On this day, an incident was recorded at Blaenau Ffestiniog, namely a derailment at the Dinas Junction points, injuring four passengers. It was investigated by Major Francis A. Marindin of the Board of Trade.
The Down passenger train consisted of a double engine (unknown), a front brake van, 2 bogie composite carriages, a short third class carriage, and 7 quarryman's carriages. The derailment began with the seventh vehicle (a quarryman's), but in total five carriages derailed, the short third class carriage and four quarryman's. The seventh and eighth vehicles (quarryman's carriages) fell on their side. Four men were injured. The quarrymans carriages were described as having "a covered wooden body with open window and door spaces and seats for 12 men" The cause was established to have been a bent, near broken, axle on one of the quarryman's carriages. Marindin stated "I attribute the run-off to the bending of one of the axles of the workman's carriage, caused probably by a sudden lurch when running over the low place in the rail".
It was established the axle was made six years previously by Caine & Kitchen of Liverpool, and was re-wheeled and re-bushed 3 weeks previously to the accident. These had not seen much service (3 full returns on the line), since then.
Marindin reported the track to be in excellent condition, with a small qualification that at a point 2 foot from the point, the outside rail of the curve was ¼ ins. low. Whilst conducting the investigation, a hairline crack was found in the axle, and it was subsequently broken with some ease. He reasoned that the crack should have been noticed when the wheels were replaced. He condemned the state of the quarrymans carriages, stating "they are nothing better than slate wagons with covers, and that I am not aware that any parliamentary or other sanction has been given for the conveyance of passengers, even at reduced fares, in such vehicles, which are undoubtedly less safe than the third class passenger carriages in use upon this line". His view on what the driver should do in these circumstances was "It appears that the upsetting of the carriages did not occur until the train was being pulled up, and these narrow gauge vehicles are undoubtedly more than usually liable to turn over if they leave the rails, it would be well to caution the drivers upon this line to pull up very gradually whenever they perceive any such accident to have occurred, unless there are some other reasons for stopping as quickly as possible". In mitigation, he ended by saying "It should be remarked that this is the first accident to any passenger train which has taken place upon the line since it was opened more than 16 years ago".
The persons questioned by Marindin in producing his report were:-
John Parry Jones - Driver
John Jones (1842) - Guard
Thomas Henry Hovendon - Inspector of Traffic & Permanent Way
Owen Morris - Signalman
William Jones - Ganger for length of 3.25 miles from Duffws