An Unsinkable Titanic/Chapter 6
THE SINKABLE TITANIC
In all the long record of disasters involving the loss of human life there is none which appeals so strongly to the imagination as those which have occurred upon the high seas, and among these the loss of the Titanic stands out preeminent as the most stupendous and heartrending tragedy of them all. The ship itself was not only the latest and largest of those magnificent ocean liners which, because of their size and speed and luxurious appointments, have taken such a strong hold upon the public imagination, but it was popularly believed that because of her huge proportions, and the special precautions which had been taken to render her unsinkable, the Titanic was so far proof against the ordinary accidents of the sea as to survive the severest disaster and bring her passengers safely into port.
The belief that the Titanic stood for the "last word" in naval architecture certainly seemed to be justified by the facts. She was not a contract-built ship in the commonly accepted sense of that term. On the contrary, she was built under a system which conduces to high-class workmanship and eliminates the temptations to cheap work, which must always exist when a contract is secured in the face of keen competition.
The famous White Star Company have pointed with pride to the fact that the excellence of their ships was due largely to the fact that they had been built in the same shipbuilding yard and under an arrangement which encouraged the builders to embody in the ships the most careful design and workmanship. Under this arrangement, Messrs. Harland & Wolff, of Belfast, build the White Star vessels without entering into any hard and fast agreement as to the price: the only stipulation of this character being that, when the ship is accepted, they shall be paid for the cost of the ship, plus a certain profit, which is commonly believed to be ten per cent.
Of the strength of the Titanic and the general high character of her construction there can be no doubt whatever. Not only was she built to the requirements of the Board of Trade and
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Titanic shows omission of inner skin, longitudinal bulkheads, and watertight decks. Transverse bulkheads are lower by 20 feet.
Fifty Years' Decline in Safety Construction
the insurance companies, but, as we have noted, she was constructed by the leading shipbuilding company of the world, under conditions which would inspire them to put into the world's greatest steamship the very best that the long experience and ample facilities of the yard could produce.
The principal dimensions of the Titanic, as furnished by her owners, were as follows:
| PARTICULARS OF THE TITANIC | ||||
| Ft. | Ins. | |||
|
882 | 9 | ||
|
850 | 0 | ||
|
92 | 6 | ||
|
64 | 3 | ||
|
73 | 3 | ||
|
104 | 0 | ||
|
34 | 6 | ||
|
45,000 | |||
|
60,000 | |||
|
38,000 | |||
|
22,000 | |||
In this connection the following table, giving the dimensions of the most notable steamships, from the Great Eastern of 1858 to the Imperator of 1913, will be of interest. How rapidly the weight (displacement) increases with the length of these large ships, is shown by the fact that, although in length the Titanic is only about 27 per cent, greater than the Great Eastern, in displacement she exceeds her by considerably over 100 per cent.
| PARTICULARS OF NOTED TRANSLANTIC LINERS | |||||||||
| NAME | Date | Length between Perpendiculars |
Beam | Plated Depth | Displacement | Horsepower | Speed | ||
| Feet | Feet Ins. | Feet Ins. | Tons | Knots | |||||
|
1858 | 680 | 83.0 | 58.0 | 27,000 | 7,650 | 14.0 | ||
|
1888 | 528 | 63.0 | 41.9 | 13,000 | 20,700 | 21.8 | ||
|
1890 | 565 | 57.6 | 42.2 | 12,000 | 19,500 | 21.0 | ||
|
1893 | 600 | 65.0 | 41.6 | 18,000 | 30,000 | 22.01 | ||
|
1895 | 536 | 63.0 | 42.0 | 16,000 | 18,000 | 21.08 | ||
|
1897 | 625 | 66.0 | 43.0 | 20,890 | 30,000 | 22.5 | ||
|
1899 | 685 | 68.5 | 49.0 | 28,500 | 27,000 | 20.7 | ||
|
1900 | 663 | 67.0 | 44.0 | 23,600 | 36,000 | 23.5 | ||
|
1903 | 678 | 72.0 | 52.6 | 26,000 | 38,000 | 23.5 | ||
|
1907 | 709 | 75.6 | 56.9 | 40,800 | 16,000 | 17.0 | ||
|
1907 | 760 | 88.0 | 60.6 | 44,640 | 70,000 | 26.01 | ||
|
1912 | 685 | 75.5 | 52.10 | 27,000 | 45,000 | 23.5 | ||
|
1912 | 850 | 92.6 | 64.3 | 60,000 | 60,000 | 22.5 | ||
|
1913 | 880 | 96.0 | 62.0 | 65,000 | 70,000 | 23.0 | ||
_page_097.jpg)
Courtesy of Scientific American
Olympic, Sister to Titanic, Reaching New York on Maiden Voyage
deck. The highest steel deck that extended continuously throughout the full length of the ship was the shelter deck. For 550 feet amidships the sideplating of the ship was carried up one deck higher to the bridge deck. The moulded or plated depth of the ship to the shelter deck was 64 feet 3 inches and to the bridge deck 73 feet 3 inches. This great depth of over 73 feet, in conjunction with specially heavy steel decks on the bridge and shelter decks, and the doubling of the plating at the bilges, (where the bottom rounds up into the side,) conjoined with the deep and heavy double bottom, served to give the Titanic the necessary strength to resist the bending stresses to which her long hull was subjected, when steaming across the heavy seas of the Atlantic. The doubling of the plating on the bridge and shelter decks served the same purpose as the cellular steel construction which, as mentioned in the previous chapter, was adopted for the upper deck of the Great Eastern.
The dimensions of the frames and plating of the hull were determined by the builder's long experience in the construction of large vessels. The cellular double bottom, which extended the full width of the ship, was of unusual depth and strength. Throughout the ship, its depth was 5 feet 3 inches; but in the reciprocating engine-room, it was increased to 6 feet 3 inches. The keel consisted of a single thickness of plating, 1½ inches thick, and a heavy, flat bar, 3 inches in thickness and 19½ inches wide. Generally speaking, the shell plates were 6 feet wide, 30 feet long, and 2½ 2 to 3 tons in weight. The largest of these plates was 36 feet long and weighed 4¼ tons.
Amidships, the framing, which consisted of channel sections 10 inches in depth, was spaced 3 feet apart. Throughout the boiler-room spaces, additional frames, 2½ feet deep, were fitted 9 feet apart, and in the engine- and turbine-rooms, similar deep frames were fitted on every second frame, 6 feet apart. These heavy web-frames extended up to the middle deck, a few feet above the water-line, and added greatly to the strength and stiffness of the hull.
Had the inside plating of the double bottom been carried up the sides and riveted on the inner flanges of these frames, as shown in the sketch on page 107, it would have served the purpose of an inner skin; and when the outer skin of her forward boiler-rooms was ruptured by the iceberg, it would have served to prevent the inflow of water to these two large compartments. Mr. Ismay, the President of the International Mercantile Marine Company, in his testimony at the Senate Investigation, stated that among the improvements, which would be made in the Gigantic, now under construction for the company, would be the addition of an inner skin. Doubtless he had in mind the construction above suggested.
The 10-inch channel frames extended from the double bottom to the bridge deck, and some of these bars were 66 feet in length and weighed nearly 1 ton apiece. The frames were tied together along the full length of each deck by the deck beams of channel section, which, throughout the middle portion of the ship, were 10 inches deep and weighed as high as 1¼ tons apiece. The transverse stiffness of the framing was assured by stout bracket knees, riveted to the frames and deck beams at each point of connection, and by the 15 watertight bulkheads, which were riveted strongly to the bottom and sides of the ship, and also by 11 non-watertight bulkheads, which formed the inner walls of the coal bunkers on each side of the main bulkheads.
The bridge, shelter, saloon, and upper decks were supported and stiffened by four lines of heavy longitudinal girders, worked in between the beams, which were themselves carried by solid round pillars placed at every third deck beam. In the boiler-rooms, below the middle deck, the load of the superincumbent decks was carried down to the double bottom by means of heavy round pillars. Such was the construction of the Titanic; and it will be agreed that, so far as the strength and integrity of the hull were concerned, it was admirably adapted to meet the heavy stresses which are involved in driving so great and heavy a ship through the tempestuous weather of the North Atlantic.
The first sight of such a gigantic vessel as the Titanic produces an impression of solidity and invulnerability, which is not altogether justified by the facts. For, to tell the truth, the modern steamship is a curious compound of strength and fragility. Her strength, as must be evident from the foregoing description of the framing of the Titanic, is enormous, and
_page_103.jpg)
ample for safety. Her fragility and vulnerability lie in the fact that her framework is overlaid with a relatively thin skin of plating, an inch or so in thickness, which, while amply strong to resist the inward pressure of the water, the impact of the seas, and the tensile and compressive stresses due to the motion of the ship in a seaway, etc., is readily fractured by the blow of a collision.
In a previous chapter it was shown that when the Titanic is being driven at a speed of 21 knots, she represents an energy of over 1,000,000 foot-tons. If this enormous energy is arrested, or sought to be arrested, by some rigid obstruction, whether another ship, a rock, or an iceberg, the delicate outside skin will be torn like a sheet of paper.
It was shown in Chapter IV that protection against flooding of a ship through damage below the water-line is obtained by subdividing the hull into separate watertight compartments, and that, roughly speaking, the degree of protection is proportionate to the extent to which this subdivision is carried. Applying this to the Titanic, we find that she was divided by 15 transverse bulkheads into 16 separate compartments. But, in this connection it must be noted that these bulkheads did not extend through the whole height of the ship to the shelter deck, as they did in the case of the Great Eastern, and therefore it cannot be said that the whole of the interior space of the hull received the benefit of subdivision. As a matter of fact, only about two-thirds of the total cubical space contained below the shelter deck was protected by subdivision. Water, finding its way into the ship above the level of the decks to which the bulkheads were carried, was free to flow the whole length of her from stem to stern. Furthermore, the value of the subdivision below the bulkhead deck depends largely upon the degree to which this deck is made watertight. If the deck is pierced by hatchways, stairways, and other openings, which are not provided with watertight casings and hatch covers, the integrity of the deck is destroyed, and the bulkhead subdivision below loses its value.
It was largely this most serious defect—the existence of many unprotected openings in the bulkhead deck of the Titanic—that caused her to go down so soon after the collision.
Referring now to the side elevation of
_page_107.jpg)
the Titanic on page 129, it will be noted that the only bulkhead which was carried up to the shelter deck was the first, or collision bulkhead. The second bulkhead extended to the saloon deck, and on the after side of this and immediately against it was a spiral stairway for the accommodation of the crew, which led from their quarters down to the floor of the ship. Here the stairway terminated in a fireman's passage, which led aft through the third and fourth bulkheads, and gave access through a watertight door to the foremost boiler-room. The seven bulkheads, from No. 3 to No. 9, extended only to the upper deck, which, at load draft, was only about 10 feet above the water-line. Bulkhead No. 10 was carried up one deck higher to the saloon deck, as were also bulkheads 11, 12, 13, and 14. Bulkhead No. 15 terminated at the upper deck.
Now, it will be asked: what was the factor in the calculations which determined the height of these bulkheads? The answer is to be found in the Board of Trade stipulations, to which reference was made in Chapter IV, page 62. These stipulations establish an imaginary safety line, below which a ship may not sink without danger of foundering. The safety line represents the depth to which a ship will sink when any two adjoining compartments are opened to the sea and therefore flooded. If the two forward compartments are flooded, for instance, the bow may sink with safety, until the water is only three one-hundredths of the depth of the ship, at the side, from the bulkhead deck. If two central compartments are flooded, the ship is supposed to settle with safety until the bulkhead deck at that point is only three one-hundredths of the depth of the side, at that place, above the water.
The raising of the height of the bulkheads, by one deck, at the engine-room, is due to the operation of this rule; for here the two adjoining compartments, those containing the reciprocating engines and the turbine, are the largest in the ship, and their flooding would sink the ship proportionately lower in the water.
Now it takes but a glance at the diagrams on page 66 to show that the application of the Board of Trade rule brought the bulkhead line of the Titanic down to a lower level than that of any of the other notable ships shown in comparison with her. It was the low bulkheads,
_page_111.jpg)
Courtesy of Scientific American
Twenty of the Twenty-nine Boilers of the Titanic Assembled, Ready for Placing in the Ship
acting in connection with the non-watertight construction of the bulkhead deck, that was largely answerable for the loss of this otherwise very fine ship.
Another grave defect in the Titanic was the great size of the individual compartments, coupled with the fact that the only protection against their being flooded was the one-inch plating of the outside skin. If this plating were ruptured or the rivets started along the seams, there was nothing to prevent the flooding of the whole compartment and the entry, at least throughout the middle portion of the ship, of from 4,000 to 6,000 tons of water—this last being the approximate capacity of the huge compartment which contained the two reciprocating engines. Now, if safety lies in minute subdivision, it is evident that in this ship safety was sacrificed to some other considerations. The motive for the plan adopted was the desire to place the coal-bunkers in the most convenient position with regard to the boilers. By reference to the hold plan of the Titanic, page 129, it will be seen that her 29 boilers were arranged transversely to the ship. With the exception of the five in the aftermost compartment, they were "double-ended," with the furnaces facing fore and aft. To facilitate shovelling the coal into the furnaces, the coal-bunkers were placed one on each side of each transverse watertight bulkhead. The coal supply was thus placed immediately back of the firemen, and the work of getting the coal from the bunkers to the furnaces was greatly facilitated. Now, while this was an admirable arrangement for convenience of firing, it was the worst possible plan as far as the safety of the Titanic was concerned; since any damage to the hull admitted water across the whole width of the ship. The alternative plan, which should be made compulsory on all large ocean-going passenger steamers, is the one adopted for the Mauretania, Kaiser Wilhelm II, Imperator, and a few other first-class ships, in which the coal-bunkers are placed at the sides of the ship, where they serve to prevent the flooding of the main boiler-room compartments. It is probable that any one of the ships named would have survived even the terrific collision which sank the Titanic.
The objection has been raised against longitudinal coal-bunkers, that they are not so conveniently placed for the firemen. A large force of "coal passers" has to be employed in wheeling the coal from the bunkers to the front of the furnaces. This, of course, entails an increased expense of operation.
The use of transverse coal-bunkers must be regarded as one among many instances, in which the safety of passenger ships is sacrificed to considerations of economy and convenience of operation.