the beam; he had not seen any damage to the beam, and the engine had run well until the beam failure. It was also noted that there were casting defects visible at the fracture surface. As the coroner had foreseen, a second inquest was needed and was held 4–6 February 1862. Sir George Grey, the Home Secretary (to whom the Mining Inspectorate reported) sent down an expert ((John) Kenyon Blackwell) to assist the coroner. Blackwell was to make a separate report on technical issues and was to use the inquest as an opportunity to collect information for his own report. At the second inquest, a variety of experts and experienced men gave their opinions on the cause of the beam fracture. They differed over some details but were in general agreement that the 'spears' linking the engine beam to the pumps it was operating had failed in tension (some held that this had been triggered by a pump piston jamming; others held that the failure occurred simply because the spear was in poor condition). With the load on the beam removed, there had been an abnormally fast and large stroke and the beam had hit equipment on the 'in-house' (steam engine) side of the beam with great force; the shock loading causing brittle failure of the cast iron. John Short, the engine-wright, gave the basic information about the engine, the beam, and the pump spears. The beam had been made nearby by Messrs Losh, Wilson and Bell of Walker. It had been assembled from three components. A central 'gudgeon' whose middle portion was hexagonal was threaded through a hexagonal hole in the central boss of two massive castings joined back-to-back with bolts, studs and spacers. Each casting had a thickness of at the central boss, and at the upper and lower edges with a web thickness of . The beam had an effective span of ; its greatest height was at the central boss; it weighed over 40 tons. The spears ran as a single main dry spear of square Memel pine to just above the high main. A 'Y' then connected the main spear both to the wet spear of the second stage pump and to the square dry spear of the bottom pump. Coulson reported that the main spear had broken 12–14 feet below the bank; the bottom dry spear was broken at a 'spear plate' (junction piece)