Page 4 - Moncrieff's Disappearing Guns
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Moncrieff’s Disappearing Guns                                                                            David Moore




           retain all the advantages of a barbette gun yet give the  allow any amount of depression for plunging fire. By
           range of the turret without the expense of the turret.  changing the curves and proportions of the elevators
                                                              any amount of elevation, depression or length of
           His ‘Protected Barbette System’ consisted of a     recoil could be adjusted for. No extra fittings that
           carriage mounted on a simple frame, consisting of  could not normally be found in a battery were
           two longitudinal beams which traversed in the usual  necessary.
           manner on a pivot and racers. The gun-carriage
           proper had cheeks which were elongated into a trail,  The aim of mounting a gun in this way was explained
                              Preview
           and during the recoil it was supported by an axle  by Moncrieff to be primarily to keep the gun
           resting on the after part of the frame, or it could  detachment under cover and the gun also, except in
           without elongation be supported by two guide rails, or  the instant of firing. The guns could be mounted
           by iron or wooden beams from the bottom of the     either below a raised parapet or below the level of the
           frame, hinged at both ends. Two curved elevators   ground. Circular pits could be employed and
           were joined together by two axles, one of which    Moncrieff commented that as yet such pits were not
           supported the  carriage and the other the          in use for artillery. He stated that the largest guns
           counterweight.                                     could be mounted in circular pits twenty feet in
                                                              diameter. He claimed that the principle could be
           In the firing position the gun projected over the  adapted to any size or ordnance from a field gun to
           parapet. On firing the gun recoiled for a short distance  the largest that was made at that time. The parts were
           parallel to its own axis and then descended into the  simple and portable and the carriage could be easily
           loading position by virtue of the curved part of the  taken to pieces to replace any part that was damaged
           trail. The elevators and rail because of their curvature  in action. The method of resisting recoil without
           allowed the recoil to be gradually met by resistance  friction meant that no shock was conveyed to the
           which rapidly increased as the gun reached its lowest  pivot through the carriage. Lighter materials could be
           point. Here it was held in check whilst the gun was  employed as there was no strain imposed on the
           loaded. When the check was withdrawn the gun       platform or carriage. On a front where guns were not
           would rise under the influence of the counterweight  exposed to enfilade and where lateral range was not
           back to the firing position. The energy of the recoil  required this method could enable more guns to be
           would be successfully stored in the counterweight and  mounted than was possible in embrasures. Moncrieff
           converted into actual energy for raising the gun.  also suggested that batteries of his guns could be
                                                              mounted in such a way that one gun could open fire
           For guns of position he suggested that the wheels be  over another whilst the front gun was being loaded.
           used for elevators and the carriage formed with a  No other method of mounting guns could achieve
           block trail. In this arrangement the recoil was stopped  this.
           by the travelling rails on the frame being made with
           an incline or curve, rising at the rear, and each wheel  Moncrieff made many other claims for his method of
           being fitted with  bushes at opposite sides of their  mounting guns. He explained that the nation’s
           circumference to take the axles of the carriage and the  harbours and arsenals required expensive defences
           counterweight. This design also allowed the gun to be  which up to then had meant that only the most
           brought into position on its own wheels when the axle  important ones had been defended. Gun-pits, he said,
           was returned to the centre of the wheel as normal.  could be built at short notice and any harbour or part
           The Protected Barbette Carriage was fitted with a  of the coast could be put in a sate of defence in a short
           reflector under the breech and in front of this, nearly  time. These gun-pits would be more formidable to
           under the trunnions, was fitted a hinged back sight.  shipping than batteries, which are easier seen and at
           This allowed the gun to be accurately laid without  the same time more vulnerable. Guns in such pits also
           exposing a man to direct enemy fire. When the      had the element of surprise. They could remain
           reflecting sight was in use the gun could be elevated  unseen until they were required to repel a sudden
           using a handle in front of the carriage. The circular  attempt to storm. He gave as an example that such a
           racer was fitted with a scale which allowed the officer  battery of guns would have saved Fort Fisher in the
           to traverse the gun according to a chart of the ground  late American War. The fire directed on that fort was
           surrounding the battery and so the gun was laid for  so heavy that those guns which were not disabled had
           line whilst it was in the lowered position. The    to be shunted out of fire, and were to all intents the
           counterweight could take the form of a tray        same as disabled. The place fell before they could
           containing spare shot, pig iron or any heavy material.  open fire on a storming party.
           A spare or disabled gun could also be used with little
           adaptation to the carriage. Another alteration could



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