I don't remember whether I've said that State Railway of Thailand should electrify North Main Line between Hua Lamphong and Don Muang, and should start frequent train service in the section.
But, it seems to be implemented.
As far as I researched, 'The 15·3 km starter section' means a part of SRT Light Red Line, and 'A second phase of the project' does a part of SRT Dark Red Line, both of which are detailed in Wikipedia
See
http://en.wikipedia.org/wiki/SRT_Dark_Red_Line
http://en.wikipedia.org/wiki/Light_Red_Line
Here are pictures when I traveled in Thailand
IMGP8913 posted by (C)gozami
Viaducts near Bang Sue
These viaducts will be diverted into SRT Dark Red Line?
IMGP8928 posted by (C)gozami
The nameplate of Thammasat University
It will be the terminus of SRT Dark Red Line.
