Migrating Cranes

WESTERN EUROPE

Tall buildings rise in Europe with a minimum of traffic tie-ups and almost no noise, in pleasant contrast to the bedlam at most building sites in the U.S. Main reason for the difference is the kind of crane builders use: in the U.S. most of them use "crawler" cranes that clog streets and growl angrily under the strain of hoisting a load; in Europe, construction men have learned over the past decade to employ the self-mounting "tower" crane, which is powered by a quietly humming electric motor instead of a diesel, operates off the street--usually from the center of a building going up--and climbs along with the superstructure.

Recently the European cranes have been migrating across the Atlantic in increasing numbers. More than 450 of them are at work--on buildings from Eero Saarinen's 38-story CBS skyscraper in Manhattan to Los Angeles' new Gateway East building. The chief beneficiaries are the two main manufacturers, Sweden's A. B. Lindenkranar and West Germany's Liebherr. The cranes range in price from $35,000 to $60,000, depending on lifting capacity, v. about $90,000 for the crawler crane.

The main advantages to builders go far beyond price. As a building rises, the tower crane hoists itself from floor to floor by means of built-in hydraulic jacks. It supports itself on the building's side or on a tower that runs up inside what will later become an elevator shaft. Its counterbalanced boom can deftly pinpoint a load anywhere on the construction floor, whereas crawlers, operating from street level, can only inch a load to the edge of the floor. And the tower's heights are unlimited, while the crawler can rise no higher than 35 stories without danger of toppling. At job's end, the contractor simply disassembles the tower crane and lowers the parts to the ground.

Lindenkranar, which has plants in Sweden and licensees in England and Finland, manufactures 500 cranes a year, exports them to 17 countries and has annual sales of $5,000,000. Bigger Liebherr, with crane sales of $20 million, turns out 2,000 cranes annually, has plants in Austria, France, Ireland and South Africa in addition to seven in Germany. Both companies expect business to rise handsomely as builders around the world discover the benefits of tower cranes. "The sky's the limit," says Lindenkranar President Elis Linden, discussing the height at which his products can work--but also describing their potentialities.

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