Industrial unionism
Industrial unionism is a labour union organizing method through which all workers in the same industry are organized into the same union—regardless of skill or trade—thus giving workers in one industry, or in all industries, more leverage in bargaining and in strike situations. Advocates of industrial unionism value its contributions to building unity and solidarity, many suggesting the slogans, "an injury to one is an injury to all" and "the longer the picket line, the shorter the strike."
Industrial unionism contrasts with craft unionism, which organizes workers along lines of their specific trades, i.e., workers using the same kind of tools, or doing the same kind of work with approximately the same level of skill, even if this leads to multiple union locals (with different contracts, and different expiration dates) in the same workplace.
Perceived disadvantages of craft unionism
In 1922, Marion Dutton Savage cataloged the disadvantages of craft unionism, as observed by industrial union advocates. These included "distressingly frequent disputes between different craft unions" over jurisdiction; modern industry results in a constant process of phasing out old skills; one trade doing the struck work of another entity is a frequent dilemma; expiration of contracts can be staggered, hindering coordination of strikes. Industrial unionists observe that craft union members are more often required by their contracts to cross the picket lines established by workers in other unions. Likewise, in a strike of (for example) coal miners, unionized railroad workers may be required by their contracts to haul "scab" coal.