Understanding the STL-22J Working Envelope in 300 kg and 460 kg Load Modes

The Onchtech STL-22J is a self-propelled telescopic boom lift with listed platform capacities of 300 kg and 460 kg, a maximum working height of 24 m, and a maximum platform height of 22 m. For industrial installation and equipment selection, these specifications must be considered together with the permitted working envelope—not as independent capabilities available at every boom position.

A working envelope defines the platform positions permitted under specified operating conditions. Choosing a load mode therefore means checking both the total platform load and whether the required work position falls within that mode’s approved reach limits.

The essential reach limitation

The STL-22J specification lists maximum horizontal outreach as 15.8 m / 14 m. The supplied specification does not explicitly assign each outreach figure to the 300 kg or 460 kg mode. Confirm that relationship against the manufacturer’s load chart for the supplied machine. Do not assume that maximum load, maximum height, and maximum outreach are available simultaneously.

What the two load modes mean for planning

The 300 kg and 460 kg ratings provide two capacity figures for evaluating personnel, tools, and installation materials. Neither figure, by itself, establishes how far the platform can extend at a particular height.

A higher capacity rating does not establish a higher occupant allowance. The detailed STL-22J parameter table lists a maximum of two platform occupants; confirm the permitted occupancy for the supplied configuration in its operating documentation.

Specifications that affect access planning

• Height: 24 m maximum working height and 22 m maximum platform height are different specifications. Use platform height when assessing the platform position relative to the task.
• Platform dimensions: 2.44 m × 0.91 m. Check material dimensions and usable space as well as total weight.
• Machine positioning: stowed dimensions are 10.8 m long × 2.49 m wide × 2.7 m high; listed standard weight is 12,200 kg.
• Rotation clearance: the specification lists 360° turntable rotation and 1.47 m tail swing. Include surrounding obstructions when planning the setup position.
• Ground conditions: the listed maximum allowable working inclination is 5°. The 45% gradeability figure applies in the stowed condition and must not be treated as an elevated-working slope allowance.

The STL-22J combines a Cummins engine, four-wheel drive with two-wheel steering, and an automatic hydraulic self-leveling chassis. These features do not replace checks of ground support, operating limits, or the permitted working envelope.

How to check the load chart for your task

1. Define the work position. Record the required platform height, horizontal offset, access route, and nearby obstructions.
2. Calculate the complete platform load. Include personnel, tools, components, and materials that will be carried together.
3. Obtain the applicable chart. Request the STL-22J load chart and operating manual matching the proposed machine configuration.
4. Check each required position. Verify the planned height and outreach within the selected load mode, including positions needed during the task rather than only its endpoint.
5. Confirm site suitability. Review ground-bearing conditions, clearances, environmental restrictions, and operating procedures with qualified site personnel.

Applying the checks to industrial installation

Heavy industrial building expansion

Assess whether the required installation position remains accessible with the planned crew and components aboard. A load that fits the capacity rating still needs a compatible working position.

Lower-level curtain-wall installation

Check façade setback, ground access, and component dimensions alongside capacity. Material handling arrangements must follow the machine’s approved instructions.

Overhead cable tray and pipe assembly

Account for tools and installation materials together, and review the required positions along the assembly route. Do not use the maximum outreach figure alone to establish suitability for continuous work.

Confirm the configuration before procurement

Share your required working height, horizontal offset, total platform load, material dimensions, site conditions, and destination market with Onchtech, the equipment brand of Hunan Hongchang Machinery Co., Ltd. Request the applicable load chart, configuration details, and quotation for your project.

This guidance supports equipment selection; it does not replace the machine’s load chart, operating manual, operator training, or site-specific safety assessment.