Shachiku Train

Shachiku Train (社畜トレイン) (lit: Corporate Slave Train) or Company Train Is a unique Prophecy T-Spin Double method which is mainly used on a relatively flat terrain. This form mainly uses S one column away from a wall and an L hanging on top of it in order to create a T-Spin Double which would then be immediately followed by another T-Spin Double. This setup was developed by Japanese players and The English name for this setup comes from Malady's 550 slides of T-Spin guide.

Generic Structure
As long as S has a place to be dropped with at least 2 blocks high wall on one end of S and a single gap on the other end of S before it hits wall, this technique's generic structure is always possible.

Variations, Other Uses, and Comparisons
As mentioned before, this technique is always possible as long S has a place to be dropped. Even though it's possible, doing it over a 3-wide hole is inefficient in most cases because the player is forced to make an unconventional overhang in order to achieve the second T-Spin Double.

If L has a place to be dropped on, players could drop the L first before spinning in the S later.

S and L could be substituted by other blocks. As long as it still maintains the same shape as the generic structure, it is still possible.

Compare the 4th example of the Company Train's variations above with Kaidan Setups (both L and J are just swapped) (credit to kazu).

Compare the 5th example of the Company Train's variations above with Cut Copy (S is just shifted one block to the right).

If possible, making the overhang for the second T-Spin Double on the other side of the build before the T for the first T-Spin Double comes could help on executing a much faster attack.

Diagonal shaped holes below Company Train could be used to make three or more consecutive Company Trains. The downside to this is that this variation requires a lot of Zs on demand and might block the Tetris hole (if there is one) located below the build for a few bags.

Company Train could also be used as a direct follow-up to a T-Spin Triple.

Company Train could be used along with Donation T-Spin Double for effective usage of pieces.

Instead of directly doing the second T-Spin Double, repeating another Company Train is also possible and it also maintains a clean stack. In theory, this could be continued infinitely. But in practice, this requires a lot of S and L on demand. This shares the same principle as Mechanical TSD v3.