OLL52 (I shape)

(R’ U’ R U’ R’) d (R’ U R) B (vertical I shape & bar on R-face)

R’ (F’ U’ F U’) (R U R’ U R) (vertical I shape & bar on L-face)

For the first one, I start with right thumb on U-face, and use it for the d turn. I regrip to turn R’ U R, and use index finger for B.

For the second one, the last U would be smoothly turned with ring finger.