John Mirehouse to Ernest S. Inman, March 1, 1875

Dear Sir: I am in receipt of your memorandum, with inclosure of (copy) letter from board of trade, dated 19th February, 1875, “about fog-signals by sound.” I have respectfully to say in reply to—

Question 1. “Whether they (the captains or officers) have experience of the system used in the United States? What is that system, and does it conduce to safety?”

Answer. That ever since I have traded to the United States (a term of over twenty years) the American river-steamers have been in the habit in clear or comparatively clear weather only of “blowing one whistle, meaning port,” and “two whistles, meaning starboard.” The steamer that blows her whistle first has, so to speak, the “right of road.” It is only A telling B to port. B should reply back with one whistle, meaning “I will port.” Again, A blows two whistles, telling B to starboard. B should reply back with two whistles, meaning “I will starboard.” This is only usage, and not compulsory. If B does not answer A, then B has not heard or does not concede “the right of road” to A. I think, on the whole, that the American system does conduce to safety in narrow channels, but only during clear or comparatively clear weather. In such places, in fog, I think it would tend to confusion and disaster if made imperative. Instance, a steamer, A, is coming into the Mersey, steering south, and another steamer, B, going out of the river Mersey, steering north. Both these steamers meeting, (“nearly end on,”) blows one whistle each, meaning port. Now, another steamer going out of dock, heading northwest, and she hears two whistles on her port bow. Thinking that these two whistles proceed from one vessel only, the vessel out of dock “starboards her helm;” by that means runs a double chance of collision.

Q. *2. “Whether the American system is easy of application and interpretation?”

A. In fog, if compulsory, no; if optional, doubtful; in comparatively clear weather, yes.

Q. 3. “Whether any similar system could with any advantage be adopted in British waters?”

A. American system, yes.

Q. 4. “If so, whether the system propounded in the inclosed will be sufficient; and, if not, system propounded, namely: One short blast to mean, ‘I am porting;’ two short blasts to mean, ‘I am starboarding;’ three short blasts to mean, ‘take care; I am taking care;’ four short blasts to mean, in case of steamer, ‘I am going full speed astern;’ if sailing-ship, ‘I am in stays.’ The use of these last-mentioned signals by short blasts is optional and not compulsory; but, if they are used, the conduct of the ship must be in accordance with signals made.”

A. In narrow and frequented places, more than sufficient, so many whistles would tend to confusion and disaster, even if both vessels answered and used the same signal, and in open sea in lesser degree. Take another instance: A, steamer, (off Nantucket Shoals in open sea,) going west, (approaching New York,) hears a whistle a little on her port bow, which proceeds from B, another steamer, going east. (Mostly eight fast steamers leave New York every Saturday.) Each steamer, A and B, going 10 or 12 miles per hour, A blows one whistle, but in the excitement two whistles might be blown. B hears two whistles, therefore starboards her helm, causing collision; or it might be A hears a whistle on her starboard bow; A starboards her helm and tries to blow two whistles, but owing to the intense cold in winter the steam has somewhat condensed, and the pipe is partly filled with water. The first whistle is not heard by B, and B, having only heard one whistle, ports her helm, causing collision.

Q. 5. “Whether they have any more simple or effective system to suggest?”

A. Nothing more than the American system as regards steamers; holding all vessels (sail or steam) when under way in fog to be responsible, each vessel standing its own risk, and each to repair (if they can) their own damage. As regards sailing-vessels, the law now states that sailing-vessels, when under way, shall make a prolonged blast with fog-horn every three minutes, no matter what tack they are on. Might I suggest this alteration? Fog-horn on port-tack only, and Chinese gong on starboard tack; a fog-horn is with some people difficult to blow, and so may sometimes cause neglect. Instance: A German steamer in open sea off Nantucket heard a foghorn on her port bow; it proved to be from a Swedish bark on port tack, heading southward, wind easterly, going 9 knots per hour; German steamer going east, 10 knots per hour, struck Swedish vessel amidships. Had there been a distinction of fog-signal, showing which tack the sailing-vessel was on, the steamer would have known how to act.

Q. *6. “Whether, looking to American experience, the system of signaling by sound should be confined to foggy and thick weather, or whether it should be extended to narrow channels?”

A. In fog, no. In moderately clear weather, as the Americans use it and herein described, yes. Both in open sea and narrow channels.

In fog, a weak whistle may appear a long way off, and a powerful whistle close to, when it is the reverse. Again, the wind deflects sound, and, therefore, the two important points about collision are unknown, namely, bearings and distance; also, original course and speed of each vessel prior to collision is unknown.

The new-suggested rules of signal by sound in fog may at first sight appear plausible and feasible, yet in execution, I apprehend, they would be non-effective, causing confusion and disaster. In short, the only thing I can see in it during fog is watchfulness, promptitude, good decision how to act according to circumstances.

I have, &c.,