Japanese wigwags!

[Agfhfrgkjklf]

(tldr; in Japan during the early 1920s, trials were run with the type DW automatic flagman)

I recently came into possession of a vintage Japanese book: JNR report - Seniors’ experiences (1958).
In the book is a passage by former signal director Nao Ishii, on the arrival of railroad crossing signal technology in Japan.

He talks about the import of American made “Auto Flagman signals” which were in tested from 1922 - 1923 behind Tokyo Station, and installed in around 7-8 places.
Ultimately they did not catch on there, due to visibility issues.

Judging by the term “Auto Flagman,” aforementioned visibility issues, his description of how the banner hid behind a board when not in use, and Japan’s heavy use of US&S equipment for their railways
(even some modern bells are inspired by teardrops), these were the type DW Automatic Flagman.
Unfortunately I don’t know of any pictures, or further information.