Page 6 - Moncrieff's Disappearing Guns
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Moncrieff’s Disappearing Guns                                                                            David Moore

           it had free lateral range and it gave protection to the  down below the parapet. When the counterpoise is
           gun and crew. It was expensive however, £2,000 for a  released the spare energy raises the gun back to the
           cupola with two 7-inch guns. In coast batteries a  firing position. The counterpoise is constructed so
           stronger one was needed at a cost of £4,000 yet the  that the shock of the discharge is gradually transferred
           Ordnance Select Committee were of the opinion that  to it and interposed between the gun and the
           Moncrieff’s method was too expensive ?             counterpoise is a moving fulcrum which takes off
                                                              horizontal strain from the platform. This carriage and
           He had achieved the same advantages as the cupola  the system of defence based upon it whereby all the
           but..                                              guns have a free sweep and can be mounted in
           ‘I have no cupola to be broken by an enemy’s shot;  gun-pits or in batteries without a visible parapet, or
           that there are no nuts to be come loose; that my   below the water level was the invention Moncrieff
           carriage will not cost much more than those of a   strove to gain recognition for with little success.
           dwarf traversing platform battery and that the free  His first attempts to produce a gun which could be
           lateral range of my guns is only limited by the    raised for firing and lowered for loading involved
           position in which they are placed.’                many plans for arriving at the result which he now
                                                              described as being so simply obtained. He had used
           Why did the Ordnance Select Committee react in this  every mechanical appliance that he could think of that
           way to a positively advantageous method of mounting  appeared suitable and a good many ‘pretty’ designs
           a gun without even allowing a test trial to take place ?  were the result before he hit upon the idea of a
           Moncrieff was not a man to be put off so easily. He  moving fulcrum and a counterpoise which he
           had already read out to the institution two letters of  described as being the principle characteristic of his
           approval for his method. One was from a Colonel C.  invention.
           Dickson of the Royal Artillery, the other was from a
           Colonel A. Robertson Retd. Both had witnessed the  Moncrieff had been encouraged by the reception
           trial with a test model. The officers present at his  which he received when he read his paper to the
           lecture, judging by their questions and comments,  Institution in 1866. He had submitted his invention to
           were of a favourable opinion. The Chairman, Captain  the Government once more with no better success
           J.H. Selwyn R.N., in summing up stated that        than before. He considered that he had three options
           Moncrieff had                                      now open to him, to let the matter drop, to take it out
           ‘...undoubtedly, by not very complicated machinery,  of England or to conduct an experiment with a full
           produced an effect which we have all long ago      sized gun at his own expense. This third option would
           thought desirable.’                                perhaps remove the scruples which the Government
                                                              had shown to incur the expense of trying his plan and
           He could not in his opinion see why a public trial  this was the option that he chose.
           should not be set up to test this invention as had been
           done with other less promising inventions requiring  General Peel supplied him with an iron 32 pounder
           much larger sums of money. Captain Moncrieff was   which on 3rd. December 1866 Moncrieff mounted in
           not going to let the matter rest there...          the neighbourhood of Edinburgh using his principle.
                                                              He saved expense by mounting the gun in a carriage
           The Argument Begins : 1867-1869                    that was not intended to be a pattern for the service
           On Monday June 3rd. 1867 Moncrieff again brought   but would thoroughly try the principle. It was simply
           to the attention of the Royal United Service       an experimental carriage and defects would make its
           Institution the practicality of his method of mounting  success more unlikely but also more conspicuous.
           guns in what he called a ‘Protected Barbette System’.  The experiment proved to be gratifying. Not only did
           He stated that he had not made as much progress    the carriage stop the recoil without strain, but it did so
           since his last paper of June 1866 as he would have  with a smoothness and an absence of vibration that
           wished but such progress as he had made under his  satisfied all those who saw it. Moncrieff conjectured
           own means had proved to be satisfactory.           that those who were aware of the destructive effects
           He outlined the history of his invention so far. It  caused by vibration and the enormous horizontal
           consists of mounting guns in such a manner that the  strain on the platform in firing heavy artillery would
           act of firing makes the gun descend below the parapet  have found that his system may have possible uses for
           where it could be loaded in a position secure from  even the heavy class of ordnance. Moncrieff thought
           direct fire. Here it could be traversed by the gun  that its other advantages may be that it would remove
           detachment without their being exposed to the enemy.  the difficulty in providing suitable foundations and
           The force of the recoil is harnessed by the use of a  traversing platforms for the largest guns.
           counterpoise which is raised as the gun is forced

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