OSL provides signalling design, installation, testing, and consulting services to rail clients in the UK and internationally. They employ over 100 professionals with 500 years of combined experience working on main line, high speed, heavy rail metro, light rail, and tram systems globally. OSL prides itself on the competence and professionalism of its staff and is committed to supporting their professional development. They have experience working with a wide range of railway control systems and technologies.