Temporary Horizontal Lifeline offering two worker bypass. MSA’s newly enhanced Gravity Temporary Horizontal Lifelines offer unique, exclusive bypass shuttles enabling two workers to share a line and pass each other while maintaining 100% tie-off.The Gravity Temporary Synthetic Horizontal Lifeline, designed for easy installation and removal, suits many applications. System mounts to any suitable 5,000-lb-rated anchorage point and uses many standard components. Integral line tensioner helps to ensure proper lifeline tensioning.