Engineers’ Blunders.

South Canterbury Times, Issue 6246, 19 June 1890, Page 2

Engineers’ Blunders.

Technical training, says the Wellington Times, will have to be universal among handicraftsmen if they are to hold their own henceforward in the fierce competitive struggle for existence. Those who lack this training, and who rely only on rule of thumb, will year by year be more and more surely (and not slowly) crowded out of tbe field. But it is not for handicraftsmen alone that technical training is requisite. Mr Scott contends that wbile it is necessary for the workmen to bo well grounded in the true (denti&o principles which underlie his work, so.it is equally necessary* for the professional man—the engineer or architect—to possess thorough practical knowledge of detail, ss well as a theoreti-

cal acquaintance with principle. He maintains that all or nearly all the failures of bridges, dams, or buildings, which have occurred, have been due to defective design or execution rather than to natural decay or stress of weather. In cogent illustration of this view, he adduces two of the most tre-. mendous catastrophes of modern times--the collapse of the first Tay bridge and the loss of 8L.M.8. Captain. The Tay bridge, which extended for more than two miles over an arm of the sea, succumbed one stormy winter night to the pressure of a moderate gale, and its middle portion sank to tbe bottom of the sea, with a train which was on the bridge at the time, all the occupants of the train, over 70 in number, perishing. The subsequent investigations showed that “ scamped work and foolhardy ignorance ’’ were mainly blameable for the disaster. The iron columns had been cast on improper principles, and so were of unequal thickness and full of “ blow-holes.” Iron of inferior quality had been used. Innumerable loose rivets had been left in ; braces loose or with faulty ends, and bolt-holes half filled, had been passed by men who were instructed to accept only good work, but who in their ignorance fully believed that all was sufficiently safe. Thus, even had the design been perfect, ft he bridge could hardly have long withstood the force of severe storms. Ex-

amination of the plans, however, conclusively demonstrated these to be so defective that a wind force of little over 301 b per square foot would suffice to overturn the structure, while gales of . nearly or quite double this force were not infrequent on that boisterous firth. Thus, through deficient acquaintance with anemometry—an essentiil branch of engineering knowledge—a bridge structurally weak in itself was designed, and through deficient technical education the execution of the design was so faulty as to weaken it still further. The consequence was the sacrifice of more than 70 human lives. The second illustration, the Captain disaster, is also very instructive. Most people will recollect how that ship capsized one stormy

night in the Bay of Biscay, when nearly 500 human beings were helplessly drowned like vats in a trap. This ea'astivphe, too, was clearly shown to have been the result of rule-of-thurab work and defective technical knowledge, coupled, it is true, with amazing recklessness- Built as a mastless monitor, she was fitted later with masts and sails, to please the fancy of certain faddists, and further alterations wore made, nil materially affecting her seaworthiness. Yet it is clearly proved that no calculations worthy of the name were made as to the in* fluence which these radical alterations in design might Lave on her stability in a seaway. Nearly all was left to more rule of thumb. She was sent out with a freeboard of only 6ft 6in when nothing loss than Bft was safe. Her degree of stability was so low that a breeze strong enough to heel her but 14 degrees would if continuous eventually capsize her. On her first trip she encountered only half a gale, but she promptly "turned turtle” and went to the bottom with hsrerow of 500 souls. These are two vast and ghastly illustrations of the consequences of trusting rule-of-thumb work, but the minor examples are deplorably numerous. Mr Scott instances " useless harbour works, cracked walls, leaky dams, ‘sagged’ beams and ‘settled’ foundations” among the number, and he maintains—supporting his view by arguments of irresistible cogency—that these failures could not occur if all engineers, architects, builders, contractors, and workmen were properly trained in the true scientific principles of their craft, and in the nature and strength of materials. Young as is this Colony, it is old enough to have furnished its full quota of “dreadful examples” of this class. With the extension of exact knowledge and technical training these should become more and more rare.