LTA should use B9TLs, Citaros and A22s for TT package. Let the
E500s stay with SMRT so that it is able to meet the demands of
other services that it will still operate.
Loyang also should be B9TLs, Citaros and A22s.
Sungei Seletar can be E500s, Citaros and A22s.
TT will also use E500 from the ones on 106/189, SMB3501L -
SMB3521D for now base on the consecutive regos...
