Does Cold Weather Stretch or Shrink Elevator Ropes? The Florida Perspective

If you’ve noticed your elevator acting a bit "off" during a sudden cold snap, you’re not imagining it. While common myths suggest elevator cables (ropes) stretch when it’s chilly, the science actually points in the opposite direction.

The Science: Contraction vs. Expansion

Technically, steel elevator ropes shrink rather than stretch in cold weather. Like most metals, steel undergoes thermal contraction when the temperature drops. While this shift is subtle, it can be enough to cause noticeable performance issues, such as inconsistent floor leveling.

The Real Culprit: Florida Humidity

In the Sunshine State, humidity often plays a bigger role than temperature.

• The 30% Rule: A 30% drop in humidity—common during dry winter fronts—can cause fiber-core ropes to shrink by one inch for every 10 floors.

• The Swelling Effect: Conversely, high humidity can cause natural fiber cores (like sisal) to absorb moisture and swell. This increases the rope's diameter and, counterintuitively, shortens its overall length.

4 Winter Challenges for Florida Elevators

1. Coastal Corrosion: When cold air meets humid shafts, condensation forms. In coastal areas, this salt-laden moisture leads to "rouging"—a red rust powder that signals internal cable failure.

2. Viscous Lubricants: Cold temperatures make lubricants thicker and more "gummy." This leads to a stiffer ride and increased mechanical wear.

3. Leveling Issues: Because ropes shrink in the cold and swell in the heat, your elevator car may stop slightly above or below the landing during seasonal shifts.

4. Brittleness: In rare, extreme cold, steel can become brittle, reducing its ability to absorb shock loads effectively.

Pro-Tip: Choosing the Right Core

For high-humidity environments like Florida, natural sisal cores are often a liability because they are hygroscopic (they attract water). To ensure a stable ride year-round, consider these alternatives:

• Synthetic Fiber Cores (SFC): Made of plastics like polypropylene, these don't absorb moisture and stay stable during humidity swings.

• Independent Wire Rope Core (IWRC): A full steel core that eliminates moisture issues and offers significantly less stretch or contraction.

Maintenance Checklist

To protect your investment, ensure your maintenance provider uses water-resistant lubricants and checks for internal rust during seasonal transitions.