Technical Tunnelling Components: With over 40 years of experience manufacturing and supplying components such as bolts & sockets, grout/lifting sockets, segment packers and grommets along with the award winning Dowelock connection system, TTC is truly the one stop shop for all precast segmental fixing and grouting systems. The in-house design and manufacturing capabilities that Tunnelling Accessories and Bosworth Plastics have can also offer bespoke products for challenging situations as well as standard segment accessories. Supplying components worldwide with an impressive product portfolio along with excellent service.