OP, can we cut to the chase regarding the contravention and pl amend for accuracy.
You parked within a Restricted Parking Zone with additional loading restrictions both of which apply 24/7.
In practical terms this means that you may not wait at any point because the BB does not afford an exemption where waiting and loading restrictions apply.
The one photo shows the front 1/3 of your car beyond transverse bay markings.
Therefore, if this was a single vehicle parking place these markings represented its boundary and a considerable part of your vehicle was in the restricted area, hence the PCN.
This has nothing to do with the bay as such, your breach was not being wholly within and therefore in consequence within the restricted zone by more than a de minimis degree.
The CEO therefore had the options not parked wholly within or waiting etc. in a restricted street. The former is the lower penalty whereas the latter is the higher.
As regards the zone sign, I've no idea what 'except in signed bays' means. It's not a permitted variation or lower plate. A RPZ controls only those lengths of street not otherwise regulated either by their own markings e.g. controlled crossings, bus stops, PARKING PLACES etc. or those where statutory prohibitions apply e.g. dropped footways etc. The lower plate is redundant, but whether to the degree that this invalidates the zone itself?.. I wouldn't like to risk money on this point alone.
At present as regards the contravention and(without scrutinising the PCN in detail yet) you could argue:
De minimis - you tried to park wholly within the bay but can now see that you did not succeed;
Penalty exceeded....circumstances of the case: should have used the lower penalty in the circumstances. At least the authority have to explain why they did not.
Exercise discretion.
Whether the argument of assisted alighting might apply, I don't know because I don't know for how long you were parked and for what purpose.
