Weight - the performance killer

Roland Whitehead, Quru CEO
October 2012

Performance and weight

(and why Oracle is such a drag on your business)

I have had the benefit of knowing or working with some truly great performance designers. Nigel Irens, Patrick Head, Lindsay Cunningham, Gordon Edge and Frank Bethwaite have all, in one way or another managed to get more performance out of their creations than anyone else working in the same field at the same time. They all have two things in common: they are great engineers and are fanatical about producing the best.

If you could watch any of them during the development cycle you would very quickly notice that whilst they all want more power, better control, more reliability, they are simply fanatical about weight*.

Almost all performance design is about reducing weight. Nigel pushed marine construction limits further than anyone else, being the first to bring aerospace construction techniques to offshore multihull yachts; Patrick would pick apart every component of a car and, when he couldn't leave it out would insist that it was too heavy; Lindsay would attach a fitting with epoxy and stainless screws and would then remove the screws, leaving just one (often drilled out) "just in case"; Frank never built a boat heavier than one he'd built before; and Gordon made me fly to Schiphol and back in order to pick up some very small springs that were just 20% lighter in order to make an insulin injector work that little bit better.

Why?

The obvious place to start is looking at acceleration. Hopefully you picked up enough physics at school to know that:

Force =

Weight x Acceleration

and this forever links weight with speed and the rate of acceleration. You can arrange the formula another way:

Acceleration =	Force
	Weight

Thus if you have a fixed force, doubling your weight will half your acceleration - it will take you twice as long to get up to the same speed.

Very simplistically, ignoring everything else, if you start from a standstill and accelerate up to 30 mph at a rate of 5 mph per second then it will take you 6 seconds during which you will have travelled roughly 0.025 of a mile (or 44 yards / 40 meters) - distance being 0.5 x acceleration x the square of the time. With twice the weight you would be accelerating at 2.5 mph per second and so, after the same 6 seconds you'd have travelled 20 meters less.

Exactly the same thing happens when slowing down - the heavier you are, the longer it takes to slow down and so you have to start slowing down earlier in order to stop where you want. Now when you add up all the accelerations and decelerations around a race course, be it the world, Weymouth Bay or Silverstone, you can end up a long way behind the leaders if you are heavier than them.

Weight is the killer

But weight doesn't just kill acceleration. More weight also adds drag. With a car, the two big drag components are aerodynamic drag and road friction.

Weight itself doesn't impact aerodynamic drag but it certainly affects road drag. The heavier the car, the more the tyre flattens and this consumes energy which slows you down. In addition, the heavier the car the more friction there is in the bearings which have to pass the weight of the car into the wheels and don't like running with extra weight.

Boats suffer three major forms of drag: aerodynamic drag; hydrodynamic skin friction drag; and wave drag. Again, weight doesn't really effect aerodynamic drag but the heavier the craft the more hull you have to have in the water. The more hull you have, the more surface area you have and hydrodynamic skin friction drag is almost directly proportional to the surface area. Wave drag is a function of speed, hull shape and weight but generally, the heavier the boat for a given length, the worse the wave drag is going to be; light boats don't make such big waves do they?

The America’s Cup

You've probably noticed that the America's Cup has finally woken up to performance sailing and realised that multihulls with wings produce much faster, more exciting sailing - and thus greater spectacle. It still staggers me that they took so long to catch on after Peter de Savary and Denis Conner showed them the way in 1988!

The current move is pretty much driven by Larry Ellison backing Russell Coutts' vision with Oracle Team USA. There is plenty that is wrong with the aerodynamic package that Oracle Team USA have forced the America's Cup to be using but they've written their own rule and they are sticking to it. The one thing that Russell has really got right is weight - they've made a step change in reducing the all-up weight of their craft using every conceivable way possible. That Oracle Team USA itself managed to break a critical foil on the first full sail of their 72ft catamaran clearly shows how far they have pushed - safety considerations are minimal!

So, apart from being very brave, how have Oracle Team USA managed to do this? Quite simply they have thrown a staggering amount of money at it - money for the latest materials; money for the huge amounts of man hours employed so far.

Success comes at a cost

It’s at this point that I have to ask how, ultimately, has this incredible performance been achieved, i.e. where has all the money come from? The sad truth is that it has come from every company, every user who has licensed the Oracle database. The more money that Oracle Corporation makes, the more money finds its way into Larry's America's Cup fund and the more that is spent on saving weight.

"So," I hear you ask, "what's it got to do with me and what can I do about it?"

Well, we are all measured by performance and just as with a car or a boat, the issue of weight counts. Only with software, the weight is generally found in the cost. Your performance won't be that great if your costs are too high. Less cost produces a more nimble, faster accelerating business with less drag on the P&L. You don't have to improve Oracle Team USA’s performance at the expense of your own so take a look at something with excitingly similar abilities and a much lighter cost.

EnterpriseDB, anyone?

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Roland Whitehead, Founder of Quru, spent many years designing race yachts, designing one Little America's Cup challenger and being involved with two America's Cup campaigns. He has been involved with software for motorsport teams, from stockcar racing to Formula One. Roland worked in more normal product design where one of his regrets is putting too much material in a plastic cat-flap thus giving a generation of cats a headache because they didn't open it fast enough. He has since been obsessed with removing weight where it isn't necessary.

* Yes, I know (as they all do) that it's not weight that counts but mass but since gravity is still constant at the speeds that all these designers and I were working at, I'll stick to calling it "weight" because you don't worry about your mass now do you?