HSCC Donington Park 30th of May

[RickT]

Hi Guys !

Another thoroughly enjoyable and relaxed HSCC meeting, even the weather was kind to us!

Anybody there get any photos ? Specifically looking for shots of Dad and Andrew Wareing in our red McLaren in the Guards race !

Cheers
Richard Taylor

[gary396]

Originally Posted by grantp

I thought you might be along soon Gary ....

So how can the transponders display things the wrong way round?

Based on lap times?

This might get a bit wordy:

The Transponder (TP) just emits a unique number, no time. That code is picked up via loops under the surface of the track e.g. at the control line (finish line) and at sector points around the circuit, although the latter are only used if the event organisers pay for sector timing.

The loops are just simple wires, a bit like TV aerial cables and these are connected back to the timing room via interface boxes on and around the pit wall (different at different circuits). The timing systems from the timekeeping companies (the ones that I've worked with anyway) sync the TP number received via these loops and the time that the TP number was received via the loop together with the timing beam 'break time' via GPS to get an accurate and consistent timing signal.

So the timing room receives a beam time from a car (or cars) that breaks the beam AND a TP time & number (more if more than one car). The 'system' marries these together to link the beam time to the TP number. That unique TP number is then 'married up' to the car's race number within the timing system - as long as the driver has bothered to inform the race organisers or timing - that's a little dig!

There can be a slight difference between beam time and TP time because of the position, state, clarity of the TP etc but the system just logs that TP time and uses the beam time which is the official time and the most accurate time. So with one car crossing the line at a time - simple.

Two or more cars alongside each other is much the same. The beam time is allocated to the first car to break the beam and the second and subsequent cars just use their TP time (the time their TP was picked up by the loop). This is because the beam can only be broken once for overlapping cars so the beam 'doesn't know' what their time was.

Say car '5' crosses the line a nose ahead of car '9' so we get just one beam time. But if the TP in car '5' is poorly positioned or has a poor signal etc its signal might get picked up by the loop a bit later than car '9' behind it. So initially the timing system will marry up the beam time (the time of the winner) with the TP of car '9' (because its signal reached the loop first) even though it finished behind car '5'. In that case the timekeepers would manually intervene to swap the cars round and give car '5' the correct beam time and hence first place.

The same situation / process can apply at the end of every lap not just finishes where two or more cars overlap. If you look at timekeepers' handwritten lap charts (yes they still do them) you'll see an indication of overlaps to help verify this.

That's why the timekeepers have to pay particular attention to finishes - TSL for example now have a video camera running constantly aimed at the finish line at some races BSB, BTCC etc.

Apologies for the long explanation - you did ask!

Hope it helps though.

[grantp]

Right, so a photo-finish, in nag racing terms, requires human observation either directly or possibly with the help of video evidence?

I spent a few minutes at an event last year partly observing the time keepers in action (but whilst chatting to someone else so not paying full attention). As I recall the way of dealing with a car with a non-functioning transponder was the side lesson of that day. Nothing as close as the .002 second win (corrected from .004 from the broadcast live timing iirc) in Benn and Rudolf's race on Saturday. That's about the thickness of a coat of paint I would have thought.

A good eye and a high resolution video required for that one!

[gary396]

Originally Posted by grantp

Right, so a photo-finish, in nag racing terms, requires human observation either directly or possibly with the help of video evidence

Yes, that's it, more often than not the transponders get it right but human observation is the ultimate decider hence the judge of fact element.

A car with no transponder or one that isn't working gets its time from breaking the beam and the timekeeper simply enters the car number against the beam time but again observation when it is overlapping or being overlapped is key. HSCC use MST for timekeeping and their system is somewhat older than TSLs system but similar processes.

[Colin McKay]

Thanks Gary, that explains how it works but I have to ask - why the reliance on human observation when the transponder seems perfectly able to provide the data? From your description the light beam is only any use for the first car in a bunch and the others are all timed on the TP signal anyway.

[gary396]

Well in the vast majority of cases the TP number does come through in the correct order so human intervention isn't required but it's still vital for someone to observe the order of cars. This is to make sure that the passing order was recorded correctly, i.e for those occasions when the TP data comes through in the 'wrong' order as mentioned above re TP signals reaching the loop.

Also it's often that during a race a TP will stop working or be intermittent or even fall off - again all reasons why someone is watching and manually recording the passing cars and checking that the computer data received is correct. So for most events TSL will have a Chief Timekeeper (publishing results, liaison with the Clerks etc), one person running the timing computer and one person writing a running list or lap chart. Fairly simple process really. Maybe more people at bigger events. Other companies tend to need one or two more people.

Also, to be clear, the beam time works for every separate car (or each group of overlapping cars) on every lap not just the first car across the line at the finish.

[retrognome]

Sorry this is a bit late but thought my sequence of Jon Finch having his accident at Redgate might be of interest. Martyn Donn in the white Lola must also have been very worried. I have a meeting gallery at www.retro-speed.co.uk/galleries.asp Images copyright.

[Chigley]

Very, very fortunate, it looked a bad one.