The main cables rest atop the columns of each main tower in huge steel castings called saddles. The diameter of one main cable is 36 and 3/8fhs inches. The length of one main cable is 7,650 feet. Each main cable is comprised of 80,000 miles of galvanized steel wires. Each main cable contains 61 bundles, or strands, of galvanized steel wire. The 61 bundled strands are comprised of 27,572 wires; the diameter of each wire is 0.192 inches.
FIRE SERVICE LEADERSHIP >>> By MARK EMERY The “Anatomy & Physiology” Of the Structural Fireground Part 5 – Tension & Compression I believe there is no better way to understand the relationship between tension and compression than to analyze how a suspension bridge works. Perhaps there is no bet- ter suspension bridge to analyze than the Golden Gate Bridge in San Francisco, CA. There are plenty of books and manuals that define tension and compression, but do firefight- ers truly understand the tension/compression relationship and why structural engineers choose either tension or compression to move stress from one structural component to the next? This article will describe how the Golden Gate Bridge uses tension and compression to transfer live and dead loads – cars, trucks, concrete, steel, rain, wind, people and concrete – to the bottom of San Francisco Bay as compression. We begin with some Golden Gate Bridge background, fol- lowed with a photographic tour that will describe how the bridge uses tension and compression to resist gravity. The Golden Gate Bridge Engineered by Joseph B. Strauss, Golden Gate Bridge construction started in 1933 and was completed in 1937 at a cost of $27 million – five months late and $1.3 million under budget. (Strauss MARK EMERY, EFO, is a shift battalion said, “It took two decades and 200 million words to convince people that the bridge was feasible.”) chief with the Woodinville, WA, Fire & Eleven workers were killed during construction; at least 1,200 people have jumped from the bridge. Life Safety District. He is a graduate of the National Fire Academy’s Executive Fire From abutment to abutment, the Golden Gate Bridge stretches 1.7 miles (8,981 feet). The total Officer program and an NFA instructor spe- length of the suspended span sections is 1.2 miles (6,450 feet). The middle span suspended between cialist. Emery received a bachelor of arts the towers stretches 4,200 feet. The length of one side span is 1,125 feet. The highest clearance above degree from California State University at the water is 220 feet. The height of the towers above the water is 746 feet. The height of the towers Long Beach and is a partner with Fire Com- above the roadway is 500 feet. The width of the bridge is 90 feet. The width of the roadway between mand Seattle LLC in King County, WA. He may be contacted at firstname.lastname@example.org or access curbs is 62 feet. The sidewalk is 10 feet wide. Each leg of each tower base measures 33 by 54 feet. his website www.competentcommand.com. As of 1986, the total combined dead load of the Golden Gate (bridge, anchorages and ap- proaches) was 887,000 tons. The live-load capacity was calculated to be 4,000 pounds per lineal 88 Firehouse ® www.Firehouse.com November 2009 >>> FIRE SERVICE LEADERSHIP foot. The
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