Brooklyn Bridge audio guide,
five stops, free.

You are climbing, and you will keep climbing for a while. The planks under your feet are the elevated promenade, and the traffic you can hear is not beside you but below you, on two roadways that run eighteen feet down on either side. Straight ahead, at the end of the line of the walk, the Manhattan tower stands over everything, with four cables swinging up to its top.

The ramp is this long because of the river. The span out there had to sit high enough for ships to pass beneath it, and the ground on both shores is low, so the bridge has to come down to street level gradually, a long way inland. The city's Department of Transportation, which looks after the bridge, puts the whole thing, span and approaches together, at 6,016 feet. The Manhattan approach alone runs 1,567 feet, far longer than the one waiting in Brooklyn.

Underneath you it is stone. The approaches stand on Renaissance-style masonry arches, their openings filled in with brick walls and small windows, and side streets pass under them through arches and iron girder bridges.

The promenade was John Augustus Roebling's idea from the start. His master plan of September 1867 had roadways and railway tracks, and above them a raised walk that existed simply for pleasure. He never saw any of it built. The deck you are standing on is a rebuilding, finished in May 1954, but look at the iron railings beside you. They came from Janes and Kirtland, a Bronx foundry that also made the dome of the United States Capitol.

Further up this ramp, before the tower, the cables dive down into the Manhattan anchorage, a trapezoidal block of limestone weighing 60,000 short tons, sitting on bedrock. From 1876 the city rented out its vaults to pay for the bridge's upkeep, and they were used for wine, which kept well at a steady sixty degrees Fahrenheit. The Manhattan vault was called the Blue Grotto, after a shrine to the Virgin Mary beside its entrance.

The ground under that anchorage has a history of its own. It was the site of the Samuel Osgood House at 1 Cherry Street, which served as the first presidential mansion of the United States, and a bronze plaque on the anchorage still says so.

One more thing about the name. For its first thirty-two years this was officially the New York and Brooklyn Bridge. The city only made Brooklyn Bridge official in 1915, though the name first turned up in a letter to the Brooklyn Daily Eagle in January 1867.

Step over to the left-hand edge of the promenade, the north side, and look up the East River. The steel bridge standing so close is the Manhattan Bridge, opened on the last day of 1909, and it is an argument with the bridge you are standing on.

Start with the cables beside you. Hanging straight down from the main cables are the vertical suspenders, and slicing across them, fanning out from the towers, are the diagonal stays. This bridge is a hybrid: part suspension bridge, part cable-stayed bridge, with both kinds of cable doing the lifting.

Now look across at the Manhattan Bridge. Vertical suspenders, and that is all. Its designer, Leon Moisseiff, built it on a new idea, Josef Melan's deflection theory, which held that the weight of the deck itself would keep the deck steady, so the stiffening trusses could be lighter. It was the first suspension bridge designed that way. It also carries subway tracks on either side of its lower roadway, and the uneven weight made it twist, by up to eight feet every time a train went over. Putting that right took a reconstruction that lasted from 1982 to 2004.

Then look down, because the height of this deck was a fight. Shipbuilders and merchants up river, where that bridge now stands, said their ships would not fit underneath. In May 1876, they sued the cities of New York and Brooklyn, and it was 1883, the year the bridge opened, before the Supreme Court declared it a lawful structure. The design had already been raised during the final surveys of 1869, from 130 to 135 feet, and 135 is the clearance at the centre that the Department of Transportation gives today. And it moves. The span grows and shrinks by fourteen to sixteen inches between the extremes of summer and winter, and in 1909 an engineering magazine reckoned the middle could rise and fall by more than nine feet with the temperature and the traffic.

In 1919 a pilot named Giorgio Pessi flew a Caproni Ca.5, one of the largest aeroplanes in the world at the time, underneath this deck.

Until 1903, when the Williamsburg Bridge opened further up the river, this was the longest suspension bridge on earth, a fifth longer than any built before it. And it changed the river below you almost overnight: within a week of the opening, the ferry crews were already reporting a sharp drop in passengers, although the last cross-river ferries kept running until 1942.

This is the Brooklyn tower, and before anything else, turn round. Facing back the way you came, north-west, the whole main span runs away from you, 1,595.5 feet of it, to the Manhattan tower, with Lower Manhattan stacked up behind. For thirteen years people on both shores watched this picture assemble itself.

It started here. This tower's caisson, built at the Webb and Bell shipyard in Greenpoint, was launched on the nineteenth of March 1870. Men went down into it under compressed air and dug. One of them, Frank Harris, a sixteen-year-old from Ireland, remembered six of them working naked to the waist in the small iron chamber at about eighty degrees Fahrenheit, the sweat pouring off them within five minutes, and all the while standing in icy water that was only kept from rising by the terrific pressure.

In December 1870 the caisson's timber roof caught fire, and the damage cost months of work. The repairs were finished on the sixth of March 1871, when the caisson reached its final depth of 44.5 feet, and five days later it was filled with concrete. By the middle of 1873 this tower stood 164 feet above the water; the arches over your head were closed in August 1874, and the last stone went up in June 1875.

Emily Warren Roebling was the first to cross the finished bridge by carriage. She rode over ahead of the official opening, carrying a rooster as a sign of victory. On the twenty-fourth of May 1883, President Chester Arthur and New York's mayor, Franklin Edson, crossed and shook hands with Brooklyn's mayor, Seth Low, at this end. Washington Roebling could not be there. Abram Hewitt gave the principal address, and in it he called the bridge an everlasting monument to the sacrificing devotion of a woman. The bridge carries a plaque to all three Roeblings: Emily, her husband and his father.

On that first day 1,800 vehicles and 150,300 people crossed. The bill came to 15.5 million dollars in the money of 1883, Brooklyn paying two-thirds of it, and an estimated twenty-seven men died building it. A year later, on the seventeenth of May 1884, P. T. Barnum sent Jumbo the elephant across at the head of twenty-one elephants, which settled lingering doubts about its strength and did the circus no harm.

A week after the opening, the critic Montgomery Schuyler wrote in Harper's Weekly that the work most likely to be our most durable monument was a work of bare utility: not a shrine, not a fortress, not a palace, but a bridge. From here the promenade runs down toward Adams Street, with that bridge at your back.