Resources on API 653 Tank Bottom Settlement Surveys

[ALO_Inspector]

Hi All! Does anyone have any good resources on Tank Bottom Settlement Surveys such as books, articles, etc. relating to the methodology? API 653 Annex B lays out the requirements and formulas, and there are numerous articles on the theory behind the concepts, but I am looking to gain more understanding on the field application.
I've done all my surveys with laser survey equipment, but how were they done before?
And we have software that computes whether the planar tilt and out-of-plane settlement are acceptable, but how was this done before we all had PCs?
Also I shadowed serveral older inspectors and none of them do it the exact same way, so what are some advantages to the different methods?

 

[Dhurjati Sen]

Old hands do it mostly as per API 653.
The theory is to measure the maximum / significant settlements with respect to a reference point outside the tank.
Then, either you go for partial or complete replacement of the bottom plates.
I still prefer the old system.

DHURJATI SEN
Kolkata, India