I have a second hand Bertie in my stock list. Always gives impeccable service. Will run very slow and smooth and at the same time haul a heavy train. Mine has the water gauge fitted and it has run for up to three hours non stop. A basic loco but with all the Roundhose good bits and a gas system that does what it says on the box. And if you get fed up with the original bodywork these models have been converted into other interesting locomotives. Including a double Fairlie that uses two chassis`s.