The new BR regions, formed largely around the management structures of the old "Big Four" companies, remained autonomous in terms both of organisation and production of locomotives and rolling stock, mostly continuing with pre-war designs – indeed, some designs were even older: the workhorse LNER Class J17 was designed in 1898. As a whole, the equipment of the new British Railways was outdated, often unreliable, and mostly in urgent need of a refurbishment. Only the Southern Region with its large electrified suburban network in South London inherited from the Southern Railway operated a significant number of non-steam-powered trains.