Reducing limiter speed, opinions wanted

UK PROFESSIONAL DRIVERS FORUMS THE UK PROFESSIONAL DRIVERS FORUM (INTERACTIVE)
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First little background info: In March 2004 there was bad accident involving bus and truck with a-frame trailer. Links text isn’t 100% accurate about the way accident happened but it gives you the picture. Here are some photos for those who are not faint hearted. Accident investigation board did some investigation and now they have announced their report about the way accident happened, contributing factors, etc. Among other safety recommendations they gave one particular recommendation from which I’d like to have your opinions.

Accident investigation board suggested that maximum limiter speed of trucks should be decreased from current 90km/h to 80km/h (which is national speed limit for trucks). Main arguments they used are (followed with my opinions):

  • Stability of trailer is considerably worse when doing 89 km/h compared to 80 km/h. Tests were made only with one particular A-frame trailer. I agree with this to a certain degree as increased stability is somehow noticeable even without spesific devices, depending from road of course.
  • Decreased fuel consumption. They state that fuel consumption drops 5-10% when speed is reduced from 90 to 80. I could agree with that BUT currently many truck drivers over here drive around 85 km/h even that countrys “habit” is to drive 90 km/h when speed limit is 80 km/h. Against that info I interpret that board is saying that driving against limiter reduces fuel consumption.
  • Board also stated that overtakes would be safer on roads where limit is 100 km/h. As I stated above, countrys habit is to drive 90 on 80 limit, and car drivers most likely would drive same speed even if trucks couldn’t do anything even near that. I think overtakes would increase when previously cars and trucks did quite same speed. That would soon eliminate any advantage what would be gained on 100 km/h roads.

I’d like to know your opinions about these arguments and how you think reducing limiter speed to 80 km/h would affect these arguments. Of course any other views and opinions are welcome.

Btw, minister of transport of Finland has said that Finland will take this matter forward when it’s Finlands turn to be “chairman of EU”. She has said they will suggest that in whole EU area maximum limiter speed would be reduced to 80 km/h…

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We have a saying in England Kyrbo ‘specific cases make bad law’ or words to that effect. In other words a knee jerk reaction to one particular accident is understandable but not helpful. A case in point is the current outcry to ‘bring back hanging’ because of the murder of the young policewoman in Bradford.

I would have thought that a reduction of speed of 10km on black ice such as caused this accident would make little difference. However, personally, I would have been doing a lot less than that under those conditions.
I would be interested to hear the follow up if you can post it here.
Was the truck driver held responsible and what reasons were given?
Was he judged to be driving too fast for the conditions, even though perhaps within the speed limit?
Was he accused of having an insecure load?

Whatever the verdict, to call for an extension to the speed limit to the whole of Europe because of an accident in specific conditions in Finland is plainly ridiculous. As I have stated on more than one occasion elsewhere in these forums, the speed limiter law as it currently operates is counter productive to road safety and should be liberalised, not made more restrictive, causing even more dangerous frustration.

Salut, David.

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Spardo:
Whatever the verdict, to call for an extension to the speed limit to the whole of Europe because of an accident in specific conditions in Finland is plainly ridiculous. As I have stated on more than one occasion elsewhere in these forums, the speed limiter law as it currently operates is counter productive to road safety and should be liberalised, not made more restrictive, causing even more dangerous frustration.

Salut, David.

I agree with the above. Sadly though, in this day and age of EU politics, there are more chances of the horses in the field behind my house taking flight than speed limits, or any law for that matter becoming more liberalised, the order of the day is increasingly restrictive and complicated laws and regulations and if we think we’ve got it bad now, I dread to think what it will be like trying to be a truck driver in say ten years time, or any other profession for that matter.

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Spardo, your thoughts are just same as mine, especially ‘specific cases make bad law’. It’s ridiculous that today politics only way to increase road safety happens by lowering speed limits. Immediately after accident transport ministry was thinking to introduce 70 km/h speed limit for trucks for winter period. :unamused:

This case hasn’t been in the court yet as prosecutor has waited this report to be finished before he takes any action.

That driver most likely didn’t suspect that hill to be covered with black ice becouse he had gone to opposite direction over that hill only little over an hour before accident. At that time road had been dry but after it small rain cloud had gone over that place. So road was now covered with black ice about 20 km onwards from that hill (and black ice isn’t always easily noticeable). When trailer begun to swerve at 85 km/h driver tried to straighten it by accelerating. Then limiter steps in and trailer was still serving.

This company moves all their cargo in demountable boxes and another driver was loaded box and trailer earlier and then drove with them to south. Driver of accident truck came from south, meet another driver and swop boxes and trailers only 50 km to north from acciden place. So driver had practically no way to improve nor check load securing (and still it’s only driver who’s responsible :smiling_imp:). Load wasn’t secured properly in the truck’s box as there wasn’t suitable hooks in the floor for securing paper rolls.

Ever heard someone driving over 4.5 hour without break? Driver of the accident truck had drove continuously 5h 10min with only 8 min “break” which box swap took. That was becouse schedules of that regular trunk route were made so tight that they couldn’t be achieved without driving against limiter whenever possible and driving little overtime. This in big company which has publicly stated that their drivers aren’t allowd to drive over 80 km/h (most of them didn’t). They have also stated that they obey driving time regulations. Then comes driver who had loaded box and trailer. Driving time in this regular shift was over 11 hour, 925 km covered… 12.5 hours when easing from limiter to 80 km/h :unamused: :imp:

One thing which this report totally ignores is road conditions. It says that they couldn’t find any clear evidence that condition of road could have been contributing factor. There are two big bumps on that downhill while it’s turning left and I have been told that there are also noticeable “tyre trails” on asphalt… Sure, those don’t affect to truck and trailer any way, especially when it’s slippery…

When the accident happened I was only about 60 km south from accident place heading to Tampere and it was raining water (-5C to -10C) best part of next 150 km. It was bloody scary to drive and I feared for same thing which had already happened that night. It was quite a shock to hear it from radio at 4am.

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I reckon this bloke’s for the high jump Kyrbo, if only because of the driving time. The company too because of the lack of load restraints. This sort of thing would have been less likely in the ‘old days’ of flat trailers. For some reason some modern drivers seem to think if it’s out of sight, it’s safe.

But a couple of other things disturb me too. Firstly you say his initial reaction was to accelerate and then I watched the video (how was that scenario arrived at?) which showed him braking. Both of these things are lethal on black ice. He should be touching nothing but the steering wheel, and keeping that pointing in the way he was going.

An A-frame drawbar is basically 2 trailers. The A-frame dolly (yes I know it may have been a full trailer with steering A-frame but the principle is the same) and the semi resting on it. What has happened here is that the first trailer, the dolly, has started to jacknife on the wagon and is seen attempting to overtake it. This suggests on a modern vehicle a malfunction in the operation of the ABS (as he was braking), that of the wagon being more efficient.

Salut, David.

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Trailer wasn’t combination of dolly and semi, it was think that “full trailer” what you mentioned is it’s type. Neither there was registered ABS malfunction on any vehicle. About load restraining I say that there is no such equipment which would have last on this kind of accident (and I’m sure you have understood this way before this). In the report was mention that negative acceleration affecting to trailer was around 5g (five times more than earths normal gravity) and load securing needs only to last acceleration which equals to earths gravity.

I didn’t notice until now that there is also english summary in accident report. English summary, starting from page 7. It’s quite large file but I couldn’t find english summary anywhere else.

Accelerating isn’t that lethal you seem to think. In the very beginnning of trailers skid, when trucks tyres still have traction, it “safe” to accelerate. This is trick from ‘old days’ before limiter and it’s used long time to rescue trailer in similar situations. It prevents truck from slowing trailer so swerve doesn’t began to “multiply”.

I have once had “priviledge” of facing similar situation when trailer began to swerve on straight motorway (there was a bump where skid started). Hopefully I was only going around 80 km/h and slight acceleration stopped swerving. After that it was time to gently slow down little more (and to stop to next service station for relaxing nerves).

When watching animation you have to keep in mind that big part of trucks behavior and line of drive is based on speculation. So it can’t be thought as an absolute truth and neither can this report I’m referring to. Differing from animation, report suggest that skid started from trailers rear bogie (in a place where is “negative bump” towards ditch (I dont know correct word but I mean “large hole which isn’t hole” if that makes any sense, a “hole” which is about 5-15cm deep and maybe one by one meter when watching from top).

I agree with you about braking but it requires quite brave man who doesn’t brake on/after 6% downhill slope while 64 tonne is some speed when there is coach coming towards you. In report is verbal description about driver actions where reads that his first sharp braking happened after he had got truck and trailer back to his own lane. At that point it’s most likely that trailer was going towards ditch and in skid braking most likely strengten this movement. Maybe driver was hoping trailer to go to ditch in effort to slowing truck when bus was approaching fast.

I ain’t saying that your method is wrong (it’s far from it) but as we all know things rarely happen “by the book” on the road. Also when doing something long time on specific conditions with specific equipment (a-frame in this case) I think it’s quite natural that “natives” develop some specific methods for those conditions.

Now it’s time for disclaimer becouse I’m not native english speaker and it wouldn’t be big suprise to me if my writings give different “picture” to you than it gives to me :blush:. My intention wasn’t to say that we over here are better drivers and if someone understood my writings like that I’m sorry as it wasn’t what I meant to say.

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Kyrbo,
Just to answer a few of your points in the order you put them.

Neither there was registered ABS malfunction on any vehicle

In that case I can only assume that the trucks brakes were more efficient than the trailer’s, hence the attempt to ‘overtake’. A classic jack-knife. I think it is worth pointing out that the English practice of wagons being generally larger than their (drawbar) trailers, the opposite to the Continental situation, makes this ‘tail wagging the dog’ phenomenon less likely. After many years on drawbars in England I was horrified on my first trip with a French one. :cry:

About load restraining I say that there is no such equipment which would have last on this kind of accident (and I’m sure you have understood this way before this).

I understood this perfectly, I mentioned it purely because the lack of restraints would be held against him and the company in such a serious case.

Accelerating isn’t that lethal you seem to think. In the very beginnning of trailers skid, when trucks tyres still have traction, it “safe” to accelerate

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I have emphasised the important phrase in this sentence. Sure but in a case of black ice this is unlikely to be the case. Not something I would want to do.

So it can’t be thought as an absolute truth and neither can this report I’m referring to.

Understood, that is why I asked ‘how is this scenario arrived at?’

(in a place where is “negative bump” towards ditch (I dont know correct word but I mean “large hole which isn’t hole” if that makes any sense, a “hole” which is about 5-15cm deep and maybe one by one meter when watching from top).

This is called in English a ‘pothole’ and of course would be lethal in these conditions at speed.

Maybe driver was hoping trailer to go to ditch in effort to slowing truck when bus was approaching fast.

I’m sure he was, I well remember losing braking on a downhill narrow road with a bend and a village at the bottom. I kept driving the tractor into the wall to stop but it kept bouncing off and I was praying it would turnover. I still wouldn’t have touched the brakes in this situation though. :wink:

I think it’s quite natural that “natives” develop some specific methods for those conditions.

Agreed :slight_smile: .

Now it’s time for disclaimer becouse I’m not native english speaker and it wouldn’t be big suprise to me if my writings give different “picture” to you than it gives to me . My intention wasn’t to say that we over here are better drivers and if someone understood my writings like that I’m sorry as it wasn’t what I meant to say.

On the contrary, I assume you have not lived in England, and you put me and my countrymen to shame with your command of our language. I understood perfectly your well written post which gave no reason for offence and there is no need for an apology. :slight_smile:

Salut, David.

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Spardo:

Kyrbo:
Neither there was registered ABS malfunction on any vehicle

In that case I can only assume that the trucks brakes were more efficient than the trailer’s, hence the attempt to ‘overtake’. A classic jack-knife. I think it is worth pointing out that the English practice of wagons being generally larger than their (drawbar) trailers, the opposite to the Continental situation, makes this ‘tail wagging the dog’ phenomenon less likely. After many years on drawbars in England I was horrified on my first trip with a French one. :cry:

Maybe it was “brake delay” which made jack-knife effect worse (as skid did start before braking). Brake differ amongst trailer bogies couldn’t be measured as first bogie damaged badly in collision. Truck was equipped with electronic brake control system, which operation is unfamiliar to me, and trailer had normal air controller brakes. On simulation drive with similar trailer and load there was 1 second “brake delay” on first bogie and 1.5 second delay on second bogie counting from moment when “control pressure” started raising.

Tail wagging the dog phenomenon is quite correct also in this case (and it’s too usual here with current trailers, especially on general haulage). Truck weighed little above 28 tonnes and trailer was little below 36 tonnes. Trucks total weight was 2 tonnes over maximum which helped little bit but trailer was still bit on the heavy side, especially when GVW was 4 tonnes over maximum.

Accelerating isn’t that lethal you seem to think. In the very beginnning of trailers skid, when trucks tyres still have traction, it “safe” to accelerate

.

I have emphasised the important phrase in this sentence. Sure but in a case of black ice this is unlikely to be the case. Not something I would want to do.

I’d still want to point that force which starts skid is considerably less than force which is needed to continue the skid. At least this is what I think to be the “black magic” behind this trick. Nevertheless most important thing is to pray that no one comes towards you before trailer is again under control (or turned over).

One thing I have heard about this company is that they tend to fire those who happen to get truck or trailer turned over (and some day there will be world without wars and pigs are flying).

… I understood perfectly your well written post …

Thank you but I can assure that isn’t always the case when I am reading english text. :laughing:

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Fair comment to all you say Kyrbo, but what about this :astonished: :open_mouth:

One thing I have heard about this company is that they tend to fire those who happen to get truck or trailer turned over (and some day there will be world without wars and pigs are flying).

Sounds like this is not an unknown occurrence with this outfit :unamused: .

My comment about the truck brakes being more efficient than the trailer brakes was irrelevant because it was the trailer which was jack-knifing on the A-frame, which then caused it (the A-frame) to jack-knife on the wagon. This seems to be born out by:

On simulation drive with similar trailer and load there was 1 second “brake delay” on first bogie and 1.5 second delay on second bogie counting from moment when “control pressure” started raising

That half second ‘start’ the A-frame had on braking (if that is what you meant by 1st bogie) would be enough to start the, by then, almost inevitable jack-knife. The instant he touches the brake and the A-frame starts braking, the weight of the trailer is trying to push it out of the way, the braking of the rear bogies half a second later is too late to help on such a surface.

Maybe it was “brake delay” which made jack-knife effect worse (as skid did start before braking).

I am sure from what I have been shown that the jack-knife was caused by the brake delay not merely made worse. What you describe as the ‘skid’ was in fact trailer swing. This will right itself or swing the whole train round and turn it over but, there is no reason for it to jack-knife without the braking. This can also be combatted, as you said, by accelerating if there is sufficient power and speed available, but only when there is good traction. Otherwise it would only cause the rear of the wagon to swing making the situation even worse.

Whether we agree or not on accelerating out of a skid on black ice, I am quite sure I wouldn’t be braking in that situation :wink: .

After all this long-windedness on my part :laughing: , IMHO this accident was caused by inappropriate speed given road conditions followed by inappropriate action and, to answer your original question, not a reason for a general reduction in limiter speeds.

Salut, David.

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Spardo:

One thing I have heard about this company is that they tend to fire those who happen to get truck or trailer turned over (and some day there will be world without wars and pigs are flying).

Sounds like this is not an unknown occurrence with this outfit :unamused: .

This kind of skid/swerving isn’t unknown amongs truck drivers but it’s still quite rare thing to happen. In many occurances it’s got under control after a while. As you most likely know A-frame trailer tend to live it’s “own life” behind the truck making it considerably less stabile than rigid or an artic and this is causing these situations (especially at nights when road service standards are lower). I don’t either know if that quote of mine was meant to mean only turn overs or if that also means driving to ditch and another similar accidents (neither I know how trustworthy that comment was).

On simulation drive with similar trailer and load there was 1 second “brake delay” on first bogie and 1.5 second delay on second bogie counting from moment when “control pressure” started raising

That half second ‘start’ the A-frame had on braking (if that is what you meant by 1st bogie) would be enough to start the, by then, almost inevitable jack-knife. The instant he touches the brake and the A-frame starts braking, the weight of the trailer is trying to push it out of the way, the braking of the rear bogies half a second later is too late to help on such a surface.

That’s exactly what I have been thinking about this situation nevertheless this Accident Investigation Board couldn’t say if this was or wasn’t one of the contributing factors of the accident.

Maybe it was “brake delay” which made jack-knife effect worse (as skid did start before braking).

I am sure from what I have been shown that the jack-knife was caused by the brake delay not merely made worse. What you describe as the ‘skid’ was in fact trailer swing. This will right itself or swing the whole train round and turn it over but, there is no reason for it to jack-knife without the braking.

You’re right, I was confusing terms skid and jack-knife here (what I just said about language skills :wink: :slight_smile:). Your thoughs are almost one to one with mines when I’m thinking in finnish :smiley:

Whether we agree or not on accelerating out of a skid on black ice, I am quite sure I wouldn’t be braking in that situation :wink: .

After all this long-windedness on my part :laughing: , IMHO this accident was caused by inappropriate speed given road conditions followed by inappropriate action and, to answer your original question, not a reason for a general reduction in limiter speeds.

Agreed, with both braking and inappropriate speed, altought such black ice conditions were unexpected by driver. I myself have gone downhill at enermous speeds at winter when I haven’t had courage to brake on such slippery conditions and I can state that I have feared much on these situations. I also think that I wouldn’t touched brake pedal in this accident but human mind is trickery under such conditions. I just hope that I don’t have to drive with HGV much any more in such conditions.

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Spardo:
Sounds like this is not an unknown occurrence with this outfit

You may have misunderstood, when I used the word outfit I was referring to the company and possibly having had several accidents.

Kyrbo:
Your thoughs are almost one to one with mines when I’m thinking in finnish

You mean I can think in Finnish now :astonished: :open_mouth: :laughing: :question: Jeez, the wonders of modern technology :wink: .

I myself have gone downhill at enermous speeds at winter when I haven’t had courage to brake on such slippery conditions

Yes, but on snow not on black ice. Trouble with black ice is you don’t always know it’s there 'till it’s too late. Possibly this driver’s only hope of a defence.

I just hope that I don’t have to drive with HGV much any more in such conditions

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Aw come on Kyrbo, you got to admit, it is fun :sunglasses:. A real adrenalin rush, better than any artificial drug, unfortunately like drugs it sometimes ends in tragedy.

Great discussion Kyrbo, I have enjoyed it and I’m only sorry that I can’t sign off in Finnish, but I checked all my dictionaries, and there are many, but I don’t have a Finnish one :cry: . Don’t think Swedish quite fits the bill does it? :wink:

Salut, David.

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Spardo:

Spardo:
Sounds like this is not an unknown occurrence with this outfit

You may have misunderstood, when I used the word outfit I was referring to the company and possibly having had several accidents.

I thought you was referring to this type of truck and trailer combination. I don’t know if this company has more or less accidents than any company of that size.

Kyrbo:
Your thoughs are almost one to one with mines when I’m thinking in finnish

You mean I can think in Finnish now :astonished: :open_mouth: :laughing: :question: Jeez, the wonders of modern technology :wink: .

:smiley: :laughing:
I mean’t that after I had “find” what you were saying it was almost same issue what I had been thinking but only in different language (which shouldn’t alter the issue but only it’s way of presentation) :wink:

I just hope that I don’t have to drive with HGV much any more in such conditions

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Aw come on Kyrbo, you got to admit, it is fun :sunglasses:. A real adrenalin rush, better than any artificial drug, unfortunately like drugs it sometimes ends in tragedy.

Well… I can’t deny what you are said, in it’s own way it is fun :sunglasses: but sometimes you can unfortunately get an overdose :frowning: