Yes, agree not fit for purpose.
I read the new CAF units for the Emirates are designed to not exceed +23c even when outside temperature is +60c, so why we have a/c that are so poor they fail at about third of that temperature differential shows lack of commitment to not upgrading the known weak parts when it was realised 30+ years ago. Of course we don't need to cope with +60 in the desert, but not coping whilst temperatures have been in high 20s earlier this week is unacceptable
40 years ago, the Met office was warning the public, (and government and industry) that climate change was advancing and everybody need to:
1) minimise creating CO2 emissions, particularly by creating power by burning hydrocarbon fuels.
2) modify infrastructure, equipment and working practices to minimise the impact of higher temperatures and more extreme weather.
Well, from the top of government to the individual in the street, we all ignored the advice, (indeed it is still being ignored by many even though the serious effects of climate change are making its presence more obvious)!
As far as the railway is concerned, at wasn't until the late 2000's and early 2010s when the major rolling stock acquisitions started, e.g. the 80xs, 700s, the CAF MUs and the Statler FLIRTs. Since then, the extensive delivery of Aventras to GA/C2C, WM/LNR, SWR, LO and the Elizabeth line have increased the number of trains that can generally handle the higher temperatures that we are now experiencing.
I am no refrigeration expert, but believe that retrofitting, or even upgrading AC on 20+ year old rolling stock could end up nearing the cost of complete rebuild, so the case for attempting that might be a severe disincentive to TOCs and RoSCos, (think aspects of class 769, - wasn't it the adding of cab AC that eventually caused GWR to withdraw?).