1. The buried anchorages at the ends of the bridge weigh 81 million pounds each.
2. The bridge deck could hold 60,000 people weighing an average of 150 pounds each without exceeding its load capacity.
3. The total weight of the deck, including paving, concrete barriers and utility conduits, is 53 million pounds.
4. Asphalt paving accounts for 15 percent of the deck’s weight.
5. The lightest of the 46 deck sections shipped from South Korea weighed 206 tons; the heaviest weighed 504 tons.
6. The main cables contain enough wire to wrap around the continental United States – twice.
7. Before the cables were installed, bridge builders pulled the tops of the towers 2 feet toward the shores. The weight of the cables and deck pulled them straight again.
8. As bridge builders lifted heavy sections of deck into place on the cables, the towers tipped back and forth more than 2 feet because of the imbalanced loading.
9. During a major earthquake, the tops of the towers will be able to sway back and forth as much as 6 feet without being damaged.
10. The bridge is designed to withstand sustained winds of 109 mph and gusts of 127 mph.
11. Altogether, bridge builders worked more than 3.5 million hours with only three injuries serious enough to keep them from work the next day.
12. The oldest person to work on the bridge was James “Sully” Sullivan, who put in full shifts as an ironworker at 78.
13. Dave Climie, the engineer in charge of building the cables and the deck, did the same job on three of the five largest suspension bridges in the world.
14. The record time for workers racing up the 210 steps from the base of the old caisson to deck level was one minute, 20 seconds.
15. For shelter from the cold wind and rain, workers on the Gig Harbor tower top built a rough shack they called Norm’s Cafe, 510 feet above the Narrows.
16. Divers working in the bottom of the Gig Harbor caisson as it was being constructed made friends with large octopuses living there.
17. Bridge workers saw a wide variety of wildlife swimming in the Narrows, including seals, porpoises, salmon, whales and at least one deer.
18. Neither Bechtel nor Kiewit, the bridge’s two main contractors, had ever built a suspension bridge before this one.
19. Most of the steel used in the bridge was made in Japan.
20. South Korea’s Koje Island, where the deck sections were built, was the site of a large prison camp during the Korean War.
21. Tacoma’s Atlas Foundry, which made the saddles that hold the cables at the anchorages, also made the saddles for the 1950 bridge.
22. The huge anchor chains used to tether the caissons during construction were melted down to make the 36-ton saddles.
23. Before building the caissons, scientists in Wallingford, England, built a 1/100th-scale model of them and tested them in a 100-foot-long flow tank.
24. The winter of 2006, when workers were lifting deck sections, included the wettest month ever recorded in the South Sound (15.23 inches of rain) and the worst windstorm (gusts greater than 60 miles per hour) in more than 10 years.
25. On clear days, Seattle’s Space Needle, 26 miles away, is visible from the tops of the towers.
26. The overall length of the bridge is 5,400 feet.
27. The two Narrows bridges tie for 26th place among the world’s longest suspension bridges.
28. The length of the main span (the part of the deck between the towers) is 2,800 feet.
29. At 1,400 feet, the Gig Harbor-side span (the part of the deck between the tower and the shore) is 200 feet longer than the Tacoma-side span.
30. The anchorages extend 63 feet underground.
31. The main cables are 20.5 inches in diameter.
32. Each main cable contains 8,816 wires, each about the diameter of that of a drinking straw.
33. The spinning wheels that carried the cable wire from shore to shore had a top speed of 14 mph.
34. Each cable exerts 25 million pounds of force on the anchorages. When the force was applied, the anchorages moved less than 1 inch.
35. The towers are 510 feet tall.
36. Each tower contains 8,500 cubic yards of concrete and 1.45 million pounds of reinforcing steel.
37. The tower legs taper as they rise from a width of 29 feet at their bases to 19 feet at their tops.
38. The towers were designed to withstand a 9.2-magnitude earthquake, which theoretically is likely to occur once every 2,500 years.
39. The concrete used in the towers can withstand compression of 10,000 pounds per square inch without crumbling. Typical construction concrete is good up to about 4,000 pounds.
40. For extra strength, concrete in the towers contains fly-ash, an ultra-fine by-product of coal-fired power plants.
41. The deck is connected to the main cables with 264 pairs of vertical suspender cables – 132 per side.
42. Fastening the 46 deck sections together took more than 2,500 bolts at each of the 45 joints.
43. The Tacoma caisson is 25.5 feet taller than the Gig Harbor caisson because the water is deeper on that side.
44. The Tacoma caisson contains 40,500 cubic yards of concrete; the Gig Harbor caisson contains 37,000 cubic yards.
45. The Tacoma caisson is embedded 62 feet into the floor of the Narrows. The Gig Harbor caisson goes down 57 feet.
46. One truck hitting its brakes as it heads off the bridge could cause the entire structure to move slightly from end to end.
47. Currents in the Narrows are fastest on the Tacoma side, where they can reach 10 mph. On the Gig Harbor side 8 mph is the top speed.
48. The green paint on the new bridge is purposely a slightly different shade than the old one, to give the bridges individual character.
49. The force of an outgoing tide sucked a Washington State Fisheries boat under a construction barge as the bridge was being built.
50. The bridge was designed to accommodate a second level for traffic or trains. If that becomes necessary, workers would add a second set of suspension cables.
Rob Carson, The News Tribune