2019
Letter No.	Date	Subject
2012/Sig/TLBI	22.05.2019	Handle Type Token less Block Instruments – Requested of Policy revision for procurement directly from RDSO approved vendors instead of through Signal Workshop/HWH/ER
2017/Sig/WP/RE works	18.12.2019	Approval for use Podanur type TLBI with UFSBI in 25KV RE area on D&E rout in Signal Line section.
2018
2017/Sig/WP/RE Works	31.10.2018	Replacement of Podnaur type Tokenless Block Instruments with Handle Type Tokenless Block (Diado) Instruments on Single Line Section for 25 KV RE Fitness.
2017
2012/Sig/TLBI	16.10.2017	Removal of existing Single Line Token Block Instrument over Chhinwawara- Parasia section of Central Railway.
2007
2005/Safety (A&R)/19/16.	16.10.2007	Failure of Block Instruments and introduction of Paper Line Clear Ticket.
2006
2005/ Safet(A&R)/19/16	29.03.2006	Failure of Block Instruments and introduction of Paper Line Clear Ticket.