Concrete Silos 83 



from a small auxiliary platform suspended below the 

 main platform of the scaffold. As the construction is 

 carried up, the mast is raised 'by means of two cast-steel 

 worm-geared winches. 



The door on this silo is of the continuous type. It 

 has a gas pipe running through the concrete on each 

 side, and around which the ladder irons are engaged. 

 The gas pipe has several strands of wire extending 

 around it at frequent intervals and running back into 

 the concrete 2 or 3 feet in order to provide a sufficient 

 anchorage. The doors themselves are of wood. 



A special roof form, making a concrete roof, with 

 dormer, is also supplied if desired. 



