990_16_9-US-NYC-HT_4HR
New York, New York: c. 1922 A sectional view of the Holland Tunnel, a marvel of modern science, and all its features: 1. Exhaust airports. 2. Telephone & telegraph cables. 3. Fire extinguisher. 4. Water supply pipe. 5. Continuous duct for fresh air supply. 6. Fresh air flues every 15 feet. 7. Exhaust air ducts running the length of the tunnel. 8. Tunnel segment weighing 3000 pounds. 9. Weight of complete ring 21.6 tons. 10. Concrete. 11. Sidewalk. 12. Power cables for tunnel. 13. Fresh air expansion chamber. 14. Fresh air flues every 15 feet. 15. Drain. 16. Fresh air duct running entire length of tunnel.
DC