The principle of targetting 2/3rds of income in retirement was a little generous in hindsight.
Well, I’ve thought about that. In my pension scheme which is DB ‘Kind of’, between me and my employer we pay about 18% of my pensionable salary (hereinafter referred to as salary) into the scheme. Previously it was rather higher, but the scheme is well funded at present so contributions reduced a few years ago. To get a two thirds ‘final’ salary pension, I would have to put in for 40 years, and retire after 60. Given that life expectancy for the average male employee is around 79-80 (full service retirees being overwhelmingly male - I have no doubt that the old BR scheme was calculated on the basis of male life expectancy), that means you would get out 20 years of 66% for putting in 40 years of 18%. To a first order approximation, your total contributions need to have grown by around 80% in real terms over the 40 years. That’s decent, but not exactly a stunning investment return for that length of time.
Of course there’s all sorts of other things in the mix: increased salaries through promotions etc., lump sums, and so on. So it’s not thst simple.
Anyone who joined BR or it’s successors from before the day the Railways Act 1993 entered the Statute Book has different (protected) Pension rights from those who joined afterwards, with rather more generous terms. There’s not many of these people left.
For clarity, the railway pension scheme is fully funded from your own contributions, and not those of future members.