EDIT
EDIT
EDIT
As per this website, it was introduced on 1/7/1997 but it is wrong as it replaced former (not the present one) Chennai Coimbatore Shatabdi in 2000. So it was introduced in 2000.
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You can serach google to get as:
click here 2023/2024 Chennai Coimbatore Shatabdi Express Policy instructions regarding Rajdhani/Shatabdi Express trains 07.06.2000

So it was existed in 2000. I can remember it was not on 2000-01 time table where 2679 (now 12679) replaced it. It also started from Coimbatore in the morning like Shatabdi and returned before midnight but immediately after replacement, the replacement train, 2679 Intercity was slower. Shatabdi (old):
2023: MAS 15:10, CBE 22:00,
2024: CBE 07:25 MAS 14:10

Note: As per this source 2021/2022 Howrah Rourkela Shatabdi was cancelled but it was not permanent, maybe it was the time when the rake was damaged because of derailment near Panskura and it was suspended. Later it was restored. It was short terminated at Tatanagar when 2002-03 time table validity started on 01.07.2002 if not Saturday, otherwise the next day, 2/7/02. Finally it was replaced by Jan Shatabdi in 2003 which was subsequently extended to Barbil. You can get withdrawing/ discontinuation story of 2021/2022 Howrah Tata Shatabdi Express by google search

Sunday Early Morning Trains At Coimbatore North Junction...
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22616 Coimbatore - Tirupati Intercity Express, 12681 Chennai Central - Coimbatore Weekly Superfast Express and 12680 Coimbatore - Chennai Central Intercity Express...
12681 was...
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