MANUFACTURE OF THE BOFORS 40mm ANTI-AIRCRAFT GUN AT CHRYSLER BOFORS GUN TEAM 58844

[Music] [Applause] [Music] [Applause] [Music] [Applause] [Music] the Bofors gun 40 millimeter anti-aircraft cannon capable of firing 120 or more explosive armor-piercing shells a minute is one of the most effective guns used by our almond a live fighting force in one Pacific craft a single American battleship shot down 32 [ __ ] planes in less than 30 minutes with its Bofors another heavy aircraft after the Navy generally uses twin barrel liquid-cooled forward on fixed mount as the ships themselves are the mobile unit maybe also using some things barrel water most of the army boaters are single guns mounted on mobile carriages although fixed guns are used for some army emplacements except for the mounts Chrysler Corporation is the chief supplier of Bofors guns for the army of the Navy this gun was originally developed in Sweden and was designed to be built largely by hand fitting methods however the US Army Navy and Chrysler redesigned it for quantity production and for greater efficiency of operation every Bofors is comprised of hundreds of individual parts from tiny Springs weighing a fraction of an ounce to the eight foot barrel weighing 330 pounds first mill working drawings had to be made because the original blueprints were in a foreign measure which few American shop men were accustomed to reading then to get the best results from the combined resources of the company's entire mechanical and engineering staff the job of making the gun was split principally into five major manufacturing operation and final assembly the DeSoto division was assigned the job of building the breech casing which is basically the housing of the firing mechanism the manufacturer of the breech ring the breech block and the buffer assembly was given to the Chrysler Division Club it was delegated the task of making the automatic loader assembly and the final assembly of the gun to dodge when to manufacture of the loading tray in a number of breech mechanism small parts the Highland Park plant was assigned the very important job of manufacturing the barrels and water jackets and also some small parts other items came from the company's air temple and flex divisions and more than a thousand subcontractors until Chrysler Corporation was asked to do this job no one had tried to manufacture a gun as large as the buffers on a quantity production basis the aim was to find ways to manufacture or have manufactured all its parts so that they would be interchangeable this would eliminate the old process of hand fitting which was costly and took a great deal of time and at the same time make the gun more efficient and more serviceable in the field actual gun production was planned and organized so that the activities of the several manufacturing divisions were closely coordinated over at DeSoto bridge casings start on the production line as two pieces or channels these are first cleaned and prepared for welding one-way interchangeability is obtained for all Bofors gun parts if through the use of specially designed fixtures jigs and templates which locate and automatically direct manufacturing operations even the welding is done semi-automatically to ensure strong uniform results the fine cutter which cuts the openings in the casing as fast as a saw bite through soft wood is guided by a planogram fast and practically error-free substantial savings and material machines and labor were made by changing the method of making the front part of the casing the original design called for a single heavy casting in order to make it better and faster it was changed to a forged plate welded to a length of two in the first two years of manufacturing this new method saved over 250,000 pounds of steel 200,000 machine hours of labour and 13 critical machines after the four part has been welded to the casing and the entire piece heat treated it goes into a booth to be cleaned by a shock blast treatment machining operations of the casing are all rigidly controlled all cutting operations of this machine are guided by this automatic finger following a master pattern in this way intricate shape can be given piece after piece they are all certain to be exactly life this is an example of the adaptation of quantity production procedure the manufacture of Bofors guns held rigidly in a fixture all holes in the casing are drilled simultaneously and in exactly the right position as the Navy guns are to function as a pair their casings are joined together before finish machine II so that no slow hand alignment will be necessary later to increase production rates wherever possible many machines were designed to handle several identical pieces on one setup such as this machine does and to doubly ensure that every part will be properly interchangeable there is constant inspection inspection by specially designed gauges after each machining operation through such rigid inspection standards it is the constant effort that no error no matter how minut be allowed to progress and be magnified until a piece has to be scrapped after final inspections the breech casings are given a protective covering of paint and ship to the final assembly live at plummer in a chrysler division plant the breech ring the breech-block and the buffer assembly are manufactured the breech ring to which the gun barrel will later be attached and which will house the breech clock comes to the plant as a forging weighing about 300 pounds nearly two-thirds of this is machined away before it is finished first location services are milled and then the other many machining operations have begun before the company began to use a forging the breech ring started as a solid block of metal weighing considerably more than a forging weighs now but the finished rings whether from solid blocks of metal or forgings weigh alike so the new method saved many tons of critical metal and machine hours of manufacture this battery of machines makes an accurate square shaped hole out of a round hole the method of making this square hole was developed by the company and also achieved savings in time and cost original specifications called from making the square hole with a single slotting tool now by undergoing a series of broaching operations the hole is shaped quicker and more accurately [Music] for each breach ring made a breach block has to be made to fit inside this important an intricate part of the firing mechanism must fit exactly the company has made no major changes in the design of the breech block but by the use of quality production methods using semi-automatic machines and constant inspections to make sure each machining operation is held to a precise tolerance block after block can be and has been made exactly alike so alike that a microscopic I could not tell them apart the proof is in the final inspection room where Master company designs gauges certify them first then pass them along to a navy inspector who makes another check before the blocks go out for final assembly to make buffer parts perfectly interchangeable they are machined here in this super finishing Department as a twist of the locking nut and the gun would fire too slow have to twist the other way and it would fire too rapidly these parts must fit exactly after being micro gauged no final buffer assembly is allowed to go to the line until it has been tested on this machine which simulates actual firing dodge main makes the loader trade an important part of the automatic loader mechanism in addition many of the smaller intricate parts of the gun are made here many of the machines in this plant such as these used to manufacture the loader trade are specially designed for the manufacture of Bofors gun parts many of these new machines increased production by being designed to handle two or more operations at the same time others do intricate jobs of form shaping operating semi-automatically in all 85 machining operations must be performed on the loader tray before it is finished each one of these operations must be performed to enter changeable precision limits batteries and machines turn out the smaller parts some of which are important pieces of the firing mechanism many machines such as these gear shakers have been converted and redesigned from automotive jobs for this work here as in the other plants manufacturing Bofors gun parts precision and skill has been built into the machines to the fullest extent possible firing pins another part of the firing mechanism are turned out by the thousands of these automatic machines mass production of the Bofors guns would not have been possible if the small parts manufactured here at dodge main buy machine methods had had to be handmade and subsequently hand fitted and they are made so accurately no hand fitting is necessary when they join other parts of the gun on the assembly line flemeth manufactures the automatic loader assembler as in the other divisions many of the machines used on this job were used in the manufacture of automobiles a large proportion had to be almost completely redesigned to be converted to the manufacture of gun parts others to a somewhat lesser degree the contours of the base are shaped by this semi-automatic machine batteries of drills accurately drill the loader base in one operation eliminating any chance that one of the holes drilled might not be located exactly in relation to the ovens converted from their former use on cylinder blocks these huge machines handled ten pieces it was the policy of redesigning machines instead of waiting for new ones saved thousands of machine hours on gun products in a manufacturer of the feed rods other savings were made this was done by machining them as rays and then cutting them into sections instead of handling each one individually in practically every operation in the manufacturer of the gun refinements have been engineered in cooperation with the Navy ordnance department to save time speed up production and lower cost in some cases new methods were used in others machines were redesigned to do a faster better job for instance formerly the rough edges of these parts were smoothed off by hand adventures a method was devised to burn smooth finish parts by putting them into tumblers with a mixture of stone and finishing compound thousands of hours of hand labor were saved and parts came out of the tumblers with a smooth even finish ready for assembly the Bofors gun barrels are made at Highland Park also many small parts and accessories the manufacture of the gun barrel is probably more spectacular than the manufacture of any other part of the gun the huge round bars of metal from which the barrels are made are big in heaven after being turned down to rough sized barrels are drilled on a somewhat similar machine they are rained or made smooth and even the bar is then finished by honing another smoothing operation all of these are done to such precise tolerances that the inside diameter of each barrel there is hardly a thousandth of an inch under battle conditions barrels sometimes have to be changed in a matter of seconds the threads which lock a barrel in the breech ring are interrupted so the barrel can be quickly locked in place with half a turn the accuracy and life of the barrel depend to a large extent upon the excellence of its rifling Chrysler Corporation developed its own method of cutting the rifling in a barrel with what is known as a wafer type broach a series of these brooches are run through the barrels with each one cutting a little bit more metal away the rifling thus produced is so much more uniform and exact than that obtained by previous methods that according to ordnance experts the life of Bofors barrels has been increased more than three times in this section water jackets are fabricated by a process of silver soldering using controlled heat through induction coil after the water jacket has been finished and tested they go to the barrel assembly line no assembly time is lost through hand fitting all the component parts have been finished to such interchangeable limits that each piece fits smoothly into place barrel assemblies are not attached to the garbage they are shipped to separate units all other gun parts made here go to Plymouth for final assembly at the final assembly location at Plymouth each part is given to final inspections before being sent to the assembly line inspections here are functional in character some sub assemblies are completed on benches near the main line this is the end of the automatic loader sub assembly line here it is made ready for a functional test on this fixture the actual performance of the loader is tested using dummy cartridges duplicating real cartridges in weight and shape firing action is simulated if the loader operates satisfactorily in this test it goes over to the main line here the breech block in all the smaller parts are assembled in the breech ring each part fits snugly in place there is no looseness nor binding calling for hand fitting without manufacturing to exact limits of interchangeability this mass production of the guns would not have been possible the breech casings get a final touching up here and are then put on the rolling trucks which will carry them down the line at this station the elevating arcs are a taxed and this is the beginning of the assembly line the breech ring assembly in linkage are swung into position and slide into the breech casing the buffer assembly is a text it's it's because it was manufactured to fit exact dimensions must be the common denominator of all the gun parts the loader mechanism and tray are the last major sub assemblies to be attached it used to take 450 hours to hand sit and assemble a gun on this line it is done in less than 11 hours the single gun assembly line runs along parallel to the twin gun mark on both lines the operations are approximately the same both prepared guns for functional testing in these fixtures the operation of the guns are tested by the use of dummy cartridges and compressed air simulating firing and recorded dummy barrels slam back and forth as wheel barrels do an actual fire cartridges feed down through the automatic loader at the rate of a hundred and twenty a minute and they are rejected just as fast now the guns are ready for an actual firing test and a nearby navy proving range live ammunition is use each gun is fired four or five times and then sent back to Plymouth where it is given another thorough inspection painted and packed and shipped out to where it will be assembled on its mouth [Music] [Applause] [Music] most of the mounts for Bofors army guns have been made by Firestone with navy gun mounts turned out by several other companies in the first three years of Bofors gun production Chrysler Corporation shipped more than 40,000 complete done mechanisms and 75,000 barrels just as it takes teamwork we use Bofors guns in action it took the teamwork of many men and women working together under a carefully worked-out plan of engineered production to turn them out [Music]

Channel: PeriscopeFilm

Views: 200,688

Rating: 4.8946824 out of 5

Keywords: Periscope Film, Stock Footage, 4K, HD, 2K, Chrysler in WWII, Bofors, Bofors gun, Bofors 40mm anti-aircraft gun, manufacture of artillery, WWII assembly line, assembly line

Id: yVeLsJtId_g

Length: 19min 35sec (1175 seconds)

Published: Fri Sep 01 2017

Reddit Comments

[u/NitrousOxideLolz]

It felt like I was watching an advertisement (I suppose it was one?), but still pretty cool. Thanks for posting.