The Space Needle's Nuts

The Sydney Harbour Bridge uses eight (I think) ginormous nuts at its base. I don’t know what would happen if Kong Kong came by with a spanner. Probably not much. The nuts hold enormous hinges in place, which allow for the bridge’s expansion and contraction. It’d probably still work without the nuts, as I think they just hold the horizontal pins in place.

Even if you removed the nuts, the tower would still be sitting on its base, held in place by its weight, some 6000 tons. It’d need to hop verticaly ~18" to jump off the vertical bolts. So it wouldn’t immediately fall over. How it’d fare in a windstorm or earthquake is another matter.

So how did they tighten them originally? Certainly not with the enormous spanner, nor do I imagine they used teams of burly men running around to ‘finger-tighten’ them before torquing them down…

I’ve walked past the tower and seen the bolts. It surprised me to think that the tower is just bolted down, but they are big ol’ nuts that would have required at least a BF wrench to tighten. It wouldn’t surprise me if someone built a machine specifically designed to tighten them. I would also imagine that the tightening process would have taken a while to avoid tilting the tower too much.


Can’t take any chances with nut nuts.

Just a wild guess but would it be such that they really don’t need to be “tightened”? If they are 6 feet across, it might be that their weight alone makes them sufficiently tight. Then, with a few welds there wont be any movement. I don’t know, just speculating.

I just assumed it had gone insane

Believe it or not a giant wrench used to be mounted at the base of Space Needle. Gone after renovations.

Tikki, do you remember the giant wrench that used to be mounted on column at base of Needle.

Wikipedia has a picture of someone rudely touching one of the Space Needle’s nuts:

They’re smaller than I expected.

I’m afraid Tikki last posted here about eleven years ago.

Welcome all the same!

I imagine they used a wrench about 100 feet long to hold the nut fixed in place and tightened the bolt from below with a 100 foot screwdriver . If you take the Underground Seattle tour, I assume you can see the screw heads.

I wonder if it’s metric or US customary. It would be annoying if the nuts turned out to be 250 mm when all you have in the toolbox is a 10" crescent wrench.

Those are fairly normal “nuts”. I am used to seeing such bolts being tensioned (tightened) using pneumatic or hydraulic bolt tensioners :

That’s what she articulated.


As the actress said to the bishop.

Always fun when your entendres get doubled.

That’s what she said

wait, what?

So … not so much a space needle as a space weeble,

It was difficult to see exactly how that hydraulic tensioner applied torque to the nuts, but the cool thing was seeing that it could torque multiple nuts at the same time to assure even pull-up around the entire flange perimeter.

Some years ago I saw a documentary that I think showed a large naval vessel on which many fasteners along the length of a shaft had to be tightened in close synchrony. Every few feet along its length there was a sailor with a wrench on a fastener, and every few seconds a particular individual called out a command - and every sailor would give his wrench a single turn.