Jeff is a pink van with U.L.P written on his sides.
Jeff was a van that lived on British Railways until he was bought by the U.L.P Company. When Oliver came back from the works after his accident with the turntable well he and the other sang rude songs which were lead by the leader S.C.Ruffey. But after Oliver pulled the old ballast truck apart Jeff realized that Oliver was not to be messed with and would always worn newer trucks about him.
Like many trucks, Jeff was rude, loud and tricky but when Oliver broke apart S.C.Ruffey he became wiser and more obedient afterwards.