Memoir of John Ericsson

Memoir of John Ericsson

Lieutenant Greene's report with reference to the position of the pilot-house calls for particular notice, his assertion being that he "could not fire ahead within several points of the bow." The distance between the center of the turret and the pilot-house being fifty-five feet, while the extreme breadth of the latter is only five feet, it will be found that by turning the turret through an angle of only six degrees from the center line of the vessel, the shot will clear the pilot-house, a structure too substantial to suffer from
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the mere aërial current produced by the flight of the shot. Considering that the Monitor, as reported by Lieutenant Greene, was a "quick-turning vessel," the disadvantage of not being able to fire over the bow within six degrees of the line of keel is insignificant. Captain Coles claimed for his famous iron-clad turret-ship the advantage of an all-round fire, although the axis of his turret-guns had many times greater deviation from the line of keel than that of the Monitor.

The statement published by Lieutenant Greene, that the chief engineer of the vessel immediately after the engagement in Hampton Roads "suggested the clever plan of putting the pilot-house on top of the turret," is incorrect and calls for notice. The obvious device of placing the pilot-house in the center and above the turret was carefully considered before the Monitor turret was constructed, but could not be carried out for these reasons:

1. The turret of the battery was too light to support a structure large enough to accommodate the commanding officer, the pilot, and the steering-gear, under the severe condition of absolute impregnability against solid shot from guns of 10-inch caliber employed by the Confederates.

2. A central stationary pilot-house connected with the turret involved so much complication and additional work (see description of turret and pilot-houses further on), that had its adoption not been abandoned the Monitor would not have been ready to proceed to Hampton Roads until the beginning of April, 1862. The damage to the national cause which might have resulted from that delay is beyond computation.

The next important part of the battery delineated on the forward section of the illustration, namely, the quarters of the officers and crew, will now be considered; but before entering on a description it should be mentioned that in a small turret-vessel built for fighting, only one-half of the crew need be accommodated at a time, as the other half should be in and on the turret, the latter being always covered with a water-proof awning. Referring again to the forward and to part of the central section, it will be seen that the quarters
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extend from the transverse bulkhead under the turret to within five feet of the pilot-house, a distance of fifty feet; the forward portion, twenty-four feet in length, being occupied by the officers' quarters and extending across the battery from side to side. The height of the aft part of these quarters is 8 feet 6 inches under the deck-beams; while the height of the whole of the quarters of the crew is 8 feet 6 inches. A mere glance at the illustrations showing a side elevation [p. 733] and top view of internal arrangement [p. 735] gives a correct idea of the nature of the accommodations prepared for the officers and crew of the vessel which Lieutenant Greene regards as a "crude" structure, and of which he says: "Probably no ship was ever devised which was so uncomfortable for the crew." If this opinion were well founded, it would prove that submerged vessels like the monitors are unfit to live in.

Fortunately, the important question whether crews can live permanently below water-line has been set at rest by the report of the chief of the Bureau of Medicine and Surgery to the Secretary of the Navy, 1864. This minute and carefully considered report enabled the naval administration, organized by President Lincoln, to prove the healthfulness of the monitors, by the following clear presentation of the subject: "The monitor class of vessels, it is well known, have but a few inches of their hulls above the water-line, and in a heavy sea are entirely submerged. It has been doubted whether under such circumstances it would be possible long to preserve the health of the men on board, and consequently maintain the fighting material in a condition for effective service. It is gratifying, therefore, to know that an examination of the sick-reports, covering a period of over thirty months, shows that, so far from being unhealthy, there was less sickness on board the monitors than on the same number of wooden ships with an equal number of men and in
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similar exposed positions. The exemption from sickness upon the iron-clads in some instances is remarkable. There were on board the Saugus, from November 25th, 1864, to April 1st, 1865, a period of over four months, but four cases of sickness (excluding accidental injuries), and of these two were diseases with which the patients had suffered for years. On the Montauk, for a period of one hundred and sixty-five days prior to the 29th of May, 1865, there was but one case of disease on board. Other vessels of the class exhibit equally remarkable results, and the conclusion is reached that no wooden vessels in any squadron throughout the world can show an equal immunity from disease."

Apart from the ample size of the quarters on board the vessel, shown by the illustration, it should be mentioned that the system adopted for ventilating those quarters furnishes an abundant supply of fresh air by the following means. Two centrifugal blowers, driven by separate steam-engines, furnished seven thousand cubic feet of atmospheric air per minute by the process of suction through standing pipes on deck. Part of the air thus drawn in supported the combustion of the boiler furnaces, the remainder entering the lower part of the hull, gradually expelling the heated and vitiated air within the vessel. It has been imagined that the fresh air supplied by the blowers ought to have been conveyed to the quarters at the forward end of the vessel, by a system of conducting pipes. The laws of static balance, however, render the adoption of such a method unnecessary, since agreeably to those laws the fresh cold air, unless it be stopped by closed doors in the bulkheads, will find its way to every part of the bottom of the hull, gradually rising and expelling the upper heated strata through the hatches, and lastly through the grated top of the turret. Naval constructors who speculate on the cause of the extraordinary healthfulness of the monitors need not extend their researches beyond a thorough investigation of the system of ventilation just described.

Turret Department. The most important object delineated on the central section of the illustration, namely, the rotating turret, will now be considered; but before describing this essential part of the monitor system, it will be well to observe that the general belief is quite erroneous that a revolving platform, open or covered, is a novel design. So far from that being the case, this obvious device dates back to the first introduction of artillery. About 1820 the writer was taught by an instructor in fortification and gunnery that under certain conditions a position assailable from all sides should be defended by placing the guns on a turn-table. Long before building the Monitor I regarded the employment of a revolving structure to operate guns on board ships as a device familiar to all well-informed naval artillerists. But although constructors of revolving circular gun-platforms for naval purposes, open or covered, have a right to
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employ this ancient device, it will be demonstrated further on that the turret of the monitors is a distinct mechanical combination differing from previous inventions. The correctness of the assumption that revolving batteries for manipulating guns on board floating structures had been constructed nearly a century ago will be seen by the following reference to printed publications.