In the beginning – which is to say in September last year – Delta Motorsport’s highly flexible new S2 autonomous and electric car chassis, one of the star exhibits of this year’s LCV Show, was only going to appear as a notional prototype, born in a computer and destined to stay there forever.  Under the original plans, this all-aluminium, skateboard-style EV chassis design – which now sits proudly in three dimensions at the centre of a specially designed stand – wasn’t even due to show its screen-based face until this time next year.  Then everything changed. In a remarkable last-minute turnaround, Delta’s two founders – engineering director Nick Carpenter and operations director Simon Dowson – decided their S2 project would be more timely and have a far bigger impact if shown this year as a live concept. As project leaders they hurriedly consulted partners in this Innovate UK-backed project – Titan (by-wire steering), Alcon (by-wire brakes), Warwick Manufacturing Group, Potenza Technology (digital safety know-how), Cranfield University (limit handling studies) – and, with everyone’s enthusiastic approval, and working alongside GCE (structure design) and Tecosim (CAE specialists), they set to work at top speed.  The chassis you see here was completed just days before the show opened. It was a true feat of execution, although Carpenter, Dowson and partners seem entirely unfazed by their achievement. It goes with the territory in their high-pressure world of technical creativity. “Being part of a small organisation with a limited budget is a really positive thing,” Carpenter explains. “The bigger you are, the more prone you are to paralysis by analysis. There’s huge pressure to find exact answers when there may not be any. In a small company, you just don’t have time.”  What’s the reason for the S2 project’s sudden change of pace and shape? Carpenter has a more eloquent explanation, but it boils down to the fact that there are currently platoons of promising researchers in the nooks and crannies of vehicle-focused autonomy and electrification, all with theories or processes that urgently need to take next steps. Trouble is, appropriately engineered test vehicles are expensive and in extremely short supply. S2 can do much to fill the void.  At the same time, Delta and its partners see a golden opportunity to prove, progress and then earn from their own technical expertise – and their well-proven car-building capabilities – while greatly aiding others in parallel fields of automotive technology: sensor designers, for example, or creators of vehicle infrastructure and even start-ups working on new forms of ‘mobility as a service’.  “S2 is a flexible chassis system with a much broader capability than the production-based machines our industry usually has to make do with,” explains Carpenter. “When you ask colleagues with a promising project what they’re going to do for a test vehicle, they’ll often tell you they’ve bought a Ford Mondeo or a Chrysler Pacifica and are going to automate it to make a test mule. It isn’t the car they really want. It’s just what they can get.”  By contrast, S2 can be configured comparatively quickly and easily to handle a huge variety of tests and customer activities, says Carpenter, and practically every use furthers the causes of Titan, Alcon and the other partners. “Let’s say you’ve developed a promising piece or process but it’ll cost £5 million and two years to convert a mule to take it further. You’re never going to do it. But if the cost is £200,000 and six months, you’ll probably give it a go.”  On the face of it, skateboard-style chassis aren’t particularly new. Plenty of players in the EV business have already employed the concept of locating motor, ancillaries and power electronics at the extremities of an electric car and connecting them with a low, rigid platform chassis that carries the traction battery-set below the cabin floor. It’s the logical way to do things.  What makes the skateboard revolutionary are the far greater levels of designed-in flexibility than those of previous offerings, to the extent that Delta is describing it to clients as ‘skateboard 2.0’, justifying the S2 name and deliberately built to take account of lessons thrown up by predecessors. It uses a self-supporting structure of fabricated aluminium, designed by GCE and Tecosim, and depends on compact box sections for its rigidity, with the double-wishbone independent suspension systems carried on the chassis longitudinals at both ends.  As well as being almost infinitely flexible in wheelbase, track, overall length, overall width, bulkhead dimensions, crossmember positioning, seating positions and ride height, it can accept a huge variety of powertrains, both hybrid and pure EV. In theory, it could also handle hydrogen fuel cell applications, and even a petrol-only version should anyone ever ask. In fact, it’s so flexible that Carpenter is reluctant to say it has a
Origin: How Delta Motorsport has reinvented the test mule