Ski lift cables carrying skiers up mountains need special grease that remains slippery at temperatures as low as -30°C, won't drip onto passengers below, and resists being washed away by snow and ice. These cables travel over pulleys at speeds up to 20 mph while supporting weights of dozens of people, so the lubricant must reduce friction and prevent wear under constant movement and tension. The grease is often bright-colored so maintenance crews can easily spot which sections have been serviced during safety inspections. Unlike most lubricants that need replacing regularly, ski lift cable grease must last an entire season through thousands of operating hours, enduring freeze-thaw cycles that would destroy ordinary oils.