Aerial Safety Belt for Optical Cables – Span Clamp

What is a Span Clamp?

Span Clamp (also called span wire clamp or mid tension clamp) is a fastener designed for overhead optical cables.

Its function is to firmly fix the optical cable on the load bearing steel strand or power conductor to prevent the optical fiber cable from slipping, excessive sag or vibration fatigue due to gravity, wind or temperature changes.

The span clamp is commonly used for mid section anchoring of ADSS optical cables, FTTH cables, and hybrid power and communication lines.

Structure

Splint body – Made of galvanized steel or aluminum alloy, high mechanical strength.

Bolts and nuts – High strength stainless steel for tension and ease of installation

Guy wire or additional damping arm – Further improve grip and vibration resistance

Advantages of Span Clamps

1. Effectively prevent cable sagging
2. Can effectively resist wind
3. Long service life and low maintenance
4. Easy to install
5. Can withstand high voltage

Mainstream Types and Applicable Scenarios

Medium tension wire clamp(suspension clamp or dead end clamp): Mainly used for cable systems with long spans.

Q type span clamp: Mainly used for FTTH optical cable lines.

E type span clamp: Mainly used in coastal areas or plain areas with strong winds.

C type span clamp: Designed for aerial optical cables, drop cables or phase cables with a diameter of 6-35 mm.

Z type span clamp: Used for lines with relatively undulating spans.

O type span clamp: Used for paralleling of lines above 15kV.

How to Choose the Model of Span Clamp？

1. Select the appropriate type of span clamp according to the outer diameter of the required optical cable
2. Depending on the environment, in areas with strong winds or snowy areas, choose a span clamp with a special shape that has higher mechanical strength and is more durable.
3. Choose the appropriate clamp according to the length or width of the guy wire.

Installation Points

Use a wrench to open the nut buckle, prevent the optical cable from being inserted into the groove of the splint or one end of the deadend, and use a wrench to tighten the bolts and nuts to prevent the span clamp from loosening.（What you need to pay attention to is: do not press the insulation layer of the optical cable）

Common Problems and Solutions

Slippage: Select a smaller clamp size: Replace with a larger one or install pre-twisted wire.

Bolt rust: Use an aluminum alloy or hot-dip galvanized span clamp, ensuring 1-2 threads are exposed.

Tracking: Forgot to use a semi-conductive pad in a high-voltage area: UUse an O-type span clamp and use tracking resistant rubber.

Wind-induced fiber breakage: No damping components are installed: Install an E-arm or spiral damper.