Water Tight Compartments
The two main ideas were carried out in the Titanic. One was comfort and the other stability. The vessel was planned to be an ocean ferry. She was to have only a speed of 21 knots, far below that of some of the modern vessels, but she was planned to make that speed, blow high or blow low, so that if she left one side of the ocean at a given time she could be relied on to reach the other side at almost a certain minute of a certain hour.
One who looked into modern methods for safeguarding a vessel of the Titanic type can hardly imagine an accident that could cause her to founder. No collison such as has been the fate of any ship in recent years, it has been thought up to this time, could send her down, nor could running against an iceberg do it unless such an accident were coupled with the remotely possible blowing out of a boiler. She would sink at once, probably, if she were to run over a submerged rock or derelict in such manner that both her keel plates and her double bottom were torn away for more than half her length; but such a catastrophe was so remotely possible that it did not even enter the field of conjecture.
The reason for all this is found in the modern arrangement of water tight steel compartments into which all ships now are diveded and of which the Titanic had fifteen so disposed that half of them, including the largest, could be flooded without impairing the safety of the vessel. Probably it was the working of these bulkheads and the water tight doors between them as they are supposed to work that saved the Titanic from sinking immediately when she struck the iceberg.
These bulkheads were of heavy sheet steel and started at the very bottom of the ship and extended right up to the top side. the openings in the bulkheads were just about the size of the ordinary doorway, but the doors did not swing as in a house, but fitted into water tight grooves above the opening. they could be released instantly in several ways, and once closed formed a barrier to the water as solid as a bulkhead itself.
In the Titanic, as in other great modern ships, these doors were held in place above the openings by friction clutches. On the bridge was a switch which connected with an electric magnet at the side of the bulkhead opening. The turning of this switch caused the magnet to draw down a heavy weight, which instantly released the friction clutch, and allowed the door to fall or slide down over the opening in a second. If, however, through accident the bridge switch was rendered useless the doors would close automatically in a few seconds. This was arranged by means of large metal floats at the side of the doorway, which rested just above the level of the double bottom, and as the water entered the compartments these floats would rise to it and directly release the clutch holding the door open. These clutches could also be released by hand.
It was said of the Titanic tht her compartments could be flooded as far back or as far forward as the engine room and she would float, though she might take on a heavy list, or settle considerably at one end. To provide against just such an accident as she is said to have encountered she had set back a good distance from the bows and extra heavy cross partition known as the collison bulkhead, which would prevent water getting amidships, even though a good part of her bow should be torn away. What a ship can stand and still float was shown a few yaers ago when Suevic of the White Star Line went on rocks on the British coast. The wreckers could not move the forward part of her, so they separated her into two sections by the use of dynamite , and after putting in a temporary bulkhead floated off the after half of the ship, put it in dry dock and built a new forward part for her. More recently the battleship Maine, or what was left of her, was floated out to sea, and kept on top of the water by her water tight compartments only.