Shachiku Train (社畜トレイン)
A donation TSD → TSD method.
Shachiku Train is often used when you have a 2 × 4 empty space (colored sky blue).
The requirement for this setup is a 2 height wall and a block at either of the 2 yellow-colored spots to place your S or Z mino. For this example, we will place an S:
After placing your S, hang an L. These two mino placements make up the core of Shachiku Train.
Create an overhang, do the TSD, and create another overhang to do the next TSD. The second overhang will almost always be created with a Z, so try to save it. If you use the ZJ combination for the mirrored setup, the second overhang will be created with an S.
Shachiku Train can be combined with a TST:
credit to kazu for this example
Here's an example of combining it with an O donation:
Compare Shachiku Train with this TSS and Cut Copy
An example built with different pieces that make the same shape as Shachiku Train:
Shachiku Train does not care which columns are empty underneath as long as there is a platform (marked yellow below) to place your S.
However, having an empty column at a position like above (marked sky blue) gives you two benefits: ① You can place your L before placing your S (instead of depending on the prior placment of S), and ② the empty column for the second TSD aligns with this empty column.
Another effect of having an empty column at that position is being able to repeat Shachiku Train.