Fire hoses should be laid out and charged before handling weapons as well as gunnery exercises, and repair lockers should be manned and ready as appropriate. When guns are trained or elevated, an audible warning alarm is sounded from within the gun enclosure. All hands should stand outside the train warning  circle. No ammunition or explosive assembly may be used in any gun system for which it is not designed. Powder cans and bags must always be in perfect condition. Care   must   be   taken   to   avoid   obliterating identification marks on ammunition or putting it into  incorrectly  marked  containers. Smokeless powder must never be exposed to the direct rays of the sun. Powder in bulk, tanks, cartridge  cases,  ammunition  boxes,  and  other containers   must   be   protected   against   high temperature. Smokeless powder, when wet, must be regarded as dangerous  for  dry  storage  and  must  be  kept immersed completely in freshwater. It must be turned in at an ammunition depot at the first chance or dumped overboard. Before   any   work   that   may   cause   either   an abnormally high temperature or an intense local heat in a magazine is started, all explosives must be removed  to  safe  storage  until  normal  conditions  are restored. Pyrotechnic material must always be kept by itself in regular pyrotechnic lockers or storage spaces. Black powder, which is most dangerous, must always be kept by itself. Containers of black powder must never be opened in a magazine or adjacent to other  explosives. Projectiles must not be altered, nor may fuzes or other parts be removed from them on board ship without  instructions  from  higher  authority. A fuzed projectile or a cartridge case, whether in a container or not, if dropped from a height exceeding 5  feet,  must  be  set  aside  and  turned  in  at  an ammunition  depot  as  soon  as  possible.  Such ammunition must be handled with the greatest care. Service ammunition is never used for drill; only drill ammunition  may  be  used. Certain  fuzes  armed  by  setback  may  explode accidentally by tapping or jarring. Extreme care must be taken to avoid dropping them. Care must be taken that nose fuzes are not struck (as by the gun in recoil). Time fuzes that have been set must be reset on SAFE before  storing  below. GUN MOUNTS LEARNING   OBJECTIVES:   Define   gun mount. Identify the different components of a gun  mount. A gun mount is the supporting structure assembly and operating device for one or several guns. The mounts may be open, or enclosed in a shield. Each mount  is  assembled  as  a  unit  by  the  manufacturer,  then hoisted on board ship and bolted in place. Modern   gun   mounts   have   been   effectively developed to meet the threat of all types of targets. They comprise an entire system of gun-supporting parts that enable  them  to  rapidly  load,  position,  and  fire  their projectiles with such speed and accuracy that they have become the backbone of the U.S. Navy’s support forces. Every  gun  system  includes  equipment  used  for  gun positioning,  loading,  and  firing.  Loading  equipment varies greatly in design from gun to gun, but its purpose remains the same–to load a complete round in the gun chamber for firing. We will describe the various loading systems later in this chapter. The greatest similarities from one gun to the next are found in the positioning and  firing  components,  which  we  will  now  describe. POSITIONING EQUIPMENT Positioning equipment includes all the machinery used to support and move the gun tube to the desired train  (horizontal)  and  elevation  (vertical)  angle. Positioning equipment includes the stand, base ring, trunnions,  carriage,  and  slide,  (fig.  6-10). Stand The stand is a steel ring bolted to the deck; it serves as a foundation and rotating surface for movement in train. The stand contains both the train beatings and the training circle. The training circle is a stationary internal gear that the train drive pinion walks around to move the gun in train. 6-15