Safety of Telescopic Boom Aerial Work Platforms

Safety of Telescopic Boom Aerial Work Platforms

As one of the mainstream aerial work equipment, the safety of telescopic boom aerial work platforms (hereinafter referred to as "telescopic boom platforms") is built on four core dimensions: design redundancy, active protection, passive protection, and operational specifications. It not only incorporates specialized safety designs tailored to aerial work scenarios but also relies on compliant operation and regular maintenance. Its safety can be analyzed in detail from four aspects: active safety protection, passive safety safeguards, structural safety design, and environmental adaptability safety, while the correlation between "equipment safety" and "operational safety" must be clarified.

I. Active Safety Protection: Prevent Risks in Advance and Reduce Accident Triggers

Active safety design aims to prevent hazards through technical means and serves as the core of safety for telescopic boom platforms. It mainly includes the following functions:

Real-Time Status Monitoring and Early Warning System

Load Limitation: Equipped with high-precision load sensors, the platform continuously monitors the total weight of personnel and equipment in the working platform. Once the weight exceeds the rated load (usually triggered when reaching 110%-120% of the platform’s rated load capacity), the system immediately activates an audible and visual alarm and locks boom movements (such as stopping dangerous operations like boom extension and luffing), preventing boom deformation or overturning caused by overloading.

Tilt Monitoring: Tilt sensors are installed at both the boom root and the working platform. When the boom luffing angle is excessively large (exceeding the safe operation range; for example, the maximum elevation angle of a telescopic boom is generally ≤85°) or the entire vehicle tilts beyond the safe limit due to uneven ground (usually ≤3°-5°, depending on the model), the system immediately restricts movements and triggers an alarm to prevent rollover.

Motion Interlock: "Multi-motion interlock" is realized through hydraulic or electronic control systems. For instance: the boom cannot be lifted if the outriggers are not deployed; the boom cannot perform large-range luffing if the working platform is not leveled; slewing and boom extension cannot be conducted simultaneously at high speed. These measures avoid center-of-gravity instability caused by compound movements.

Precise Control and Stability Regulation

Proportional Control Hydraulic System: Boom movements (including extension, luffing, and slewing) are controlled by proportional valves. The operation speed can be fine-tuned according to working conditions (e.g., low-speed precise movement for close-range operations, and stable acceleration for long-distance operations), avoiding platform sway caused by sudden starts or stops of movements and reducing the risk of personnel instability.

Boom Buffering Technology: When the boom extends or luffs to its limit position (e.g., fully extended boom, maximum elevation angle), the hydraulic system automatically decelerates to avoid rigid impact on the boom structure and the overall vehicle stability, while preventing personnel in the platform from swaying due to inertia.

II. Passive Safety Safeguards: Mitigate Harm When Accidents Occur

Passive safety design acts as the "last line of defense" and focuses on protecting the safety of personnel in the working platform:

Working Platform Protection Structure

Fully Enclosed/Semi-Enclosed Guardrails: The platform is equipped with guardrails with a height of ≥1.1m around it (in compliance with GB/T 9465 Aerial Work Machinery). A kickplate of over 15cm is installed at the bottom of the guardrails to prevent tools and materials from falling and avoid personnel accidentally leaning out of the platform.

Anti-Slip Platform Floor: Patterned steel plates or anti-slip rubber mats are adopted to increase friction even in rainy or oily environments, preventing personnel from slipping.

Emergency Stop Device: Red "emergency stop buttons" are installed both inside the platform and on the ground control console. When either party detects a hazard, the button can be pressed immediately to cut off all power/hydraulic sources for movements and force the equipment to stop operating.

Emergency Rescue and Escape Design

Emergency Descending System: When the main hydraulic system fails (e.g., oil pipe rupture, power failure), a manual pump (or electric emergency pump) can be used to drive the boom to descend slowly, safely returning personnel in the platform to the ground and avoiding the risk of "personnel being trapped at height".

Platform Emergency Exit: Some large-tonnage telescopic boom platforms are equipped with quickly openable emergency doors on the side of the platform. If the boom cannot descend, personnel can escape with the help of safety ropes and descent control devices (requiring operators to have received professional training).

Fall Protection

Safety Belt Anchorage Points: At least two standard-compliant safety belt anchor rings (with a load-bearing capacity of ≥22kN) are installed inside the platform. Personnel must fasten the safety belt hook to the anchor ring during operation, forming a "double insurance" (platform guardrails + safety belts).

Fall Arrester Compatible Design: Some models reserve installation interfaces for fall arresters. For ultra-high-altitude operations (e.g., above 50m), rail-type fall arresters can be additionally equipped to further enhance personnel fall protection safety.

III. Structural Safety Design: The Equipment’s "Risk Resistance Capacity"

The structural strength of telescopic boom platforms directly determines their safety upper limit. The core designs include:

Boom Structural Strength

High-Strength Steel: The boom is made of high-strength alloy steel of Q690 grade or above (30%-50% stronger than ordinary steel). Its structure is optimized through finite element analysis to reduce self-weight while improving bending and torsion resistance, preventing the boom from deforming or breaking under full load.

Synchronized Telescoping of Multi-Section Booms: A "nested" telescopic boom structure (usually 2-5 sections) is adopted. During telescoping, the boom sections are driven by synchronized cylinders or chains to ensure uniform force distribution among all sections, preventing jamming or damage caused by excessive force on a single section.

Automatic Leveling Function: The outriggers are equipped with level sensors. When deployed, they can automatically adjust the extension length of each outrigger to keep the entire vehicle level (with an error of ≤0.5°), eliminating the need for repeated manual adjustments and reducing the risk of overturning caused by uneven ground.

Slewing Mechanism Safety

Slewing Brake Lock: The slewing platform is equipped with hydraulic brakes and mechanical locks. The hydraulic brakes remain activated during operation, and the mechanical locks automatically lock when slewing stops, preventing the platform from rotating accidentally due to slewing inertia (especially in windy conditions).

IV. Environmental Adaptability Safety: "Special Protection" for Complex Working Conditions

Telescopic boom platforms need to adapt to different scenarios, and their safety designs for complex environments include:

Wind Resistance Capacity

Wind Speed Limitation: Based on the vehicle’s tonnage and boom length, the "maximum wind speed for safe operation" is clearly marked (e.g., ≤Level 6 wind for models with a boom length of less than 20m, ≤Level 5 wind for models with a boom length of over 50m). Some high-end models are equipped with wind speed sensors to monitor wind speed in real time and automatically lock boom movements when the wind speed exceeds the limit.

Wind Sway Suppression: For models with long booms (e.g., over 30m), wind sway sensors are installed at the top of the boom. The electronic control system actively adjusts the hydraulic valves to offset part of the boom sway caused by wind, improving platform stability.

Ground Adaptability

Off-road chassis: Some telescopic boom trucks utilize an off-road chassis (equipped with four-wheel drive and differential lock), enabling operation on gravel and muddy surfaces.

Safety for indoor operations: Small telescopic boom trucks (arm length ≤ 16m) utilize low-grip tires to minimize damage to indoor tiles and flooring.

V. "Prerequisites" for Safety: The Importance of Operation and Maintenance

It should be clarified that the "equipment safety" of telescopic boom platforms must be combined with "operational safety"; otherwise, safety designs may fail:

Operator qualifications: Must be familiar with equipment operating procedures, safety warnings and emergency response. Unlicensed operation is strictly prohibited.

Regular Maintenance: In accordance with the requirements of the instruction manual, regular inspections should be conducted on the hydraulic system (oil pipes, seals), electrical system (sensors, emergency stop buttons), and structural components (boom welds, outrigger pins). Worn parts should be replaced in a timely manner to avoid safety accidents caused by "operation with faults".

On-Site Safety Management: Before operation, a warning zone (with a radius of ≥1.5 times the boom length) should be designated to prohibit irrelevant personnel from entering; the ground bearing capacity (≥outrigger ground pressure, usually ≥0.3MPa) should be checked, and operations above foundation pits and underground pipelines should be avoided.

Conclusion: Safety Positioning of Telescopic Boom Aerial Work Platforms

The safety of telescopic boom aerial work platforms is at a "mid-to-high-end level". Its design logic is centered on "prevention first and multiple protections". Under the premise of compliant operation and regular maintenance, it can effectively respond to risks such as overturning, falling, and equipment failure during aerial work. Compared with traditional equipment such as scaffolding and suspended platforms, its advantages lie in:

Stronger active early warning capabilities (real-time monitoring of load, tilt, wind speed, etc.);

More comprehensive passive protection (guardrails, safety belts, emergency descending systems, etc.);

More reliable structural strength (high-strength booms, wide-span outriggers, etc.).