[2] From around 1843 to 1857 Dübs appears to have worked for the Lancashire locomotive builders Beyer, Peacock & Company in Manchester.
He lost his position as works manager in 1857 for reasons which may have had to do with his managerial style rather than his technical abilities.
[citation needed] In 1858 Dübs was appointed works manager and company partner at the Clydeside engineers and locomotive builders, Neilson & Company, in place of the existing works manager, James Reid, on the strength of his knowledge of locomotive building.
Neilson & Company were at that time changing from being a general engineering concern into specialist locomotive builders.
[3] Neilson rapidly grew disenchanted with Dubs who "turned out to be an excellent draughtsman, but was a poor engineer".
"Dubs made himself so excessively disagreeable and having offered to give up his partnership and leave the works upon my paying him a certain sum of money which I accepted".
[3] Although making locomotives was its main business, Dübs & Company also manufactured traction engines and steam cranes.