Lisa, our guide up the Sydney Harbour Bridge, was a laugh.

Standing at the top (that's not spoiling it, of course I made it to the top...), she told us how far it was down. 139 metres or 439 feet. "Or 5 seconds", she said "if you choose to go that way..."

Actually the whole Bridge Climb operation is utterly professional. Right down to its little yellow clips, which are the most important safety feature of the climb. They clip everything you might possibly have to take up with you to your fashionable grey boiler suit to avoid you dropping it onto the traffic 5 seconds below. When the guy setting up the climb proposed the idea to the council, who own the bridge, they gave him 96 reasons why it wouldn't be possible.

Like a true entrepreneur, he researched and solved all 96 points of objection and that's why you can climb the bridge today.

One of them was the dropping things. Glasses, hats, handkerchiefs, fleece, radio, headsets (with special bone induction headphones - you don't put them over your ears, they rest on your cheek bones)... the whole lot has to be clipped on for dear life.

Then they have to clip you onto the bridge and you practise this before you get out there on a bit of scaffolding'n'ladders they have rigged up in the reception building. It's done using a bloody clever bit of equipment actually - a little rotating mechanism of cogs and gubbins which means that you can't become detached from the high tension steel safety wire which follows you round the entire route.

A couple of bits are ladders and they show you safely how to get up and down them. When you are actually out on the bridge, she calmly tells you over the skull-vibrating headsets that the real ladders take you up between lanes 7 and 8 of the traffic. (And between two express train lines on the way down.) She's so reassuring though, that you don't worry.

Here's a photo I took later from one of the bridge towers, which show a little of the route you take... (You'll have to zoom in to see properly...)



You can't take your camera up on the real climb because you might drop it. I think they could find some ingenious way of yellow-clipping it to you so that you could, but then they wouldn't be able to overcharge you for the official photos they take... Of course I bought them - I'm probably never doing it again!





It's a real sense of achievement - you even get a certificate!

But your legs don't half ache afterwards...

As you can tell...



...I am now seriously worried about doing this.

I am booked to do the Sydney Harbour Bridge Climb on Tuesday and, while not particularly afraid of heights, it is looking like an increasingly stupid thing to have committed to do.

In Brisbane, The Story Bridge is a vast web of metal...



(apparently "The Symbol of Brisbane" said the guide, although I notice the City Council have wisely eschewed this ugly Mecanno in favour of "Picturesque Town Hall and suntopped palm tree"...)

Anyway, in the best traditions of jumping on the bandwagon and fleecing tourists, you can climb this one as well...



Don't those people look small?

And vulnerable...!