Tipper crash in Bath

Commuting, Day rides, Audax, Incidents, etc.
User avatar
bigjim
Posts: 3135
Joined: 2 Feb 2008, 5:08pm
Location: Manchester

Re: Female Cyclist Death In North London

Postby bigjim » 14 Feb 2015, 3:43pm

As for the driver being 19 that as got to be wrong as you definitely need to be 21 to drive an eight wheel tipper which I think the vehicle is.

EU changed that to 18 a few years ago because of the shortage of drivers. I'm suprised that they could get insurance though. It's usually 25 plus before insurance will touch you.
Nothing left to prove.

reohn2
Posts: 37454
Joined: 26 Jun 2009, 8:21pm

Re: Female Cyclist Death In North London

Postby reohn2 » 14 Feb 2015, 4:41pm

bigjim wrote:As a, sometimes truck driver, I can confirm that the default on brake failure is to stop the vehicle immediately. It has happened to me in the past. There is also an exhaust brake option. On a steep hill on approach he should be, brake, change down, brake, change down until he is in almost crawler gear using engine braking. I can't imagine why this was not happening.


+1
My thoughts too.
-----------------------------------------------------------
I cycle therefore I am.

Vorpal
Moderator
Posts: 17733
Joined: 19 Jan 2009, 3:34pm
Location: Not there ;)

Re: Female Cyclist Death In North London

Postby Vorpal » 14 Feb 2015, 5:00pm

There are many failure modes that can cause the primary braking system to work incorrectly without initiating emergency braking. Most of them stem from poor or incorrect maintenance. The fail safe is a separate system. The emergency brakes use the pressurised air to hold springs in place. When the air pressure is insufficient, the spring overcomes the air pressure and the emergency brakes come on. The system has to be repressurised to take the emergency brake off again.

Failure modes that do not cause a reduction in air pressure will not cause the emergency brakes to come on.

Poorly maintained brakes may not have the correct balance. It should be apparent in inspection. In some circumstances, the only time it will be an issue is in an emergency. It is caused by replacing some, but not all brake shoes, replacing them with incorrect material, or incorrect adjustment. Brakes can overheat during prolonged braking without causing the emergency brake to come on. If the drums expand and the brakes are already marginal in terms of adjustment, there simply wouldn't be enough stopping power. The automatic adjusters can be manually adjusted, and mechanics sometimes do this. If it is done too many times they may no longer function correctly. I imagine that someone who is expert in this sort of thing has a long list of failures that can occur without making the emergency brakes come on.
“In some ways, it is easier to be a dissident, for then one is without responsibility.”
― Nelson Mandela, Long Walk to Freedom

User avatar
bigjim
Posts: 3135
Joined: 2 Feb 2008, 5:08pm
Location: Manchester

Re: Female Cyclist Death In North London

Postby bigjim » 14 Feb 2015, 5:10pm

Yes but.
You still have the exhaust brake and he should not be in a position where he has to rely on braking on that hill. A dab of the brakes and a downchange that is all that is needed. I used to travel all over Yorkshire using Bedford KMs and 20+ ton of spuds on board. I hit a lot of steep hills where I could not rely on the brakes. No exhaust brake either. Modern trucks are so much better in regard to braking, but I'm still in the habit of not relying on them. I still double de clutch! We don't know the cause so it's unfair to apportion blame. However I do wonder how the age thing can have an effect. Young car drivers rely on their brakes more than my generation ever did. This should not occur in HGV but does this car driving behaviour crossover?
Nothing left to prove.

Vorpal
Moderator
Posts: 17733
Joined: 19 Jan 2009, 3:34pm
Location: Not there ;)

Re: Female Cyclist Death In North London

Postby Vorpal » 14 Feb 2015, 5:50pm

bigjim wrote:Yes but.
You still have the exhaust brake and he should not be in a position where he has to rely on braking on that hill. A dab of the brakes and a downchange that is all that is needed. I used to travel all over Yorkshire using Bedford KMs and 20+ ton of spuds on board. I hit a lot of steep hills where I could not rely on the brakes. No exhaust brake either. Modern trucks are so much better in regard to braking, but I'm still in the habit of not relying on them. I still double de clutch! We don't know the cause so it's unfair to apportion blame. However I do wonder how the age thing can have an effect. Young car drivers rely on their brakes more than my generation ever did. This should not occur in HGV but does this car driving behaviour crossover?

That's fair enough.

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. I used the highway code (which says that drivers shouldn't 'coast' because they cannot take advantage of engine braking) to argue with her, but she said I should leave my car in the gear it was in when I start braking, and only clutch and downshift when I was preparing to accelerate again, or coming to a complete stop. I managed to break my habit enough to take my driving test. I didn't ask the driving examiner about it, but I did ask other driving instructors, and they all told me the same thing.
“In some ways, it is easier to be a dissident, for then one is without responsibility.”
― Nelson Mandela, Long Walk to Freedom

User avatar
661-Pete
Posts: 9475
Joined: 22 Nov 2012, 8:45pm
Location: Sussex

Re: Female Cyclist Death In North London

Postby 661-Pete » 14 Feb 2015, 7:45pm

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?
Suppose that this room is a lift. The support breaks and down we go with ever-increasing velocity.
Let us pass the time by performing physical experiments...
--- Arthur Eddington (creator of the Eddington Number).

SA_SA_SA
Posts: 1836
Joined: 31 Oct 2009, 1:46pm

Re: Female Cyclist Death In North London

Postby SA_SA_SA » 14 Feb 2015, 9:01pm

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. ...


Surely there is a difference between using engine braking to augment normal braking (as described above) where braking is short with no risk of fade and using the engine as a "drag brake" on long steep hills where there is a risk of brake fade (eg as instructed by "select low gear now" type signs). Surely driving instructors should be explaining the difference?

I suspect engine braking increases air borne pollutants out of the exhaust but whether that is better than some extra brake dust....
------------You may not use this post in Cycle or other magazine ------ 8)

thirdcrank
Posts: 28686
Joined: 9 Jan 2007, 2:44pm

Re: Tipper crash in Bath

Postby thirdcrank » 14 Feb 2015, 9:21pm

The official advice for descending this hill is LOW GEAR FOR ONE MILE. Fair enough, but from streetview, it looks as though that's right at the start of the steep bendy bit. There's no greater advocate than I am for the personal responsibility of drivers for their actions, but if warning signs are to be of any use at all, they need to be positioned where they can be seen in time to be acted on.

https://maps.google.co.uk/maps?ll=51.41 ... 3&t=m&z=11

vorpal

Thanks for splitting the topics.

Vorpal
Moderator
Posts: 17733
Joined: 19 Jan 2009, 3:34pm
Location: Not there ;)

Re: Tipper crash in Bath

Postby Vorpal » 14 Feb 2015, 9:25pm

The driving instructors I spoke to did not explain the difference to me. They told me 'gears are for going and brakes are for slowing' or some such thing. One of them told me it would be okay to revert to my habit of downshifting after the driving test :roll:
“In some ways, it is easier to be a dissident, for then one is without responsibility.”
― Nelson Mandela, Long Walk to Freedom

SteveHunter
Posts: 186
Joined: 24 Aug 2014, 10:02pm

Re: Tipper crash in Bath

Postby SteveHunter » 14 Feb 2015, 9:29pm

When my daughter learnt to drive her driving instructor told her engine braking put unnecessary wear on the engine so you shouldn't do it. You should always use the brakes for slowing down as the brakes are cheaper to replace than the engine.

That's what she was told anyway.

It doesn't feel right to me if I'm not in the correct gear for the speed I am doing, I have always changed down through the gears and always will.

User avatar
Heltor Chasca
Posts: 3016
Joined: 30 Aug 2014, 8:18pm
Location: Near Bath & The Mendips in Somerset

Tipper crash in Bath

Postby Heltor Chasca » 14 Feb 2015, 9:33pm

It's a tragedy. 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. Budgets?

My oldest daughter goes to school just up the road and a few of her friends went to this local school (WASPS). I have also done a few landscaping projects right in this neighbourhood. To say the local community isn't heartbroken would be an untruth. Bath has close links to our Welsh cousins and it's a very sad such a thing has happened. They and the media are also in deep pity for the young lorry driver....hc
Last edited by Heltor Chasca on 14 Feb 2015, 9:49pm, edited 1 time in total.

SA_SA_SA
Posts: 1836
Joined: 31 Oct 2009, 1:46pm

Re: Tipper crash in Bath

Postby SA_SA_SA » 14 Feb 2015, 9:38pm

Vorpal wrote:The driving instructors I spoke to did not explain the difference to me. They told me 'gears are for going and brakes are for slowing' or some such thing. One of them told me it would be okay to revert to my habit of downshifting after the driving test :roll:


Perhaps they assumed you already knew from your previous driving test, rather than treating you as a new driver. I can't remember if my driving instructor said anything but it said low gear for hills in the "book of driving" I read :)

I was taught to change down when I braked normally but I think the "official reason" given was to just to be in the correct gear for the speed not for engine braking.
------------You may not use this post in Cycle or other magazine ------ 8)

Vorpal
Moderator
Posts: 17733
Joined: 19 Jan 2009, 3:34pm
Location: Not there ;)

Re: Female Cyclist Death In North London

Postby Vorpal » 14 Feb 2015, 9:41pm

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.
“In some ways, it is easier to be a dissident, for then one is without responsibility.”
― Nelson Mandela, Long Walk to Freedom

SA_SA_SA
Posts: 1836
Joined: 31 Oct 2009, 1:46pm

Re: Tipper crash in Bath

Postby SA_SA_SA » 14 Feb 2015, 9:42pm

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...
------------You may not use this post in Cycle or other magazine ------ 8)

User avatar
hondated
Posts: 2382
Joined: 27 Mar 2008, 7:59am
Location: Eastbourne

Re: Female Cyclist Death In North London

Postby hondated » 14 Feb 2015, 9:53pm

bigjim wrote:
As for the driver being 19 that as got to be wrong as you definitely need to be 21 to drive an eight wheel tipper which I think the vehicle is.

EU changed that to 18 a few years ago because of the shortage of drivers. I'm suprised that they could get insurance though. It's usually 25 plus before insurance will touch you.

Well Jim I stand corrected and I am absolutely amazed to learn that. I thought I was young at 21 when I first got mine and I had mates of the same age who wanted to do it but could not afford the HGV course.
I just cannot believe there was a shortage of 21 year olds that wanted to drive HGV vehicles.