Long-span crossings present unique challenges requiring precision and specialized techniques. Best practices that our equipment supports include:

• Pilot Wire Installation: Often, a light pilot rope is first installed using a drone or a pilot helicopter. This rope is then used to pull in progressively larger pulling ropes, and finally the conductor.

• Sag and Tension Monitoring: Utilizing a dynamometer and sag scopes (or modern digital GPS-based systems) is critical. Our hydraulic pullers provide real-time tension readouts to ensure the conductor is not over-stressed.

• Use of Multiple Tensioners/Brakes: For exceptionally long or heavy conductors, a multi-reel tensioning system or braking systems on the pulling side might be employed to manage the immense forces involved.

• Communication: Clear and constant communication between the puller operator, tensioner operator, and spotters along the span is paramount for safety and success.

Our high-capacity pullers (8 tons, 10 tons, and higher) and multi-conductor tensioners are specifically designed to provide the power and control needed for these demanding crossing projects.

While both are used for pulling cables, they serve different scales of projects:

• Cable Winch: A cable winch is generally smaller, more portable, and suitable for shorter, lighter pulls, such as final-section installations inside buildings, lighter-duty utility cables, or fiber optic cable in conduits. They offer good pulling force but may have less precise speed and tension control.

• Hydraulic Cable Puller: This is a much larger, more powerful machine designed for heavy-duty, long-distance underground cable laying (e.g., high-voltage power cables in trenches or large conduits). Key advantages include:

  • Precise Control: Variable speed and adjustable tension limiting to prevent cable damage.

  • High Capacity: Capable of pulling forces from 3 tons to over 20 tons.

  • Data Logging: Many of our models include instruments to record pulling force and distance for quality assurance reports.

For any significant power distribution or transmission underground project, a hydraulic cable puller is the industry-standard choice. We offer a full range of both winches and pullers to match any project scope.

The choice of roller is critical to minimize pulling tension and prevent cable jacket damage. For heavy HV cables in trenches, we recommend:

• Straight Line Rollers: Heavy-duty, wide-diameter steel rollers with smooth bearings placed every 2-3 meters along straight sections of the trench.

• Corner Rollers (Manhole Rollers): These are essential for any bend or corner. They feature multiple vertical and horizontal rollers to create a smooth, large-radius curve for the cable to pass through without kinking or abrasion. We offer both triple-roller and high-strength specialized corner roller systems.

• Bell Mouths / Conduit Feeders: These are placed at the entrance of ducts or conduits to provide a smooth, rounded edge, preventing the cable from scraping on sharp edges as it enters.

Using a combination of these high-quality rollers, supplied by Ningbo Changshi, can reduce the required pulling force by over 50%, protecting both the cable and your pulling equipment.

1. As an international buyer, how do you handle after-sales service, spare parts, and technical support?

This is a top priority for us at Ningbo Changshi. As a "one-stop supply and service" provider, our commitment extends far beyond the sale:

• Comprehensive Documentation: Every machine is shipped with a detailed user manual, maintenance schedule, and a complete parts list with diagrams.

• Spare Parts Package: We typically include a package of essential wearing parts (e.g., filters, seals, specific bolts) with the initial shipment to minimize downtime for routine maintenance.

• Remote Technical Support: Our experienced engineers are available via email, phone, and video call to diagnose issues and guide your on-site technicians through troubleshooting and repairs.

• Fast Spare Parts Shipping: We maintain a large inventory of spare parts and can dispatch them globally via express air freight (like DHL/FedEx) to get your equipment operational as quickly as possible.

• Local Partnerships: In select regions, we are developing partnerships with local service agents to provide on-the-ground support. Please inquire about your specific country.

2. You mention being a "one-stop" supplier. What does that mean for a large-scale transmission line project?

Being a "one-stop" supplier means we can provide virtually all the tools and machinery required for your stringing and installation project from a single, reliable source. This provides immense value by:

• Simplifying Procurement: You deal with one supplier, one point of contact, and one set of paperwork, which drastically reduces administrative overhead.

• Ensuring Compatibility: All equipment, from the puller-tensioner to the stringing blocks, come-along clamps, and swivels, is designed to work together seamlessly.

• Optimizing Logistics: We can consolidate your entire order into one shipment, saving you significant costs and simplifying customs clearance.

• Streamlining Support: When you need support, you have a single expert team to call who understands your entire equipment fleet.

Our catalogue covers everything from hydraulic machines and stringing blocks to gin poles, conductor grips, hoisting tackles, and personal safety equipment. We equip your entire project.

Answer (publish): CTCS is increasingly expected for long spans, bundled conductors and HTLS installations because it maintains steady tension during payout and reduces conductor damage and sag variance. Project specs increasingly call for CTCS-capable tensioners for spans where sag and conductor integrity are tightly controlled.

This is a critical question for grid modernization projects. Modern HTLS conductors cannot be handled by standard equipment due to their composite cores (carbon or composite fiber) and softer aluminum outer strands. Using the wrong equipment will cause irreparable damage.

Ningbo Changshi has engineered specific solutions for these advanced conductors:

• Larger Diameter Bull-Wheels: Our puller-tensioners designed for HTLS feature bull-wheels with a much larger diameter. This wider bending radius prevents the sensitive core from cracking or breaking under tension.

• Specialized Lining: The grooves of our bull-wheels are lined with high-density nylon or polyurethane sectors that cushion the soft aluminum strands, preventing scratches and deformation.

• Precision Tension Control: Our hydraulic systems offer extremely fine-tuned, stable tension control, which is essential for preventing the core and strands from separating or being over-stressed during the stringing process.

• Special Conductor Grips: We provide specialized "core-gripping" or "full-tension" grips designed specifically for ACCC® and other composite core conductors that safely hold the conductor without compromising its integrity.

Before starting any HTLS project, it's vital to consult with us to ensure you have a fully compatible and certified equipment set.

As safety standards evolve globally, our equipment incorporates the latest safety technologies as standard features. For 2025, you can expect:

• Negative Self-Acting Hydraulic Brakes: This is a crucial failsafe. If the hydraulic system or engine fails for any reason, the brake automatically engages, securely holding the conductor in place and preventing a catastrophic failure.

• Hydraulic Over-pull Protection: Our machines have a pre-set maximum pulling force system. If the load exceeds this limit (e.g., the conductor gets snagged), the system automatically stops the pull to prevent damage to the conductor or tower infrastructure.

• Integrated Reel Winders with Level Wind: For safe and efficient drum management, our pullers often come with hydraulic reel winders that include an automatic level wind mechanism. This ensures the old conductor or pulling rope is wound onto the drum evenly, preventing tangles and ensuring operator safety.

• Emergency Stop Buttons: Multiple, easily accessible emergency stop buttons are located on the main control panel and often on a remote-control unit, allowing for immediate shutdown from various positions.

These features not only protect your personnel but also safeguard your multi-million dollar investment in conductors and infrastructure.

We are committed to supporting environmentally responsible construction. Our equipment contributes to this in several ways:

• High-Efficiency Engines: We use engines from world-class brands like Cummins and Deutz that comply with the latest emission standards (like EU Stage V or EPA Tier 4), reducing the project's carbon footprint.

• Biodegradable Hydraulic Oil: We offer the option to equip our machines with biodegradable hydraulic fluids. In the event of an accidental leak in an ecologically sensitive area, this minimizes soil and water contamination.

• Reduced Noise Levels: Our modern power packs are enclosed and insulated, significantly reducing noise pollution, which is critical when working near residential areas or in wildlife habitats.

• Precision Control: The precise control of our puller-tensioners allows for helicopter or drone-assisted pilot rope stringing, which can drastically reduce the need for ground vehicle access, access roads, and vegetation clearing in forested or mountainous terrain.

Yes, this is a key trend for improving project management and quality assurance. Select models of our hydraulic puller-tensioners are equipped with advanced electronic control panels that function as data loggers. These systems can:

• Record Key Metrics: They digitally record and display real-time data such as pulling force (tension), stringing speed, and distance pulled.

• Generate Reports: The data can be easily exported via a USB port. This allows project managers to generate detailed reports for clients, verifying that the conductor was installed according to the precise engineering specifications and sag-tension charts.

• Improve Quality Control: Having a digital record of the entire pull provides irrefutable proof of a quality installation and is invaluable for commissioning and future maintenance records.

This "smart" feature is becoming a requirement for many utility companies and EPC contractors worldwide.

While the initial investment in a hydraulic puller-tensioner is higher than for a mechanical winch, the return on investment (ROI) is significantly better and faster. Here's why:

• Increased Speed & Efficiency: Hydraulic machines can pull longer lengths of conductor at a faster, more consistent speed. This dramatically reduces the number of days required for stringing, leading to major savings on labor, fuel, and overall project timelines.

• Reduced Manpower: A single skilled operator can manage a hydraulic machine, which often features remote controls. Older mechanical methods typically require more personnel to manage the pull, brakes, and communications.

• Prevention of Conductor Damage: The smooth, controlled tension of a hydraulic system prevents the jerking and over-pulling common with mechanical methods. Replacing even a single section of damaged high-voltage conductor can cost more than the machine itself.

• Versatility: One hydraulic machine can be used for a wide range of conductor types and sizes, from OPGW to the largest bundled conductors, making it a more versatile and valuable asset for your fleet.

The investment pays for itself through faster project completion, lower labor costs, and the elimination of costly damages.