8 METHOD OF CONSTRUCTION OF CONCRETE SHIPS. 



line lor which they were intended. It was then a simple matter to apply the di- 

 mension A, B and C at the critical points M, U and L, Fig. 30 (a), and obtain points 

 which when connected gave the proper width of form for the entire length. At 

 this stage all brackets and beams framing in to the frames as shown on the frame 

 detail were provided for, so that the measuring and fitting in the ship were reduced 

 to a minimum. 



The next step was to assemble the W of one frame with an N of another and 

 connect them with the panel forms P, Fig. 30 (c). Before the forms A'^ and W 

 were lifted from the floor, water-lines and offsets in even feet were scribed on-; for 

 example, in Fig. 31 (a), Plate 10, the 12-foot and 24-foot water-lines and 20-foot 

 and 18-foot offsets. This, of course, coordinated them precisely in two dimen- 

 sions and gave the proper position which they would occupy in the ship. There only 

 remained to place them in some sort of a rigid rig which would maintain them in 

 their proper relation, the correct distance apart, while the panel boards P were being 

 nailed on and the whole form braced so that it could be handled and erected. 



Fig. 31 (&), Plate 10, shows sketches of this rig. The panel boards were nailed 

 to cleats on the sides of the forms in approximate length. They were then sawed 

 with their edges in the same plane as the side of the frame, so that the right-angled, 

 beveled chamfer strip could be nailed on. 



It is worthy of note that the forms built up in this way fitted the varying bevels 

 of the shell with great accuracy and no trouble was experienced in maintaining the 

 proper shell thickness at all places. 



INSERTS. 



There are from 5,000 to 6,000 so-called "inserts" or fittings which must be cast 

 into the hull of the concrete ship as the concrete is placed. These are composed 

 largely of anchor bolts, sockets, pipe sleeves and miscellaneous holes which must 

 be provided for attaching equipment and furnishing openings for pipes, drains, etc. 

 There are also many large inserts which must be provided, such as stern frame, 

 stem plate, hawse pipes, sea chests, outboard discharge fittings and the like. Large 

 fittings like the cast-steel stern frame and stem shoe were anchored to the concrete 

 by means of bars which were bolted or riveted to the fitting-s, and the free ends of the 

 bars were cast into the concrete. There was a wide difference of opinion as to the 

 type of anchorage which should be provided to secure the stern frame to the hull, 

 and certain variations of the construction of this detail were permitted. Sea chests 

 and all other large pipe connections were provided with large flanges on either face, 

 and the reinforcing bars were placed between the flanges, which were later filled 

 with concrete, the faces of the flanges being in a plane with the surface of the fin- 

 ished concrete wall. 



Wherever possible, the inserts were placed on the forms immediately after the 

 forms were erected and before the reinforcing steel was placed. Bolts, sockets, and 

 similar fittings for securing equipment were usually set in fixed templets fastened 

 in the forms. 



