. The railroad and engineering journal . flanges. For ground mines the turtle-back or mushroomshape is recommended. An air space that much exceeds in volume three timesthat of the charge has been found to produce considerablediminution of explosive effect. In all cases the size of theenvelope should be kept down to the lowest dimensionscompatible with the work required of it. V.—AUTOMATIC MINES. Notwithstanding the grave objections that can be urgedagainst the automatic or self-acting mine, from the iactthat it will act alike against friend and foe, there aretimes when, in planning for the def
. The railroad and engineering journal . flanges. For ground mines the turtle-back or mushroomshape is recommended. An air space that much exceeds in volume three timesthat of the charge has been found to produce considerablediminution of explosive effect. In all cases the size of theenvelope should be kept down to the lowest dimensionscompatible with the work required of it. V.—AUTOMATIC MINES. Notwithstanding the grave objections that can be urgedagainst the automatic or self-acting mine, from the iactthat it will act alike against friend and foe, there aretimes when, in planning for the defense of a harbor, its usebecomes judicious. It called upon to defend a wide water area, or shallowchannels not likely to be used by friendly vessels in wartime, these could well be closed with automatic mines ;or if called upon to improviie a scheme of mine defensewithout the time or material necess irv for ihe preparation. of an elaborate system, resort could easily be^had to minesof this class. An automatic mine should. General Abbott says, fulfilthree conditions : (0 That no safety arrangement whichrequires the act of the planting party to remove is admis-sible ; (2) that some arrangement to cause the immediateexplosion of the charge if the mine gets adrift is essential ; (3) that every possible means should be taken to maketheir removal difficult. He adds that upon the latterpoint there is a wide difference of opinion among engi-neers. The Confederates, with no navy to take the sea, with nocommerce to be interfered with, if we except the few lightdraft blockade-runners, could well afford to blockade theentire harbor area of their coast with this class of ol those devised or improved upon by them remainas types of the best. The Automatic Mechanical Mine was a favorite typewith the-Confederates. Fig. 5 represents one of the bestof this class, the Brooke mine. The case is of metal, coni-cal i
Size: 1770px × 1412px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1880, booksubjectrailroa, bookyear1887
