Pisa - details matter over time

Kicking the can down the road is a workable strategy for certain situations where the problem is minor and not likely to get too much worse during your lifetime.  Let someone else worry about it. This isn't a commentary about the US debt, but rather an amusing story of how an engineer made a mistake at the beginning of a big project and decided it wasn't all that bad. All involved resolved not to worry about it. For a while they got away with it. 800 years "down the road" that initial mistake is on view for everyone to clearly see.

oops

The story of Pisa bell tower is pretty well known. What I found interesting is that, if not for a war between Pisa and Genoa, we would never have heard of The Leaning Tower of Pisa. But first, where is it? 

By Luca Aless - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=37407707
Pisa is a city of 100,000 in central Italy (Tuscany region)

The tower itself is behind these walls:

The "Miracle Square"

The Miracle Square (Piazza dei Miracoli) is comprised of 4 stunning marble structures.  

This is the Baptistery

That slight lean to the right is not me having fun with camera angles.  It actually does lean (.6 degrees). "The Pisa Baptistery is an example of the transition from the Romanesque style to the Gothic style" OK, fine. 

Our lovely tour guide tried her best to educate me on architecture (good luck, I'm hopeless. All I did was fall in love with her)

I think the statue on top of the Baptistery is of John the Baptist on his way to go fishing (the "fishing rod" is really a lightning rod)

Notice how one side of the roof is tile and the other side is unfinished?  That's 11th century cost cutting for you.  The tile side faces the river (where most visitors would be coming from). 

The Baptistery has some terrific stained glass windows:

Check out John's head

John looks kind of like he might have guest starred on SNL.

The Baptistery also has an odd looking bronze statue:

runway model skinny

And a creepy guy screaming on the column volute:

  

Wasn't LSD only discovered in the 1960's?

Of course every Baptistery needs a Jacuzzi:

But the Baptistery is famous for something else entirely - acoustics. 

The concave ceiling is largely responsible for the echoing efect

Any sound reverberates quite clearly.  It's eerie.
This feature is put on display every day at 10.

Docent with a good voice.  He's singing just a single note. You can hear the sound of his voice a good three seconds after he stops.

He looks like the screaming guy on one of the columns pictured above.

Across from the Baptistery is the medieval  cathedral. 

"Jump, jump, jump"

I always love water spouts

 Construction began in 1064, but in 1595 they had a bad fire. The original wooden doors were replaced with three magnificent bronze doors.  They were built by this guy:

Giambologna

Giambologna had some serious talent. He studied and worked in Italy, but he wasn't Italian - he was Dutch. He was such a gifted sculptor that the Medici family forbid him to leave Italy (afraid that another country would steal him).  The doors are breath-taking (but not very practical - they're so heavy that parishioners use side doors):

God I hate my mother-in-law. Always lecturing me from the podium.

I don't know Mary. He looks like he's getting cold.

I should have stuck my hand in the picture for perspective - this figure is only a few inches tall

Close-up this one reminded me of:

The inside of the cathedral is as regal as the outside

I got the milk, now where did that idiot cat go?

I like to scratch with my right hand

I've always preferred my left hand

I think I went to a party at this frat house back in college. Musta been a good time because I don't remember much.

"Hold my beer"

It's cold out. Here, I brought ya a sweater.

Even the ceiling is cool

"Hey guys, how long do we hav'ta hold up these stupid candles? My arms are killing me."

No idea who the dead guy is. He looks warm though.

So what went wrong with the bell tower? Two things; they built it on an old riverbed of mud and sand instead of rock, and the foundation is only 10 feet deep (the tower is 183' tall). 

This is what happens when you build tall and narrow with a shallow foundation

Construction started in 1173. In year 5, during the build out of the second story, they noticed that it was already starting to lean (only a couple millimeters, aaaa whatza da bigga deal eh?). At that point war broke out between Pisa and Genoa over (what else?) control of the Mediterranean. This worked out in favor of the construction of the bell tower as, during the work stoppage, the structure settled into the ground. Sort of. If they hadn't inadvertently given the tower base time to settle somewhat - the completed tower would have fallen over long ago. As you would expect, after completion (nearly 200 years later) the tower continued to lean further and further. By 1989 the Pisa tower was leaning some 15 meters off center.  The Italians still weren't concerned enough to take drastic action until disaster struck the even older Civic Tower of Pavia in 1989:

Technically, the Civic Tower of Pavia wasn't leaning.  Still, water damage over the 900 years took it's toll and it collapsed, sadly killing 3 people.

Fall down, go Boom! 280,000 cubic feet of brick, sand, and marble rubble crumbled in seconds.

After the collapse of the Civic Tower of Pavia the Italians immediately closed the tower in Pisa. Then they had a go at trying to correct some of the lean. They were only marginally successful. 4 different schemes were tried - steel cables holding it up, lead weights, undercutting and removing soil, etc. 

Nothing worked until they hired this guy:

Professor John Burland, a soil engineer at the Imperial College London

Professor John placed 120 sensors in, on, and around the tower. What he noticed (after two years study) was that the tower leaned more after a rain storm. As it turns out, the water table on the north side (the tower leans to the south) rose during rain storms - shoving the tower over.  They dug an extensive drainage system on the north side and the tower stopped moving. Since then, the tower has actually moved back 17 inches. The Italians have removed all the steel cables, lead weights, construction equipment, and gave it a good power washing.  The tower now looks quite pristine.

No Italian stone mason worth his chisel can resist a flat piece of marble

Tower entrance (when photographing the tower you have to resist a powerful urge to correct the lean by tilting the camera). 

The quality of the stone work reflects the expertise of the masters. It's rare to find this level of perfection outside of Italy (or Greece).

The inside of the tower has been re-opened.  For 16 euros you can climb up and down the 284 steps to your heart's content. 

The entrance is to the right. The tall guy with the dark beard is a Moroccan grad student on holiday. Nice guy and very interesting to talk to. 

Looking up. Since the tower leans it doesn't crick your neck as much to look up.

Security is tight

Inside the tower you can see some of the monitoring equipment.

Some is high tech

Others are low tech

The beer-can shaped weight is attached to a thin wire connected to the middle of the cross member at the ceiling

Walking on the stairs is a bit disconcerting due to the angle (notice all the hand marks on the wall? You can't help yourself).

Quite a few people have made the trek over 800 years. The worn steps show that this is the south side (the part that leans out).

Conversely, on the other side of the tower the steps are worn on the right (towards the inner wall)

The view from the top meets expectations

When you get to the top you find out that the Tower of Pisa really is a bell tower.

Yes, I smacked the bell with my knuckles to hear the sound (that hurt).  Yes, the guard yelled at me. Totally worth it.

Especially when they're ringing

I don't know why, but even at the top of the tower tourists feel obligated to do stupid poses.  The poses you see in the gardens surrounding the tower are just plain embarrassing (I refused to pretend I was pushing up the tower). 

I rest my case.

In the late 1500's Galileo  is said to have dropped two spheres of different masses from the Leaning Tower of Pisa to demonstrate that their time of descent was independent of their mass (disproving Aristotle's theory of gravity which states that objects fall at speed proportional to their mass). 

This looks like the most likely spot Galileo would have used

Scholar that I am, I couldn't resist the temptation to recreate the moment.

 

Apparently the two cans of coke (one full, one empty) I dropped off the roof wasn't appreciated by the crowd below.