How to operate mobile scaffolding safely in narrow spaces?
When using mobile scaffolding in narrow spaces such as indoor corridors, equipment gaps, and areas with dense pipelines, due to limited working space, small operating range, and easy collision with surrounding objects, it is necessary to strengthen safety control from the aspects of scaffolding selection, operating procedures, and protective measures. The following are specific safety operation points:
1、 Advance planning and frame selection: adapting to the characteristics of narrow spaces
Choose a miniaturized and lightweight frame
Prioritize the use of narrow body mobile scaffolding (width ≤ 0.8m, conventional scaffolding width is mostly 1-1.2m), such as foldable narrow body scaffolding (unfolded width 0.6-0.7m), to reduce the risk of collision with walls and equipment.
Avoid using large frames with wheels. If movement is required, choose small frames with universal locking wheels (diameter ≤ 10cm) that have dual brakes (foot pedal+manual locking pin) to prevent accidental sliding in narrow spaces.
Height control: The height of the frame in narrow spaces should not exceed 4m (as it is difficult to fix it with wall connectors), and double-layer operations are prohibited. The center of gravity height should be lowered to enhance stability.
Exploring spatial obstacles and traffic paths
Measure the clearance dimensions (width, height, distance between obstacles) of narrow spaces before homework, mark the positions of pipes, beams, and protruding objects on walls, and ensure that the safe distance between the frame and obstacles during movement is ≥ 30cm (to avoid scratching and tilting the frame).
If there are wires (especially exposed cables) in the space, it is necessary to cut off the power in advance or wrap them with insulation sleeves. The minimum safe distance between the frame and the live body is: low voltage (≤ 1kV) ≥ 1m, high voltage (1-10 kV) ≥ 2m.
2、 Frame construction and fixation: enhancing the stability of narrow spaces
Simplify the structure and reduce redundant components
Complex composite frames (such as multiple splices) are prohibited from being erected in narrow spaces. The spacing between the uprights of a single frame should be ≤ 1.5m (usually 1.8m), and the step distance between the horizontal bars should be ≤ 1.2m (usually 1.5m). The structural rigidity should be improved by increasing the number of nodes.
Cancel non essential components: For example, the outer protective fence can be changed to single-sided protection (no need to set it on the side close to the wall), but the working layer must retain a 1.2m high protective fence+18cm high toe board to prevent personnel or tools from falling.
Targeted fixation to counteract operational impact force
If space permits (such as near the wall), use adjustable top braces (one end to tighten the frame upright, the other end to tighten the ceiling or crossbeam) to fix, set one set every 2 meters in height, and control the pre tightening force of the top brace at 5-8kN (to avoid wall cracking due to excessive tightening).
Ground fixation: 5cm thick rubber pads are placed at the bottom 4 corners of the frame to increase friction. If the ground is smooth (such as tiles or cement), anti slip steel plates (with an area of ≥ 30cm × 30cm) can be placed under the wheels to prevent the frame from sliding due to personnel movement.
Do not rely on "collision force": When operating in narrow spaces, it is strictly prohibited to push the frame to move by stepping on the wall or equipment. Personnel must be evacuated first, and ground personnel must slowly push it (pushing speed ≤ 0.5m/s). Before moving, confirm that there are no obstacles around.
3、 Homework process control: narrow down the scope of operational risks
Strictly limit the load and number of personnel
The load on the scaffolding in narrow spaces needs to be reduced by 30%: the load on the conventional scaffolding operation layer is 3kN/㎡, which should be controlled within 2.1kN/㎡ (approximately equivalent to one worker+50kg tools), and only one person is allowed to work (to avoid center of gravity shift caused by multiple people moving).
Tools and materials should be placed in the central area of the frame (with a deviation of ≥ 50cm from the edge), and should not be hung on protective barriers or poles to prevent excessive local stress.
Code of Conduct for Operations: Avoid Significant Actions
Operators need to wear double hook safety belts, with one hook fixed to the upright pole of the frame (1.2m above the working level) and the other hook connected to surrounding fixed components (such as pipes and wall embedded rings), forming a dual protection.
Do not turn, cross or bend over the frame to the outside (with a distance of ≤ 30cm). If you need to retrieve or place distant objects, you must first move the frame to a suitable position, rather than stretching your body.
Before moving the frame, the operating layer must be cleared (all personnel and tools must be evacuated). When pushing, 2 people should cooperate (1 person in front and 1 person in the back). The person in front should observe the path, while the person behind should slowly apply force and stop immediately when encountering obstacles.
4、 Emergency and Inspection: Adapting to the Special Characteristics of Narrow Spaces
High frequency inspection of key nodes
Check the verticality of the pole every 30 minutes (deviation ≤ 1/200 of the height of the frame, such as a 4m elevated body deviation ≤ 2cm) to prevent the frame from tilting due to collision.
Key inspection of fastener tightness: Use a torque wrench to test, and the bolt torque should be between 40-65N · m to avoid loosening due to vibration (vibrations are more likely to be transmitted to nodes when operating in narrow spaces).
Emergency evacuation plan
Emergency stop signals should be set up in narrow spaces (if it is agreed that 3 strikes on the frame are evacuation instructions), and operators should memorize the escape route (even if the space is narrow, a passage with a width of ≥ 60cm should be reserved).
If there is a slight tilt of the frame (deviation>3cm), personnel should maintain a low center of gravity and slowly evacuate. Running or jumping is prohibited, and ground personnel should not blindly pull the frame. Wooden wedges should be placed first to prevent the tilt from expanding.
summarize
The core principles of narrow space operations are "adaptation, simplification, and strict control": by selecting appropriate space dimensions, reducing collision risks through simplified structures, and ensuring stability through strict control of operating behavior and loads. Compared to open areas, the safety redundancy in narrow spaces is lower, and it is necessary to control the position, operating range, and node strength of the frame with "millimeter level" accuracy in order to effectively avoid risks such as overturning, collision, and falling.
