SKELETON

Early stages of construction on Olympic. The double-bottom is in place and work has started on the Tank top. At the far end of the gantry, the jib of the floating crane can be seen.

Once the keel and the Tank top were finished, the next stage of construction concerned the frames, or transverse ribs, which were of various designs and sizes depending on where they were to be used. These, supported by girders, pillars and beams, made up the skeleton of the ship. This gigantic scaffolding was spaced out with frames relatively close to one another. For this purpose, the hull had to be divided into a series of numbered fore and aft (F and A) segments from an unnumbered central point in the precise middle of the ship. The frames either side of this central position were designated 1F and 1A, and so on fore and aft until reaching the aftermost frame, 148A, and the

August 1909, and the after-end frames at the

Foremost, 156F. Fore numbers 156-134 were spaced at 2 feet; 134-119 at 2 feet 3 inches; 119-107 at 2 feet 6 inches; 107-95 at 2 feet 9 inches; and 95 to amidships at 3 feet. Moving aft, amidships to 111 were at 3

Feet; 111-121 at 2 feet 9 inches; 121-133 at 2 feet 6 inches; 133-148 at 2 stern of Olympic

Are in place.

Feet 3 inches.

Erecting the structure was exacting. Girders were cut to slightly longer than required. The rivet holes were punched in and then the girders were bent to shape before being trimmed to their exact size. The rest of the structure was made up principally of web-frames for greater strength and rigidity, beams to unite the frames in terms of struts and ties and to support the deck-plating, and solid, vertical pillars that supported the transverse beams. Extra support was given to the engine - and boiler-room floors.

The near-vertical stem, which is the foremost part of the hull, was formed from castings and bars made by the Darlington Forge Company and totaled 7.5 tons in weight. It was joined to the keel by a cast-steel forefoot weighing an additional 3.5 tons, and was a virtual upward extension of the keel, bound securely to the main structure by the shell plating.

At the other end of the ship, the stern frame was designed to provide support for the rudder and the shaft for the center propeller, which would be driven by Titanic’s turbine engine. It had a hole in it, of course, through which the shaft connected to the propeller. There was a stern-post to which the rudder was attached, and this also supported the somewhat slender but still massive rudder. The post needed to be as strongly built as possible because the lower part of it stood free of the hull itself, and it had to withstand the vibrations set up by the propeller and the lateral force exerted by the rudder as it turned.

The whole assembly, and the brackets that would support the port and starboard propellers, driven by the two reciprocating engines, was designed by Harland & Wolff, as was the rudder itself. But each of the huge constituent parts was made by the Darlington Forge Company, and nearly all the pieces were manufactured from Siemens-Martin mild steel. The rudder gudgeons—the lugs forged on the stern-post on which the rudder was hung and hinged—were lined with removable gunmetal bushings since these holes took a lot of strain, and replacing worn-out bushings was easier, faster and less costly than replacing the whole post.

Similarly, the stern frame itself was cast in two pieces, bound together by scarves (joints made by notching the ends of two pieces of timber or metal so that they lock together end to end). The justification for this was that if one part (usually the lower) were damaged, it could be replaced without the need for replacing the whole stern-post. This plan failed, though, when Olympic collided much later with the Fort St. George in New York harbor and the resultant damage was so severe that the entire stern frame of Olympic had to be replaced. Some indication of the difficulty of doing this may be deduced from the fact that the frame weighed 70 tons and had a height of just over 67 feet.

The two wing propeller bracket casts stood clear of the line of the hull, but were cased in steel plates called bossings.