Presumably because some GN services will be terminating at Kings Cross and the Maidstone services terminate at Blackfriars that increases the total number of units required to operate the service until 2019.
Though we don't have details yet if the additional GN Cambridge Semi-fast will be operating in to Kings Cross from May 2018, or brought in as a new service next December. The off-peak GN stoppers could stay as 4 coaches for a while !
Though we don't have details yet if the additional GN Cambridge Semi-fast will be operating in to Kings Cross from May 2018, or brought in as a new service next December. The off-peak GN stoppers could stay as 4 coaches for a while !