The first phase of investment (Band A) commenced in 2014 and represented a £1.4 billion investment over the five-year period ending in 2018/19.
Dechreuodd cam cyntaf y buddsoddiad (Band A) yn 2014 gan fuddsoddi £1.4 biliwn dros y cyfnod o bum mlynedd a ddaeth i ben yn 2018/19.