MANUFACTURING 3-INCH ANTI-AIRCRAFT SHELLS WORLD WAR II ORDNANCE FILM FRANKFORD ARSENAL 10414

this picture will show the sequence of machining and other incidental operations of the three inch anti-aircraft m42 shell has manufactured at Frankfurt Arsenal by the upsetter method Frankfurt Arsenal is located in a thickly populated area in the northeast section of the city of Philadelphia this fact is brought out to emphasize the point that no hazards are involved in machining shell and that machining operations can be done in commercial machine shops located in thickly populated cities and towns this shows a stack of two and 3/8 inch diameter x 1335 steel bars as they are received from the steel mills the bars are cut off in a high speed cutoff machine in lengths of 22 and 1/2 inches each it should be noted that four bars are cut at one time these four bars will make 8 3-inch shell body forgings as will be shown later the cutoff lengths are placed in a high frequency induction furnace wherein approximately 75 seconds one end is heated to a temperature of 2,100 degrees Fahrenheit taking the bar with the heated end from the induction furnace it is placed in the first station of the upsetting machine where the heated end of the bar in one heat passes through four stations coming out from the fourth station as a completed three-inch anti-aircraft shell forging the interior cavity of this forging is finished to the finished drawing dimension size this is the bar before heating this shows the cross-sectional shape of the bar after passing the first station the second station the third station the fourth or final station the opposite end of the bar is next heated and forged in the same manner as was shown in the preceding views this shows the forgings after completion on the national upsetter after the forgings have been completed on the national upsetter they are placed in a vertical crank press where they are sheared the forgings are now conveyed to the outside of the building where they receive an air quench when using x13 35 steel if the forgings are given an air quench as shown here heat treatment becomes unnecessary because the air quench improves the physical properties to the extent that they meet the minimum physical properties demanded for a high-explosive shell the rotating bands for the shell are cut from tubing of gilding metal on a hollow spindle lathe with collet Chuck the bands are next annealed they are then pickled and washed a percentage of the shell is selected from which tensile test specimens are taken the test specimen is cut from the walls of the shell it is machined to the standards of a point five zero five inch threaded test specimen the test specimen is next placed in a standard hydraulic tensile testing machine attached or connected to the testing machine is an automatic recorder which records a graphic curve showing the proportional elastic limit of the steel in the specimen when the proportional elastic limit has been determined the recording instrument is detached from the testing machine the specimen is then broken this gives the tensile strength of the steel after a reading has been obtained to determine the tensile strength the specimen is taken from the testing machine it is placed in a fixture and measured for elongation and reduction in area the combined results of this test give the physical properties of the steel and determine whether or not the heat treatment was satisfactory the forgings are next placed in shot blasting machines where a scale is removed from the forged cavity it is essential that the cavity not only be free from scale but it must be free from rough spots and sharp edges because explosive is to be loaded into this cavity after the forgings have been shot blasted they are placed on conveyors which carry them into the shell machining shop on arrival in the shell machining shop the shell is centered in the next operation the shell is faced on the open end for rough depth of cavity process inspection on a portion of the work at the various stages is made to ensure proper functioning of the machines next the shell is finished turned on a vertical lathe process inspection is made frequently at this stage from here the shell goes to a drilling and tapping machine where a set screw hole is drilled and tapped the shell now goes to a moto Matic vertical lathe which Wars the face under cuts and touched the front end removes the lug on the rear end rough cuts and finishes the base and does the band seating operation this shows the shell as it comes from this machine with the mouth undercut and tapped the band seat and grooves cut and with the base finished in the next operation the shell is not this notching is to provide points at which the fuse can be staked in position from the notching machine the shell goes to a stamping machine where the caliber type manufacturers initials and lot number are placed on the body of the shell after stamping Michelle is placed in an early machine where the band seat is nerve the shell is now ready for the application of the band this operation is performed on a hydraulic press it will be noted that the band is applied cold and that the pressure used to place the band in the band seat to ensure a tight band is 1000 pounds gauged pressure after the band has been applied it has turned to finish size the machine used in this operation is semi-automatic and its capacity is approximately 1,000 shell per eight-hour day after the band has been turned on the shell it is placed in an electric welding machine whereas field disk is welded to the base of the shell it will be noted that the disk is securely attached to the base by an overlapping spot weld after the shell has had the base cover applied it is washed in a hot soda bath it is then rinsed in clear hot water to remove all grease dirt and other foreign matter the shell now goes to the final inspection table where it is gauged by the inspector for the following principle dimensions thread at mouth mouth diameter burl a diameter diameter of body diameter of band diameter at rear of band tightness of band overall length placement of band base thickness and concentricity of the interior bore with the outside diameter not only does the she'll have dimensional tolerances but weight tolerances as well therefore if dimensional tolerances are taken advantage of to the fullest extent shell may be produced which do not come within the weight tolerances liberal tolerances are placed on the drawings for the convenience of the manufacturer who must decide which ones to take advantage of or to decrease in order to bring the completed shell within the weight tolerance it should always be remembered in shell manufacture that lightweight shell are a frequent cause of rejection after inspection the threads at the mouth of the shell are given a protective coating grease the set screw is inserted in the locking pin hole the shell next goes to the paint spray booth where the interior is sprayed with a coat of acid-proof black paint the exterior is given a protective coating of clear lacquer shells are then packed in corrugated containers for shipment to the loading and assembly plant

Channel: PeriscopeFilm

Views: 456,221

Rating: 4.8875608 out of 5

Keywords: Periscope Film, Stock Footage, 4K, HD, 2K, 16mm film, 8mm film, 35mm film, film transfer

Id: BPGqLjnNIJY

Length: 20min 38sec (1238 seconds)

Published: Sun Mar 22 2020