On Sunday, Gov. Andrew Cuomo joined MTA officials to announce that work on the first tube was completed with crews finishing in five months.

MORE: Cuomo: 1st phase of L train project done, ahead of schedule

Officials toured the tunnel along with cameras, reviewing the new construction methods and technology used to keep the train running as repairs are made.

Included in the work completed so far is a new cable racking system, fire resistant cables, new tracks and a stronger pumping system to prevent flooding.

Originally, officials had planned to shut down the line all together to repair it, but instead opted to slowing service on nights and weekends to allow crews to complete the work.

Gov. Cuomo and the MTA leaders say the new methods used will help them complete future projects within the new capital plan. The MTA board approved $51 billion for work improvements over the next few years.

As phase two begins, officials are reminding commuters that night and weekend service changes will remain in place, but they say the work is three months ahead of schedule. 

Officials say they hope the project will be completed by April 2020.