Flying the Glider: Roadster Owner Ken Jacobs Tours Assembly Plant and Test Track

Ken Jacobs, Roadster Owner, 18 juli 2008

Ken Jacobs was one of the first employees at the relational database pioneer Oracle Corporation. He and his wife Margaret are thrilled to be early adopters and advocates for the pioneering Tesla, the car and the company.

My wife and I, returning home to the US from a week in Morocco, spent a couple of days in London, where we enjoyed the better sanitary conditions and also took in a couple of theatre shows. We also saw the fabulous King Tut exhibit at The O2. The next day, we set out to see how well the Tesla Roadsters are coming along – a highlight of the entire trip.

We took a pleasant two-hour train ride from London Liverpool Station to Norwich, where we met Glyn Owen, who runs the UK operation for Tesla. Glyn drove us through some beautiful English countryside from Norwich to Hethel, where the Lotus plant is located. Along the way, he shared his background and feelings for Tesla. He's a well-experienced automotive professional, and is obviously very committed to the success of Tesla Motors. Glyn is a perfect gentleman, and very forthcoming about Tesla's management and technology, and the progress of development.As you know, Lotus has responsibility for assembling the Tesla Roadster, but Tesla has a reasonable presence on-site. We saw the space that Tesla rents from Lotus. Previously, a lot of engineering was done there, but now, as production has begun, the staff is reduced, and there is a large area with empty desks. The 40 or so Tesla employees in Hethel are monitoring the production process, and verifying engineering information as it arrives from San Carlos, CA and the suppliers. The Tesla employees are also responsible for quality assurance checking, including specifically the inspections done from the customer-viewpoint rather than the engineering/assembly viewpoint.

We didn't actually see any Tesla Roadsters being assembled at the time we visited. One Roadster was being painted, and thus was off-limits to us "civilians". On the other hand, we did see a couple of nearly finished products, including Martin Eberhard's vehicle, and quite a beauty it is! It's now in the US and hopefully will soon be in Martin's garage – or on the road!

What happens in Hethel is assembly, not manufacture. There are, as I recall, some 3,000 parts (or sub-assemblies) that ship to the Lotus plant from various suppliers throughout Europe and elsewhere. These parts are then put together to build a Tesla Roadster. They keep a relatively small inventory of parts on hand, so it is something of a just-in-time inventory management system. Of course, the rate of production will always be relatively small, so Lotus doesn't need to have a large inventory.

I was amazed to see that it is entirely a manual process. No robots. No power tools. Just simple screwdrivers and wrenches and some pulleys mounted from above to hoist heavy components. The Roadster is clearly a hand-made vehicle, with a lot of love and personal attention given to each vehicle as a result. The main assembly line in Hethel has 12 stations, at each of which the workers have 43 minutes to do the work required to move the car along. Each station has 2 or 3 guys working on a phase of the assembly process, whether it's integrating the pre-built chassis with the frame, installing the wheels and brakes, the windshield, the body panels or the seats.

At each step, the technicians must be very aware of the specific car they are building, and whether it is a Tesla Roadster or a Lotus Elise. The Roadster and the Elise are different vehicles, of course, and have many different parts, even though they share the same assembly line. The workers ensure that each Roadster gets the right Tesla parts, installed to Tesla specifications for such things as the proper torque levels for tightening bolts, etc. At the end of the line, after 12x43 minutes (about 8 hours), something very much like a Lotus Elise or a Tesla Roadster will emerge.

The Lotus assembly line was specially modified for the Roadster, to accommodate the installation of the 900-pound ESS ("energy storage system"), the car’s battery. The original intent was to ship complete and drivable Roadsters from the UK to the US. This has now changed. My understanding is that when Tesla begins installing powertrain 1.5 in new Roadsters, it will be done in California. Thus, everything but the battery and powertrain will be installed in Hethel. The resulting so-called "glider" is then shipped to California (about 5-6 weeks by boat, I'm told). For each battery, 6,831 lithium ion cells are sent from Japan to California, where the battery is built. This change saves Tesla shipping costs, and makes the Roadster a "California car". The Tesla Store about to open in Menlo Park will do the final installation of the battery and powertrain.

One of the more interesting steps on the assembly line is where the body panels are installed. There is a special frame that holds the body panels and aligns precisely with the body and chassis of the car being built. There are two sides to this frame, one for Lotus cars and one for the Tesla, and it rotates 180 degrees on its vertical axis depending on which car (and whether the right or left side of the vehicle) is being fitted with the panels. The panels are both bolted and glued to the frame. Apparently the glue is strong enough to hold the panels on, but the bolts give the body extra rigidity and integrity.

No doubt you know that the Roadster uses carbon-fiber body panels, not more conventional fiberglass or metal parts. These parts require a highly specialized manufacturing process. Glyn told us that the latest glitch in the production of the Roadsters was a need to change the supplier for the body panels. Tesla was simply not getting the required quality. By now, this problem has been fixed, and the plant is currently ramping up production with body panels from the new supplier.

The body panels are painted before they are installed. The panels for a given vehicle are mounted to, and painted on, a special frame that holds the parts roughly in the shape of a Roadster. It's like one of those "exploded" views of a car, where all you see are the body panels floating in space. This approach ensures that the paint job is uniform for any given vehicle. We were not allowed anywhere near the painting area, which is kept scrupulously clean. The inspection of the paint job is also meticulous. Each car is closely examined and paint touch-ups are done in a dust-free enclosed area with bright lights so workers can find and fix the slightest defects.

There are several other stages during the rest of the process of assembly, including installing the seats, the doors, and all the rest of the interior and exterior details. Naturally, inspections take place at several points along the way, so problems can be detected as soon as possible, and close to where they can be addressed. Each vehicle has its own checklist, recording the items that require attention before the car can be released. The Tesla team at the Lotus plant has final authority for a "customer inspection". After all, Tesla Motors is a customer of Lotus, just as most of us are customers of Tesla Motors.

I had an enormous thrill at the end of our visit to the Lotus plant: a couple of fast laps around the track in a Roadster validation prototype! It was a dark green one, and showed the signs of how tough life must be for a prototype vehicle that gets driven and modified often. A nice young man named Sean, who'd obviously been around the track more than a few times, drove, thank goodness. The track is about 2 miles long, and we completed each lap in about 60 seconds. Two laps at 115 mph really gave Sean the opportunity to show how well he can drive, and to demonstrate the incredible handling and acceleration of which the Roadster is capable.

The track is not a simple oval, but has a few straight-aways and many sharp turns, some with piles of tires on the side of the pavement. Sean wasn't shy. We took every turn with gusto, and only once did we experience anything like slipping. The Roadster holds the road like a train holds the rails, and it accelerates like the Space Shuttle (well, almost!).

We had just about overstayed our time. We quickly got in Glyn's car and he drove us back to the train. Though Glyn didn't have to speed (much) on the way to the train station, I'm convinced that if Sean had driven only 114 mph, we would have missed the train back to London.

It took me several days to wipe the smile off my face, and I was reluctant to leave without taking a Roadster with me! It was a great day. Thanks, Zak, for arranging this visit, and thank you Glyn and Sean and the others we met in Hethel for your hospitality. The only Roadster experience that will top our visit to the plant will be the day we take delivery. I can hardly wait!