660mm Sheave Diameter Seven Sheave Conductor Stringing Block with 75KN Rated Load for UHV Conductor Pulling

660 Series Stringing Block for Large Diameter Transmission Conductors

The 660 series is the heavy end of the stringing block range: a 660mm sheave, frames up to seven sheaves and a rated load of 75KN for large diameter, heavy weight conductors on UHV and 500kV projects. Where a 508mm block runs out of bend radius and frame stiffness, the 660 series takes over.

Design Features and Field Benefits

• Designed Around the Largest Conductors in Service: A 660mm sheave keeps the bend radius above the minimum recommended for large diameter ACSR and AACSR, limiting the bending stress that leads to strand fatigue after installation.
• Seven Sheave Frame for Full Bundle Pulls: The SHQ660A carries seven sheaves at 75KN, allowing a complete bundle to be pulled in one pass and keeping every sub-conductor at the same tension and spacing.
• Cast Steel Where the Load Is: On bundle blocks the centre sheave takes the highest radial load, so it is supplied in cast steel while conductor contact positions use softer materials. This balances durability against conductor protection.
• Handling Points for Crane and Gin Pole Work: Lifting eyes and balance points are positioned so the block hangs level when lifted, which keeps sheave planes aligned with the pull direction and avoids side load on the frame.

660 series configurations

Dimensions and ratings are nominal. Confirm the exact model against the datasheet before ordering.

Product Overview

Frames are fabricated from structural steel, welded in fixtures and straightened after welding so the sheave planes stay parallel under load. Axles are oversized and retained at both ends, and the centre positions on bundle blocks use cast steel sheaves to carry the concentrated load while the outer conductor positions use rubber lined aluminium or MC nylon to protect the conductor surface.

Typical Applications

• UHV and 500kV transmission line construction
• Large diameter ACSR and AACSR pulls
• Seven conductor bundle installation
• Long span river and valley crossings

Selection Guidance

• Specify conductor diameter and bundle configuration; the sheave count follows from the number of sub-conductors.
• For pulls above 60KN, confirm the frame rating and the shackle rating together, not separately.
• Choose MC nylon sheaves where weight must be kept down for manual handling at height.

Quality Control and Delivery

Units are assembled in an ISO 9001 certified workshop. Frames are checked for sheave alignment and axle straightness, load bearing parts are inspected before assembly, and finished units are function checked before packing. Export packing is a plywood case with a moisture barrier, and a 12 month warranty covers manufacturing defects. Inspection records and, on request, third party load test certificates can be supplied with the shipment.

Frequently Asked Questions

For project specific configurations, drawings or inspection requirements, send the conductor size, rated load and destination port with your enquiry.