper Communication: Enhanced communication between all crane operators and ground coordinators is mandatory in multiple crane operations. Use clear, predefined signals and possibly radio communication to coordinate movements precisely.
  • Synchronization: The lifting, moving, and lowering of the load must be synchronized between the cranes to avoid imbalanced loads or sudden shifts that could destabilize one or more cranes.

These practices are not just recommendations but are essential to the safety and efficiency of operations involving multiple cranes. Adhering to these guidelines helps prevent accidents and ensures that complex lifts are carried out smoothly and safely.

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Types of cranes at construction site

There are various types of cranes used at construction sites, each with its unique features and capabilities. Here are some of the most common types of cranes used in construction:

  1. Tower cranes: These are tall, stationary cranes that are typically used in the construction of high-rise buildings. They have a long horizontal arm (jib). The jib of a tower crane is typically not raised or lowered. Instead, the trolley on the jib moves in and out to position the load. The crane can also rotate (slew) to position the load in a different location around its base. Some tower cranes have a luffing jib that can be angled up or down

  2. Mobile cranes: These cranes are mounted on wheeled vehicles or tracks and can be easily moved around the construction site. They are typically used for heavy lifting tasks and have a telescopic boom that can extend to great heights.

  3. Rough terrain cranes: As the name suggests, these cranes are designed for use on rough and uneven terrain. They have large, wide wheels and are often used in off-road construction sites.

  4. Crawler cranes: These cranes have tracks instead of wheels and can be used on soft ground or in areas where a wheeled vehicle might get stuck. They are typically used for heavy lifting tasks and have a wide range of motion.

  5. Overhead cranes: These cranes are mounted on rails or beams and are used to move heavy loads horizontally along the length of the rail. They are commonly used in manufacturing and warehouse environments.

  6. Gantry cranes: These cranes are similar to overhead cranes, but they have legs that support them instead of being mounted on rails or beams. They are often used in shipyards or to move containers.

Each type of crane has its own advantages and disadvantages, and the choice of crane will depend on the specific requirements of the construction site and the lifting task at hand.

General parts of crane

Here are some of the general parts of a crane:

  1. Boom: This is the long, horizontal arm of the crane that is used to lift and move heavy loads. The boom can be fixed or telescopic, allowing it to extend or retract to different lengths.

  2. Hook: This is the device at the end of the boom that is used to attach and lift loads. The hook can be attached to different types of lifting equipment, such as chains or slings.A crane typically has two hooks: a main hook and an auxiliary hook. The main hook is the primary hook used for lifting heavy loads, while the auxiliary hook is a smaller hook used for lighter loads or for assisting with lifting tasks. The auxiliary hook is often used to attach rigging equipment, such as slings or chains, to the load being lifted. Having two hooks allows the crane operator to perform more efficient and versatile lifting tasks, using the appropriate hook for the specific load being lifted.

  3. Jib: Some cranes have a smaller, secondary arm called a jib that is attached to the end of the main boom. The jib can be used to extend the reach of the crane or to lift loads at an angle. To use Jib 3rd party inspection certificate is required

  4. Counterweight: A counterweight is often used to balance the weight of the load being lifted and to provide stability to the crane. It is typically a large weight that is attached to the opposite end of the crane from the load.

  5. Cab: The cab is the enclosed area where the crane operator sits and controls the crane&#;s movements. The cab is usually located near the top of the crane and provides a clear view of the construction site.

  6. Outriggers: Outriggers are extendable legs that provide additional support and stability to the crane. They are typically used when lifting heavy loads or when the crane is operating on uneven ground.nal support and stability to a crane when it is lifting heavy loads or operating on uneven ground.  The outrigger is an extendable leg that is positioned perpendicular to the crane and is supported by a spreader plate, which is a large plate that spreads the weight of the outrigger over a larger surface area.

  7. Spreader mates (plates):  The spreader plates prevent the outrigger from sinking into the ground and provide a stable foundation for the crane to operate on. When the crane is not in use, the outriggers can be retracted and stored on the crane itself. The use of outriggers with spreader plates is an important safety feature that helps prevent the crane from tipping over during lifting operations.

  8. Anti tube block/limit switch: An anti-two-block system is a safety feature on cranes that prevents the hook block and load block from colliding. It uses a limit switch that triggers when the hook block is raised too high, sending a signal to the crane&#;s control system to stop the hoist and prevent the collision. It is an essential safety feature required by law in many jurisdictions.
  9. Center Pin : A center pin is a part of a crane&#;s boom system that connects the different sections of the boom together. It is typically located at the base of the boom and allows the boom to be extended or retracted as needed. The center pin is designed to withstand heavy loads and is an essential component of the crane&#;s lifting system. It is important to ensure that the center pin is properly lubricated and maintained to prevent damage and ensure safe and efficient operation of the crane.
  10. Superstructure : The superstructure of a crane refers to the upper portion of the crane that houses the crane&#;s machinery and components. It includes the cab, engine, counterweights, and boom system and is designed to be strong and stable to support heavy loads and allow the crane to maneuver with precision. It is an essential part of the crane&#;s overall structure and must be properly maintained for safe and efficient operation.

These are some of the general parts of a crane, although the specific parts and features of a crane will vary depending on the type of crane and its intended use.

 

General Lifting

Hazards

| Crane Hazards:

Shifting of materials from one place to another place using Crane and Boom truck (Lifting) is a critical work which has the following hazards:

  1. Load falling: When lifting a load, there is a risk of it falling, which can cause injuries to people and damage to property.

  2. Hitting and crushing: Loads can swing and collide with existing facilities, causing damage or injury.

  3. Crane toppling: If the crane is not properly set up or overloaded, it can topple over, potentially causing serious injury or death.

  4. Environmental factors: High wind speed, poor communication, and poor visibility can also contribute to crane accidents.

  5. Damage to underground utilities: When moving heavy loads, there is a risk of damaging underground utilities or other infrastructure, which can be costly and dangerous.

  6. Electrical hazards: When working near power lines or electrical equipment, there is a risk of electrocution, which can be fatal.

  7. Inadequate training: Operating a crane or boom truck without proper training and certification can result in accidents and injuries.

  8. Equipment failure: Equipment failure can occur due to a lack of maintenance or faulty parts, leading to accidents and injuries.

  9. Human error: Accidents can also occur due to human error, such as miscommunication or improper use of equipment.

It is important to take appropriate safety measures and precautions when using cranes and boom trucks to ensure the safety of personnel and property.

 

General Lifting safety | Crane safety precautions 

  1. Check and level ground conditions: Before operating a crane or boom truck, the soil or ground conditions should be checked and leveled to ensure stability and prevent accidents.
  2. Use appropriate spread mate size: A spread mate size of 1:3 should be used to ensure that the load is evenly distributed and the crane is stable.
  3. Fully extend outriggers: The outriggers should be fully extended and at least 1 meter away from manholes and trenches to provide maximum stability and avoid accidents.
  4. Do not overload: Always lift up to the safe working load (SWL) and avoid overloading the crane or boom truck, as this can result in equipment failure and accidents.
  5. Follow regulations: Crane and boom truck operations should be performed according to the regulations set by the relevant authorities, such as KNPC, and the crane should not be used beyond 75% of its capacity.
  6. Avoid adverse weather conditions: Crane and boom truck operations should not be performed in high winds or raining conditions, as this can increase the risk of accidents and injuries.
  7. Barricade the swinging radius: The swinging radius of the crane should be barricaded, and only trained and certified riggers should be allowed in the area.
  8. Wear appropriate personal protective equipment: Riggers should wear jackets or other appropriate personal protective equipment.
  9. Proper communication protocols: The only rigger should give signals to the crane operators, and a minimum of two tag lines should be used to control the swinging of the load. Miscommunication or misunderstanding of signals can result in accidents and injuries.
  10. Avoid man entry: Under no circumstances should anyone be allowed under the suspended load, even if they are a rigger.
  11. Use appropriate hitching methods: Straight, basket, and choker hitching methods should be used to secure the load properly and prevent accidents.
  12. Reverse beep horn: The crane should have a reverse beep horn to alert workers and prevent accidents while the crane is in motion.
  13. Regular inspections and maintenance: Regular inspections and maintenance of the crane and its components can help to identify any issues that may increase the risk of accidents and prevent equipment failure.
  14. If multiple cranes are being used, a risk assessment should be performed.

Generally What are the things we have to check in cranes?

When inspecting a crane, the following items should be checked:

 

 

Questions and Answers during Interview

Question: Can you provide a detailed explanation of the various parts of a crane and their functions?

Answer: A crane consists of several parts, including the boom, jib, hoist, trolley, hook, counterweights, outriggers, and cab. The boom is the main arm of the crane that lifts and lowers the load. The jib is a secondary arm that can extend the reach of the boom. The hoist is the mechanism that raises and lowers the load, and it is connected to the trolley, which moves the load horizontally along the boom. The hook is attached to the load and is raised and lowered by the hoist. Counterweights are added to balance the load and prevent the crane from tipping over. Outriggers provide additional stability by extending the crane&#;s base. The cab is where the operator sits and controls the crane.

Question: What are the potential hazards of crane operations, and how can they be prevented?

Answer: The potential hazards of crane operations include electrocution, struck-by accidents, caught-in/between accidents, and crane tip-overs. These hazards can be prevented by following safety guidelines and regulations, ensuring that the crane is in good working condition, providing proper training to operators and workers, conducting regular inspections and maintenance, and ensuring that the work area is clear of any hazards.

Question: How many 3rd party certificate you will check?

Answer:  the operator&#;s third-party  certificate and license, the rigger&#;s third-party certificate, the crane&#;s safety certificate, the lifting appliance&#;s third-party certificate, and third party certificate of Jib.

Question: What is the maximum weight capacity of the crane for lifting, and how is it determined?

Answer: The maximum weight capacity of a crane for lifting is determined by several factors, including the crane&#;s configuration, boom length, counterweight, and load radius. The crane&#;s load chart provides information on the crane&#;s lifting capacity for different configurations and load radii. The load chart takes into account the crane&#;s stability and the weight distribution of the load.

Question: As a safety supervisor, what specific points will you check in a crane to ensure safe lifting operations?

Answer: As a safety supervisor, specific points that should be checked in a crane to ensure safe lifting operations include the crane&#;s condition and maintenance, the crane&#;s load capacity, the crane&#;s positioning and stability, the work area and ground conditions, the communication between the operator and ground personnel, the use of proper lifting equipment, the use of a tag line, and the use of personal protective equipment.

Question: What is the purpose of an anti-two block system, and how does it enhance crane safety?

Answer: The purpose of an anti-two block system is to prevent the crane&#;s hook from coming into contact with the boom tip or other parts of the crane. This system enhances crane safety by preventing damage to the crane and load, reducing the risk of accidents and injuries, and increasing the efficiency of crane operations.

Question: How is a tag line used in crane lifting operations, and why is it essential for safety?

Answer: A tag line is a rope or line that is attached to the load being lifted by the crane. It is used to control the load&#;s movement and prevent it from swinging or spinning during lifting. The tag line is essential for safety as it helps to ensure that the load is lifted and positioned correctly, reduces the risk of accidents and injuries.

What are the main factors that determine the load capacity of a crane?

The load capacity of a crane is determined by several factors, including the weight of the load, the distance between the crane and the load, the angle of the boom, the wind speed, and the ground conditions. All of these factors must be taken into account when calculating the safe working load (SWL) for a particular lift.

How do you assess the ground conditions before starting crane operations?

The ground conditions must be assessed to ensure that they can support the weight of the crane and the load. The assessment should take into account factors such as the type of soil, the slope of the ground, and the presence of any underground pipes or cables. The ground should be firm, stable, and level, and if necessary, mats or other supports should be used to distribute the weight of the crane and prevent sinking or shifting.

What is the difference between a boom truck and a crane, and when is each one used?

A boom truck is a truck-mounted crane with a telescopic boom that can be extended and retracted, while a crane is a stationary machine with a fixed boom. Boom trucks are generally used for smaller lifting operations or in areas with limited access, while cranes are used for larger lifts and heavy-duty applications.

What are some common causes of crane accidents, and how can they be prevented?

Common causes of crane accidents include overloading, improper rigging, unstable ground conditions, operator error, and mechanical failure. These accidents can be prevented by following safe working practices, conducting regular inspections and maintenance, providing proper training for personnel, and ensuring that the equipment is operated within its safe working limits.

 

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