PHILADELPHIA | THE LAUREL @ 1911 Walnut | 604 FT | 48 FLOORS

[Philly Fan]

Originally Posted by iheartphilly

Yeah, I was wondering about that too. Like they were just pouring over dirt. I thought it was be crushed stone and rebar before pouring.

Any concrete expert now what's going on?

They're pouring a concrete "mud slab," which is a nonstructural base on which the actual steel reinforced foundation will be constructed and poured.

[Redddog]

Originally Posted by Philly Fan

They're pouring a concrete "mud slab," which is a nonstructural base on which the actual steel reinforced foundation will be constructed and poured.

And there you go.

Thanks PF!!

[GtownFriend]

Starting to put down rebar under the main tower.
The back part along Sansom is deeper, but nearing completion on that dig too.

[Jawnadelphia]

Construction update video, it's a week old, forgot to post it:
https://www.instagram.com/p/B53gKV4Dw7d/

[Marcos]

Originally Posted by Jawnadelphia

Construction update video, it's a week old, forgot to post it:
https://www.instagram.com/p/B53gKV4Dw7d/

Great video. Something I’ve always wondered about when I look at the base of these cranes is that they just look so damn flimsy given the massive weight they hold? I don’t understand engineering so while I know this all works, I don’t understand how. It looks like a few bolts holding the red section onto the base, does the red section go deep into the concrete? Also, what is the diameter of that base, I’ve seen them in person from a distance and it’s hard to tell in the pictures but they never seem big enough considering what they hold up. When I think of that thing hoisting 21,000lbs plus its own weight, add in wind & other forces, all 300 feet off the ground without any support up high - it just seems impossible.

[iheartphilly]

^
I had the same thoughts. I could swear other cranes and how their bases are attached were more robust!

[PHL10]

Look at the yellow ladder in the foreground. Standard ladder width is about 16". So those members are pretty substantial. Also it appears the mount is embedded in the concrete.

[ironhead401]

Originally Posted by Marcos

Great video. Something I’ve always wondered about when I look at the base of these cranes is that they just look so damn flimsy given the massive weight they hold? I don’t understand engineering so while I know this all works, I don’t understand how. It looks like a few bolts holding the red section onto the base, does the red section go deep into the concrete? Also, what is the diameter of that base, I’ve seen them in person from a distance and it’s hard to tell in the pictures but they never seem big enough considering what they hold up. When I think of that thing hoisting 21,000lbs plus its own weight, add in wind & other forces, all 300 feet off the ground without any support up high - it just seems impossible.

Those are solid steel pins holding the base tower section to the anchors.
The towers are incredibly strong with the way they are built and the steel tubing they are constructed from.
The red tower section does not go into the concrete it is pinned to the anchors and they are what is poured into the concrete and rebar.

The towers are 8' x 8'

[ironhead401]

Originally Posted by iheartphilly

^
I had the same thoughts. I could swear other cranes and how their bases are attached were more robust!

This is actually a typical setup for all tower cranes anchoring into concrete.
From the shortest of cranes to the crane the was atop the W hotel was anchored this way.

[Marcos]

Originally Posted by PHL10

Look at the yellow ladder in the foreground. Standard ladder width is about 16". So those members are pretty substantial. Also it appears the mount is embedded in the concrete.

good catch, I didn't even notice that thing until you pointed it out, does give a good perspective as to the size of those sections. I got pretty close to the ones at CTC when they were disassembling it on the west end & recall they were fairly hulking in size. I'm more amazed at how they're attached to the ground than anything, & read one of the other replies that the initial red section that joins the base doesn't go deep into the concrete, that to me seems crazy, if a lot of lateral force is exerted how does it not rip those pins out. I guess most of the wind just blows right through it rather than causing it to lean in any direction? Does the jib and the counterweight move like a weather vane into the wind? Once there's a tie-in to the building to stabilize it, it all makes perfect sense (even to me ), but just in its free standing form it's tough to comprehend.

[ironhead401]

Originally Posted by Marcos

good catch, I didn't even notice that thing until you pointed it out, does give a good perspective as to the size of those sections. I got pretty close to the ones at CTC when they were disassembling it on the west end & recall they were fairly hulking in size. I'm more amazed at how they're attached to the ground than anything, & read one of the other replies that the initial red section that joins the base doesn't go deep into the concrete, that to me seems crazy, if a lot of lateral force is exerted how does it not rip those pins out. I guess most of the wind just blows right through it rather than causing it to lean in any direction? Does the jib and the counterweight move like a weather vane into the wind? Once there's a tie-in to the building to stabilize it, it all makes perfect sense (even to me ), but just in its free standing form it's tough to comprehend.

The lower tower sections of this crane are larger than the upper sections (beefier steel) but same size overall dimensionally, which allows it to free-stand higher.

The cranes do "WeatherVane" when they are not in operation. On a typical windy day, after working hours, if you look at all the cranes in the city they will more than likely be pointing the same direction due to them being able to spin freely.

[El Duderino]

Originally Posted by ironhead401

The lower tower sections of this crane are larger than the upper sections (beefier steel) but same size overall dimensionally, which allows it to free-stand higher.

The cranes do "WeatherVane" when they are not in operation. On a typical windy day, after working hours, if you look at all the cranes in the city they will more than likely be pointing the same direction due to them being able to spin freely.

love this first hand info - thanks so much for providing all of these insights

[Jawnadelphia]

Few days ago...


https://www.instagram.com/p/B6Ow9SaDFqp/

[TK2001]

[Yurkek]

[Jawnadelphia]

Red Crane...


https://www.instagram.com/p/B7AMyeAjLKp/

[New2Fishtown]

Originally Posted by Jawnadelphia

Red Crane...


https://www.instagram.com/p/B7AMyeAjLKp/

Looks like The Laurel will partially or completely obstruct views of Liberty Place from the South Street Bridge. That's been an iconic shot since 1 Lib opened in '87. I'm all for this project, but I confess I'll miss that classic view. The Laurel is several blocks closer to the bridge than most of the high-rises in view so it is really going to dominate the right side of the frame.

[JohnIII]

I don't think this building will obstruct the view of Liberty Place; its a tall building but if its near the height of the building formerly known as the Blue Cross Building; it won't be tall enough to obstruct the view.

I may certainly outshine Liberty Place at night; I sort of wish Liberty Place would return to its classic look.

[TK2001]

[Milksteak]

^That works out nicely.