I've been out of the scene for years, recently rekindled this old pastime, so I bought a few books to get me up to speed, namely Colin Marsden's 'Traction Recognition' and Platform 5's 'Locomotives 2021'. There's a whole section on class 31's in the Traction recognition book (no mention of withdrawals), but in this year's Locomotives book it seems there's only one single class 31 remaining in service. As a kid I'd see loads of 31's every day, possibly the most common loco on the reailway, yet they've suddenly disappeared. I can't find any info on why the entire fleet was condemned. Anyone have any info they could share?