Please post the PCN, with only name and address redacted.
We've seen quite a few of these Rotherhithe Tunnel PCNs and, to be frank, those who have taken the matter to London Tribunals haven't got on well. The heavily reduced weight limit is fairly recent, and having seen the signs array, could well be too much for a driver to take in whilst proceeding at 20mph. There are six symbols for prohibited traffic; far too much to take in whilst approaching at 20mph, the symbols for weight limit (2 tonnes) is so small it is almost impossible to read the '2t' on the truck symbol until going past it.
However, so far, the adjudicators have sided with TfL, but I don't think anybody has appealed so far on the lareg number and small size of the signs for prohibited traffic. OK if it's one on its own, but with six ?