I am one of nine adventurers being fast-tracked through Bridgeclimb's preparations for the climb of a lifetime - to the top of Australia's Sydney Harbour Bridge.
Breathalysing is part of the thorough run-up to one of the most exhilarating and unique tourist experiences in the world. I am dressed in a grey, pocketless coverall and snug around my waist is a heavy woven belt, carrying an impressive array of attachments; a black bag containing a stitched-in windbreaker, a similar bag with a fleece liner, a walkie-talkie radio and an ingenious lifeline hook-up. This item looks like a yo-yo with teeth on the inner faces of the two wheels. But this is no toy - it rolls easily on to a stout stainless steel cable that delineates the entire route, and it won't come off!
Apart from the breathalyser, each person has been checked for balance, relieved of coins, watches, large rings and even clip-on earrings. We have signed indemnity forms and donned our gear. Some climbers select from the optional items; a hat with a tag on the back which must go through the ring on the zip of your coverall; a lanyard for your sunglasses which must go through the same ring and a handkerchief which is attached to an elastic wrist band. "We don't want you wiping your noses on our cuffs, do we!"
Then it changes from the amusing to the deadly serious; someone deftly slips a locking tab through the release latch on your belt. Nothing carelessly or deliberately falls off this bridge.
I observe our climb leader, Eric Kho. He is young, easy-going, but businesslike, and he has been subtly appraising each of us. His positive, efficient actions inspire confidence.
Finally we thread the yo-yo harness onto the cable, tentatively climb the steel steps, traverse a catwalk, ease the harness around to back down a ladder. . . and we are still inside the building! It is the last test. "It's just a nice stroll really" is Eric's typically Australian understatement. He has accepted us and now we are ready for the real thing.
Far from being tedious, the whole procedure serves to heighten the excitement and you scarcely notice that an hour has passed. We start out mundanely with a short walk down the road before we actually begin the climb. In our grey uniforms we unconsciously form a single line.
For Bridgeclimb to gain ready access to the structure, only one permanent modification was required. A portal had to be cut through the southern abutment of the approach spans. This was thought to be 3m of solid concrete, but workers discovered it had a rubble core. Among the curious items uncovered was an old shoe and a blanket. They are still there - see if you can spot them.
Traversing the bottom chord of the eastern approach trusses, yo-yos whirring and clicking confidently, we pass maybe 15m above the remains of the old fortification that was demolished to make way for great structure ahead of us. Into the first pylon, up and up. There are 1336 steps altogether, many of them in the pylon.
Suddenly, we're out in the open; halfway up the cliff face of the 89m pylon. Two things surprised me about this bridge and this was the point at which I met surprise number one. Ahead of us is the 57m vertical king post of the eastern arch and at no point is it attached to the pylon. Those huge granite-faced concrete pylons provide no structural strength to the arch at all, they are principally architectural features meant to inspire confidence in the structure.
At this point begins a long vertical climb to the base of the upper chord. We trade our yo-yos for a more sophisticated type which has a reverse lock to prevent a vertical fall. Experienced and ever-cheerful staff members handle the exchange. Once at the base of the top chord, we revert to the original harness. The view is already spectacular over Sydney Cove, the magnificent Opera House shrinking into the emerging panorama. The day is bright, but lightly overcast and we can feel the wind picking up. Some climbers unzip their bags and haul on a windbreaker.
The immense rivetted chord which looks so slender from the ground is actually 3m wide - reassuring as we look upwards to the grey steel horizon ahead. 'An arch never sleeps,' says an ancient Hindu aphorism and we can feel this one breathe gently beneath us as our yo-yos whirr and click towards the summit.
The flags and aircraft beacons gradually appear ahead and suddenly we are there, 134m above the water, the wind whipping our clothing, the New South Wales flag snapping loudly over us. The view is so striking that everyone is quiet with his or her own thoughts for a moment, savouring the high.
I have marvelled at the scene from the carpeted comfort of the CN Tower, high above Toronto. I have jostled with the cosmopolitan crowd behind tall railings at the top of New York's Empire State Building and have viewed vast panoramas from a lookout high on the Great Wall of China, but none compare to this. Nothing gives the impression of being on top of the world quite like seeing all solid footing falling away on either side.
To the north there is the impressive spread of the Olympic venue and the country stretching far beyond. To the east, past the great sails of the Opera House and beach-rimmed bays lies the Pacific. To the south are the competing towers of the bustling city. To the west are the twin towers of the Anzac cable-stayed bridge - "Madonna's bra" to Sydney-siders - and 80km distant rise the Blue Mountains and yes, they are blue.
Also to the west lies the way down, for to make our return descent we must traverse the top lateral over to the western arch. Here is surprise number two; this bridge is wide. Two rail tracks, eight vehicle lanes and two walkways make a total width of 49m, unusual for a bridge of this vintage. From 3m of solid steel underfoot, we cross the peak of the bridge on a 1m wide open grill catwalk. Secure with the whirr and click of the harness, I smile as I remember the story related by Dave Wood, an inspector for the Road & Traffic Authority. They are used to finding evidence of unofficial climbers on the bridge, but one Monday morning the maintenance men found a supermarket buggy full of empty beer bottles up here.
At this and other points throughout the climb, Eric pauses to explain various sights and to take photographs. Paste on a grin. Don't let them see you sweat.
The return trip is no letdown. Climbers chat about their feelings and observations. Everyone is thrilled; the jaded retiree, the young school teacher, the old construction hand and the quiet pharmacist. All are relaxing a little in the confidence that this great arch can throw them no more curves. As the group clamours around the computer monitors laughing at the 'candids' shot by Eric, I thumb through their comment sheets. 'Awesome', 'inspiring', and 'stunning' are some of the epithets. There is not a negative word. 'Professional' I add, thinking of our climb leader and Paul Cave, the entrepreneur who had the foresight and determination to set up the company and persuade the authorities that such a venture could be undertaken.
Just a nice stroll? Call it what you want. Fly there, sail there, get there somehow and do it. It is truly the climb of your life.
Barrie Atkinson is director of engineering at Cosmec in Massachusetts, USA. When not climbing bridges he designs bearing systems.
