|From Ocean Navigator #139 |
Although it is still found aboard many a vessel as a backup in the event of an electrical failure, the sounding lead has, sadly in the eyes of traditionalists, gone the way of the taffrail log and tarred hemp rigging. There was a time, however, when no vessel set to sea without one of these devices, perhaps among the earliest navigator’s tools.
The sounding lead, or blue pigeon, as it was affectionately known by sailors, came in several weights, from a bantam 7-lb hand lead to the more hefty 28-lb deep-sea or, dipsey, model. Hand leads were used most often near shore, for depths of 20 fathoms or less, while the dipsey lead could be used as deep as 100 fathoms.
The lead itself is a long, slender affair, the dipsey version measuring about 18 inches tall, 3 inches wide at its base, and tapering in to 1.5 inches at its head, which is equipped with a hide becket for bending on the lead line. The hand lead shared similar, albeit abbreviated, proportions. Both hand and dipsey leads included a cup-shaped depression in their bottom ends, which facilitated arming, or filling, this area with tallow. The mission of the armed lead was not only to plumb the depths but also to retrieve a sample of the bottom. This could be compared to bottom descriptions found on charts, a practice that continues today, even though few modern vessels retrieve bottom samples for navigational purposes.
The hand lead was typically deployed by a single leadman, always from the weather side of the vessel. On medium- to larger-sized vessels, this was accomplished while standing outboard at the chain wales, often referred to simply as the chains, which is the equivalent of a chain-plate attachment on a contemporary sailing vessel. In square-riggers, the chains often incorporated a small platform outboard, which ideally suited the leadman’s task.
With a vessel moving at no more than 10 or 12 knots, the leadman would swing the hand lead in a vertical wheel-shaped motion, the wheel turning against the motion of the ship, casting it after two or three revolutions nearly parallel to the sea’s surface. As the lead sank, the leadman paid out lead line until it was vertical, when the ship and he passed over the lead. At that moment, he would tug the line smartly, so that the lead bounced on the bottom. This ensured an accurate reading, while embedding bottom material within the arming.
Because the lead line had to be used in varying weather conditions, day or night, the creation of a marking code on the line itself, for identifying depth, which was tactile as well as visual in nature, was a necessity. For the hand line, the marks were as follows: two strips of leather at two fathoms, three strips at three fathoms, a piece of leather with a hole at 10 fathoms, white linen at five and 15 fathoms, red bunting at seven and 17 fathoms, and blue serge at 13 fathoms. At 20 fathoms a cord was tied with two knots. The areas between marks were known as deeps. At night in cold water, it was not unusual for the leadman to hold the mark to his lips or tongue, benumbed fingers being too insensitive to distinguish the feel of certain marks.
Using the dipsey lead involved several crewmen, each holding a coil of line outboard of all rigging. The vessel would be hove-to and the lead cast, usually by the boatswain’s mate, from the weather cathead, while he sang out, “Heave!” When the line was expended from the coil held by the crewman abaft the boatswain, he sang out, “Watch there, watch,” letting the next crewman abaft know that the tension of the lead was coming his way, and so on until the lead touched bottom or the line reached the stern without finding it. In Frank Worsely’s – Worseley is best remembered as Shackleton’s able navigator – First Voyage in a Square Rigged Ship, he recounts this procedure, naming each crewman in the dipsey lead detail. “The lead struck the surface of the Channel of old England and rapidly disappeared leaving a trail of bubbles €¦ watch there, watch cried Collins at the break of the forecastle €¦ watch there, watch warbled Cockroach in the fore rigging, watch there, watch sang Linkey by the fore brace-block, watch there, watch chanted Lewis by the bumkin and watch there, watch growled Parsons as the last coils ran from his hand.”
Although it is a welcomed convenience, reading ultra-accurate backlit digits from a multifunction display will never evoke the reverence of the leadman’s call, “By the mark, 42 fathoms, sir!”