The NHS 2015 scheme builds a pension of 1/54 (about 1.85%) of your pensionable pay each year, revalued by CPI plus 1.5% while you work. So 30 years on GBP 35,000 average pay builds roughly GBP 19,400 a year, payable from your State Pension age. It is a defined benefit promise, not a pot.
GBP 27,000 - GBP 10,000/yr - GBP 15,000/yr
GBP 35,000 - GBP 12,963/yr - GBP 19,444/yr
GBP 45,000 - GBP 16,667/yr - GBP 25,000/yr
GBP 60,000 - GBP 22,222/yr - GBP 33,333/yr

freedomisntfree.co.uk/guides/nhs-pension-calculator