Going under Wroxham Bridge

[Seriously]

Well I  am daft but not sure I'll try that first time but I will try sidewards at some point lol.

[CaptinDread]

I wouldn't try with Captain dread as it has a square back end, I would hit the bridge no matter how low the tide was.

there just isn't that much clearence for my boat ;(

[SPEEDTRIPLE]

Lightning still has the Brooms flag on a swiveling pole on the pullpit. It nearly touched under the old iron bridge at Gt Yarnouth, with an inch to spare. However, there was around 3-4"clearance on the highest point of the superstructure. With that in mind, i`l be more than happy to take her through Wroxham at 6` 10". I do like to go through Wroxham bridge against the tide though, as no matter how slow the tide runs, it offers that little bit extra steerage way, and will help if an emergency stop is required.

[Wussername]

5 hours ago, Strowager said:

This image shows the arched profile height relative to the gauge heights three years ago.

 

This is a great photograph and graphic display, and my comment Strowager is not meant as a criticism of your good self.

Why is it that we must be one of the only civilised countries in the world that has two types of measurement. Half the population understand and use metric and the other half, myself included, to all intent and purposes it might as well be written in goat!

The gauge on the bridge gives a clue as to the measurement to use. Every person is using imperial measurement with regards to their boat. So why over egg the pudding.

Oh! And by the way, if we do come out of the EU does this mean that I will be able to go down to my local wood yard and ask " have you got five foot of two by two mate?"

[BroadScot]

1 hour ago, Wussername said:

Why is it that we must be one of the only civilised countries in the world that has two types of measurement. Half the population understand and use metric and the other half, myself included, to all intent and purposes it might as well be written in goat!

Hi Andrew,

Metric is great for reading electrical plans, for houses etc, but give me good old brit imperial for most other measurements, its what WE were taught in our young days!

The first sniff of the dodgy metric was when new apprentices hadn't a clue when I quoted BI to them! Cut a length of conduit 4ft6" was a foreign language

Iain

[Guest]

9 hours ago, Wussername said:

Oh! And by the way, if we do come out of the EU does this mean that I will be able to go down to my local wood yard and ask " have you got five foot of two by two mate?"

But I've already got well into the habit of asking for "2 metres of 2 by 2" Wussername.

To be fair though, the bridge gauges show the clearance in imperial and metric, as the photo shows.

I'd hate to be taken for a "Euro" though, so here's the specially commissioned Imperial only version, which hopefully may again reign supreme.

(That would be a real challenge for the younger generation, having to learn lbs & ounces & feet & inches......)

[MauriceMynah]

I support the seasonal change of metric/Imperial measurements used in temperature.

A nice day in the Summer is between 75 and 80 degrees, yet in the Winter the rivers freeze at zero!    .. Spring and Autumn are just warmish or chilly. Simples!

[Timbo]

Metric measurement bleh! Only useful for anything under an eighth of an inch. I regularly have to 'educate' shop assistants. One idiot decided to give me a chewing out yesterday when I asked for 'an ounce of tobacco'.
'What's that?' they asked.'I only do the 12.5, 25 and 50 thing, but stupid to have 12.5!'

I took a leaf from Maurice Mynah's book and pointed out 'I only buy things that are not in 12.5, 25 and 50 things' and took my custom to a shop that spoke English instead of French.

Although the metric system was responsible for one of Britain's most famous military victories at Waterloo. French forces using the newly imposed metric system miscalculated their positions allowing the British to fight a retreat and make the famous stand. As Stephen Fry pointed out, you can't be 'kilometers better' than the British who are 'miles better'.

One of the biggest annoyances I find in boating is the introduction of the metric system. All of the materials are now in metric, yet the tools to work the material and the boats are designed in imperial. Even my modern car is in imperial, as is my height, chest size, inside leg and hat size. It's only my weight, measured in French by the NHS, and my shoe size, measured in 'barley corns' for some reason, that are not. I'm sad to say I find myself in agreement on something with our 'Merkin cousins...even if they get the measurements wrong.

[TheQ]

Celsius (centigrade), Fahrenheit, Kelvin, 3 different systems.

Sometimes I'm sure going metric is just to make more money out of us.

A 8ft by 4ft sheet of ply is normally 2440mm by 1220mm, but sometimes they are a metric Sheet 2400 by 1200... but the price doesn't drop...

[HakunaMatata]

It isn't such a big deal with the both systems, since 40 years now i ahve to use both, due to the fact that all aircraft related measurement are given in imperial - plus some extras like inch HG ,   inH₂O .

The only disadvantage for you guys is like the sheet of ply.. the dealer making some extra money.

Keep your imperial system, in Germany which is metric, but to buy a waterhose or the tubes for water inside the houses the diameter is still in inch measured, but the lenght in metre. All strong logical.

[Guest]

I was deep into Civil Engineering a few decades back, shortly after metrication, so I had to be able to think in metric and imperial linear measurements, working from historic drawings as well as new.

Luckily, 25mm equals 1" was close enough, accuracy-wise for most of the dimensions involved, so you could very quickly convert something like 475mm as being 19".

Funny thing though, whenever I actually looked at anything, my English mark 1 eyeball still communicates to the brain in imperial units.......

[fishtone]

Your information is very interesting Strowager. Good to see some real figures . My airdraft using Robins method is 6ft 8inches.Have had boat 2 years but not been under yet. Gives me confidence to try it now. Was always told gauge did under read.

[Wussername]

Well. I still think that the whole thing is a pigs dinner. 

"2 lbs of potatoes please" the young girl behind the counter looks at you as if you have come from Mars! If you ask the price you are informed that they are "so much a kilo" I don't want a kilo......whatever that is.

Cars are calibrated in miles per hour. Fuel is measured in litre's. Distance is measured in miles on sign posts and fuel efficiency is measured in miles per gallon. And then, and then, people refer to distance in kilometres. The military refer to it as click's.  No wonder we have to have sat navs !

I like pints. I know what a pint looks like. What's all this litre nonsense? And by the way, as for wine, up until quite recently I thought a unit was a bottle!

Now, I would like to make it clear, and on behalf of my generation, none of this has anything to do with me. It is all down to you young lot. Who confidently have conveniently have abandoned us with a muddle and seemingly gravitated to global warming.

Andrew

[Gracie]

A unit IS a bottle in my house

Grace

[Guest]

1 hour ago, fishtone said:

Your information is very interesting Strowager. Good to see some real figures . My airdraft using Robins method is 6ft 8inches.Have had boat 2 years but not been under yet. Gives me confidence to try it now. Was always told gauge did under read.

I have to emphasize a note of caution with my "real figures".

That was the exact real situation in 2012 when the photo was taken, but if the BA ever reset the river mounted gauges then it could change.

The basic logic should remain though, because presumably it would be silly for them to quote the maximum clearance under the semi-circular apex of the bridge, since most cabin craft are much more rectangular in cross section.

It's always been a guess therefore as to what notional "square" width the height boards relate too, so the photo was taken to find out what it actually was then, (in 2012).

Claude Hamilton had a similar stab at giving measurements for the cross section of Potter bridge many years ago in one of his wonderful Broads guides.

He wouldn't have had a fifteen megapixel digital camera, so maybe he used a rowing boat and a tape measure instead.....

[SPEEDTRIPLE]

11 hours ago, HakunaMatata said:

It isn't such a big deal with the both systems, since 40 years now i ahve to use both, due to the fact that all aircraft related measurement are given in imperial - plus some extras like inch HG ,   inH₂O .

The only disadvantage for you guys is like the sheet of ply.. the dealer making some extra money.

Keep your imperial system, in Germany which is metric, but to buy a waterhose or the tubes for water inside the houses the diameter is still in inch measured, but the lenght in metre. All strong logical.

Ah, another Aircraft engineer on the forum.

Ibuild aircraft interiors for Airbus, AND Boeing, all units for Airbus are drawn, and built in Milimetres, whereas all units built for Boeing are built in decimal inch form, which has caused some confusion in recent months. Last year, we had to make a variation of an existing unit, but to be supplied direct to Boeing, rather than be retro fitted bt BA. When said unit was supplied direct to BA, it was designed and built in milimetres, but to be supplied direct to Boeing, the whole drawings had to be con verted to Decimal inches. The a light sensor housing would`nt fit, and they did the conversion calculations on a computer. The designers still thought they got it right, but had to admit defeat when i suggested THEY try to fit it. 

It`s hardly surprising that a lot of the younger guys and appretices simply CAN`T measure in inches. I recently had to teach a new apprentice how to measure in inches, which took nearly a whole day.  What`s worse was about 20 years back, i was overseeing a guy who had never used inches, and when he built some panels, they all turned out half an inch short. Where he was always told "never mind about the odd half a millimetre, as it was in tolerance, well, i`m sure you can work out the rest.

 

[SPEEDTRIPLE]

11 hours ago, Strowager said:

I was deep into Civil Engineering a few decades back, shortly after metrication, so I had to be able to think in metric and imperial linear measurements, working from historic drawings as well as new.

Luckily, 25mm equals 1" was close enough, accuracy-wise for most of the dimensions involved, so you could very quickly convert something like 475mm as being 19".

Funny thing though, whenever I actually looked at anything, my English mark 1 eyeball still communicates to the brain in imperial units.......

An inch is actually 25.4 inches Strow, so over a 19 inch distance, those extra 19.4s on top of the 475 actually mean 482.6.19 inches is not a big distance, so imagine the shortfall if you estimate 25mm to the inch, but over a distance of say 20ft?. That`s one hell of a shortfall.Strow, and by a quick calculation, that equates to 96 milimetres over 20ft. Or should i say 3 25/32nds of an inch?.

[BroadAmbition]

An inch is actually 25.4 inches 

I always thought an inch was in fact just an inch ?

Griff

[Viking23]

3 hours ago, SPEEDTRIPLE said:

482.6.19 inches 

How can you have two decimal points in a length measurement?

Mind you over 20 years ago, a Birmingham flight,  the copilot of an aircraft was sucked out of the window because the window blew out, due to a mismatch of using the incorrect nut on some fixing bolts. Luckily the copilot was saved by other crew members dragging him back into the cockpit.

If you go back to imperial measurements, you had bolts that were measured simply by the spanner size, eg 3/8 " AF  you also had Whitworth, coarse and fine, UNC still used in America, and of course BA fixings, like 0BA 2BA .....  6BA etc These were common place in Lucas distributors of the 60's and 70's petrol engines and fixed the points in.

Then you have pipe measurements, they still use BSP measurements, 1/2" BSP,    3/4" BSP etc even then,  some are even tapered.

Some oil filler plugs on some Japanese gear boxes are BSP....

No wonder we get confused.

 

I don't get confused, I have an imperial and a metric adjustable spanner that I use lol....

 

[Matt]

On 29 February 2016 at 8:46 PM, SPEEDTRIPLE said:

Lightning still has the Brooms flag on a swiveling pole on the pullpit. It nearly touched under the old iron bridge at Gt Yarnouth, with an inch to spare. However, there was around 3-4"clearance on the highest point of the superstructure. With that in mind, i`l be more than happy to take her through Wroxham at 6` 10". I do like to go through Wroxham bridge against the tide though, as no matter how slow the tide runs, it offers that little bit extra steerage way, and will help if an emergency stop is required.

I have been through Wroxham on Thunder  at 7 foot. I would not be rushing to go through at 6ft 10!

Although it is Thunder's Nav lights that look the most "vulnerable"! So yours might be fitted somewhere else.

 

I will be carrying out Thunders measurements "Griff style" at Easter so it will be interesting to see what I come back with.

[TheQ]

I still remember reciting Rods, Poles and Perches at school.

My other Hobby is model railways and I have to work from old railway drawings, they are measured in Chains. 4 Rods Poles or Perches in a Chain...

[Bound2Please]

20 hours ago, Gracie said:

A unit IS a bottle in my house

Grace

And here Garce Darlin xx xx

[Bound2Please]

42 minutes ago, TheQ said:

I still remember reciting Rods, Poles and Perches at school.

My other Hobby is model railways and I have to work from old railway drawings, they are measured in Chains. 4 Rods Poles or Perches in a Chain...

Your forgot Furlongs there my friend

22chains = 1 Furlong

[Guest]

9 hours ago, SPEEDTRIPLE said:

An inch is actually 25.4 inches Strow, so over a 19 inch distance, those extra 19.4s on top of the 475 actually mean 482.6.19 inches is not a big distance, so imagine the shortfall if you estimate 25mm to the inch, but over a distance of say 20ft?. That`s one hell of a shortfall.Strow, and by a quick calculation, that equates to 96 milimetres over 20ft. Or should i say 3 25/32nds of an inch?.

I quite agree Neil, but if you re-read my whole paragraph in the original context, I said:

"Luckily, 25mm equals 1" was close enough, accuracy-wise for most of the dimensions involved, so you could very quickly convert something like 475mm as being 19". "

The half inch inaccuracy on nineteen inches would indeed be disastrous with aircraft components, but in civil engineering it was mostly on things like thicknesses of earth or compacted ballast, so it could not even be measured with any greater accuracy than that.

The much greater lengths involved were a different matter, always calculated to decimal places, in metres or yards with a wheel or tape.

[ZimbiIV]

When I started work it was pikers, nomples, leads, thin leads, ems and ens!

Don't ask about my old bosses measurement of, the hair of a gnats F****.

paul