Tipper crash in Bath

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SA_SA_SA
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Re: Tipper crash in Bath

Postby SA_SA_SA » 14 Feb 2015, 9:56pm

Highway code rule 160
...select a lower gear before you reach a long downhill slope. This will help to control your speed.....

https://www.gov.uk/using-the-road-159-to-203/general-rules-159-to-161

Learners should be reading that (others should be re-reading it).
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Re: Female Cyclist Death In North London

Postby hondated » 14 Feb 2015, 9:59pm

Vorpal wrote:
661-Pete wrote:
Vorpal wrote:Drivers currently are taught to rely on their brakes. I had to take a UK driving test about 10 years ago, and I was in the habit of downshifting. I was told by a driving instructor in no uncertain terms that I must not do that.
News to me. Blimey! So I've been doing it all wrong, ever since I took my driving test some 45 years ago?! I had to google. From this site:
Engine braking during normal driving: Years ago it was considered ideal when slowing down or coming to a stop in a car, to use engine braking as the primary source of slowing or stopping. During a driving test for example, the driving examiner wouldn't be too impressed by a driver constantly using the gears as a means to slow down as the brake is the preferred method in modern driving.

The issue with engine braking and using the gears to slow the vehicle is that one of the drivers hands spends a good deal of time on the gear stick, where it would be better placed on the steering wheel. A certain amount of a drivers attention will be devoted to these downward gear shifts that would otherwise be better placed on the road ahead.

One thing I noted: this website is clearly aimed at British drivers, but this passage appears to have been written by an American writer (in the UK we talk of the 'gear lever' not the 'gear stick', and 'gear changes' not 'gear shifts'). I wonder whether this trend to rely on brakes is America-driven, seeing as almost all cars in the USA are automatics and engine braking is virtually unheard-of? :shock:

Another point: almost all cars nowadays have disk brakes on all four wheels. This was not so when I took the test: many cars back then had disks only on the front wheels, and drum brakes on the rear - and some (my old banger amongst them) had drum brakes all around. Now drum brakes are more prone to 'fading' during prolonged braking such as a long downhill (I've had experience of this!). So engine braking would certainly have been de rigeur in those times.

And another thought. In my old-banger days (again) brake linings were all made of asbestos. Now, even though the full dangers of asbestos were not as well known then as they are now, it was certainly regarded even then as a Bad Thing to pump too many clouds of asbestos straight into the atmosphere. So don't use the brakes too much! Nowadays of course, brake pads are made of something else (what?) so it's no longer an issue.

Perhaps someone with more knowledge of cars than I have, can confirm or correct these thoughts?

An American would never refer to a driving examiner. Drivers take driving tests in the USA, usually from a police officer. And the phrasing otherwise sounds British to me. Maybe it could be written by an Australian?

Brake pads thes days are made of composites or ceramics. Many of the composites are metallic, but there are also non-metallic composites. No asbestos, anymore :)

Disk brakes get more air circulation, so they are less prone to overheating. Drum bakes are more likely to experience fade, though modern brakes are less prone to that than older designs. Modern self-adjusting brakes, if correctly adjusted should compensate for the expansion of the drum. They can't compensate if the shoes get hot enough to glaze, but modern materials are less prone to that, and it is certainly possible to buy brake blocks that withstand very high temperatures without affecting function.

Vorpal just as a matter of interest do they still get you to change down to the crawler gear on the test now then.

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Re: Female Cyclist Death In North London

Postby Vorpal » 14 Feb 2015, 10:42pm

hondated wrote:Vorpal just as a matter of interest do they still get you to change down to the crawler gear on the test now then.

No. I was expected to be in the correct gear for the speed when I started accelerating again, but I did not downshift for engine braking. But I don't know what they might do on the B-auto test.

p.s. I think only trucks and lorries technically have crawler gears these days :wink:
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Re: Tipper crash in Bath

Postby Vorpal » 14 Feb 2015, 10:45pm

SA_SA_SA wrote:Highway code rule 160
...select a lower gear before you reach a long downhill slope. This will help to control your speed.....

https://www.gov.uk/using-the-road-159-to-203/general-rules-159-to-161

Learners should be reading that (others should be re-reading it).

I don't remember discussing that with driving instructors, but as you pointed out they may have assumed I knew. Or maybe they checked that I did it correctly, and never said anything.
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Re: Tipper crash in Bath

Postby 661-Pete » 14 Feb 2015, 10:50pm

SA_SA_SA wrote:
661-Pete wrote:....I wonder whether this trend to rely on brakes is America-driven, seeing as almost all cars in the USA are automatics and engine braking is virtually unheard-of? :shock:


But automatics have low gear slots (eg 1,2) just for that:
it caught Dave Gorman out in America; he thought automatic meant low gear was selected automatically down steep hills (so didn't move the lever to such a low gear slot) and glazed the (fading) brakes whilst wondering why they weren't working so well as he descended...

We had a rental car in the USA - automatic of course - and it had five selector positions: P N D R and S. The 'S' position baffled me, not something I've come across in the UK, and I couldn't find a handbook in the car - but eventually with a bit of googling, I discovered it means "Sport" and gives the driver the option to manually over-ride the automatic gear-changes and use a pushbutton on the selector lever to change up or down. I didn't experiment - by then I'd got used to the car's quirks and foibles... :roll: Anyway it didn't seem at all intuitive to me - perhaps I should have done my homework better?

Anyway, despite doing quite a lot of ups and downs in the Appalachians, I didn't notice any brake fade. The hills were not at the Hardknott or Rosedale level, of course!
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Re: Tipper crash in Bath

Postby mark a. » 14 Feb 2015, 11:05pm

The Institute of Advanced Motorists also advise (at least they did a few years ago) the old "gears are for go, brakes are for slow" rule. Using the gears to slow down means you're using wrenching the clutch, unless you're double-declutching / rev-matching / heel-toeing, which most people don't know how to do. Brake pads are cheaper to replace than a clutch. There's also the issue of doing too many things at once, so the IAM technique means you've got hands on the steering wheel and one foot on the brake, not having to juggle gear levers, steering wheel, clutch and brake (and accelerator if rev-matching).

The IAM also wants you in the most suitable gear at all times. Most of the time these two rules align: brake to the desired speed, release the brake, then change down to the correct gear. The rules don't quite match on steep downhills, where you also want to be in a low gear - here IIRC they recommend that you can brake and change gear at the same time. Once you're in the low gear you're sorted.

My knowledge only applies to cars. I have no idea how HGVs do it, so relevance to this horrible crash is limited. I'm just replying to the side-topic of modern driving techniques and standards.

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Re: Tipper crash in Bath

Postby thirdcrank » 15 Feb 2015, 7:49am

Heltor Chasca wrote: ... The weight restriction sign banning such large vehicles on this road had been mowed down by a car weeks earlier and the council hadn't replaced it. ...


Are you sure about this? I'm interested because it would partly explain what I've been getting at above. OTOH, the streetview image to which I linked above showing width restriction signs but no weight restriction signs is dated August 2012. Also, signs of that type tend to be installed in pairs, as is the case with the width restriction signs here and one would normally remain in place if a crash knocked down the other.

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Re: Tipper crash in Bath

Postby Vorpal » 15 Feb 2015, 8:00am

According to the Guardian...
Police are continuing to investigate why the truck was on Lansdown Lane in Bath, where residents have long complained about lorries and other vehicles using it to skip around the centre of the city. The road has a width restriction but no weight limit.


http://www.theguardian.com/uk-news/2015 ... lip-potter
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Re: Tipper crash in Bath

Postby honesty » 15 Feb 2015, 8:09am

Tests have changed. When I took mine 20 years ago I was taught to downshift 1 gear at a time and always be in the right gear for the right speed. My wife who only passed 5 ish years ago was taught to brake down then shift to the appropriate gear even if that meant missing 1 or 2.

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Re: Tipper crash in Bath

Postby Heltor Chasca » 15 Feb 2015, 8:35am

thirdcrank wrote:
Heltor Chasca wrote: ... The weight restriction sign banning such large vehicles on this road had been mowed down by a car weeks earlier and the council hadn't replaced it. ...


Are you sure about this? I'm interested because it would partly explain what I've been getting at above. OTOH, the streetview image to which I linked above showing width restriction signs but no weight restriction signs is dated August 2012. Also, signs of that type tend to be installed in pairs, as is the case with the width restriction signs here and one would normally remain in place if a crash knocked down the other.


Pretty certain. I read it on a Twitter feed. It was either Bath Chronicle or Somerset Guardian....hc

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Re: Tipper crash in Bath

Postby bigjim » 15 Feb 2015, 9:41am

Thats how they are taught these days. In the early days we were taught to downchange because older braking systems were not adequate. Modern braking systems on cars are superb in comparison. But that driving style does not apply to laden trucks.
I don't think though that new car drivers are taught to approach a red light at speed and brake at the last minute. Or drive as close as possible to the car on front. :)
When I was taught to drive a truck [used to be called lorries, when I first started] it was always about smoothness and mechanical sympathy. You can't throw a truck about or your load would be all over the place and the vehicle becomes unstable. I really don't know how this young man has got in this position, carreering downhill, out of control. .
I have an idea of course but can't say.
Last edited by bigjim on 15 Feb 2015, 10:35am, edited 1 time in total.

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Re: Tipper crash in Bath

Postby Vorpal » 15 Feb 2015, 10:14am

There's a thread on Pistonheads forum that has links to other articles, one of which included this information
Residents described hearing the frantic sounding of a horn just before the crash and police said early witness reports suggest the driver of the 32-tonne lorry lost control after taking evasive action to avoid an earlier accident.
from http://www.dailymail.co.uk/news/article ... crash.html

Pistonheads thread also said that there are two width restriction sign on the road, but one of those had been flattened by an earlier incident.

More information from witnesses http://www.dailymail.co.uk/news/article ... crash.html

So very sad, whatever the cause.
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Re: Tipper crash in Bath

Postby Mick F » 15 Feb 2015, 10:41am

mark a. wrote:The Institute of Advanced Motorists also advise (at least they did a few years ago) the old "gears are for go, brakes are for slow" rule. Using the gears to slow down means you're using wrenching the clutch, unless you're double-declutching / rev-matching / heel-toeing, which most people don't know how to do. Brake pads are cheaper to replace than a clutch. There's also the issue of doing too many things at once, so the IAM technique means you've got hands on the steering wheel and one foot on the brake, not having to juggle gear levers, steering wheel, clutch and brake (and accelerator if rev-matching).

The IAM also wants you in the most suitable gear at all times. Most of the time these two rules align: brake to the desired speed, release the brake, then change down to the correct gear. The rules don't quite match on steep downhills, where you also want to be in a low gear - here IIRC they recommend that you can brake and change gear at the same time. Once you're in the low gear you're sorted.

My knowledge only applies to cars. I have no idea how HGVs do it, so relevance to this horrible crash is limited. I'm just replying to the side-topic of modern driving techniques and standards.
Yes.
The method is to use the brakes to slow .......... NOT the engine and gearbox.

We have a Fiat 500. Two cylinders, 875cc Turbo. Goes like a rocket!
One thing I've found when driving it, there is little or no engine braking available. We live on the side of a steep valley and we need to brake far more than we ever did in other cars.

Also, near here, the main road goes from a short stretch of 40mph to 30mph down a slight hill. In all the other cars, if you take your foot off the gas as you approach the 40 limit and allow the car to slow down gradually, you go into the 40 at 40 and as you reach the 30, you're doing 30. Simple, but takes practice and no brakes required.

With the 500, I have to brake. Even with my foot off the gas at 40 through the 40, I'd still be doing 35 or more at the 30, so I need to brake. Changing down into 3rd doesn't help, whereas in the 1.6 16v Clio we (still) have, I can do the whole thing in 5th gear and not need the brakes at all.
Mick F. Cornwall

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Re: Tipper crash in Bath

Postby thirdcrank » 15 Feb 2015, 12:03pm

From vorpal's Daily Mail link:

Another local resident described the tragedy as an ‘accident waiting to happen’, claiming he had warned the authorities that lorries had been a problem on the narrow thoroughfare as long ago as last April.

He said the problem had been exacerbated by construction work at the primary school.

Minutes from a council meeting in April show he asked: ‘Who will be held accountable if a child is killed or seriously injured?’ (My emphasis)


That's a phrase we've discussed before. There'll be some frantic backside-covering taking place now. I fancy it won't be long before there's some effective traffic-calming at the top of this hill, rather than the pathetic measures at the bottom. (eg big kerbs, separated by a narrow gap only passable by cars and light vans.

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Re: Tipper crash in Bath

Postby bigjim » 15 Feb 2015, 1:36pm

We have a Fiat 500. Two cylinders, 875cc Turbo. Goes like a rocket!
One thing I've found when driving it, there is little or no engine braking available.

Thats because you don't need it with modern dual safety crossover brakes. Mind you if your engine stops you may be struggling a bit with braking power. :)