Bridge Cranes vs. Gantry Cranes, Select for Your Aluminum Plant

Bridge Cranes vs. Gantry Cranes, Select for Your Aluminum Plant. Bridge cranes offer overhead efficiency, while gantry cranes provide versatility. Choose wisely to optimize material handling in your aluminum plant. Click!

Bridge Cranes vs. Gantry Cranes: Choosing the Right Solution for Your Aluminum Plant

In aluminum production, where efficiency is king and every operation counts, the role of crane systems cannot be overstate These mechanical marvels are the backbone of any aluminum plant, facilitating the movement of raw materials, semi-finished products, and finished goods with precision and spee However, not all cranes are created equal, and selecting the right type can make all the difference in optimizing operations.

The importance of choosing the appropriate crane type cannot be emphasized enough. It's not just about lifting heavy loads; it's about maximizing efficiency, ensuring safety, and ultimately, driving profitability. That's where the comparison between bridge cranes and gantry cranes comes into play. By understanding the unique strengths and limitations of each type, aluminum plant managers can make informed decisions that align with their specific needs and goals.

Bridge Cranes

Bridge cranes, also known as overhead cranes, are versatile lifting devices that are essential in various industrial settings, including aluminum plants. They consist of a horizontal beam (the bridge) that spans the width of the working area, supported by parallel runways on either side. The bridge is equipped with a hoist and trolley mechanism, allowing for horizontal movement along the length of the crane.

Types of Bridge Cranes Commonly Used in Industrial Settings

In industrial settings like aluminum plants, several types of bridge cranes are commonly employed:

Single Girder Bridge Cranes:
Description: Single girder bridge cranes feature a single horizontal beam (girder) supported by end trucks, allowing for light to moderate lifting tasks.
Suitability: These cranes are suitable for applications where the lifting requirements are not overly demanding, such as light manufacturing, assembly lines, and maintenance operations.
Advantages: Single girder bridge cranes are cost-effective, easy to install, and require minimal maintenance. They offer versatility and maneuverability, making them suitable for facilities with limited space.
Limitations: While single girder cranes are efficient for lighter loads, they have lower lifting capacities compared to double girder cranes and may not be suitable for heavy-duty applications.

Double Girder Bridge Cranes:
Description: Double girder bridge cranes feature two parallel horizontal beams (girders) supported by end trucks, providing increased stability and lifting capacity.
Suitability: These cranes are ideal for heavy-duty lifting tasks in industries such as steel manufacturing, foundries, and shipbuilding, where large and heavy loads need to be lifted and move
Advantages: Double girder bridge cranes offer superior lifting capacity, longer spans, and greater height under the hook compared to single girder cranes. They provide enhanced stability and durability for handling heavier loads.
Limitations: Double girder cranes are typically more expensive and complex than single girder cranes. They may require additional overhead clearance and installation space due to their larger size and height.

Advantages of Bridge Cranes in Aluminum Plants

Let's elaborate on the advantages of bridge cranes in aluminum plants:

High Lifting Capacity:
Double Girder Bridge Cranes: These cranes are capable of handling heavy loads commonly encountered in aluminum plants, such as aluminum ingots, coils, and large machinery components. Their robust construction and dual girder design provide increased lifting capacity compared to single girder cranes.

Precise Positioning:
The overhead design of bridge cranes allows for precise movement and positioning of loads, essential for the delicate processes involved in aluminum production. Operators can accurately maneuver the crane to place materials precisely where needed, minimizing the risk of damage or waste during handling.

Efficient Use of Space:
Bridge cranes operate overhead, utilizing the vertical space within the aluminum plant effectively. This overhead configuration frees up valuable floor space that would otherwise be occupied by traditional material handling equipment, storage racks, or transport vehicles.
By maximizing floor space utilization, bridge cranes enable aluminum plants to optimize workflow efficiency, streamline material flow, and accommodate additional production equipment or processes as neede

Versatility:
Bridge cranes can be customized and equipped with various attachments and accessories to suit the specific requirements of aluminum production processes. For example:
Magnets: Bridge cranes can be outfitted with electromagnets for lifting and handling ferrous materials such as aluminum scrap or metal sheets.
Specialized Lifting Fixtures: Custom lifting fixtures and attachments can be designed to securely grip and manipulate aluminum coils, billets, or other irregularly shaped products.
Rotating Trolleys: Some bridge cranes feature rotating trolleys or hoists, allowing for efficient material rotation or flipping during processing or inspection.
This versatility enhances the adaptability of bridge cranes in aluminum plants, enabling them to handle a wide range of materials, products, and production requirements effectively.

In summary, bridge cranes offer several advantages for aluminum plants, including high lifting capacity, precise positioning, efficient space utilization, and versatility in handling various materials and products. By leveraging these benefits, aluminum manufacturers can enhance productivity, streamline operations, and maintain a competitive edge in the industry.

Limitations and Considerations When Using Bridge Cranes

Let's explore the limitations and considerations associated with the use of bridge cranes in aluminum plants:

Height Restrictions:
The height of the building structure must be sufficient to accommodate the vertical clearance required by the bridge crane, including the height of the load and the hook height when fully raise
In facilities with low ceilings or limited overhead clearance, the installation of bridge cranes may be impractical or require costly modifications to the building structure to meet clearance requirements.

Installation Complexity:
Installing bridge cranes typically involves significant structural modifications to the building, including the installation of runway beams, support columns, and runway rails.
Structural engineers must assess the load-bearing capacity of the building structure and design reinforcement measures to support the weight of the crane and the loads it will be lifting.
Crane installation may also require coordination with other trades, such as electrical and HVAC contractors, to ensure proper integration with existing building systems.

Limited Mobility:
Bridge cranes are confined to the area between the parallel runways, limiting their mobility compared to mobile crane systems such as gantry cranes or mobile overhead cranes.
The movement of bridge cranes is restricted to the length of the runway rails, requiring operators to reposition the crane by traversing along the runway beams.
In facilities with irregular layouts or changing production configurations, the limited mobility of bridge cranes may necessitate the installation of multiple cranes or additional material handling equipment to cover larger work areas effectively.

Operational Considerations:
Bridge cranes require trained operators to operate safely and efficiently, necessitating investment in operator training programs and ongoing maintenance to ensure compliance with safety regulations.
Overhead obstacles such as pipes, ductwork, and lighting fixtures must be considered when planning the installation and operation of bridge cranes to avoid collisions and clearance issues.
Routine inspections and maintenance are essential to ensure the safe and reliable operation of bridge cranes, including checks for wear and tear, proper lubrication, and alignment of runway rails.

Cost Considerations:
The initial cost of purchasing and installing bridge cranes, including structural modifications and electrical wiring, can be significant compared to other material handling equipment options.
Additionally, ongoing maintenance and operational costs, including electricity consumption, replacement parts, and labor expenses, should be factored into the total cost of ownership over the crane's lifespan.

Integration with Existing Operations:
Integrating bridge cranes into existing production processes and workflows requires careful planning to minimize disruptions and ensure compatibility with existing equipment and operations.
Coordination with production schedules, downtime allowances, and logistics planning is essential to facilitate a smooth transition and optimize the benefits of bridge crane utilization within the aluminum plant.

Considering these limitations and considerations is crucial for making informed decisions about the suitability of bridge cranes for specific applications within an aluminum plant. While bridge cranes offer numerous advantages, careful planning, engineering expertise, and operational considerations are necessary to maximize their effectiveness and return on investment in aluminum manufacturing operations.

Gantry Cranes

Gantry cranes are another vital lifting solution commonly found in industrial environments like aluminum plants. Unlike bridge cranes, gantry cranes are supported by legs or uprights, allowing them to straddle the workspace and provide greater flexibility in movement. The key components of a gantry crane include the bridge, end trucks or wheels, hoist mechanism, and supporting legs.

Types of Gantry Cranes Suitable for Aluminum Plant Operations

Let's delve into more details about the types of gantry cranes suitable for operations within aluminum plants:

Single Leg Gantry Cranes:
Description: Single leg gantry cranes feature a single supporting leg on one side, typically equipped with wheels or casters for mobility. The crane's hoist mechanism is mounted on a horizontal beam (bridge) that spans the length of the gantry legs.
Suitability: These cranes offer a compact and versatile lifting solution for areas with limited space or uneven ground conditions. They are commonly used in outdoor storage yards, loading docks, and assembly areas within aluminum plants.
Advantages: Single leg gantry cranes provide flexibility in positioning and maneuverability, allowing operators to move loads within confined spaces or across uneven terrain. They are easy to install and relocate as needed, making them suitable for temporary or mobile applications.
Limitations: Single leg gantry cranes have lower lifting capacities compared to double leg gantry cranes due to their asymmetric design. They may require additional support or stabilization measures to ensure stability and safety during operation.

Double Leg Gantry Cranes:
Description: Double leg gantry cranes feature two supporting legs on either side, providing increased stability and lifting capacity compared to single leg gantry cranes. The crane's hoist mechanism is mounted on a bridge that spans the distance between the gantry legs.
Suitability: These cranes are ideal for handling heavier loads and providing greater stability in high-capacity lifting applications within aluminum plants, such as moving aluminum ingots, coils, or machinery components.
Advantages: Double leg gantry cranes offer superior lifting capacity and stability, making them well-suited for heavy-duty lifting tasks and continuous operation in demanding industrial environments. They provide reliable performance and precise load control for critical material handling operations.
Limitations: Double leg gantry cranes require adequate space for installation and operation, as well as a level and stable foundation to support the weight of the crane and loads being lifte They may be more complex to install and require longer lead times for fabrication and delivery compared to single leg gantry cranes.

These types of gantry cranes offer versatile lifting solutions for various applications within aluminum plants, providing flexibility, stability, and efficiency in material handling operations. By selecting the appropriate type of gantry crane based on specific requirements and operational considerations, aluminum manufacturers can optimize productivity, safety, and performance in their facilities.

Advantages of Gantry Cranes in Aluminum Plants

Gantry cranes offer several advantages that make them well-suited for use in aluminum plants:

Flexibility and Maneuverability:
Gantry cranes offer exceptional flexibility and maneuverability, allowing them to move effortlessly along the length and width of the workspace. This versatility enables efficient material handling in various areas of the aluminum plant, including production lines, storage yards, and loading docks.
Operators can easily position the gantry crane precisely where needed to lift, move, and place materials with accuracy, minimizing the need for manual handling and streamlining workflow processes.

Easy Installation:
Unlike bridge cranes, which require structural modifications to the building for installation, gantry cranes are freestanding and can be set up quickly and easily without the need for extensive construction work.
Gantry cranes typically come pre-assembled or in modular components, allowing for straightforward assembly and installation by trained personnel. This ease of installation reduces downtime and costs associated with crane implementation in aluminum plants.

Outdoor Operation:
Gantry cranes are designed for versatile operation and can be used both indoors and outdoors, offering flexibility in handling materials in different environments.
Outdoor gantry cranes are commonly used in aluminum plants for loading and unloading materials from trucks, transporting materials across outdoor storage yards, and handling oversized or heavy loads that may not fit within the confines of indoor production facilities.

Adjustable Height:
Many gantry cranes feature adjustable height options, allowing for customization to accommodate different lifting requirements and workspace configurations.
The ability to adjust the height of the gantry crane provides flexibility in handling materials of varying sizes and shapes, as well as the ability to navigate obstacles or overhead obstructions within the aluminum plant.

Cost-Effectiveness:
Gantry cranes offer a cost-effective material handling solution for aluminum plants, providing efficient lifting capabilities without the need for costly structural modifications to the building.
The ease of installation, versatility in operation, and ability to handle both indoor and outdoor tasks contribute to the overall cost-effectiveness of gantry cranes compared to other types of lifting equipment.

In summary, gantry cranes provide numerous advantages for material handling operations in aluminum plants, including flexibility, maneuverability, easy installation, outdoor operation capability, adjustable height options, and cost-effectiveness. By leveraging these benefits, aluminum manufacturers can optimize productivity, streamline operations, and enhance safety in their facilities.

Limitations and Considerations When Using Gantry Cranes

Let's elaborate on the limitations and considerations associated with the use of gantry cranes in aluminum plants:

Stability on Uneven Surfaces:
Gantry cranes rely on stable ground conditions for safe and efficient operation. Uneven or sloped surfaces can affect the crane's stability and performance, potentially causing instability or tipping hazards.
Operators should conduct thorough site assessments to identify potential hazards and address any uneven ground conditions, such as grading or leveling the surface or using stabilizing measures such as outriggers or leveling jacks.

Height Restrictions:
The height of the gantry crane legs may impose limitations on the maximum lifting height and clearance available for material handling operations.
In facilities with limited overhead clearance or height restrictions, the design and configuration of the gantry crane legs must be carefully considered to ensure compatibility with the workspace and operational requirements.

Reduced Hook Coverage:
Compared to bridge cranes, gantry cranes may have limited hook coverage, particularly in areas where the supporting legs obstruct the movement of the hoist.
Operators should be mindful of potential blind spots or restricted areas within the crane's operating range and take appropriate precautions to ensure safe and efficient material handling operations.
Supplemental equipment such as remote-controlled cameras or additional lighting may be used to enhance visibility and improve operator awareness in areas with limited hook coverage.

Environmental Considerations:
Gantry cranes used in outdoor environments are exposed to various environmental factors such as rain, wind, temperature fluctuations, and corrosive substances.
Proper maintenance and corrosion protection measures, such as regular cleaning, painting, and lubrication, are essential to prolonging the lifespan of gantry cranes and ensuring reliable performance in harsh environmental conditions.

Operational Safety:
Operators must undergo comprehensive training and certification to operate gantry cranes safely and effectively. Proper procedures for load handling, crane operation, and emergency response should be established and followed to minimize the risk of accidents or injuries.
Regular inspections, maintenance, and safety checks are essential to identify and address potential issues or defects that could compromise the safety and integrity of the gantry crane system.

Cost Considerations:
While gantry cranes offer cost-effective material handling solutions compared to bridge cranes, there are still associated costs for installation, maintenance, and operation.
Aluminum plants should carefully evaluate the total cost of ownership, including initial investment, ongoing maintenance expenses, and operational costs, to determine the feasibility and return on investment of implementing gantry cranes in their facilities.

By considering these limitations and operational considerations, aluminum plants can make informed decisions about the suitability and implementation of gantry cranes for their material handling needs, ensuring safe, efficient, and reliable operations within their facilities.

Comparison of Bridge Cranes and Gantry Cranes

Load Capacity and Span

• Bridge Cranes: Double girder bridge cranes typically offer higher load capacities compared to gantry cranes, making them suitable for lifting heavier materials such as aluminum ingots. The span of bridge cranes is limited by the width of the building, but they can cover large areas with proper runway installation.
• Gantry Cranes: Gantry cranes come in various configurations to accommodate different load capacities and span requirements. While they may have slightly lower load capacities compared to bridge cranes, gantry cranes offer the advantage of spanning over outdoor areas and uneven surfaces, providing more flexibility in handling materials.

Mobility and Flexibility

• Bridge Cranes: Bridge cranes are confined to the overhead runway system, limiting their mobility within the designated working are However, they offer precise movement and positioning capabilities, making them ideal for repetitive tasks and production lines.
• Gantry Cranes: Gantry cranes are highly mobile and can be moved along the length and width of the workspace, providing greater flexibility in material handling. This mobility allows gantry cranes to reach areas where bridge cranes cannot, making them suitable for outdoor operations or areas with limited overhead clearance.

Installation and Infrastructure Requirements

• Bridge Cranes: Installing bridge cranes typically requires significant structural modifications to the building, including the installation of overhead runways and supporting structures. This can be time-consuming and costly, especially in existing facilities where retrofitting may be necessary.
• Gantry Cranes: Gantry cranes are generally easier and quicker to install compared to bridge cranes since they do not require modifications to the building structure. Gantry cranes can be set up on a flat, stable surface, reducing installation time and associated costs.

Operational Efficiency and Maintenance

• Bridge Cranes: Bridge cranes offer high operational efficiency and precision in material handling tasks. However, they may require more frequent maintenance due to the complexity of their overhead runway system and components.
• Gantry Cranes: Gantry cranes are known for their reliability and low maintenance requirements. With fewer moving parts compared to bridge cranes, gantry cranes are easier to maintain and require less downtime for servicing.

Cost Analysis: Initial Investment and Long-term Expenses

• Bridge Cranes: While bridge cranes may have higher upfront costs due to the need for structural modifications and specialized equipment, they offer long-term reliability and efficiency, leading to lower overall operating expenses over their lifespan.
• Gantry Cranes: Gantry cranes typically have lower initial investment costs compared to bridge cranes, thanks to their simpler installation requirements. While they may have slightly higher operating costs due to maintenance and energy consumption, gantry cranes offer excellent value for money in terms of flexibility and versatility.

These key differences and considerations can help aluminum plant managers make informed decisions when choosing between bridge cranes and gantry cranes for their material handling needs.

Case Studies and Real-world Applications

Case Study 1: Successful Implementation of Bridge Cranes in an Aluminum Smelting Facility

In a aluminum smelting facility, the need for efficient material handling is paramount to ensure smooth operations and meet production targets. By implementing bridge cranes tailored to their specific needs, Company X achieved significant improvements in their material handling processes.

Key Highlights:

• Increased Efficiency: The overhead design of bridge cranes allowed Company X to maximize floor space utilization and streamline material flow, resulting in improved operational efficiency.
• Enhanced Safety: With precise positioning capabilities, bridge cranes ensured safe and accurate handling of molten aluminum and other hazardous materials, reducing the risk of accidents and injuries.
• Cost Savings: Despite the initial investment in structural modifications and crane installation, the long-term cost savings achieved through improved productivity and reduced downtime outweighed the upfront expenses.

Case Study 2: Gantry Cranes Optimizing Material Handling in an Aluminum Extrusion Plant

In an aluminum extrusion plant where space constraints and outdoor operations are common challenges, Company Y turned to gantry cranes to optimize their material handling processes.

Key Highlights:

• Flexibility: Gantry cranes provided Company Y with the flexibility to move materials both indoors and outdoors, accommodating the diverse needs of their production processes.
• Quick Installation: Unlike bridge cranes, gantry cranes could be installed quickly and easily on a flat, stable surface, minimizing downtime and disruption to operations.
• Improved Accessibility: The mobility of gantry cranes allowed Company Y to reach remote areas of the facility, enhancing accessibility and efficiency in material handling tasks.

Lessons Learned and Best Practices from Case Studies

From these case studies, several key lessons and best practices emerge:

• Tailored Solutions: Choosing the right crane type based on the specific needs and constraints of the facility is crucial for achieving optimal results.
• Safety First: Prioritizing safety considerations in crane selection and implementation is essential to mitigate risks and ensure a safe working environment.
• Continuous Improvement: Regular evaluation and optimization of material handling processes are necessary to adapt to changing demands and maximize efficiency.

By learning from these real-world applications, aluminum plant managers can glean valuable insights to inform their decision-making and drive continuous improvement in their material handling operations.

Factors Influencing the Decision

Choosing between bridge cranes and gantry cranes for material handling in an aluminum plant is not a one-size-fits-all decision. Several factors must be considered to ensure the selected crane system aligns with the unique requirements and objectives of the facility.

• Specific Requirements and Constraints of the Aluminum Plant : Every aluminum plant has its own set of requirements, constraints, and operational challenges. Factors such as available space, building structure, material types, and production processes must be carefully assessed to determine the most suitable crane solution. For example, if the plant has limited overhead clearance or uneven ground surfaces, gantry cranes may offer greater flexibility compared to bridge cranes.
• Production Volume and Workflow Patterns:  The production volume and workflow patterns of the aluminum plant play a significant role in crane selection. High-volume facilities with continuous production lines may benefit from the precision and efficiency of bridge cranes, which excel in repetitive tasks and material handling at fixed workstations. Conversely, plants with more diverse production requirements or fluctuating demand may prefer the versatility and mobility of gantry cranes to adapt to changing workflows.
• Safety Regulations and Compliance Standards:  Safety is paramount in any industrial setting, and aluminum plants are no exception. Compliance with safety regulations and standards is a non-negotiable aspect of crane selection. Both bridge cranes and gantry cranes must adhere to applicable safety guidelines to ensure the protection of workers, equipment, and materials. Factors such as load capacity, stability, operator training, and maintenance procedures must be thoroughly evaluated to mitigate risks and prevent accidents.
• Environmental Factors and Sustainability Goals:  As environmental awareness and sustainability become increasingly important considerations for businesses, aluminum plants are under pressure to minimize their environmental footprint. When choosing crane systems, environmental factors such as energy efficiency, emissions, and resource usage should be taken into account. Gantry cranes, with their ability to operate outdoors and their lower installation requirements, may offer advantages in terms of energy consumption and environmental impact compared to bridge cranes.

By carefully weighing these factors and considering their implications, aluminum plant managers can make informed decisions that maximize efficiency, safety, and sustainability in their material handling operations. Ultimately, the selected crane system should align with the overarching goals and objectives of the plant, contributing to its overall success and competitiveness in the industry.

Decision-making Process

Navigating the decision-making process between bridge cranes and gantry cranes for material handling in an aluminum plant requires careful consideration and a structured approach. Here's a step-by-step guide to help aluminum plant managers make an informed decision:

• Assessment of Current Needs and Future Growth Projections:Begin by conducting a comprehensive assessment of the aluminum plant's current material handling needs, production processes, and constraints. Consider factors such as production volume, workflow patterns, available space, and safety requirements. Additionally, forecast future growth projections and anticipate any changes or expansions that may impact material handling operations. This analysis will provide a solid foundation for selecting the most suitable crane system to meet both current and future needs.
• Consultation with Crane Manufacturers and Industry Experts: Engage with crane manufacturers and industry experts to gain insights and expertise in crane technology, applications, and best practices. Discuss the specific requirements and challenges of the aluminum plant and explore the capabilities and limitations of both bridge cranes and gantry cranes. Manufacturers and experts can provide valuable guidance and recommendations tailored to the unique needs of the facility, helping to narrow down the options and inform the decision-making process.
• Cost-benefit Analysis and Return on Investment Evaluation: Perform a thorough cost-benefit analysis to evaluate the financial implications of implementing bridge cranes versus gantry cranes. Consider not only the upfront costs of crane acquisition and installation but also the long-term operating expenses, maintenance requirements, and potential return on investment. Compare the total cost of ownership for each crane system over their expected lifespan, taking into account factors such as efficiency improvements, labor savings, and reduced downtime. This analysis will provide a quantitative basis for decision-making and ensure that the selected crane system delivers optimal value for the aluminum plant.
• Final Decision and Implementation Plan: Based on the assessment of current needs, consultation with stakeholders, and cost-benefit analysis, make a final decision on whether to invest in bridge cranes or gantry cranes for material handling in the aluminum plant. Develop a detailed implementation plan that outlines the steps required for crane acquisition, installation, commissioning, and training. Assign responsibilities, establish timelines, and allocate resources to ensure a smooth and successful implementation process. Communication and collaboration among all stakeholders are critical to align expectations and facilitate a seamless transition to the new crane system.

By following this decision-making process, aluminum plant managers can make well-informed decisions that optimize material handling efficiency, safety, and cost-effectiveness, ultimately driving the success and competitiveness of the plant in the aluminum industry.

Conclusion

Recap of the Key Differences between Bridge Cranes and Gantry Cranes

In summary, bridge cranes and gantry cranes offer distinct advantages and considerations for material handling in aluminum plants:

• Bridge cranes are overhead lifting systems supported by parallel runways, offering high load capacities, precise positioning, and efficient use of space. They are well-suited for indoor operations with ample overhead clearance.
• Gantry cranes are mobile lifting systems supported by legs or uprights, providing flexibility in movement and accessibility to outdoor areas. They are ideal for applications where overhead clearance is limited or where outdoor material handling is require

The choice between bridge cranes and gantry cranes is not one to be taken lightly. Selecting the right crane solution is crucial for optimizing efficiency, productivity, and safety in aluminum plants. A carefully considered decision can lead to improvements in material handling processes, streamlined workflows, and ultimately, enhanced competitiveness in the industry.

Final Considerations and Recommendations for Decision-makers in Aluminum Plant Management

For decision-makers in aluminum plant management, here are some final considerations and recommendations:

• Conduct a thorough assessment of the specific needs, constraints, and objectives of the aluminum plant to determine the most suitable crane solution.
• Seek guidance and expertise from crane manufacturers and industry experts to explore the capabilities and limitations of bridge cranes and gantry cranes.
• Perform a cost-benefit analysis to evaluate the financial implications and return on investment of each crane system over their expected lifespan.
• Prioritize safety, reliability, and sustainability in crane selection, ensuring compliance with regulatory requirements and environmental standards.
• Develop a detailed implementation plan and allocate resources accordingly to facilitate a smooth transition to the selected crane solution.

By taking these considerations into account and making informed decisions, aluminum plant managers can optimize material handling operations, enhance productivity, and drive success in the dynamic and competitive aluminum industry.