When the square-frames have been set up, the stem and main stern-frames are then erected and the keelsons and deadwood put down and fastened, after which the half frames or cants are set up, thus completing the frame.

Half frames and cants are assembled on small platforms to one side of the ship, and since they are in separate halves horning and half-breadth battens cannot be used. To assemble the lower tier to the proper shape, the timbers are placed on the platform in their proper order and shifted until they fit the mold from which they were marked out. This tier is dogged down, the butts cut in, and then refaired and dogged fast in the same maimer as described for square-frames. The top tier is also handled in the same way as described for the top tier in square-frames.

To assist in placing half frames or cants, curved timbers called harpins are used. For the bow they extend from the stem to and past the last square-frame, as shown in Fig. 54. For the stern they will extend from the knuckle, rim, or last transom frame, as the case may be, to and past the last square-frame. In either case they follow the true shape of the vessel. Molds for these harpins are furnished from the loft and they are usually sawn to shape from straight grained timber.

At the bow harpins are usually set on a water-line, as shown in Fig. 54. At the stern they are set on a buttock line. Putting it another way, the harpins at the bow will curve in a horizontal direction only, while those at the stern will curve in a vertical direction only.

The frame centers should be marked on each harpin, as this will avoid the trouble of spacing around the curve of the bow and stern. With the harpins in place, forming a cradle in which the half frame or cant may rest, the fitting of the heels of these frames remains as the only troublesome task. In some yards where the heels are dapped into the deadwood, the mold is set up in the position of the frame after the dap has been cut and the heel of the mold corrected, after which the heel of the frame may be corrected very accurately before the frame is slung into position. Even with this precaution, some refitting is very often necessary.

Figure 55. Bow Framing - Showing Two Differemt Types.

As soon as a pair of half frames or cants is in position they should be cross-pawled to take the weight off the harpins. If this is delayed too long the weight of the frames will spring the harpins out of their true curve. It is good practice to scribe the length of the cross-pawls from the loft at a stated height', then the frames can be brought to the marks on the cross-pawl and there is no danger of the spring of the harpin throwing the frame out of proper alignment.

For purposes of illustration, in Fig. 54 the harpins are shown on the 16-foot and 30-foot waterlines. In practice they may be placed on any suitable waterline. Harpins for the stern are not shown, as they involve precisely the same principles.

Figure 55 shows bow-framing of two types, cants, and half frames. Cants are seldom used at the bow of steamers but are frequently used at the stern. This figure also shows the knight-heads as usually fitted to a steamer. The knight-heads here are fitted to fill out the bearding on the stem so as to obtain the proper room for the planking fastening. They are molded from single timbers and fit solid against the apron and stem. Knight-heads should be fastened with bolts driven through both knight-heads and apron and clinched on each end.

Where the anchor hawse pipes cut through the hull the space between the frames is filled solid with a timber extending some distance above and below the hole. This timber, or there may be more than one, is called the hawse timber. Fastening should be kept clear of the location for the hole. The procedure for hawse pipe holes also holds good for any opening to be cut in the bottom or sides of the hull and, before the planking or ceiling is put on, the spaces between frames in way of such opening should be chocked solid.

Heels of half frames or cants at the bow may be fitted to the deadwood in three different ways, as shown in Figs. 56, 57 and 58. The plain fit, shown in Fig. 56, is seldom used except in small vessels, and even for them it cannot be considered the best construction. The dapped fit, shown in Fig. 57, is most commonly used. However, the style shown in Fig. 58 has all of the advantages of the dapped fit, and the additional advantage of providing a limber for drainage at the ends of the vessel.

Heels of cants and half frames at the stern are fitted in the same manner as those at the bow, though structural arrangements may often prevent their being dapped in.