The last few Sundays have seen an operation between Hexham & Carlisle.
These are also happening on Sunday 19th coming up...
http://www.northernrail.org/pdfs/trackwo..._-_CAR.pdf

Sunday 26th January see's rail replacements extended to operate between Prudhoe & Carlisle
http://www.northernrail.org/pdfs/trackwo..._-_CAR.pdf

Then on Sunday 2nd & 9th February it is back to Hexham & Carlisle
http://www.northernrail.org/pdfs/trackwo..._-_CAR.pdf

Sunday 2nd & 9th March sees rail replacements in operation between Newcastle & Sunderland. There may potentially be some Metro replacements out also?

Sunday 16th & 23rd March sees rail replacements in operation between Sunderland & Hartlepool for both Northern and Grand Central