Standalone Oyster Card readers

Pink readers are "via" ones, touching one won't increase your fare but might decrease it.

AIUI standalone readers are provided where you can arrive by train from outside Oyster and want to change to it. For example with Stratford I could have a Chelmsford to Stratford paper ticket, then touch the standalone reader to start an Oyster PAYG journey.

There has been talk that Greater Anglia were going to put stand alone readers on the platforms at Shenfield. Whether this is ever going to happen, who knows!

I use the Stratford ones all the time, generally in my case leaving national rail and heading for the central line to avoid the mayhem of changing at Liverpool Street in the rush hour!

There is also another, more limited, use of Standalone readers. For staff who have privilege PAYG Oyster Cards they can start and end a National Rail journey using PAYG at the point where their staff pass validity ends. For example Hackney Wick to Ilford - staff pass valid H Wick to Stratford and PAYG needed for Stratford to Ilford.

The main use is, as explained above, for NR paper ticket holders who have a ticket to the interchange and then wish to use Oyster PAYG. Although TfL have thinned out the numbers of stand alone validators they are still at interchange or validity boundary points. The concept of those validators, to remove the need for people to slog to the exit and then re-enter again (imagine doing that at Highbury from the GN and then back to the Vic Line), is something I invented in the original Prestige specification for London Underground.

Actually, I didn't consider those points and are somewhat obvious now thinking about it! I guess because I don't travel outside the oyster area, I haven't experienced this!

Thanks for the answers!