While most of us celebrated over Christmas, members of Network Rail's "Orange Army" of engineers spent the festive season laying more than 200 metres of new track and making repairs in Ipswich tunnel.
Sections of track and baseplates were replaced and engineers also cleared drainage ducts to try to ensure there were no flooding problems in future.
No trains ran on Christmas Day or Boxing Day, giving Network Rail a clear 48 hours to get into the tunnel and complete the work before services resumed on Wednesday morning.
The tunnel requires regular maintenance - but nothing on the scale of the rebuild in 2004 which saw the track lowered to handle larger container trains and forced its closure for eight weeks during the summer.
The Christmas work was completed on time and the line handed back to operators as scheduled allowing trains to start running again as planned.
Although the tunnel is back open, it does not mean services are back to normal.
The line will remain closed north of Chelmsford until the end of New Year's Day as other engineers continue the work which will allow the construction of the new Beaulieu Park station just off the A12.
That means people travelling to London face the prospect of a bus ride for part of their journey between Witham and Billericay.
In the other direction Cambridge Station is closed until New Year's Day as well with bus connections between Bury St Edmunds and the university city,
All lines are expected to be fully reopened and running a normal train service from next Tuesday, January 2.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here