SADD TUNNEL PARS Consulting Engineers Co. (STP) has been established in Iran in 2004 by a number of experienced engineers in the field of dam and tunnel projects. STP, from the beginning, has played a key role in large hydroelectric power plant projects. STP brings together professionals of complementary skills from diverse disciplines and to achieve sustainable results, lower costs and managed risks for clients. The depth of expertise, quality of work and creative vision allow STP to take part on vital development and improvement plans.