A: Machines are factory load-tested; CE/ISO paperwork is available and third-party inspection (FAT) can be arranged on request.

OPGW installation requires specialized equipment to protect the delicate optical fibers within the cable. While the basic process is similar to stringing standard conductors, key differences include:

• Specialized Grips: OPGW requires non-damaging, soft-lined grips (come-along clamps) that distribute pressure evenly to avoid crushing the fibers.

• Grooved Sheaves: Stringing blocks (pulleys) must have a groove profile specifically designed for the diameter of the OPGW cable and be made of materials like nylon or polyurethane to prevent abrasion.

• Controlled Tension: A hydraulic puller-tensioner with highly sensitive controls is essential. It must maintain a smooth, constant tension to avoid sudden jerks or excessive sag that could damage the optical fibers.

• Swivels: High-quality, anti-twisting swivels are crucial to prevent the OPGW from rotating during the pulling operation, which can cause internal fiber damage.

At Ningbo Changshi, we offer complete OPGW stringing solutions, including specialized puller-tensioners, nylon-sheave stringing blocks, and appropriate swivels designed to ensure the integrity of your fiber optic network.

This is an excellent and crucial question for international projects. Our hydraulic puller-tensioners are engineered for global deployment and feature:

• High-Altitude Performance: For high-altitude projects where air density is lower, we equip our machines with powerful, often turbocharged, diesel engines (e.g., Cummins, Deutz) that are calibrated to perform efficiently with less oxygen. The hydraulic cooling systems are also oversized to dissipate heat effectively in thin air.

• Tropical/Hot Climate Resilience: Our equipment features advanced cooling systems with large-capacity radiators for both the engine and hydraulic oil. This prevents overheating during continuous operation in high ambient temperatures, ensuring consistent performance and protecting hydraulic components.

• Cold Climate Operation: We offer optional packages for cold climates that include engine block heaters, hydraulic oil warmers, and specialized fluids that maintain low viscosity at sub-zero temperatures, ensuring reliable start-up and operation.

We work directly with clients to understand their project's environmental conditions and recommend the optimal machine configuration.

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.