McConnel Dowell Sunday 1 December 2024, 12:30 PM to Saturday 1 February 2025, 12:30 PM Heysen Tunnels Mount Barker Road, Glen Osmond 5064 Conditions: Ninth Schedule permit for Heysen Tunnel Project24 hours 7 x days a weekWelding etc Heysen Tunnel Refit & Safety Upgrade