The entire railway is fitted with the rack rail. On sidings and around the yard at Llanberis it comprises a single rack bar, but on the running line, and through all the loops up the mountain, two rack bars are used, mounted side by side with their teeth staggered by half a pitch. This is one of the major features of the Abt system, and helps to reduce the shock of the pinions running along the rack. It also ensures the pinion maintains continuous contact with the rack. The joints between rack bars are also staggered and align with the sleepers – each sleeper supports the rack rail as well as the running rails.