KiwiRail CEO Peter Reidy said the $500 million project to electrify Auckland's rail network is comparable to recent rail upgrades in some of the world's largest cities.
"Some of the equipment on the network had not been upgraded since the 1960's so we have achieved a giant leap forward."
The installation of overhead lines involved 650,000 hours' worth of construction activity, the installation of 3,500 masts, carrying 560km of 25kv overhead wires across 175km of railway tracks.
KiwiRail has also invested in state of the art technology that overrides drivers if they are travelling too fast towards red signal lights and advanced automated signalling equipment that is a 'world-first' for New Zealand.
Over the next six months KiwiRail will progressively complete and commission other parts of the network to coincide with Auckland Transport's planned rollout of electric passenger services.
Auckland Transport's Chief Executive, David Warburton said the introduction of electric trains marks the start of a new era in public transport for Auckland.
"We are on target as we count down the days until we introduce modern trains to Auckland, line by line until we have all 57 trains in place near the end of 2015." Warburton said.
The first electric trains passenger services will run along the Onehunga Branch Line on 28 April.