TRANSPORTATION AND ERECTION 197 



work. Some very large coils must be heated internally with 

 current. Direct current is best for this purpose. Usually one of 

 the exciter sets will be of the proper capacity; failing this it may 

 be necessary to secure an electrolytic generator of the proper 

 capacity and drive this by motor or engine. Current is also 

 needed for heating the coils in the split where the armatures are 

 shipped in sections. 



Crane Service. This is usually the cause of considerable 

 friction between the various erectors and oftentimes one man will 

 tie up the crane unnecessarily simply to prevent some other gang 

 from using it, although this action is delaying the job as a whole. 



The general superintendent, or resident engineer, should 

 allot the crane without fear of favor, considering the progress of 

 the work as a whole, or else allot it to the various gangs for stated 

 periods. In some cases the scheme of allowing the wheel erector 

 the crane mornings and the generator erector afternoons has 

 worked well. Both men can then plan their work ahead and avoid 

 delays. 



Protective Features. All electrical apparatus and finely 

 finished parts of all machines must be protected from injury by 

 water, dirt and falling material during the erection and until the 

 power-house is roofed and glazed. In most cases a liberal supply 

 of tarpaulins will answer, although some cases warrant a tem- 

 porary shelter of lumber and roofing paper. 



Some fire-fighting equipment should be installed before start- 

 ing the erection. Trash, excelsior, packing cases and skidding 

 should be cleaned out promptly, as the fire danger is great under 

 the best conditions. Competent watchmen should be in charge 

 whenever the erectors are not working, to guard against fire, 

 thieves and malicious mischief. This last is by no means a negli- 

 gible item, as every large installation sooner or later shows dam- 

 age, or attempted damage, of this character. 



It is unsafe and almost foolhardy to start any machine while 

 the general construction is going on without a thorough inspection 

 just before turning over. There are numberless cases where these 

 inspections have brought to light bolts, tools, rocks and miscella- 

 neous metal that had no excuse for being anywhere near the 

 machine. These pieces are always in the air gap or at some 

 adjacent point where the motion of the magnetic field will draw 

 them into the air gap. 



