At the same time as Pepy's announcement, Richard Brown announced that Eurostar's plans for expanding its network potentially included Amsterdam and Rotterdam as destinations, using the HSL Zuid line. This would require either equipment upgrades of the existing fleet, or a new fleet equipped for both ERTMS and the domestic signalling systems used by Nederlandse Spoorwegen.[251] Following the December 2009 opening of HSL Zuid, a London–Amsterdam journey is estimated to take 4 hr 16 min.[252]