Another bridge strike

[someone]

The last time I was at a clinic, I did bring my own bathroom scales to the clinic to calibrate it against the clinic's scales (I weigh myself every week as part of my diabetes monitoring regime).

So do you understand mmol/mol?

I was only diagnosed six years ago, and it still means nothing to me. I have to look up the percentage.

Mind, I grew up in the last days of using Fahrenheit alongside centigrade, and still only understand the former so need to convert to that. I guess when faced with two systems I naturally pick up the one which makes most sense to me.

Sorry for going off-topic. To bring it back, although I am not typical, I agree with KeithW about people still fully understanding certain metric measurements in certain contexts.

If a height restriction was only in metres it would mean nothing to me, I would do a rough yard per metre calculation, but on a motorbike rarely do they matter anyway. Although there was once a very low overbridge, possibly the underpass by Ely station but I think lower than that, which felt close enough to pay attention.

As I understand it, the reason that metric height limits became a requirement was because of the risk of foreign lorry drivers confused by the system, not British ones who grew up with it. Even if you only use metres in any other context, knowing that all signs are written in feet and inches then you would learn your vehicle height in that system. After all, you only need to know which number is the bigger. There is no need to have a specific feel for how big 12ft is unless you are also guessing your vehicle height. In which case you should not be driving over-height vehicles in the first place.

[Ruperts Trooper]

Many British-born drivers may only understand metric - but drivers originating from a metric country should have enough nous to realise they don't know what 12 ft means on a height restriction sign, especially when driving a tall vehicle.

I dont believe that is a factor, anyone under the age of 60 will have been taught in metric units but a high percentage of them will still use imperial units every day. Ask people how tall and heavy they are and most will say some thing like 5ft 8" and 11 stone.

Take a look at the Highway Code and it still quotes stopping distances in both metric and imperial units. All you have to remember is 1 metre is about 3 ft 4" or even just 3 and a bit.

Even though I have lived in the UK for 40 years, eleven stones means little to me. I convert it first to pounds - ie 154 pounds and then to kilograms to get 70 kg. The reason - I was brought up in South Africa where nobody used stones - when I was young, people in South Africa used the American system and would have said "154 lbs" rather then "11 stone". Then in the early 1970's South Africa went metric and I got used to using kilograms rather than pounds. I settled in the UK in 1978 and decided that since the UK was in the process of going metric, there was no point in getting to grips with stones and pounds - things were going to change anyway. Now, when I have my weight taken at a clinic, the reading is always in kilograms and when the nurse is about to convert to stones and pounds for my benefit, I tell him or her not to worry as I use kilograms anyway. The last time I was at a clinic, I did bring my own bathroom scales to the clinic to calibrate it against the clinic's scales (I weigh myself every week as part of my diabetes monitoring regime).

I was brought up with UK Imperial measures and taught that at Junior School, learning metric at Grammar School - my interest in cars and my aptitude for mathematics has meant that my adult life has used a mixture of the two systems, with frequent conversions between the two done in my head, but I've learnt to accept that most people use one or the other rather than a mixture - my wife is equally capable at mathematics but is rigidly stuck in the Imperial system for everyday things.

[Vierwielen]

The last time I was at a clinic, I did bring my own bathroom scales to the clinic to calibrate it against the clinic's scales (I weigh myself every week as part of my diabetes monitoring regime).

So do you understand mmol/mol?

I was only diagnosed six years ago, and it still means nothing to me. I have to look up the percentage.

Mind, I grew up in the last days of using Fahrenheit alongside centigrade, and still only understand the former so need to convert to that. I guess when faced with two systems I naturally pick up the one which makes most sense to me.

... snip

I understand the concept of mmol/mol. A mole (symbol mol) is an Avagadro number of molecules and in this case, it is a measure of the number of molecules (x 0.001) of sugar per molecule of water. Unless you are a chemist, moles don't mean much - when I was working in Germany and had some blood tests done there, my blood sugar level was given in mg/dL. The choice of decilitres was to ensure that the reading was of the order of 100 (no decimals needed). I preferred using mg/dL as that has some meaning.

You also mentioned "[degrees] centigrade". To be pedantic, you should have written "degrees Celsius. The reason I mention this is not to criticise you , but rather to relate why we use "degrees Celsius". When SI was being defined, there was a problem with the term "centigrade" - as far as the French were concerned, there were 100 grades in a right angle, so one centigrade was 0.001 right angles. This meant that on any great circle on the earth's surface, one centigrade was approximately one kilometre (the earth's polar circumference being 40,007 km). After a certain amount of deliberation, it was decided that the symbol "°C" would mean "degrees Celsius" rather than "degrees centigrade in honour of Anders Celsius who first proposed a scale similar to the centigrade scale. (Celsius first proposed that 0°C would be the boiling point of water and 100°C would be the freezing point of water. After as few years, the two fixed points were changed round).

[Vierwielen]

... snip - my wife is equally capable at mathematics but is rigidly stuck in the Imperial system for everyday things.

That sounds like a friend of my wife's who worked in a laboratory. She was quite happy to weigh our 100 grams of sodium chloride, but ask her to weigh our 100 grams of salt at home and her mind went blank.

[someone]

I understand the concept of mmol/mol… when I was working in Germany and had some blood tests done there, my blood sugar level was given in mg/dL. The choice of decilitres was to ensure that the reading was of the order of 100 (no decimals needed). I preferred using mg/dL as that has some meaning.

I was meaning with regards to measuring average glucose levels through an HbA1c test.

The I.F.C.C. standardized testing to resolve inconsistencies, which resulted in values slightly lower than those aligned with the D.C.C.T., as was used in the U.K. Rather than have to deal with it causing sa change to existing results, they instead changed to a different scale — mmol HbA1c/mol Hb rather than the mean average A1c percentage — just to avoid confusion. It also does not use decimals.

This was adopted pretty quickly in Europe but a bit longer in the U.K., where we had a period of dual use before switching completely. The latter I think occurred not long before I was diagnosed, but I was given my results in percentages and so that is how I understand them and struggle with mmol/mol.

As for mg/dL against mmol/L, I have only known the latter. The difference there seems to be akin to using L/100km and km/L. Not in a like-for-like sense, but that there are two systems using scientific or metric units and it is entirely arbitrary which is used where.

[Vierwielen]

I understand the concept of mmol/mol… when I was working in Germany and had some blood tests done there, my blood sugar level was given in mg/dL. The choice of decilitres was to ensure that the reading was of the order of 100 (no decimals needed). I preferred using mg/dL as that has some meaning.

I was meaning with regards to measuring average glucose levels through an HbA1c test.

The I.F.C.C. standardized testing to resolve inconsistencies, which resulted in values slightly lower than those aligned with the D.C.C.T., as was used in the U.K. Rather than have to deal with it causing sa change to existing results, they instead changed to a different scale — mmol HbA1c/mol Hb rather than the mean average A1c percentage — just to avoid confusion. It also does not use decimals.

This was adopted pretty quickly in Europe but a bit longer in the U.K., where we had a period of dual use before switching completely. The latter I think occurred not long before I was diagnosed, but I was given my results in percentages and so that is how I understand them and struggle with mmol/mol.

As for mg/dL against mmol/L, I have only known the latter. The difference there seems to be akin to using L/100km and km/L. Not in a like-for-like sense, but that there are two systems using scientific or metric units and it is entirely arbitrary which is used where.

As far as I can recall, the standardised HbA1C test was introduced maybe five years ago. I remember the diabetic nurse going over it and commenting on the changes, but it is not something that I follow that carefully. I do however monitor my own blood sugar levels and I record my weight regularly - my routine for recording my weight is to take my weight every Wednesday morning, standing naked on the scales after having been to the loo and before breakfast. In this way, I am satisfied that I am measuring like for like.

My scales are quite old, so when I had a diabetic appointment a year or two ago, I took my scales in and calibrated them against the surgery scales. There was no discernable difference - my scales were digital and weighed to the nearest 0.2 kg (0.5 kg above 100 kg and 0.1 kg below 50 kg) while the surgery scales were analogue Class IV scales with a reading to the nearest 0.5 kg (approx).

[avtur]

Would it be practical to design and use a sign that says if a bridge is unsuitable for double deck buses?

No - some double-deckers are lower-roofed specifically to allow them under certain bridges to widen their route availability.

Back in the 60's & 70's one of the major bus service providers in Stockport was 'North Western Road Car Company', their double-decker buses were known for having a plaque in the cab stating "This bus will not fit under Wilmslow Station Bridge". The company did have a handful of 'low-line double-deckers, I forget what they were called. Unfortunately having a mixed fleet is not the answer, because, just as drivers make mistakes so can anyone else involved in making sure the right bus is on the right route. Custom-fit solutions can simply result in custom made incidents.

I've been involved in providing vehicles where length, articulation, kingpin, axle configuration and position, and overhangs were all variables that gave rise to different handling characteristics. Sometimes it is unavoidable but the greater the variation in vehicles the more demanding it is of drivers to be mindful of the characteristics of the exact vehicle they are driving. However in the case of the incident being discussed exact knowledge of the bus height and bridge height would be unlikely to change the outcome, this wasn't a matter of judgement, it looks more like the driver just forgot he was driving a double-decker.

[FleetlinePhil]

Would it be practical to design and use a sign that says if a bridge is unsuitable for double deck buses?

No - some double-deckers are lower-roofed specifically to allow them under certain bridges to widen their route availability.

Back in the 60's & 70's one of the major bus service providers in Stockport was 'North Western Road Car Company', their double-decker buses were known for having a plaque in the cab stating "This bus will not fit under Wilmslow Station Bridge". The company did have a handful of 'low-line double-deckers, I forget what they were called. Unfortunately having a mixed fleet is not the answer, because, just as drivers make mistakes so can anyone else involved in making sure the right bus is on the right route. Custom-fit solutions can simply result in custom made incidents.

I thought you might have given folks a nod towards my North Western RCC avatar . All their double-deckers were lowbridge (ie side gangway upstairs) or, in later years, on lowheight chassis. They had Daimler Fleetlines, AEC Renowns and Dennis Lolines, and finally a batch of Bristol VRs that was delivered to their successor SELNEC. All these would, I think, have been around the 13'6" mark, so still too high for Wilmslow bridge, which is marked at 13'0". This would compare to perhaps just over 14'0" for a standard vehicle, although some were a little more than that.

I've been involved in providing vehicles where length, articulation, kingpin, axle configuration and position, and overhangs were all variables that gave rise to different handling characteristics. Sometimes it is unavoidable but the greater the variation in vehicles the more demanding it is of drivers to be mindful of the characteristics of the exact vehicle they are driving. However in the case of the incident being discussed exact knowledge of the bus height and bridge height would be unlikely to change the outcome, this wasn't a matter of judgement, it looks more like the driver just forgot he was driving a double-decker.

Assuming you are referring to the Winchester school bus incident, it appears the bus was on completely the wrong road, for a reason as yet unclear. According to comments I've seen on another forum, Stagecoach do not operate under the bridge in question at all. Having gone wrong, then I would agree that it is very possible that under stress the driver momentarily lost focus on the kind of vehicle they were driving and did not appreciate the significance of the bridge height. There may be questions to be asked about the thoroughness of Stagecoach's route training for drivers, and perhaps the signage both at the bridge and in advance, but I doubt whether the human factor behind the driver's decision will ever become entirely clear.

[jervi]

Not quite as dramatic and lethal as other bridge strikes, but today my mother came across this stuck van under a low bridge when out cycling.
I think it is the lowest restriction in West Sussex on a road open to motor vehicles at 8 foot 0 inches (2.4m), interestingly on the signs to approach it says for high vehicles to use the centre of the road, however in this case almost all vehicles (especially horse riders) count as a high vehicle!
https://www.google.co.uk/maps/@51.04283 ... 312!8i6656

Also looked up the height of horse riders and it appears that a mounted rider is normally no less than 2.55m, and that 3.7m meters of clearance should be provided, but reduced to 3.4m when restricted. But there are no blocks to help horse riders dismount either side of the bridge.

[Bryn666]

Not supposed to use circular signs at arch bridges because the headroom isn't constant across the entire structure - should really be a triangle. Dual units.

[RichardA626]

The former 11 foot 8 bridge in Durham North Carolina, now 12 foot 4 is still claiming victims.

http://11foot8.com/

[Barkstar]

The former 11 foot 8 bridge in Durham North Carolina, now 12 foot 4 is still claiming victims.

http://11foot8.com/

Quite taken by the T-shirt and the 'van made' pieces of art are hilarious in their shop.

[KeithW]

Given that the USA has land borders with Mexico and Canada who use metric units and that the US Army switched to metric units in 1918 I am surprised they have not mandated dual units signage. There are some near the borders with Canada and Mexico but that has been done at the State and County level. As far as I know the only federal road to use metric signage is I-19 from Tucson to Nogales.
https://www.google.co.uk/maps/@31.34868 ... 312!8i6656

[Bryn666]

Given that the USA has land borders with Mexico and Canada who use metric units and that the US Army switched to metric units in 1918 I am surprised they have not mandated dual units signage. There are some near the borders with Canada and Mexico but that has been done at the State and County level. As far as I know the only federal road to use metric signage is I-19 from Tucson to Nogales.
https://www.google.co.uk/maps/@31.34868 ... 312!8i6656

There was an attempt to use dual units in New England but this seems to have vanished. The NY Thruway in particular used to use km/miles on some signs.

[KeithW]

Given that the USA has land borders with Mexico and Canada who use metric units and that the US Army switched to metric units in 1918 I am surprised they have not mandated dual units signage. There are some near the borders with Canada and Mexico but that has been done at the State and County level. As far as I know the only federal road to use metric signage is I-19 from Tucson to Nogales.
https://www.google.co.uk/maps/@31.34868 ... 312!8i6656

There was an attempt to use dual units in New England but this seems to have vanished. The NY Thruway in particular used to use km/miles on some signs.

There are still some in New England but they are fairly localised. I saw quite a few in upstate New York near the Canadian Border and also around Niagara.

[bothar]

Bus couldn't quite squeeze through here in Cork.
The bus route should have passed over the bridge.

[trickstat]

Bus couldn't quite squeeze through here in Cork.
The bus route should have passed over the bridge.

Driver must have missed this sign about 500m before:

https://www.google.ie/maps/@51.8746519, ... 384!8i8192

[Chris5156]

Driver must have missed this sign about 500m before:

https://www.google.ie/maps/@51.8746519, ... 384!8i8192

In fairness, that's a dreadful sign and it's badly positioned. I clicked my way along GSV for quite some way before realising the sign referred to the other road at the junction.

That area appears to have a rash of wordy yellow signs where a standard warning sign would do the job - within a few hundred metres you can also see PEDESTRIAN CROSSING AHEAD, TWO WAY TRAFFIC, CAUTION PEDESTRIAN CROSSING AHEAD, and even (in advance of some traffic lights) PREPARE TO STOP. What a way to run a railroad!

[trickstat]

Driver must have missed this sign about 500m before:

https://www.google.ie/maps/@51.8746519, ... 384!8i8192

In fairness, that's a dreadful sign and it's badly positioned. I clicked my way along GSV for quite some way before realising the sign referred to the other road at the junction.

That area appears to have a rash of wordy yellow signs where a standard warning sign would do the job - within a few hundred metres you can also see PEDESTRIAN CROSSING AHEAD, TWO WAY TRAFFIC, CAUTION PEDESTRIAN CROSSING AHEAD, and even (in advance of some traffic lights) PREPARE TO STOP. What a way to run a railroad!

I agree that is both weirdly positioned and angled. It also doesn't give a distance.

[mikehindsonevans]

Bus couldn't quite squeeze through here in Cork.
The bus route should have passed over the bridge.

Driver must have missed this sign about 500m before:

https://www.google.ie/maps/@51.8746519, ... 384!8i8192

Never mind "500m back" - what about the big yellow diamond sign, saying "3.4m", on the wall to the right of the aperture: and therefore surely visible to the driver?

Mike.