Welcome to Semaphores.net


This is the professional website of Derek Yu, a Railway Signal Engineer currently residing in the United States of America.

With 10 years of experience in the rail industry, I specialize in solving complex problems and clearly communicating their solutions. I do this by combining state-of-the-art test and measurement tools with practical knowledge of railway signaling learned in the field.


I currently implement and support the following technologies:


I believe that modern transit and freight rail systems are essential to ensure the economic viability of our cities and nation. I desire to apply my knowledge and creative energy to realizing the next generation of railway signal infrastructure which will allow these critical rail systems to provide safe, fast, and efficient transportation for future generations.