Thailand’s tropical monsoon climate is characterized by high humidity and long rainy seasons. Traditional steel stringing blocks used outdoors for extended periods are prone to corrosion, water ingress into bearings and reduced rotation performance. When pulleys start to rust or jam during stringing, they not only slow down construction but can also cause uneven loading and potential damage to the conductors—creating hidden costs for contractors.

On this grid upgrade project, the construction company decided to replace part of its old pulley fleet with the SHSQN320X60(S) Triple Stringing Pulley. This model is designed with Thailand’s humid and rainy conditions in mind:

• The combination of high-quality nylon sheaves and reinforced side plates reduces overall weight while improving resistance to corrosion.

• The key rotating parts are equipped with better-sealed bearings, which help prevent water and contaminants from entering and ensure long-term smooth rotation.

• Surface treatments and fastener choices focus on anti-rust and anti-corrosion performance, reducing the frequency of maintenance interventions.

After deploying the new pulleys on several sections, the project team observed clear improvements:

• The number of stoppages due to pulley jamming during stringing dropped significantly.

• Even in rainy or highly humid conditions, pulley rotation remained smooth and conductor passage resistance was lower.

• Maintenance intervals were extended, with only simple inspections and lubrication needed to keep the pulleys in good working condition.

The project manager commented that although the unit cost of the SHSQN320X60(S) Triple Stringing Pulley is slightly higher than some older products, the overall economics are better when considering improved stringing efficiency, reduced downtime and lower maintenance costs. The contractor plans to continue replacing aging pulleys with this model on future grid upgrade and new-build projects to better cope with Thailand’s high-humidity, high-rainfall environment.