• Drivers who regularly use the M27 motorway near Southampton
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airport may have noticed that in December last year there was a sudden increase in the number of trucks on it carrying scrap metal. Few could have realised that this was connected directly with the then-iminent launch of the new Transit range.
In 20 days last December, around 1,000 tonnes of steel was taken out of Ford's Southampton plant. The production lines which had been responsible for Transit number two million bein delivered in the summer of 1985, and which right up to midNovember had been building up to 230 oldstyle Transits a day, were making way for new equipment which had to be turning-out the new model well in advance of its January 9, 1986 launch.
Had this massive re-equipping exercise been a straightforward, new-for-old one it would have been noteworthy enough but it was more, much more, than that. An indication of just how much more comes from the fact that it cost fully 25% of the total £400 million that Ford spent in planning, researching and developing the new Transit range.
What Ford has got for its £100 million is one of the world's most advanced commercial vehicle manufacturing plants in terms of its use of robots and the flexibility they bring.
Southampton plant manager Stan Kelly says that the two primary objectives were to boost capacity to 300 vehicles a day and to gain complete freedom to choose how that output is divided between the 36 basic model derivatives that make up the Transit range.
To achieve that cost-effectively while maintaining stringent quality control standards on a highly automated van body and chassis/cab production line is nowhere near as easy as it might at first seem. "As far as we know, no other manufacturer, including the Japanese, approaches this level of flexibility," says Kelly.
Computers and robots
Not surprisingly, computers and robots, or UTD's (universal transfer devices) as they are more correctly called, are the two key elements in the advanced manufacturing techniques employed at Southampton and at its sister plant in Genk. Belgium, which is similarly equipped and has the same capacity. (The Genk factory also builds Sierra cars and consequently is much larger than Southampton.) Two computer systems are used, with a common data base. One schedules the body construction, the second tracks the complete vehicle from paint shop to delivery.
The main role of the body construction scheduling process, which begins when a customer places his order, is to ensure that the correct sub-assembly arrives at the correct point on the assembly line at the appropriate time. An additional complication with the new Transit is that its body panels are not pressed at the assembly site. Southampton's press shop has been closed and dismantled; the new Transit's pressings coming from Dagenham, lIalewood and elsewhere.
Kelly reckons that about 75% of the 2100 million spent at Southampton has gone on automating body manufacturing. Following a two-year installation and training programme involving robot suppliers from the UK, Italy and West Germany principally British Federal, Lamp-Sceptre, Comau and Kuka there are now 125 robots in operation at Southampton, handling about 70% of all the Transit's bodyshell welds.
Body construction begins with the largest assembly, the underbocly, which can be one of four basic designs: for long or shortwheelbase vans and buses and for long and short-wheelbase chassis/cabs. The underbody has two U-section main longitudinal members which are capped to form chassis sidemembers on chassis/cab models. All short wheelbase models have an additional subframe at the front to can-y their independent front suspension.
On the first of the 15 stations on the 100 metre underbody assembly line the ladder frame's main components, longitudinal and cross members and step assemblies are automatically clamped and welded into place. Other underbody components, such as the floor pan and cross member closing panels, join the line and are welded into place at later stations.
There are 38 robots on the underbody line, which will make, depending on vehicle type, up to 1.800 welds. Two separate lines, each with 16 robots, assemble the left and right hand body sides, which come in two lengths, with and without side loading door aperatures. All completed body sides are lifted vertically and held on hooks, rather like drying fish, in an overhead storage area known to Kelly and his team as the kipper store".
Rediffusion vision A short assembly line, with only four robots, produces the Transit range's three different roof panels, for short-wheelbase low-roof, and long-wheelbase high-roof models. There are three main pressings in each complete roof panel. The front and rear sections are common to long and shortwheelbase roof panels, a longer centre section being used to convert a short to a long-wheelbase roof panel.
All the body sub-assemblies eventually come together on the 10-station, 100 metre body framing line, where 37 robots weld complete body shells. The level of automation on this line is greater than anywhere else in the Transit plants. At one station it employs a computer vision system which is believed to be the first of its kind to go into operation anywhere in the European motor industry.
The system, designed and built by Rediffusion Robot Systems of Crawley, is installed at the point on the line where the two body sides, rear panels, and underbody meet. Its function is to ensure that there is no mis-match between body components, such as long-wheelbase body sides being welded to a short wheelbase underbody, and to check that the model actually being built is the one on the order specification held in the production scheduling computer's memory.
The station after the computer vision point houses a giant, Lamp-Sceptre multiwelder. If a shell which was being assembled incorrectly were to pass into that and beyond it would be a very expensive mistake. Stan Kelly admits that the risk of a serious mismatch of components is very small, but dismisses any suggestion that therefore, at .60,000, the Rediffusion system represents an extravagant insurance premium.
"The Lamb-Sceptre multi-welder is the most complex assembly station in the plant. It would probably only need one error to be avoided here for the Rediffusion system to pay for itself," he says.
Certainly the technology behind the system is impressive. A laser reader automatically checks a bar code on the underbody, which identifies the model being built. Simutaneously, five closed circuit television cameras scan the body shell beneath them. Two cameras are directed at each side and one at the rear. The body front is common to all models and so does not have to be checked at this stage.
The body is lit by a specially designed light box which floods the inside and bottom of it with light. Each camera scans systematically the scene in front of it, the image it generates being divided into horizontal lines. Each line in turn is divided into discrete picture elements or 'pixels'. Each pixel is coded into an electrical signal for transmission to the vision computer.
Thus a digitised image of the body shell is built up and can be compared with the digital data in the computer which says what type the body shell should be. Any discrepancy will cause the shell to be rejected before it passes into the multi-welder.
From the end of the framing line complete body shells are transferred by conveyor to the paint and anti-corrosion treatment lines, then to the final assembly lines where glass, trim, drive line and suspension are fitted. While in all these sections the Southampton and Genk plants are bang up to date, they have nothing quite so advanced as the framing line's computer vision system. Not yet that is.
With the first six months of new Transit production now successfully behind him, Stan Kelly expects Southampton's 1986 full year production total to be a record 48,000 vehicles, 25% up on last year's figure. Now he is confidently looking to the future, and ways of further streamlining Transit production. These might include automatic electrostatic enamel paint spraying, and more extensive use of metal-to-metal adhesives.