Rapid 3-ton W.D. Lorry Production upon the Principle of Carrying
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the Job to the Part by Means of an Assembly Conveyer, as Practised by the Associated Equipment Co., Ltd.
UANTITY PRODUCTION, according to the tenets Of American faith, can . only be suecesSfully attempted if handling and moving are reduced to .limits with which engineers
, in this country are i not n actual practice familiar. Constructive prac tice, in British factories where the produced item is fairly bulky, follows the lines of shipbuilding—the construction is begun and completed in situ—on the stocks, as it were. As with a ship, so with a railway engine, a gun turret, a three-ton lorry, even a bicycle. We have seen shells produced in some factories in the British way, each process involving a certain amount. of handling, and we have also seen them going through• the later stages of their progress on a convayer which reduced, handling to the minimum. We have the same idea delightfully reversed in the American sausage factory, where the raw material enters one end of thd machine as a squealing pig and where the sausages emerge at the other, packed and labelled, and where the only thing lost is the squeal.
• At the Walthamstow works of the Associated Equipment Co., Ltd., where, before the war, the peaceful occupation of omnibus manufacture was eonducted, theref is a " machine " where parts enter at one end and at the two sides, and where the completed 3-ton lorry .emerges at the other end, no hand having, been put ont, to accelerate its progress. In-this case the "machine" is a roofed building in the form of a passage, the floor of which is a conveyer, moving at a speed that would never disturb the day dreams of a Surrey policeman, as it only. reaches one foot per minute. The operating levers and cogwheels in the "machine" are the deft and busy fingers of 25 me-n and 20 women. And the capacity orthis active little band of workers is one three-ton lorry completely erected, painted, filled up and ready for its road test every half-hour I In a ten-hour clay, often 19 or 20 such vehicles are produced, and, Sunday being F. shortstaff day, every week there emerges from the .doors of the factory an average of 110, which equals 5720-per annum. The figures could rise to the daily maximum if frames were not temporarily, so difficult to obtain. Figures like these are apt to be unbelievable to those who have watched the more leisurely mode of erecting motor chassis in other works, but we ourselves have initialled the first component of a. projected vehicle as it took its place on the conveyer and, in the short space of time of four hours, have seen it ready with' its tank, radiator and oil reservoir filled and its number plate ;tied on ready for the road, and the longest operation of the whole lot was the drying of the paint I Watching the 'work of erecting on the conveyer, one is struck first with the obviousness and the simplicity of it all, but the mechanical mind is able, at once, to hark back and visualize the enormous amount of un.seen work which has been involved before the conveyor stage is reached—just as the qualified architect, wrapt in admiration of a glorious cathedral, insensibly. pictures to himself the character and design of the hidden foundations.
Next one realizes how the saving in time is effected, for the vehicle in the course of its erection is brought to its next required part and to the gang who are to wed the part to the chassis, and there is no chance or opportunity for half-an-hour or more to go by with nothing being done to a vehicle.. The process of erection goes on inexorably, and delays are not possible. The conveyer beats the time like a relentless metronome, and the erecting staff must inevitably keep pace with it! And they are keen to do so! One can argue that building on the stocks—to take our shipbuilding simile—will effect just as rapid production as building on a conveyer. We doubt it ; nor can we reoall a works where the same productive efficiency is attained by the earlier method. Erecting on the conveyer, to the lay mind, is, of course, the impressive side. But the mechanical mind is equally appealed to by the machining and assembling shops I We do not, however, propose to describe the shops or the work ea,rried out-in them, as the shou practices employed by the Assoeiated Equipment Co. Ltd., do not differ materially from those adopted elsewhere. Suffice it to say that the machining and erecting shops at Walthamstow are devoted to the output of every detail of the chassis except the engine and the frame. Adjoining the gallery in which the conveyer is situated, are departments to which are brought the whole of the completed units. These departments are disposed at the end and on ether side of the conveyer gallery.
To the upper end of the building (as it were in the bar of the letter T) -are brought the front axle and rear axle components and the wheels, and here the wheels are 'erected on the a,.es. Passing through the different departments on the left-hand side of the conveyer. We first Of. all come to the frame department, where the frames are received from the maimfaotnrers completely riveted Up, and Moreover, with all necesSary holes drilled. In the frame department they have added to them the springs, brackets, buffers and towing hooks, while the hack spring cross-Shaft is also erected in position. The 'frames are tested for• truth of drilling • by means of jigs. Further down on this side of the conveyer iS the store of springs, each spring being examined and gauged at the eye, and any slight inaccuracy corrected before it. is passed on to the frame-assembling shop. It takes four groups of frame .assemblers to keep pace with the conveyer.
At the lower end of the shops on this side are stored the bonnets. On the right-hand side of the conveyer there is a number of component Stores, the first one containing gearboxes, the second engines, the third pedal-shaft gear, the fourth steering columns, the fifth radiators, and, at the lower end, the petrol tanks. Every half-hour, two men will wheel on to the upper end of the conveyer a front axle, chocking it in place; they will then wheel On a back axle, setting the two axles at ap proximately t h correct distance apart. The front axle will have its spring clips loosely in place on the spring beds, and it will have the tie rod and connecting rod for the steering properly mounted ; the rear axle carries its brake connections. When the conveyer has brought this pair of axles opposite the entrance to the frame department, a frame is swung out on chain lifting tackle, t Ire jenny running on an overhead run-way, arid lowered in position on the axles. A couple of fitters and their mates then proceed to bolt the springs into place in the spring pads on the axles, another fitter and his mate proceeding to erect in position the selector gear for connecting the gear lever to the gearbox.
At the end of half an hour, or, in all, 'one hour, from the time when the axles were first placed on the conveyor, the ,chassis has reached a position near the gearbox store. The gearbox, with its cardan shaft, is swung out and lowered on to the floor of the conveyer below the chassis, whence, by means of chain-lifting tackle travelling on the overhead run-way,. it is lifted by the' gearbox fitter and is laid into position in the frame, the cardan shaft coupled Up to the worm shaft drive and the bolts to connect the gearbox to the frame are dropped into position and nutted up. A steering
column, complete with steering gear, is now brought from the store, and 4 couple of girls take this in hand and erect it in position, connecting up the Steering lever to the connecting rod, belting the Steering gearbox in its place on the chassis, and mounting the steering wheel.
. The next component to be swung out of the store is the engine, 'which is lowered in place On the sub frame. The engine is complete in every detail, even down to the water couplings Clipped ter the pipes,
' The conveyer shown in course of construction.
ready to be coupled to the inlet and outlet of the radiator. by four studs and nuts. Tho universal joint
• between the engine crankshaft and the primary gearshaft is coupled up, connection is made .from the silencer to, the exhaust pipe of the engine, and the
• starting handle component is erected in place and coupled up. These jabs round the engine run very close to the maxinaion tithe' limit, so much so that on
one occasion we noticed that the fitter working 4 the front end 'of the, turned round and pushed backwards for a cuple of feet the radiator which was swung out on the overhead fun-way, the conveyer having brought the chassis---arnd the fitter—Litt-to al; radiator well up to tithe The radiator is lowered into position on the frame and bolted up, and the water connections t the engine .made good. The pedal gear, in the meantime, has been fastened in position, followed by the connecting up of the selector gear, and a fitter has been at work for, some little time carefully checking every point of connection. This is the only difficult piece of fitting throughout the whole chassis, as there are so many points that have to agree. If the frame should draw in on riveting, or should there he a slight variation in the position of the holes for the attachment of the Selector rod guides,' or the gear gate bracket, or should there be a variation in the distance between the first cross member behind the engine and the next which carries the front of the gearbox, binding in the selector gear will result. Pertain points of minute -adjustment are available, and skilful fitting ensures that ev er y part works sweetly. The dashboard is swung nut; of its bay, is dropped and bolted in position on the frame, and the °armee. tions are made between the accelerator pedal and the carburetter, and t h e other control fittings are coupled up.
The radiator guard. with its bracket at each end, is n o w offered up in place, and the rear stays of the brackets are bolted up to the frame, the holes in the frame being already bored. The front stays of the brackets have their holes bored in them, but the holes in the frame are left to be bored when the rear stays have been bolted Up, as any Slight variation in stay length would throw the holes out of position. These four holes are the only holes bored whilst the job is on the conveyer. . .
The petrol tank is placed in position and clamped 'down to the frame and the petrol pipe is coupled up to the carburetter, whilst the bonnet is brought from the bonnet bay and duly fastened on. The chassis now having reached the end of the conveyer (its front wheels having been pushed off the end whilst the petrel tank was being fitted and the general finishing. touches being put on), it is pulled forward by hand to the extent of a couple of yards, and, by means of flexible hose. oil is run into the •base chamber, water into the radiator, and petrol, from a wheeled tank, into the petrol tank. The gearbox and differential casing receive, a charge of • grease, and, the engine being now started, the Vehicle runs to the paint shoP. Should the engine prove obstreperous, the vehicle is towed from the conveyer gallery along a passageway and the engine started up by engaging first gear and letting the clutch in, the journey to the paint shop always being completed under the engine's own power. In the paint shop, a couple of hands don respirators and, each gripping a paint-spraying jet with its double piping, spray workshop grey" over the whole of the chassis.. The job is done with rather 'greater speed thlin one would probably expect and, a quick-drying paint being used, it is sufficiently dry for the engine to -hie started up and the vehicle driven off to the running shed before the half-hour is up and the next vehicle is ready to come under the swaying hand of the painter ! And, strange to relate; spraying the paint is more economical of' material than application by bruSh, despite the fact that the floor, wall and screen of the painting shop are coaL.-?(I with workshop grey." • From the running shed the chassis goes through the usual routine of testing, reporting, final adjustrnent and then delivery to the body and final painting shop, the road test being. over a, distance of 30 miles with a four-ton load, Chmgford Mount (a hill of 800 yards long with a maximum gradient of 1 inn) hating to be negotiated on top gear. But with the of the lorry chassi_s from the shop where the body coat is applied, we .reed not concern ourselves. 'What we have seen from the moment when the axlee were wheeled on to the conveyer to dm completion of the painting 'occupied four hours only, and we doubt if any assembling job Of equal magnitude is carried out in this country in the same short space of time, taking into account the general fineness of tolerances permitted in motor chassis construction. The saving of time is effected by the avoidance:of much handling of material or the shifting of the chassis. The job comes to the part instead of every part having to be wheeled laboriously to the job, and, in the long run, it is the most economical method.
, Some of the operations that, would take a little too long for the table or conveyer have two men inStead of one. Thus there are three lots of hands fitting up brake gear on three chassis siniultaneously, as there are so many brake connections to be made, but, gener
ally speaking, the work of assembling is timed so that half an hour covers each phase of it. EaCh, unit comes on to the conveyer complete and correct with nothing to doto it. Without this provision the scheme of course would fail.
Just' a word About the conveyer. It is articulated and is 274 ft. between centres. Ten chassis Can be asSembled on it, and the 4nass of platform, chassis and fitters then.totals 40 tons: It is driven by a 5 h.p, electric-motor which runs at 750 to 1200 revs., according to requirements, arid, by gearing down from 4800 • a table .speedof from 11i ins. to 10 ins.per minute can be obtained. The power normally developed by the motor is about -If h.p. and as 1 h.p. is absorbed in the gearing, only a quarter borse-power is utilized to run the conveyer. Two. component departments at the Wallitamstoiv works are of immense interest, calling really for a descriptive article devoted sedely to themselves. In one radiators are built up, the gilled tithes being tested, nested in their top and bottom plates and sweated in place, when they undergo another test, after which the top and bottom tanks and side plates are fastened, on and a final testing given.• In the dashboard assembling shop, the boards are fitted with battens and mouldings, lamp brackets, accelerator gear,, oil gauge, bonnet rest, and heat shield, being carried all the time on a pivoted jig, and all -the holes being drilled from the jig. The dash brackets, footboard brackets and footboards are then fitted, and the complete jeob is turned out with a considerable saving in cost over previous methods. Altogether, for efficiency of production methods, for skilful planning and for clooklike regularity of output, we should imagine that the table or conveyer system of assembly adopted by the Associated Equipment Co., Ltd.' is unequalled in this country and, probably, not even bettered in the land of efficiency in production across the Atlantic.