-------+----------------------------------------------+----------------- | Whitehead Fish Torpedo. | Woolwich Fish | | Torpedo. +--------------+---------------+---------------+----------------- |14' long, 16" | 14' long, 16" | 14' long, 14" | 14·5' long, 14" | max. diam. | max. diam. | max. diam. | max. diam. Yards. | one screw. | two screws. | two screws. | two screws. -------+--------------+---------------+---------------+----------------- 200 | .. | .. | 20 knots. | 25-1/4 knots. 250 | 9-1/2 knots. | .. | .. | .. 300 | .. | 12-1/4 knots. | 19-1/4 knots. | 24-1/2 knots. 400 | 8 knots. | .. | 18 knots. | 23 knots. 600 | .. | 11 knots. | .. | 20 knots. 750 | .. | 10-1/2 knots. | .. | .. 800 | 7 knots. | .. | 16-1/2 knots. | 18 knots. 1000 | .. | 9 knots. | .. | 15-1/2 knots. -------+--------------+---------------+---------------+----------------- Pressure of air in engines varies for distance and speed from 40 atmospheres to 140 atmospheres. _Placing the Charge._--The explosive is generally placed in what is termed the cartridge case, which case is similar in shape to the interior of the charge chamber (1), and is fixed thereto by means of wooden wedges.