Submarine Appliances And Their Uses
Deep Sea Diving, &c., &c.

COMBINED DIVING BELL & DECOMPRESSION CHAMBER Copyright. For use in connection with deep sea operations, Professor Leonard Hill, P.R.S., has designed a special diving bell (see illustration above), which comprises also a decompression chamber. This chamber can also, in case of need, be used on deck for recompression purposes (see page 7). The idea is to use this bell in special cases where the diver may remain for long periods on the bottom at great depths, or when stress of weather or other circumstances compel the diver to come to the surface hurriedly, so that he has not time to decompress in accordance with the tables on pages 47_49- The diving bell, which is constructed of mild steel plates, and is weighted with kentledge in the ordinary way, is divided into two compartments by a partition (c), one of the chambers (0) being open at the bottom in the usual way, the other chamber (Æ) being- entirely closed. The partition is provided with a manhole (<Z) and cover (?), which can be opened or closed from either side, and with a valve (/) operated either from the inside or outside, for allowing the pressure in the closed chamber to be gradually reduced. Each chamber of the bell is fitted with an air inlet valve (g and 7z), which is connected to an air compressor or compressors ; and the diver is provided with a separate pump, the air pipe of which may be carried through a stuffing box in the roof of the open chamber of the bell, or it may be worked quite independently of the bell in the usual way. The bell may be furnished with means for electrically or otherwise heating it, and also with means for drying and for partially removing- the oxygen from the air supplied to the bell, and also with a telephone and electric light. In making use of the bell, the diver, upon entering or re-entering, passes into the closed chamber through the man-hole, which is then hermetically closed, and the bell is then raised to the surface and placed upon the deck of the diving- vessel or upon the shore, the pressure in the closed chamber being- meanwhile kept at the same pres- sure as that existing at the place where the diver entered or re-entered the bell. The air in the closed chamber is then slowly decompressed, or allowed to slowly escape through the valve (/) at the rates set forth in the tables given on pages 47-49. 72