The continuous permanent means of access may be a wide longitudinal,
which provides access to critical details on the opposite side by
means of platforms as necessary on web frames. In case the vertical
opening of the web is located in the way of the open part between
the wide longitudinal and the longitudinal on the opposite side, platforms
should be provided on both sides of the web to allow safe passage
through the web. A "reasonable deviation", as noted in TP, paragraph
1.4, of not more than 10 per cent may be applied where the permanent
means of access is integral with the structure itself.