There are many styles of stern-frames, three of which, being typical, are shown in Figs. 63, 64, 65 and 66. Figure 63 shows the center-line construction of a stern-frame that is almost universally used on small single deck western steamers, called steam schooners, and Fig. 64 shows the same frame completed. This construction is peculiar in that from the propeller-post aft, the center-line timbers are so arranged that a series of transom frames may be fitted, thus securing great thwartship strength at this point. One of these transom frames is illustrated in Fig. 59.

These sterns are fitted with a rim, having a rabbet for the plank ends, and supported by the horn timbers and transom frames. It will be noticed that the horn timbers extend over the top of the rim, to and against the solid work around the stern, thus affording an opportunity to drive several clinch bolts through rim and ends of the horn timbers. The ceiling, when laid, is also carried up over the rim, where possible, to and against the solid work, and is well fastened into the rim. The top of the rim is left flat and the decking, where the ceiling does not land in the way, is carried to the solid work and fastened into the rim. These vessels are fitted with a heavy fender or guard strake in line with the rim, this strake being scarfed to the forward ends of the latter, as shown in the figure.

The solid work around the stern extends to the first frame carried above the deck and carries all of the detail of the bulwark, rail, etc. This feature will be more fully discussed later on.

The poop erection on these vessels is often very short, and forward of same, in way of the bulwark, but one-half of the frame, that is, the stanchion, is carried above the deck, as shown in Fig. 64.

The figure shows the rudder trunk stopped at the main deck, but very often this is carried up to the poop deck. Other details may vary somewhat, according to the size of the vessel and the ideas of the builder, but in general the construction shown is typical, and forms a valuable basis of comparison with the other detail arrangements of sterns shown in Figs. 65 and 66. The latter types are at present being used on large vessels and while quite different in detail construction, both are considered good for the particular class of vessel in which they are used.

The center-line construction in Fig. 65, it will be seen, consists of a large propeller- or stern-post backed by the ends of the keelson, shaft-log, and deadwoods, and supporting by means of two very large natural crook knees, a false rudder-post, upon which, later, is mounted the bearing for a steel rudder. The rudder trunk is fitted and fastened to the after side of the false rudder-post. The lower knee is dapped into the propeller post at B to provide support in addition to that given by the fastenings.

Figure 63. Stern Frame As On Typical Single Deck Western Vessel.

Figure 64. Stern Frame As On Typical Single Deck Western Vessel.

On each side of this center-line detail, is placed a horn, or whisker timber, extending from the shaft-log to the knuckle. These timbers are slightly dapped into both the propeller and false rudder-posts. The space between them is filled solid with wood extending above their top edges, against which extension, later, the ceiling is butted. Aft of the false rudder-post this filler also extends below the edge of the whiskers to form a butt rabbet for the outside planking. Outside, a knuckle timber is fitted, carried around the stern until the side becomes straight enough to carry planking unbroken to the poop, or shelter, deck. The under side of this knuckle timber shows a rabbet for the lower hull planking. The planking above the knuckle runs parallel with the knuckle and the top face of the knuckle timber becomes, therefore, a seam.

A small rim is fitted inside the cants with its top face on the deck line, to receive the ends of the decking.

It will be noticed that the cants and half frames land on the whiskers, and that they are so molded that the planking will land on and fasten to the outer face of the timbers, while the ceiling will land on and fasten to the inner face of the timbers.

A steel knee is fitted at the lower end of the propeller-post onto the keel, and on the under side of the keel a steel shoe is fitted, with long side straps extending up each side of the propeller-post, the shoe also extending aft to carry the lower bearing of the steel rudder. The side straps of the shoe are clinch bolted to each other through the propeller-post. The lower leg of the knee is clinch bolted to the shoe through the end of the keel, and the upper leg is bolted through the propeller-post with bolts having nuts on each end, the nuts on the forward end being mortised in. These mortises are afterwards filled with cement. The extension of the shoe along the keel is also well fastened with heavy drift bolts.

Detail arrangement of fastening for the center-line timbers of this stern is shown in Fig. 67.

Figure 66 shows a center-line detail consisting of a large propeller, or stern-post, backed on the forward side by the ends of the keelsons, shaft-log, and deadwoods, and joined to the keel by a natural crook wood knee. Aft of the propeller-post is a full wood rudder-post stepped to the end of the keel, and the space between the upper ends of the two posts is filled solid with vertically disposed deadwood fillers, flush with the siding of the posts. Arch knees are fitted across the lower ends of these fillers to finish off and strengthen the construction. On each side of the upper ends of the posts there is a horn timber extending aft to, and supporting, the rim, which is here placed some distance above the deck line. Between the forward ends of the horn timbers there are several tiers of deadwood extending to the shaft-log, the lower ends fitting between the side pieces C, which are placed on top of the log at each side. The tops of the propeller-post and fillers show cuts in way of deck beams so that they may be carried through from side to side in one piece. The sterns of these vessels above the rim are generally built up of solid work, as indicated in the figure. Some have been built with radial frames extending up from the rim and mortised into the same, but this construction is somewhat weaker than that obtained with the solid work.

The lower face of the arch knees is lined with a steel reinforcing strap extending down on each post and well fastened.

Side plates of steel are fitted on each side of the keel, with arms extending up on the propeller- and rudder-posts. These plates are fastened to each other through the keel and posts with clinched bolts.

Fastening for this type of stern is shown in detail in Fig. 68. Details for this and other fastening discussed here, are usually shown on the plans of the ship, which may vary considerably in detail arrangement from that shown in these figures. Sizes of bolts are not indicated in the figure, as they vary with the sizes of the timbers and the requirements of the Classification Society under which the vessel is being built.

Figure 65. Stern Frame - Special Type With Steel Rudder.