You can get it earlier much so...............heres how Contact MOD and ask for a medical to activate your pension early. You have to prove having seen a medical referee youre too ill to work and need the pension on ill health grounds but it has to be injury related.......................... caused in the job
If you don't commute, you get your full pension straight away at the 22 year point which for most people is 40 ish years of age.
However, it is frozen at that sum until you reach 55.
Then all the intervening index linked rises are added to it and from age 55 you get the increased sum, with normal index-linked pay rises every year.
Not that I've give it much thought, you understand.
If you leave before the 22 years (immediate pension point), 'fraid you have to wait until you're 60, and I believe it has changed to 65 on the new scheme.