STT Solutions is the premier supplier of railway signalling equipment in Ireland. We have been involved in all signalling upgrade work carried out by Irish Rail since 1980. We have installed around 100 SSI Interlockings and over 120 Siemens S7-400 based PLC Level Crossings. STT Solutions was formed in 2011 as a result of a management buyout of Ansaldo STS Ireland Ltd. which was originally formed in 1979 as WABCO Westinghouse Ltd., a wholly owned subsidiary of Union Switch and Signal Inc.  The company was formed to manufacture and supply signalling equipment for the Dublin Suburban (DART) project and continues to be the leading supplier of railway signalling equipment in the Irish market to this day.