For driving fast in Scandinavian forests

Sophie, my Volvo XC60 car, is bristling with sensors of one kind or another. So it was no surprise to discover a pair of little horn-like devices half-hidden in the front radiator grille. This was one of them:

The rectangular housing off to its right in the picture hides the front radar, and naturally I supposed that this small horn-like device was itself scanning the road ahead in some way, especially as there was another just like it on the other end of the radiator grille, so that they formed a symmetrical pair. I dismissed both from my mind: I didn't know what they did exactly, but if they were part of my Volvo's external equipment they must fulfil some important function.

So when one broke off the other day, while I was cleaning the front of the radiator, I was immediately concerned that I'd damaged a sensor that mattered. No doubt it wouldn't affect the actual running of the car, but it might rob me of some useful hazard detection. I did rely quite a bit on my car's sensors and what they warned me of. With a long holiday looming, it needed sorting out urgently! 

I examined the thing. 

Well, for a start it wasn't wired in. Odd, that: how could it send any electronic information? Or was it some kind of slave unit, activated by the adjacent radar? The two lugs seemed to have snapped. It had been held to the radiator by a plastic bracket. Odd again: that seemed too flimsy for a factory-installed Volvo part. It had two holes: one at the front, and a larger one at the side. Surely a sensitive device wouldn't be designed to draw in rushing air (and insects)? Ah, maybe it was for 'tasting' the atmosphere in some way, for air quality or temperature perhaps? There were external light and temperature sensors on the door mirrors. Why not elsewhere, on the front radiator, for instance?

I consulted the online handbook. No joy there. I went online. Nor there. Either I was looking for the wrong kind of information (i.e. it wasn't a sensor, but something else) or it was a part that ordinarily never failed and nobody had seen fit to put anything online about it. But the Volvo dealer would surely know. 

I wanted to go out for the afternoon. I might as well head for Eastbourne first, and drop in at the Volvo dealer there. Which I did. Happily I saw the same young chap I saw just a few days earlier, when calling by to arrange Sophie's annual service and MOT, and to ask a technical question on the wisdom/feasibility/cost of an auto gearbox fluid change, since one wouldn't have been carried out before, and I did a lot of towing. 

I showed him the broken-off object. He too wondered what it was. I took him outside to Sophie and showed him the other one, still in place. Yes, it certainly looked like some kind of sensor! But offhand he didn't know what it did. However, another colleague might know. He went off to consult. A little later he returned, with a twinkle in his eye. Yes, it might well be an important little device in certain circumstances. It depended where I intended to take the car. It wasn't a sensor. It was a deer whistle, for driving in forests where deer might be around. A warning device then. It worked when air at enough speed was forced into the front hole. It then emitted a high-pitched sound that deer would hear, and be warned of my approach in the car. 

Really? I'd never heard of such a gadget. 

This and the other whistle were attached to the radiator grille with a sticky pad. They weren't Volvo parts. There were plenty to buy on the Internet. 

It seemed that I had been a bit daft. But I didn't feel that way: why should I know what the thing had been? He hadn't. Besides, I was now spared the expense of getting a new sensor fitted - quite a relief!  (Although on reflection it would have been covered by the one-year Volvo Selekt Used Car Warranty, which had two months left to go) 

Happy ending then. I went off to Bexhill, and enjoyed viewing an art exhibition (Barbara Kasten) at the De La Warr Pavilion. 

While in the car, I had a fresh look at the broken-off deer whistle.

I blew through it, and it sounded just like an ordinary whistle. I could hear it clearly, and I don't make any special claims for my elderly hearing. So much for it emitting an ultra high-pitched noise that only deer could hear! 

If I could make it sound by blowing through it with no special force, it must be sounding all the time as the car sped along, if going fast enough. How irritating for others. Why couldn't I hear it inside the car? Obvious answer: it wasn't audible above the noise of the diesel engine. Then why should any deer up ahead pay it any attention? 

I began to think that the previous owner had fitted a gadget that couldn't do what it said on the tin. Once home, I removed the other whistle. It came off very easily. I was glad to be rid of it. I disliked having useless extras on my car.

I also looked up 'deer whistle' on the Internet, discovering a host of examples for sale, generally for not much money. This one was very like my two whistles. Click on the screenshots to see the detail:

It was more expensive than most. Look at the claims made. The whistle will activate at speeds over 35mph. Neither humans nor pets inside the car will hear anything. It will alert deer a quarter of a mile away. Huh. I think that's a load of phooey. I can't see how a tiny toy-like plastic device like this, that relies on driving fast enough, can send out a 'ultrasonic' shriek that any animal a quarter of a mile ahead will notice above the sound of my engine.  

Deer still abound in the countryside, more than one might think. And rural Sussex, with its woods and hedges and remote tracts of lonely farmland, may well have more deer than most Southern counties. Certainly Ashdown Forest, which I drive through every few weeks, is home to plenty of deer. I sometimes see them when coming home in mid-evening, crossing the road ahead of me, usually in pairs though occasionally there's a herd. Yes, the odd animal will dart out suddenly, but it's far more usual to see deer from a distance, and they are well gone by the time you pass the crossing-point. It's a dawn and dusk hazard mostly. During the day they must retreat to the deeper forest. 

The thing is, I am deer-aware; and after sunset, or in mist, I am anticipating an encounter. Besides, in such conditions I probably never go fast enough to activate a whistle like this. I feel it's a superfluous gadget. If deer were a constant and very pressing danger to driving, as they might well be in Canada or Scandinavia, I would fit something likelier to get their attention and make them move away in good time. It would be powered and substantial and very noisy indeed. And not make of flimsy plastic that could snap off.

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