27th May: The Golden Gate Bridge

Golden Gate Bridge in San Francisco first opened on this date in 1937. Here are 10 things you may not know about the Golden Gate Bridge:

1. It's a much loved landmark now, but the proposal to built a bridge in that location met with stiff opposition at first. It took ten years to persuade some parties that there should be a bridge there. The US Department of War was afraid it would interfere with ship traffic, and that sabotage of the bridge would block entry to the harbour completely. Another opposing voice was the Southern Pacific Railroad. They feared loss of profits, because they ran the existing ferry service. They even filed a lawsuit against it. San Francisco was the largest American city still served primarily by ferry boats - its lack of a permanent link with communities around the bay meant the city's growth rate was below the national average.
2. The official name for the colour of the bridge is international Orange. It could have looked very different: the US Navy wanted it to be painted with Black with Yellow stripes to ensure visibility by passing ships.
3. The head engineer was Joseph Strauss. One of his innovations was the use of safety nets below where men were working during construction. Of the eleven men killed during construction, ten died because the platform they were working on fell into the net, but was too heavy for the net to hold.
4. Nineteen others were saved by the net. While some of them were recovering together in hospital, they formed an exclusive club called the "Half Way To Hell Club."
5. The opening celebrations lasted a whole week, and included 200,000 people crossing either on foot or on roller skates; a motorcade past three ceremonial "barriers", the last being a line of beauty queens who asked Joseph Strauss to present the bridge to the Highway District before allowing him to pass; an official song, There's a Silver Moon on the Golden Gate; President Roosevelt pushing a button in Washington DC. signalling the official start of vehicle traffic over the Bridge; parties and at one point, a riot.
6. The Golden Gate Bridge's clearance above high water averages 220 feet (67m). Its towers, at 746 feet (227m) above the water, were the world's tallest on a suspension bridge until 1998. It was also the world's longest suspension bridge main span in the world, at 4,200 feet (1,300m) until 1964.
7. Its height above the water has made it a popular site for committing suicide, in fact, it's the second most popular bridge in the world to commit suicide from (the Nanjing Yangtze River Bridge is the most popular). Only 5% of people who jump survive the impact with the water below, and most of those die of drowning or hypothermia - so it's quite effective.
8. It's estimated that 110,000 vehicles pass over the bridge every day. There is a toll for southbound traffic. Northbound vehicles, pedestrians and cyclists cross for free. There are six lanes of traffic and two walkways for cyclists and pedestrians. Traffic configuration changes several times a day according to traffic flow. Off peak, it's three lanes each way, but in the morning four lanes run into the city and in the afternoons four lanes run out. In January 2015, a moveable barrier was installed which cost $30.3 million, almost as much as it cost to build the bridge itself ($37 million).
9. The bridge has only been closed due to bad weather three times in its history. It also closed while it was being retro-fitted with better Earthquake-proofing.
10. Joseph Strauss was a poet as well as an engineer. When the bridge was completed, he wrote a poem called The Mighty Task is Done, which is now on the bridge. The first verse is below.

At last the mighty task is done;

Resplendent in the western sun

The Bridge looms mountain high;

Its titan piers grip ocean floor,

Its great steel arms link shore with shore,

Its towers pierce the sky.