Union Electric Welding Co

of 14-16, Cockspur Street, London, S.W.1.

Welding Contractors, Ship and Boiler Repairers.

1921 'REPAIRING THE FRAME OF A DIESEL ENGINE.
An interesting application of electric welding to the repair of a large casting was recently carried out at the St. Martin’s-lane sub-station of the Charing Cross, West End and City Electricity Supply Company, Limited. A three-cylinder Sulzer-Diesel engine of 600 brake horse-power capacity fractured the base of the columns supporting the end cylinder, one column being completely broken off and the opposite having cracks running inwards from each side, so that only a comparatively narrow strip of solid metal left at the centre. The fractures took place just above the flanges by which the columns were bolted to the bedplate, the broken metal varying from 2 1/2 in. to 3 1/2 in. in thickness at this point. The cause of the breakdown was water in the cylinder, leakage having occurred through a faulty jacket.
It was decided to attempt to repair the fracture by means of electric welding, the oxy-acetylene process being unsuitable because it would have involved dismantling the engine in order to heat the casting. The work was entrusted to the Union Electric Welding Company, Limited, of 14, Cockspur-street, London, S.W. 1, who undertook to carry out the repair on site without disturbing the engine. The first thing to be done was to chip out a vee-groove along the cracks on both the inside and outside of the columns, this groove being 2 1/2in. wide and varying in depth with the thickness of the casting. A double line of small studs was then screwed into the chipped faces, studs being inclined to the normal face of the casting, and thus acting as an anchorage for the metal with which the grooves were to be filled. The grooves were next welded up solidly so as to restore the metal which had been removed by chipping The electrodes used were of the "A.W.P." brand, approximately 700 ft. of electrode being used up in the work, representing about 50 lb. of added metal. In addition to this the joint was strengthened by a steel gusset plate at each side of the column, connecting the flange with the column wall. These gusset plates were fastened entirely by electric welding, and while they add considerably to the security of the job they do not detract from its appearance.
The welding up of the fractured columns was done in sections of 9 in. at a time, and every care was taken to ensure the added metal being thoroughly united with the original metal of the casting. The photograph reproduced in the subjoined illustration [not included here] shows the character of the job, and its appearance when almost completed. The current for welding was supplied by the Charing Cross Company, so that the only equipment which had to be brought by the Union Electric Welding Company, Limited, consisted of a portable resistance, the electrode holders and some cables. The pneumatic chisels used for chipping out the grooves were supplied with air from a portable compressor.
By the courtesy of Mr. C. M. Mayson, the Substation's Engineer, we were able to examine the finished job, the engine being on load at the time, and the repair appeared to be all that could be desired. As we have already indicated, it was carried out without dismantling the engine in any way, and the engine was running on load again within four weeks of the commencement of the repair work.

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