At mid-century, the north bank companies faced two main problems: wharf competition and the failure of earnings to keep pace with an increase in the shipping and cargoes handled. Adding to these challenges from the 1860s was accommodating steam shipping by investment in facilities, including new docks, and in the 1880s, a resurgence of fierce rivalry between themselves and a financial crisis created by the new Tilbury dock resulted in effective amalgamation. Their common response to diminishing profitability was the introduction of sub-contracting – to the detriment of the lives and livelihoods of a resistant workforce. Skilled port workers were unionised, unskilled generally not, but strikes by particular groups were not uncommon. Port-wide action by dock workers in the 1850s failed but stoppages in the early 1870s achieved wage rises, as also did the port-wide 1889 Great Dock Strike.