crossing a red line
 

Does anyone know what this red line is for at Southend?
I cannot find a definition for it in CAP637, a security man was adamant i mustn't cross it!
https://cimg7.ibsrv.net/gimg/pprune....f2f460104c.png

Might it be defining the ‘critical point’ - the part of the airfield considered secure - only accessed via the formal security channels by both passengers and crew? Passenger aircraft coming from outside the CP (eg the GA apron or maintenance hangers require an enhanced security check (pretty much every nock and cranny inside and out that could be accessed and have some mischief hidden in, checked.)
As crew, if one went through security and accessed the CP but crossed the red line, you are instantly considered ‘impure’ so to speak, and cannot go back!

I think you are correct, left of the line seems to be international, right side being domestic.

Last time I was there (several years ago) I walked past it by mistake trying to go to the old tower. Got berated by security and subjected to full body and scan search. If I recall there are 2 doors with C on them and no signage telling which is for domestic. There was definitely no sign saying: Do not cross the red line.

Oooh, Nice Vulcan ! (sorry).

looking for the like button