The quarries around Tanymanod - especially Craig Ddu - were not rail connected and were on the proposed route of a northward extension of the Corwen and Bala Railway. In October 1866 some quarry owners issued a prospectus announcing the formation of the Festiniog and Blaenau Railway Company to construct a line from Llan Ffestiniog to Blaenau where it would connect with the Ffestiniog Railway. In the short term this "poured water into a blocked drain" as the F&BR led only to the overstretched FR, but the line contained the seeds of at least two ambitions-cum-threats: it took a step towards the south where it might eventually meet the Corwen and Bala's ambitions from the south east and the same step south lent itself to ambitions to connect with the Cambrian Railways to the southwest. This latter bore at least legal fruit when the Merionethshire Railway gained parliamentary approval in 1871. That line would have continued from Llan Ffestiniog to a junction just north of , but no construction ever happened, "the threat of it had played its part". The prospectus made brief mention of the line being able to use the FR to "command a very large traffic in goods", but saved its most lavish imprecations for the passenger potential, notably for workmen ("very great") and tourists ("immense").