In New York, the Hi Line project, a public-private consortium, attracts all kinds of new businesses. It was built on old raised railway tracks.   In London entrepreneurs Richard Ballard and Steven Dring will transform passageways under London’s Northern Line. Old air raid shelters are being transformed into hydroponic vegetable gardens.  The backer of this project is a Micihelin-star chef who wants fresh food on his table and that of other London restaurants.  The entrepreneurs can deliver produce in 48 hours max. Outside supplies take at least five days.  The entrepreneurs are in the midst of a crowdfunding campaign.