EU-OPS about 125 m take offs:
(i) Subject to the approval of the Authority, and provided the requirements in paragraphs (A) to (E) below have been satisfied, an operator may reduce the take-off minima to 125 m RVR (Category A, B and C aeroplanes) or 150 m RVR (Category D aeroplanes) when:
(A) Low visibility procedures are in force;
(B) High intensity runway centreline lights spaced 15 m or less and high intensity edge lights spaced 60 m or less are in operation;
(C) Flight crew members have satisfactorily completed training in a flight simulator;
(D) A 90 m visual segment is available from the cockpit at the start of the take-off run; and
(E) The required RVR value has been achieved for all of the relevant RVR reporting points.
My understanding is that pilot assessment cannot replace RVR readings for take-offs in 125 m visibility. And taking the book literally I guess you need 15 meter spacing from the start of your take off. But this is not the case at LGW you say?