Double Sheave Block Double Sheave Rigging Block for 180 Degree Direction Change with 2KN Rated Load and 2:1 Mechanical Advantage

Double Sheave Block for Direction Change and Mechanical Advantage

A double sheave block does two jobs that come up on almost every stringing site: it turns a pulling line around an obstacle, and it builds a 2:1 advantage when the available winch or crew is not strong enough for a straight pull. This block is sized for OPGW, pilot wire and light conductor work at 2KN.

Product Overview

Two sheaves run side by side on a common axle inside a coated steel frame. Threading one sheave redirects the line by up to 180 degrees; threading both and anchoring the frame creates a 2:1 system that halves the force needed at the rope while doubling the rope length pulled. The frame is compact enough to hang from a tower member or a gin pole eye.

Double sheave block models

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

Design Features and Field Benefits

• Changes Pulling Direction Without Moving the Winch: Anchoring the block at a corner lets the winch stay on stable ground while the load follows the required route, removing the need to reposition heavy pulling equipment.
• Builds a 2:1 Mechanical Advantage: Threading both sheaves and anchoring the frame halves the effort at the rope. This is enough to lift a gin pole or tension a pilot wire with a small crew.
• Compact Frames for Tower Work: Both frames are under 2.5KG and narrow enough to hang inside a tower panel, which keeps the block clear of the conductor path.
• Sealed Bearings and Coated Frame: Sealed bearings keep grit out and the coated frame resists site corrosion, so the block stays free-running across a long project.

Selection Guidance

• Use the larger 152x110mm frame where rope diameter and bend radius are bigger; use the 128x65mm frame in tight tower panels.
• Keep the angle between incoming and outgoing rope within the frame's side load limit.
• For 2:1 systems, confirm the anchor point rating is at least twice the load.

Typical Applications

• OPGW pilot wire pulling
• Pulling line redirection around obstacles
• Gin pole lifting with 2:1 advantage
• Light conductor tensioning

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.