Extensive external corrosion, where the plates rested against the brickwork, rendered the boiler too weak to bear the ordinary pressure.
No.53. Norwich. ([Fig. 23.])
September 25th.
7 killed.
Fig. 23.
One Tube Cornish, 20ft. long, 4ft. 6in. diameter, tube 2ft. 6in. diameter, 3/8 inch plates, 100 lbs. It was double-rivetted, and the crown of tube was strengthened with angle iron. The shell was formed of six rings, each of two plates alternately jointed top and sides. The third ring from the front had stripped off, and was thrown to the right and forwards against a wall. The line of rent was confined to the plates forming the ring, which was an outer one, and covered the two adjoining rings in the laps, the rent being from the edge of the inner lap to the nearest rivets. The first rent had taken place in the solid iron, about 1 inch from the rivets of a seam on one side, and from this the rent had extended along the seams on either side, and of course the whole ring soon tore off when the equilibrium was destroyed by the first rent.
The fittings of the boiler were sufficient, except that there was only one safety valve, and that was so constructed that it could only open a very little way.
The cause was a defect in the iron at the point of the first rent, and accumulated pressure during the time of standing.
No.54. Macclesfield.