By Larry DunvilleY - Dearborn Overhead Crane

1 And install building steel, but runwaysteel, although similar-looking, is asignificantly different it is unlikely the contrac-tor would adopt this more stringentstandard temporarily, it is not impos-sible. The silver lining for you, thebuyer, in using the augmented specsas part of the contract is that the cor-rections no longer are your problemor Redefine the scope of build-ing contractor and Crane technicallycorrect, practically viable solution isthe least used of the three, simplybecause of lack of knowledge andhigher up-front common scope of the cranebuilder s contract is to supply and in-stall the Crane , runway rail, and con-ductor bar.

2 This leaves a critical gapin which the buyer is exposed to thepreviously mentioned problems. Thescope should be changed to moveresponsibility for the runway girdersfrom the building contractor to thecrane are, the Crane builderwill insist on very tight tolerancesfrom the steel supplier and will takeprecautions to account for reasonablefloor and column tolerances. Also,having the Crane builder s employeesinstall the runways can help to im-prove installation accuracy becausethis job is their specialty.

3 If the plantis a union plant, however, the runwayconductor bar installation should beawarded to a local electrical contrac-tor, while the Crane builder remainsresponsible for the It Right the First TimeIn summary, runway steel is notbuilding steel. Poor runways will re-sult in premature wheel failure, mo-tor and or gearbox failure, and pre-mature runway replacement. Witha typical wheel replacement costing$8,000 and new runways costing$50,000 or more, not to mentiondowntime, getting it right the firsttime can be a real bargain.

4 Using aug-mented Overhead Crane runway specsin conjunction with the informationprovided here can help you to stayout of court and maintain good rela-tions with valuable vendors. Larry Dunville is President of DearbornCrane & Engineering, 1133 E. 5th Street,Mishawaka, Indiana 46544, phone 219-259-2444, fax 219-256-6612, Web Dearborn Crane & Engineering designs, manufactures, in-stalls, and services electric Overhead travelingcranes and Crane 5 on reply cardFebruary 2001 The Permissible VariationsArea and weight variation: percent theoretical or specified out-of-square:1 64in.

5 Per in. of depth, or of flange width if it is greater than the and SweepPermissible Variation, with flange widthAllequal to or greater than6 with flange widthAllless than 6 Shapes, HP Shapes1 8in. x(total length ft.)101 8in. x(total length ft.)51 8in. x(total length ft.)10 Figure 2 This specification is for the design, fabrication, and erection of the structural steelfor buildings as published by the American Institute of Steel Construction, a runway to ensure proper installation is not as simple as itmay seem.

6 Three issues are critical to a proper analysis:1. Proper tools2. Correct measuring points3. Acceptable measuring processTaking into consideration the sag in an outstretched tape measure ormeasuring to the web and not the edge of a wide flange are just two of themany points to consider when measuring a Crane runway that you can t fix a measurement problem until you determinewhat the problem is. You could spend tens of thousands of dollars, only tofind you ve made the problem worse. Proper runway measurement is essen-tial for preventing subsequent FrameColumnSpacer RodsCrane RailCraneRunwayBeamSeparate CraneColumnBracing as RequiredBetween building Columnand Crane ColumnStiffenersFigure 3 The runway beam/girder is the wide-flange structural shape that supports the run-way, while the rail is the track upon which the end truck wheels : Copyright American Institute of Steel Construction, Inc.

7 Reprinted with permission. All rights 474 on reply card Big Bite lifting clamps byModel VLModel VL-UniversalModel HLDW New Product Catalog with 7 new models Service Center for clamp inspection, repair, and recertification Full Inventory of clamps and parts for immediate shipment Visit our web site at 800-456-2809 fax 904-786-2116 e-mail Inc.