Blessing

When an Army engineer prophesied last fall (TIME, Oct. 26) that some fine day the shattering clangor of pneumatic rivet-hammers would no longer be heard upon the metallic skeletons of city buildings, having been replaced by electric welding devices, the urban public pricked its abused ears and hotel managers sighed their hopes.

Last fortnight the prophecy of this blessing to mankind had its first fulfillment. The Morgan Engineering Co., of Alliance, Ohio, announced the completion of a two-story automobile sales and storage plant, built throughout with metal lumber, welded throughout electrically. Not a single rivet was used.

Comparison of the estimates for riveting with the actual figures for the welding was overwhelmingly in favor of the new method. In labor costs it had saved 23%. Where riveting-gangs of four men would have been required, single operators had manipulated portable arc-welders, thus interfering less with other workmen. The time saved was over 20%. Strength tests showed the welded joints to be 100% strong, as against a 65% to 70% average for riveted joints--that is, the welds were as strong as the girders they joined, often stronger under test stresses. Rivets shear or rip out their holes sooner than the girders break.

Electric welding is not new to machine shops, especially locomotive works, but for structural steel work a new type of welder had to be evolved. The "Stable-Arc" welders used by the Morgan Co. were built by the Lincoln Electric Co. of Cleveland and mounted on hand trucks. The process: a high frequency arc up to 300 volts is applied to a bar of steel corresponding to a bar of tinsmith's solder, which is pressed along the crevice between two surfaces that are to be joined. The bar is melted, as are both the girder surfaces along the line of the joint, and the molten strip thus formed fuses instantly to a connection of solid metal.