Content Menu
● Understanding the Scaffold Runway System
● Key Design Considerations for Maximum Stability
● Installation and Testing
● Best Practices for Design and Implementation
● Conclusion
● FAQ
>> 1. What is a scaffold runway system?
>> 2. How do I determine the appropriate load capacity for my scaffold runway system?
>> 3. What are the key factors to consider when designing the support structure for a scaffold runway system?
>> 4. What tests are required after installing a scaffold runway system?
>> 5. How important is it to have a professional engineer involved in the design of a scaffold runway system?
● Citations:
A scaffold runway system is an invaluable asset on construction sites, enabling the safe and efficient movement of materials, particularly when used with hoists[6]. However, its effectiveness hinges on its stability. Designing a scaffold runway system for maximum stability requires meticulous planning, careful component selection, and adherence to safety standards. This article explores the key considerations in designing a stable scaffold runway system, supported by technical information and best practices.
Understanding the Scaffold Runway System
A scaffold runway system typically consists of a horizontal track suspended from a scaffold structure, along which a trolley or hoist can move to lift and transport loads[1]. The system clamps onto existing scaffolding, offering a flexible solution for material handling[2]. The primary goal of the design is to ensure that the system can bear the intended load safely and without excessive deflection or risk of collapse[1].
Key Design Considerations for Maximum Stability
1. Load Capacity (SWL/WLL)
- The first step is to determine the Safe Working Load (SWL) or Working Load Limit (WLL) required for the scaffold runway system[1]. This dictates the selection of appropriate components, including the track, trolley, and support structures.
- Niko's scaffold runway systems, for example, offer various load trolleys to accommodate different SWLs, ranging from 80 kg to 2000 kg[1][2].
- Example: If you need to lift materials weighing up to 500 kg, you would select a load trolley and track system rated for at least that weight[1].
2. Track Selection and Layout
- The track must be robust enough to handle the maximum expected load without excessive deflection.
- Available in straight and curved sections, the track layout should optimize material flow and minimize unnecessary bends or inclines[2].
- The modular design allows for easy extension and reconfiguration to suit changing site conditions[2].
- Example: Use straight tracks for long, linear movements and curved sections for navigating corners. Junction switches can be added for changes in direction[2].
3. Support Structure and Spacing
- The scaffolding itself must be strong enough to support the weight of the runway system and the loads it will carry[1].
- Ensure the scaffolding design is strong enough to support the runway system weight and has enough support points to suspend it from. Support point loadings can be supplied upon request[1].
- Intermediate supports are positioned along the track lengths at specified intervals to prevent sagging and maintain stability[1]. The support centers depend on the specific system and the load[2].
- Example: For an SRS24 system with a 125 kg capacity, the track support centers should be no more than 1.0 meter apart[2]. For an SRS27 system with a 1600kg capacity, the track support centers should be no more than 1.0 meter apart[2].
4. Bracing and Connections
- Proper bracing is essential to prevent lateral movement and ensure the overall stability of the scaffold structure[5].
- Horizontal members should be adequately secured to prevent lateral movement and should not have splices between support points[7].
- Connecting devices between frames should provide positive engagement in tension and compression[7].
- Example: Use cross bracing on the scaffolding to resist wind loads and maintain structural integrity.
5. Foundation and Ground Conditions
- Scaffolds must be installed on surfaces that can adequately support the loads they apply[4].
- The ground must be well- compacted and leveled. Mud and soft soil should be replaced with compacted gravel or crushed stone[4].
- Scaffolds installed on any type of soil or gravel must be supported by a sill plate[4].
- Example: Use sill plates made from spruce, pine, or fir (SPF) planks that are a minimum of 50 mm x 250 mm (2 in. x 10 in.) to distribute the load evenly[4].
6. Anchoring and Tie- Ins
- The scaffold should be adequately secured at vertical intervals not exceeding three times the least lateral dimension of the scaffold, measured at the base, to prevent lateral movement[7].
- If mesh, netting, or knotted tarp is added to a scaffold structure, the design drawing for the scaffold must be re- engineered by a professional engineer to include these elements, ensuring the scaffold can withstand potential wind forces[8].
- Example: Tie the scaffold to the building at regular intervals to provide additional stability, especially in windy conditions.
7. Fall Arrest Compatibility
- Some components of the scaffold runway system should be approved per EN795 for fall arrest, providing an additional layer of safety for workers[2].
Installation and Testing
1. Pre- Installation Checks: Before installing the system, ensure the scaffolding design is strong enough to support the runway system weight and has enough support points to suspend it from[1]. Also ensure that the system will be fitted onto a level scaffolding structure[1].
2. Testing: After installation, thorough testing must be carried out by a competent person before the system is put into service[1]. Tests include:
- Deflection Test: Measure deflection at SWL, ensuring it does not exceed 1/300th of the span between supports or 1/200th of the cantilever length[1].
- Proof Load Test: Apply 125% of SWL[1].
- Function Test: Verify proper operation of all components[1].
- Static Test: Apply 125% of SWL[1].
- Dynamic Test: Apply 110% of SWL[1].
Best Practices for Design and Implementation
- Consult with a qualified engineer to ensure the scaffold runway system is designed and installed correctly.
- Adhere to all relevant safety standards and regulations.
- Regularly inspect the system for wear and tear, and perform maintenance as needed.
- Provide comprehensive training to workers on the safe use of the system.
Conclusion
Designing a stable scaffold runway system demands a holistic approach that considers load capacity, track layout, support structure, bracing, foundation, and anchoring. Adhering to safety standards, performing thorough testing, and implementing best practices will ensure a safe and efficient material handling solution on any construction site. By carefully considering each design element and prioritizing safety, construction companies can maximize the benefits of a scaffold runway system while minimizing the risks.
FAQ
1. What is a scaffold runway system?
A scaffold runway system is an overhead track system attached to scaffolding, designed to support and move materials using trolleys or hoists[6].
2. How do I determine the appropriate load capacity for my scaffold runway system?
Determine the Safe Working Load (SWL) or Working Load Limit (WLL) required for the system based on the heaviest materials you will be lifting[1]. Select components, such as the track and trolley, that are rated for at least that weight[1].
3. What are the key factors to consider when designing the support structure for a scaffold runway system?
Ensure the scaffolding is strong enough to support the weight of the runway system and the loads it will carry[1]. Properly space intermediate supports to prevent sagging[1]. The ground must be well-compacted and leveled[4].
4. What tests are required after installing a scaffold runway system?
Required tests include a deflection test at SWL, a proof load test at 125% SWL, a function test, a static test at 125% SWL, and a dynamic test at 110% SWL[1].
5. How important is it to have a professional engineer involved in the design of a scaffold runway system?
Engaging a qualified engineer is critical to ensure that the system is designed and installed correctly, meets all safety standards and regulations, and can safely handle the intended loads[7][8].
Citations:
[1] https://niko.co.uk/bmcms/uploads/Scaffolding%20Runway%20Handbook%2006-2018.4.pdf
[2] https://www.ulslifting.com/lifting-equipment/scaffold-runway-system/
[3] https://www.niko.eu.com/wp-content/uploads/2019/08/Scaffolding_runways_June_2019_UK.pdf
[4] https://www.safemanitoba.com/Page%20Related%20Documents/resources/GD_ScaffoldsAndOtherElevatedWorkPlatforms_16SWMB.pdf
[5] https://search-ohs-laws.alberta.ca/legislation/occupational-health-and-safety-code/part-23-scaffolds-and-temporary-work-platforms/
[6] https://liftingequipmentstore.com/products/scaffold-runway-system-for-hoists
[7] https://ohsguide.ihsa.ca/en/topic/scaffolds_safeguards
[8] http://www.ontario.ca/page/achieve-compliance-construction-sites-access-and-egress-work-area
