The pump is driven by a jackshaft and helical gear. The wheels were connected by coupling rods and driven by a jackshaft. The drive to the wheels was by coupling rods from the jackshaft. The wheels were driven by a jackshaft. Nine of these came from the first series with the jackshaft. The two axles were driven via a jackshaft and external connecting rods. The Baltimore and Ohio Railroad was a pioneer in the use of jackshaft driven locomotives. There is additional gearing to a jackshaft which drives the wheels through side rods. The 4-cylinder engines were coupled to the driving wheels through a jackshaft and side rods. The motors drove big cogwheels in the jackshaft over spring-loaded sprockets. Recently another type of opener, known as the jackshaft opener, has become more popular. The ten-coupled Italian E550 of 1908 had paired motors, each with a jackshaft. The first, from 1936, had a single motor driving the wheels through a jackshaft. However, some inside cylinder versions were built using indirect drive, then known as a "jackshaft". Final drive is via a Hunslet reversing gearbox and jackshaft.