There is, therefore, ample evidence that the strip steel was inferior, We learn that before the increase of the Marine Surveyor Staff in 1929, recognised—steelmakers' certificates were accepted for new strips, and B.O.T. certificates were not insisted on, but that since 1929 either they are produced or B.O.T. tests are applied locally.
As regards the adequacy of the survey, all the experts agree that if fatigue along the lap joint caused ihe failure, no examination of the boiler, external or internal, could detect it: the hydraulic test is usually relied on to show such a defect, ud undoubtedly is a case where it failed to do so, probably because such cracks as there were microscopical at that time.
Corrosion pitting as the cause of failure has been ruled out, as no such pitting exists in the whole boiler shell, There is also evidence that the crack was wholly internal, as there were no signs of its having been external when the boiler was examined just after its salvage on May 18. The inspection in 1936 appears to have been thorough and adequate.
Text read from the printed page and cleaned; old type leaves the occasional error.