Mines (naval)

“ In January, 1917, the only vessels equipped for this service were four merchant ships and the Flotilla Leader Abdiel, with a total minelaying capacity of some 1,200 mines per trip. It was not advisable to carry out minelaying operations in enemy waters during the period near full moon owing to the liability of the minelayers being seen by patrol craft. Under such conditions the position of the minefield would be known to the enemy. ”

“ In planning mining operations in the Heligoland Bight, it was necessary to take into consideration certain facts. The first was the knowledge that the Germans themselves had laid minefields in some portions of the Bight, and it was necessary for our minelayers to give such suspected areas a wide berth. Secondly, it was obvious that we could not lay minefields in areas very near those which we ourselves had already mined, since we should run the risk of blowing up our own ships with our own mines. ”

“ The enormous number of mines used can be gathered from the fact that in the large minefields in home waters alone, there were some 34,300 mines laid in the Dover area and Narrows of the North Sea (including 9,500 in the Sir Roger Keyes' Folkestone to Gris Nez barrage) ; the Bight absorbed some 43,000 and the Northern barrage 70,117. There can be little doubt that too little importance was attached to the mine in British pre-war views on naval strategy. There was too great a tendency in those days to interpret war at sea wholly in terms of hitting a target at long ranges with a heavy gun. ”

“ Linder?” drawled the visitor.
“Huh?” returned the Honorable William Linder, startled.
“Submarine mines,” explained the other., “Mines in the sea, if you wish words of one syllable.”
The lids of the Honorable Linder contracted.
“You’re in the wrong joint,” he said, “this ain’t the Naval College.”
“Thank you. A submarine mine is a very ingenious affair. I’ve recently been reading somewhat extensively on the subject. The main charge is some high explosive, usually of the dynamite type. Above it is a small jar of sulphuric acid. Teeth, working on levers, surround this jar. ”

“ The great minefield which was declared by our Government in the summer of 1917, the preparation of which was a gigantic undertaking, extended from the Frisian Islands to about latitude 56 degrees north. The Dutch, for their own purposes, removed their lightships from their coasts to the western side of this minefield, thus forming a line of lights running north and south, roughly along the 4th degree of east longitude. This our sailors facetiously named Piccadilly Circus. It was the business of the submarines to lay mines on the eastern part of this minefield, that is, near to the coast. ”

“ After an hour at last sighted the minesweepers, which had already started work.'
"One may judge of these North Sea activities from the record of a single lieutenant of the Naval Reserve who, besides attending to other matters, destroyed forty or fifty mines, twice drove off an inquisitive German Taube, attacked an equally inquisitive Zeppelin, twice rescued a British seaplane and towed it into safety; rescued in June the crew of a torpedoed trawler, sixteen men, also the crew of a sunk fishing vessel; in July assisted two steamers that had been mined, saving twenty-four of the sailors ”

“ An account is given of the mine barrage in the North Sea, one of the outstanding anti-submarine offensive projects of the year, thus closing the North Sea, and for which 100,000 mines were manufactured and 85,000 shipped abroad. A special mine-loading plant, with a capacity of more than 1,000 mines a day, was established by the Navy Department.
A star shell was developed which, when fired in the vicinity of an enemy fleet, would light it up, make ships visible, and render them easy targets without disclosing the position of our own ships at night. ”

“ A submarine mine of to-day consists of a mine case, shaped like a ball or egg, about one yard in diameter, mounted on an anchor in the form of an iron box about 30 inches square, connected by a wire rope mooring cable, about 3⁄8 inch in diameter. The mine case contains the charge of high explosive—300 pounds of TNT in our mines—and the firing mechanism. The combination stands about 5 feet high and weighs 1400 pounds. Four small car wheels on the anchor run on steel tracks, allowing the mines to be easily moved along the decks to the launching point. ”

“ For the work on the water there will be needed five boats, viz., a mine planter or suitably fitted-up heavy tug, a small tug or heavy launch called the distribution box boat, and three launches or yawls. The capacity of the planter is such that a group of 19 mines can be handled at one time. ”

“ The thing most astonishing to me about that experience was how a submerged submarine can thread its way through a mine field. For though the water is luminous and translucent one can hardly make out the black hull of the boat under the turret and a mine would have to be on top of you before you could see it. The men who watch for mines must have a sense for them as well as particularly powerful sight. ”

“ The task of making four freight ships habitable for crews of 400 men, at the same time carrying twice as many mines as any other vessel of their size, is not done by a wave of the hand, and as for the four passenger steamers taken, they were gutted like fish—saloons and cabins ripped out—before their conversion could begin. Although plans had to be based upon what could be done within a reasonable time, with material and labor scarce, all features had to conform to the requirements of the mining installations. ”

“ They could also see the mine-sweepers at work, clearing the fairway from those foul nests of floating mines which the crafty foe had been busy laying with their submarines. Once or twice they thought they could make out some dark-grey object like a mine or sunken vessel beneath the surface of the water. ”

“ It required twenty-four steamers, running constantly, [Pg 289] to keep the ten mine-planters supplied with mines. Only one fell a victim to a submarine.
Our mine squadron arrived at Inverness May 26, 1918, and twelve days later started on its first mine-planting "excursion." On this excursion, June 7, the squadron planted a mine field 47 miles long, containing 3,400 mines, in three hours and thirty-six minutes. One ship emptied herself of 675 mines without a single break, 1 mine every eleven and one-half seconds through more than two hours, the longest series ever planted anywhere. ”

“ Even if they could navigate the mine-field, so thickly strewn with both our mines and their own, and so constantly and thoughtfully rearranged, they would not find it possible to slip, as we are doing, past the elaborate boom at the harbour mouth, or to escape being sunk53 by the guns which dominate it, and the seaplanes which are constantly passing over it. ”

“ Mines for the open sea in great numbers, moored “flying”—that is, by ships steaming at considerable speed—need anchors with automatic depth regulation. Such mechanism had undergone important changes during the war, and the new American mines needed all the improvements, to make them sure to plant at the intended level. ”

“ Some folk ha' got a notion,” continued Bob, “that the mines is sowed all in nice, neat rows, like cabbages, which bein' so, a ship might truly pass betwixt two rows. But it so happens that them gentle Germans don't sow mines for ships to pass through. Grant ye, they may leave a goodish distance betwixt each mine—'cause, bein' economical, they knows the concussion o' one might set off others, wasteful-like, if they was too close. But they do sow 'em just so that a ship gettin' into the field has the best possible chance o' strikin' one sooner or later. ”

“ Thus, if such a mine were to be used at all, we should have had to plant several layers, one under the other, down to a depth of about 250 feet, so that the submarine, at [Pg 250] whatever depth it might be sailing, would be likely to strike one of these obstructions. This required such a large number of mines as to render the whole project impossible. We Americans may take pride in the fact that it was an American who invented an entirely new type of mine and therefore solved this difficulty. ”

“ But as the laying of mines, speaking generally, is a defensive 21mode of warfare and the policy of the British Navy—owing to its supremacy—is attack and not defence, the mine-laying fleet is of second importance to the sweeping fleet, the work of which, although much augmented by additional small steamers pressed into service, was, during the first few weeks of the war, of a nature more arduous and dangerous than will ever be realised. ”

“ A mine, as the reader probably knows, is a cask filled with high explosives and fastened by means of weights and anchors so that it floats some feet below the surface. Mines can be planted in fields, as it were, by torpedo-boats or submarine and then a hostile fleet can be lured or chased in among them. The North Sea, as we know, is at present thickly strewn with them and fatal results have already been chronicled. Air-ships and aeroplanes can help by finding the whereabouts of the hostile fleet and designating by wireless the spots where the mines should be planted. ”

“ But whether the submarine is used for mining its own or enemy harbors, the outstanding feature of its [121] work is that it does it all under water and therefore the operations cannot be seen by spying eyes.
As we said in Chapter III, the mines are stored in a compartment in the hull of the submarine and this can be shut off from the other compartments by a bulkhead door. It also has a hatch opening through the hull to the water outside, just as the door of a kitchen opens into the back yard. ”

“ The Northern Barrage would be too long a front, and much of it too far from base, for effective patrol without a great number of vessels. A wide, thickly sown minefield, however, would watch night and day in all weathers without relief, and would be even more effective against passage submerged than against passage on the surface, because of the less wear and disturbance of the mines by wave action, deep down under water. ”

“ At an early stage in the training in mines, one learns to treat them with respect always—no liberties. Even the safest explosives, the surest mechanism, have an occasional, inexplicable aberration.
Loading Mines into Lighters.
At Base 18, on the Caledonian Canal, at Inverness.
The ready mines are swung up into open freight cars, for hauling to the water side, whence they go, 40 to 80 together, in lighters out to the ships. ”

“ The line of ships then takes the narrower route formation, and we head back for the base. Butler, Canaga, and I exchange quiet congratulations. Our work together has been to good purpose.
The men clean up the decks, get a wash for themselves, and those off duty drop asleep—anywhere—the deck is covered with them. On top of the duties common to all men-of-war, to move the 400-ton masses of mines, in slow but steady time, is very fatiguing, even with steam winches to help. ”

“ NOTES BY THE FIRST LORD Mining is mainly of two kinds, ambush mining and blockade mining.
Ambush Mining. Ambush mining depends on the whereabouts of the field remaining unknown. These mines may be scattered about in patches, or short lines in the neighbourhood of the enemy’s ports or of the approaches to your own ports or landing places on the chance of enemy ships running into them. This chance is not great. The seas are very large; the area mined, even if on a great scale, very small. ”

“ This class of mine is used in side channels which it is intended to close entirely, or to reduce the width of navigable channels where too wide to be defended by observation mines. Their principal advantage is that if the firing switch is closed they are effective in fog or mist, when observation mines could not be worked, and when the guns of the defence would be equally out of action. As they are fired only when close against the side of a ship, the charge can be comparatively small and the mines themselves are handy and easy to lay. ”

“ In deep channels the submarine mines are buoyant; in comparatively shallow waters they are placed upon the bottom—the object in both cases being to touch or nearly approach the hull of the vessel. Submarine mines are not accessaries to defence, but are essential features wherever they can be applied.”
The Senate Committee on Ordnance and War-ships reported: “Concerning another class of torpedoes, ‘fixed’ or ‘anchored’ or ‘planted,’ technically known as submarine mines, there is a great popular misapprehension. Their value is greatly overestimated. ”

“ Such mines are necessarily placed near the surface, and are to this extent an interference with friendly traffic. A vessel passing by mistake through a mine field of this class would run no risk of an explosion while the mines are inactive, but might do some damage to the mines. ”

“ A great deal of the East Coast work concerns mine-fields—ours and the enemy's—both of which shift as occasion requires. [69] We search for and root out the enemy's mines; they do the like by us. It is a perpetual game of finding, springing, and laying traps on the least as well as the most likely runaways that ships use—such sea snaring and wiring as the world never dreamt of. We are hampered in this, because our Navy respects neutrals; and spends a great deal of its time in making their path safe for them. The enemy does not. ”