| Silambu Superfast Express | |
| Type: | Super Fast train |
| Locale: | Tamil Nadu |
| Operator: | Southern Railways |
| Stops: | 21 |
| Distance: | 683km (424miles) |
| Journeytime: | 12 hours 20 mins |
| Frequency: | Tri-weekly |
| Class: | AC First, AC Two Tier, AC Three Tier, Sleeper class, General Unreserved |
| Seating: | No |
| Sleeping: | Yes |
| Observation: | Large windows |
| Entertainment: | No |
| El: | Partially electrified (till Virudhunagar Junction) |
| Trainnumber: | 20681 / 20682 |
| Routenumber: | 8 / 8A[1] |
| Maintenance: | Tambaram Railway Yard |
| Speed: | 52.5km/h average with halts |
| Sharing: | Tambaram Nagercoil Triweekly Express |
The Silambu Super fast Express (20681/20682) is a train that runs between and via . Initially it ran up to Manamadurai, later it was extended up to Sengottai.[2] It was the only train in Indian Railways where LHB rakes were replaced by ICF coaches again. According to IR if a train gets new LHB coaches it won't be converted to ICF. But this train was again replaced with ICF coaches after getting new LHB rakes.
The name of the train commemorates Kannagi, a legendary Tamil woman who is the protagonist of the South Indian epic Cilappatikaram (100–300 CE) who used her silambu (anklet) to prove her husband Kovalan's innocence, who was executed by the Pandya king.It is a standard train consisting of commercial coaches. The train operates tri-weekly in each direction and covers a distance of 683 km. Initially, the train was announced between Chennai Egmore and Karaikudi Junction but due to public demand it started its Maiden Run until Manamadurai via Sivagangai Instead of Terminating at Karaikudi Junction. From 04/03/2017 onwards this train was further extended to Sengottai[3] via Aruppukkottai, Virudhunagar Junction, Sivakasi, Tenkasi Junction. The Silambu Express was announced in the Railway Budget 2013 and the service started on 22 June 2013, extended to Sengottai from 5 Mar 2017.[4] From 25 Feb 2019, the frequency of the service was increased from bi-weekly to tri-weekly.[5] From April 15, 2022, Chennai Egmore – Sengottai Silambu Express was converted to Superfast category with new number 20681 MS SCT Silambu Superfast Express and Sengottai - Chennai Egmore Silambu express with new number 20682.
At present,the train has 17 standard ICF utskrit coaches.
Till November 2021, it has different coach composition.
When it ran as with LHB coaches only for three trips in 2016, it had different coach composition.
But due to replacement of ICF Coaches again it was replaced with new coach composition.
Till October 2017 from its introduction it ran with the following composition,