Corregidor Island Railway *LINK*

I've been reading a book on signficant WWII battles, including the siege of Corregidor. In the chapter mention was made in a couple of places about a railroad. This sent me scrambling to the Net to see what I could dig up. Indeed, I did find a neat site.
Corregidor had several miles of 36" gauge electric line which served not only the military needs, but also was a public transportation system uwing what looks like 4-wheel open side Birney cars. According to the map of the island, the line had hairpin turns, and switchbacks, and the line went from sea level to about 400' on 4% grades. Enough to set any NG fan's ears a twitching.
But alas, other than a photo or two of the Birney cars, there was no information on the type of freight motors used. And I'm sure there were passing sidings and car storage areas, but they don't show up on the map. The book makes mention that are dispatcher was used, so apparently it was a busy operation.
What I would like to ask is does anyone have a further source of information on this line? I'm going to keep digging. If a book hasn't been written on this subject, it would make a dandy project.
Thanks.
CJ