Thomas Michael had been charged with manslaughter, by causing the deaths of the ten men by being a trespasser and committing an illegal act by unauthorised operation of the keeps. On Saturday the 2nd February 1884, he appeared at Llandeilo petty-sessions, which were held at the Shire Hall, Llandeilo.
The prosecution presented the bench with the verdict from the jury at the inquest. He did this by producing a newspaper report, rather than presenting the formal documentation. The defence pointed out that not all the enquiries were over and the inspector of mines believed that the rope had been weakened due to exposure to steam and that it was this that had caused it to break, rather than there having been a jerk. The defence also stated that the accused was not trespassing, as he was employed at the mine, neither was his operation of the keeps "absolutely illegal", because the banksman was standing nearby and did not stop him. The trial was adjourned until Monday the 25th February.
The next hearing opened with lengthy statements from the prosecution, outlining the whole of the events. George Bartlett, a man employed at the works, told the court that he saw the defendant operating the lever for the keeps and the cage descending. When the cage was nearly out of sight, he said that it stopped as if caught by something. He said that he didn't think that the engine had stopped, because the rope was still coming out. Shortly afterwards, the cage restarted and he heard the fall at the bottom of the shaft.
Another man, Thomas Morgan, said that he saw the cage shaking and struggling in the mouth of the pit. When the cage was set free he heard the scream of the men and the rope broke with a loud noise. He also said that almost every man in the pit had worked the lever at some time. It was a common occurrence when the banksman wasn't there. He told the court that the cage sometimes caught in the keeps, even when operated by the banksmen, especially if the horse door was on. He stated that if the lever was worked properly, it was impossible for the keeps to catch at all. When challenged by the prosecution, the witness said that only the banksman worked the levers when there were superior officials present at the colliery.
The representative of the rope company gave statistical evidence regarding the rope. He stated that he did not agree with Mr. Wales, the government inspectors' opinion, that the accident was caused merely by the corrosion and weakness of the rope. He stated that on the day after the accident, he had conversed with the banksman, who appeared very nervous and didn't seem to know what he was talking about. The banksman had told him that there had been no jerk on the rope and that he had let the cage down himself.
Mr. T. H. Hosgood, a colliery and mechanical engineer, also gave his opinion regarding the rope and said that he also disagreed with Mr. Wales, the government inspector, who believed that there had been no jerk on the rope. He estimated that in its corroded condition, it should have still been able to bear a strain of at least 12 tons. He also said that he had seen the keeps and that they were quite clear of the cage when it was being lowered, although one of them had very little space to spare.
The case was adjourned until the following Saturday.
The final hearing, which occurred on Saturday March 1st, again took place at Llandeilo Petty Sessions. The first witness was a collier, Thomas Morgan, who, on being recalled, told the court that the fangs on one side of the keeps did not recede as they should and would frequently catch the cage as it was going down. He said that no one knew why it didn't occur every day.
The second witness was the overman. He said that the fangs would catch when the engine man did not lift the cage high enough, or the banksman did not work the levers in time. He also told the court that it was not dangerous and that as far as he knew, no one except a banksman ever worked the levers. He said that since the accident, the collar board had been cut away a little to allow the fangs of the keeps to recede further when opened.
Next the fitter/mechanical engineer testified that he had tested the rope on the previous morning, by running it through his hand and that not a single broken wire was found. He admitted that where there was a large accumulation of grease on the rope; he was unable to tell whether the wires were broken or not. He also said that where the rope had broken, some of the wires were corroded and reduced in size, therefore causing it to be weakened. On being re-examined, he said that when a wire broke, the end sprang out and no amount of grease would cover it.
The day banksman was next to give evidence. He said that he had not given permission to the accused to work the lever and that although he saw the accused standing by the lever; he had no opportunity to stop him. He said that if the lever had been drawn back properly, the fangs would not have caught on the horse door of the cage. On being cross examined, he admitted that for several days after the accident, he told people that he himself had been the one operating the levers, because he thought that it would smooth things over. He also told the court that he had let four men down in the other cage before the accident that morning. This had been prohibited by the colliery manager, as the rope holding this other cage had been found to have a broken wire. The defence accused the banksman of being elsewhere and of committing an illegal act, while the accident was taking place.
John Hay, the colliery manager, then gave evidence. He said that he had himself travelled to Cardiff to have a section of the rope tested after the accident. He said that there would be some sulphur coming out of the pit and this had a corrosive effect on wire ropes. He also said that the alteration in the fangs after the accident had been carried out in order to satisfy the men and that it did not add to the safety of the descent.
The case for the defence was opened with comments stating that the prosecution was brought only nominally by the police and that the case was really brought by the colliery company. The defence solicitor continued by saying that the rope was weakened by steam and corrosive agents at the point of fracture. This opinion was backed up by the government inspector of mines when he later took the stand. The government inspector was the only independent party giving evidence and he was also the most experienced in this kind of matter. The defence also had a large number of witnesses willing to say that many men had worked the levers for the keeps, not only the trained banksmen.
Mr Wales, the government inspector, said that if the fangs were worked properly, they did not catch on the horse door. He also said that the fact that a horse door had been put on the cage was kept back and not disclosed until near the end of the inquest. He said that in his opinion, if the cage did stop it was because the machinery stopped and not because the cage had caught on the fangs.
He disclosed the fact that he had had a conversation with the manager of the rope manufacturers, on a train, a day or so after the accident and even he held the opinion that the accident was due to a weakness in the rope, rather than the cage catching. When the bar of the horse door was produced as evidence at the inquest, to show where the fangs caught, it was evident that the marks passed over it.
The case against the accused was dismissed and this was met with the approval of many of the accused's fellow workmen.
Having failed to obtain a successful prosecution against Thomas Michael, the colliery company then brought a separate prosecution against David Jenkins, the banksman, who was charged with breaking a special rule of the colliery, by allowing more than 8 men to go down in a cage at a time.
The Magistrate called it rather a curious case, stating that the only conclusion to be arrived at was that he had not neglected his duty, but that someone else undertook it. It was acknowledged that David Jenkins could not see how many men had entered the cage, due to there being obstacles in his line of vision, but the colliery company were keen to make an example of him. David Jenkins admitted liability and he was fined £19 8s.