During the first six months of 2017, 148 acts of vandalism on the rail network were reported to AT and documents released to the Weekend Herald under the Local Government Official Information and Meetings Act (LGOIMA) revealed authorities were concerned about the growing costs to repair damage.
In the financial year to June 2015 AT spent $533,557 on fixing vandalism to the train network but two years later that figure had more than doubled to $1,297,590.
During the same period, rail patronage increased by 41 per cent.
AT told the Herald in June that graffiti to trains cost about $500,000 a year to repair.
It wasn't completely clear what was behind the rising cost, however an AT staffer told attendees at a Combined Safer Network Group meeting on January 19 - including police and staff from Transdev, which runs the network for AT - the presence of security guards at stations did little to deter trespassers and fare evaders.
Because the Trespass Act required a specific location for a notice to be issued, it prevented AT from trespassing people who caused problems on trains or at stations from the entire network, leaving the organisation "a little powerless".
AT and police said they worked closely withe each other and other agencies - including Auckland Council and Transdev - to prevent graffiti on the network and hold offenders to account.
Auckland City police district prevention manager Inspector Gary Davey said a private investigation firm was also helping police investigate incidents of recidivist tagging.
If large pieces of graffiti were reported to police they would investigate if there were "positive lines of inquiry".
Brendon Main, AT's group manager of metro operations told the Weekend Herald AT was rolling out two new initiatives it hoped would help - installing electronic gates at more stations and hiring at least 200 transport officers.
AT announced earlier this year it would create the new role of transport officer after central government passed a law allowing the officers to issue infringement notices - which train managers were unable to do.
The change, in effect by 2019, will not mean there will be an officer on all trains; instead AT will roster the officers on the routes and at the times with the most need.
New electronic gates requiring commuters to scan their Hop card before they can get to the platform will be installed at Parnell, Middlemore, Manurewa, Papakura, Papatoetoe, and Glen Innes stations.
Gates have recently gone in at Henderson and Otahuhu, bringing the number of gated stations to five: Britomart, Newmarket and Manukau already have them.
When the new gates were installed, 90 per cent of train users would have to travel through at least one gated station during their trip, AT spokesman James Ireland said.
The combination of on-board transport officers and more electronic gates aimed to "reduce vandalism, reduce fare evasion, and create a better experience for our customers", he said.
However the strategy has drawn criticism from the Rail and Maritime Union - which represents Transdev staff - and the Public Transport Users' Association (PTUA).
PTUA spokesman Jon Reeves said the move away from having staff on every train would "backfire".
"Every train should have at least one person from Auckland Transport on board it, not only for the safety of the passengers, but also for reducing vandalism on board the trains.
"With their new transport safety officers they're not going to be on every single train -
that's going to leave trains completely open for vandalism and also put passengers' safety at risk and that's not acceptable when they're trying to encourage more people on to the network."
He told the Weekend Herald AT's strategy to gate Parnell, Middlemore, Manurewa, Papakura, Papatoetoe, and Glen Innes stations didn't go far enough. He believed all stations on the network should have electronic gates.
Railway and Maritime union organiser Stuart Johnstone said AT should be putting more staff on all trains instead of taking some off if it wanted to reduce crime, including vandalism.
"If you've got a group of people standing there who are going to vandalise the train there's not really much that one person can do.
"The best way to improve safety and reduce incidents on board the train, including vandalism, is actually to be more visible, not less visible."
He said instead of creating a new role, AT should upskill the existing train managers - giving them the powers the proposed train officers would have.
