Page 29 - British Inquiry into Loss of RMS Titanic Day 19 - 22

believe happened. 20426. We know that in these watertight bulkheads there are watertight doors? - Yes. 20427. At the bottom of the ship, descending vertically? - Yes. 20428. And capable of being actuated from the bridge? - Capable of being actuated from the bridge, amongst other places. 20429. In the alleyways, I think, sliding laterally? - Yes. 20430. Because they could not descend vertically through the next deck? - Yes. 20431. And actuated by hand either on that deck or on the deck above? - Quite right. 20432. Of course, these watertight doors are metal things? - Cast iron or steel plates. 20433. Working in cast iron? - Or cast steel. 20434. Can you describe to the Court how it is they are watertight doors? - I have a model which will perhaps describe it. 20435. How does that fit in a watertight way; just describe it? - The model is one of the vertical doors on the tank top. In the cast iron frame there is a fairly loose fitting groove which allows the door to slide pretty freely up and down like that. (Illustrating.) On the face of the door, and forming part of the casting, and machined in the fitting shop so as to produce a good fit - the back of the door is also machined to be a good fit - there are a number of tapered wedges. In the door frame are a number of lugs with the under side also machined, forming corresponding wedges tapered the same way, so that when the two wedges come together they will fit. As the door comes down it is quite free until the wedges are opposite their corresponding lugs in the frame, and then the wedges engage and wedge home. There are 6 on each side, 12 in all; they wedge home the machine-backed surface of the door against the machined surface of the frame. Those two machined surfaces, carefully prepared, pressed carefully together, make a very good means of obtaining watertight work. 20436. The principle being that in the earlier stages of its descent it is perfectly loose? - Not loose, but perfectly free vertically. 20437. And no danger of sticking. When it gets to the bottom the wedges force the machined edges at the back against the corresponding machined surface of the frame and so make it watertight? - Yes. 20438. Supposing at the bottom there was a little bit of coal or something which prevented it getting quite down? - The door is falling; it is falling freely until it overlaps that place, and the door would smash through any small thing. This is not a very big model, but it will smash through a lead pencil if I let it go. 20439. Supposing the door, having overlapped the step at the bottom still nevertheless is prevented by some little obstacle from getting down quite as far as is intended? - As this is falling with a rush, until the wedges actually press it home, the distance through which there is contact is only a matter of an inch or so - except just during that last inch when the door is stopped - the weight of the door would be sufficient to clear any obstacle. 20440. Overcome anything like a piece of coal? - Yes; it would simply knock it out of the way. Some of the big doors weigh, I think, 15 cwt., three-quarters of a ton, so that it would want a pretty substantial obstacle. 20441. Some of us saw those doors being closed, and, of course, they did not fall with a drop like a guillotine, but they descended gradually? - They descended gradually. 20442. Just explain how that was? - In order to give time after the automatic release from the bridge or by the float, so that no one coming through the door, or just passing through the door, should be injured, a hydraulic cataract cylinder, something like a gun recoil cylinder, was arranged, so that the earlier part of the drop shall be comparatively slow, depending on the leakage of a fluid back past the piston in the cylinder. To the last 18 inches or 2 feet there is a bye-pass round the piston, and the door is practically free to fall quickly just for the last 2 feet or