SDI is a joint venture between Strukturas AS of Norway and New Dafang of China; established in Zhengzhou China in 2010 with the aim of providing a full range of bridge build equipment to the international market.

In its first two years of trading SDI has designed, fabricated and installed 7 segmental launching gantries, 5 MSS, 1 full span launcher, 1 low loader and 4 x500t gantry cranes; a total of 12500 ton s of steel to projects in Asia and Persia.