Railpen, one of the biggest pension schemes in the UK, doubled investment returns to 16.3% last year, putting it level with some of the largest European funds.

The pension fund system for the UK railways and related industries expanded overall assets to £17bn (€25bn), according to its annual accounts filed at Companies House. The lion's share is accounted for by the £15bn Railways Pension Scheme, with the remainder in eight smaller funds, of which only two are open.