There is no shuttle train from CCK to BBT.
So, for northbound direction, there got 2 destinations:
1. Marina Bay to Choa Chu Kang
2. Marina Bay to Bukit Batok
Alternate I think: CCL, BBT, CCK, BBT and CCK & so
on....
Reason: Limit the number of trains travelling from CCK to
BBT
But Don't know why I saw 049/050 resting at Platform B BBT
station with door close...