Meaning of new definition of th in F.4.1 1

[vesselguy]

Hi,
The new Addendum 2, Appendix F.4.1 for the max design pressure, definition for the participating roof thickness to now include some kind of composite roof. I have never seen a "stiffened" roof plates as described in the new text. What exactly are they refering to? All the self-supported roof I've seen are just plates making up the cone roof.

 

[JohnGP]

Hi vesselguy,

You need to get out more! :-D

We have some 32m diameter tanks with self supporting cone roofs, but the roof plates are stiffened externally with radial I-beams, so obviously contributing to the weight of the roof structure.

Cheers,
John