A week of filming was undertaken at Great Clifton, and at St Helens Colliery, Siddick, in Cumberland, followed by seven weeks of shooting at London's Denham and Twickenham Studios, where an elaborate mine-head was simulated. Also there is a shot at Derwent Crossings looking towards Mossbay pig iron works in Workington and the railway station used was Workington Central on the Workington to Cleator Moor line. Also included are several shots of Middle Row and Back Row, Northside, a village at the northern end of the town of Workington. Later the set was moved to Shepperton Studios for another week of shooting. The original set of the pit-head was used to make up a huge composite set of 40,000 square yards, then the largest exterior set ever constructed for a British film. The set consisted of a replica of the Workington pit where the location work had been done, including a pit-head complete with cage, ramp, outer buildings and rows of miners' cottages. To make secure authenticity, pit ponies from the Cumberland mines were used and the miners' costumes consisted of clothes purchased from colliery workers.
For the US release, a year and a half after the British premiere, the opening and end credits were changed and supplemented with a voice-over narration by Lionel Barrymore. In addition, the departing scenes and dialogue at end between Davey and his mother were cut out completely. In the original UK version, opening credits appear against documentary-style establishing shots of the pithead and the men emerging from underground and walking down towards the pit owner to begin their strike. The US version used a plain background for the main title and an explanatory voiceover that lessens the graphic impact of the original. The US version ends with the rising camera above the pit as the Lord's Prayer is spoken after the disaster with added verses of the prayer heard and a final shot of heavenly clouds added with a longer voiceover. The original UK release has the first line of the Lord's Prayer heard only as the camera rises to the black sky above the pit, it then fades in to the final scenes as Davey's mother is downstairs preparing her son's packed sandwiches for his return to work at the pit. Davey emerges down the stairs dressed not in work clothes, but a suit. He tells his mother he is going to work for the union. "You are all I have left now ..." says his mother, who takes an apple and gives it to Davey for the train journey. He goes to the front door and turns back to his mother, who stands impassively at the hearth. The final shot is an exterior of the cottage with Davey leaving while his mother is watching framed closely in the window. Her shoulders droop in a sigh of resignation, and it dissolves quickly to the end credits.
