Do double standards exist in this hobby?

[BG John]

Brunel's extra quarter inch came about because it gave better running than his original 7ft. Rather like EM changing from 18mm to the slightly more correct 18.2mm, or OO going the wrong way from 16.5mm to 16.2mm!

[Colin_McLeod]

Why does no one fit smoke generators to diesel?

 

Smoke units that replicated that would have your layout room at fatal pollution levels in a few minutes.  Glad you took the loco out of the shed first though.

[Graham456]

I thought the quarter inch was on bends only to allow the long fixed wheelbase "no bogie" locos of the time a bit of give on the bends

But I only read this in a book so it might not be gospel which is why I asked about the quarter inch

 

Hurray the guests have come back I can go to a much needed bed and rest this addled brain. 4"71/2 what was I thinking?

Edited July 4, 2016 by Graham456

[sharris]

I have never understood the logic behind track gauges. Why did almost no one pick a round number? Why 4'8 5/8" and not 4'9"? Why 1' 11 1/2" rather than 2'? What's up with Brunel's extra quarter inch?

At least some places managed to pick a round nominal figure - 1m, 3'6", 5'...?

I wonder if it was a way the early railway engineers ensured the necessary precision for reliable running. I don't know when it became standard practice to include tolerances in specifications, but to an early 19th century track layer, having a measurement that ended in a 1/2, 1/4 or 1/8 inch might have suggested requiring a higher accuracy in workmanship than one that was a whole number of inches - just my theory.

[newbryford]

Has this thread become "Do double standards exist in the prototype?"

 

 

Cheers,

Mick

[Colin_McLeod]

Candidate for job as a fitter at Harland & Wolf shipyard, Belfast:

"I am very skilled and can worked to within one thousandth of an inch"

 

Foreman:  "That's no good. For this job you have to be dead on".

[ozzyo]

Also a bit like it has to be brass not plastic in a model, to be correct and it should be soldered not glued.

 

A lot of trains are now made of steel and aluminium glass Etc. AND get this plastic and glue. Not that many trains are made of brass. The front end of the H.S.T. is a big fibreglass moulding to start with.

 

OzzyO. 

[PatB]

Also a bit like it has to be brass not plastic in a model, to be correct and it should be soldered not glued.

 

A lot of trains are now made of steel and aluminium glass Etc. AND get this plastic and glue. Not that many trains are made of brass. The front end of the H.S.T. is a big fibreglass moulding to start with.

 

OzzyO.

So that's what happened to Q Kits then :-D.

[Bernard Lamb]

I wonder if it was a way the early railway engineers ensured the necessary precision for reliable running. I don't know when it became standard practice to include tolerances in specifications, but to an early 19th century track layer, having a measurement that ended in a 1/2, 1/4 or 1/8 inch might have suggested requiring a higher accuracy in workmanship than one that was a whole number of inches - just my theory.

It is certainly not just your theory. It is a long standing method in engineering. If a tolerance is not specified convention takes it to mean + or - half the last figure. So 1" means + or - half an inch.

In which case 1/8" is plus or - 1/16". When you get down to smaller tolerances you need a more accurate measuring device but the principle still holds good. However lots of things have to fit in other things so you will often get all minus tolerances.  Other things are all plus. Track gauge I think might be one example. Now you might think to yourself what is meant by a dimension of 18.83mm expressed in these terms. Can of worms!

The fun starts when you convert to metric. A dimension of 1/32" can be read on a tape measure, however the same dimension expressed in metric would be around 0.8mm which is not a dimension that can be read on a tape measure. Open up the tolerance to 1.0mm might not work and tightening it to 0.5mm might be too costly in terms of the extra work required. The answer is to check all the dimensions and start again on calculating tolerances or changing the measuring equipment. Been there and it was a painful exercise

Bernard

[PhilH]

I thought that in the early days of railways tolerances depended on two things...macro, size of hammer used, micro, how hard you hit it.

[Nearholmer]

As an aside, track workers on the "traditional railway" rarely, if ever, needed to actually measure track gauge; they gauged it, hence the name.

 

Gauging-sticks were traditionally made of hardwood, with the faces shod in steel to resist wear, and IIRC there were versions with more than one setting, to allow for a couple of steps of "plus" for gauge widening on sharp curves.

 

Once the gauges were made (by careful measurement), track was either "to gauge", or in need of adjustment, repair, or replacement of worn rails.

 

What track workers were traditionally taught about how much over-gauge was allowable before an intervention was needed, I don't know, but I bet someone on here has an ancient text book that sets it all out, and there are plenty of current track engineers here who could give us current chapter and verse.

 

K

[Bernard Lamb]

I thought that in the early days of railways tolerances depended on two things...macro, size of hammer used, micro, how hard you hit it.

The actual dimension being described using the term "knat's". Better not put the full version. You can even have half a knat's.

Funnily enough I have only ever heard the expression in imperial. I wonder what the metric equivalent is.

People might laugh but it can be accurate to around 0.005".

I never did learn the exact relationship between a knat's and a tad. Or a touch or a smidgeon now I come to think of it.

Bernard

[Jeff Smith]

As an aside, track workers on the "traditional railway" rarely, if ever, needed to actually measure track gauge; they gauged it, hence the name.

Gauging-sticks were traditionally made of hardwood, with the faces shod in steel to resist wear, and IIRC there were versions with more than one setting, to allow for a couple of steps of "plus" for gauge widening on sharp curves.

Once the gauges were made (by careful measurement), track was either "to gauge", or in need of adjustment, repair, or replacement of worn rails.

What track workers were traditionally taught about how much over-gauge was allowable before an intervention was needed, I don't know, but I bet someone on here has an ancient text book that sets it all out, and there are plenty of current track engineers here who could give us current chapter and verse.

K

In engineering gauges are often supplied in pairs, a 'go' and 'no-go'. The differences between the two gauges represents the tolerance. For checking the 'gauge', first the smaller is dropped in, if it doesn't fit the track is under-gauge. If it does fit you then try the larger one. This time if it fits the track is over-gauge. If it does not fit then the track is within tolerance. This is a very basic engineering principle that has existed for many years however I have no idea whether it was actually employed in track gauge checking but easily could have been......

[The White Rabbit]

I never did learn the exact relationship between a knat's and a tad. Or a touch or a smidgeon now I come to think of it.

 

[Clears throat]

 

Smallest of all is a ‘whisker’. Five of these make up a ‘smidgen’ and two smidgens equal a ‘hint’, except in S+T where a hint is three smidgens. A tad is a european term for two whiskers, named after Count Tadeusz, infamous in physics circles. In the case of liquids, a ‘hint’ translates to 0.7 of a ‘drop’. (And four drops are a ‘dash’.) Unless we're talking about alcoholic beverages, in which case a drop is a pint, at least in Yorkshire. Three hints make an ‘inkling’ and six a ‘trace’. Twelve hints (or four inklings) constitute a ‘touch’. Five touches equal a ’bit’ and half a bit is a ‘trifle’. Ten bits equal a ‘way’, or only six in the case of older people, especially ex-railwaymen. A way is sometimes referred to as ‘quite a bit’. Quite simple really…

[newbryford]

[Clears throat]

 

Smallest of all is a ‘whisker’. Five of these make up a ‘smidgen’ and two smidgens equal a ‘hint’, except in S+T where a hint is three smidgens. A tad is a european term for two whiskers, named after Count Tadeusz, infamous in physics circles. In the case of liquids, a ‘hint’ translates to 0.7 of a ‘drop’. (And four drops are a ‘dash’.) Unless we're talking about alcoholic beverages, in which case a drop is a pint, at least in Yorkshire. Three hints make an ‘inkling’ and six a ‘trace’. Twelve hints (or four inklings) constitute a ‘touch’. Five touches equal a ’bit’ and half a bit is a ‘trifle’. Ten bits equal a ‘way’, or only six in the case of older people, especially ex-railwaymen. A way is sometimes referred to as ‘quite a bit’. Quite simple really…

 

 

I often use "rack o' th' eye" to get it "bob on"

 

Cheers,

Mick

[Paragon]

IMHO and experience, a "drop" in Yorkshire is surely equatable to up to 6 aforementioned pints, owt above that is anywhere between a skinful and a lashing.

Paragon

(Jon)

[lightengine]

Surely the rivet counters who point out that the green is the wrong shade are not counting rivets. Small bobbles of plastic or transfers are being counted.

Thanks for the amusing comments in this thread, its been an enjoyable read.

I waited in all day expecting the Spanish Inquisition but just like DHL they never turned up.

[Nearholmer]

And the next day, three inquisitions, one after the other, eh?

 

K

[rab]

Candidate for job as a fitter at Harland & Wolf shipyard, Belfast:

"I am very skilled and can worked to within one thousandth of an inch"

 

Foreman:  "That's no good. For this job you have to be dead on".

Or as my Dad used to say

"Near enough isn't good enough,

when tiz zackly (exact),

thats near enough"

[Legend]

It is odd isn't it. Absolutely guilty of double standards. It's strange but I have to run locos of certain periods together and not mix them . So I can run Grouping, BR Steam/ green diesel and BR Blue. So getting the correct stock for time periods is important to me and yet in the BR steam period Panniers rub shoulders with A4s , Duchesses and even Bullied Pacifics . I blame catalogues in my youth which tended to do same thing. But then again maybe I need therapy.

 

Would like to support local model shops but I'm afraid door has already closed on that one!

[Graham456]

Haveing thought about it a bit ...

Yes there are double standards...in this hobby

 

Double O standards!

 

They might be two narrow for some ! But their standards

[Al51]

I have never understood the logic behind track gauges. Why did almost no one pick a round number? Why 4'8 5/8" and not 4'9"? Why 1' 11 1/2" rather than 2'? What's up with Brunel's extra quarter inch?

At least some places managed to pick a round nominal figure - 1m, 3'6", 5'...

Why do we use scales that mix imperial and metric (x mm to the foot)?

 

I think originally it was 5' to the centre line of the rails, which made it 4' 8 1/2" between the rails.

 

Al

[Bernard Lamb]

I think originally it was 5' to the centre line of the rails, which made it 4' 8 1/2" between the rails.

 

Al

Proper railways worked to a gauge of 5' 1/2" or 1537mm.

Long live the London and Blackwall Railway.

Bernard

[railsquid]

Interesting what differing levels of authenticity are acceptable or unacceptable to each of us.

 

I'm quite relaxed about 16.5mm track; there, I've said it.  For me, being able to fit in an operationally satisfying layout rather than a shunting plank or a BLT that will barely hold a 2-coach train trumps having track of compromised appearance. That said, if I had uncompromised space to play with, I might well feel different.

 

By contrast, I get uptight about SR or BR vans finished in supposedly pre-grouping era PO liveries carrying the names of breweries that have only existed since the 1990s.  

 

Funny lot, aren't we.

 

So, what floats your boat, and what sinks it?

 

Roads. In no particular order:

- roads with implausibly steep slopes

- roads with impossibly tight bends

- road layouts which look like they've been copied from a child's playmat

- roads which have been "laid onto" the landscape, not embedded in it

- level crossings where the track appears to have been laid over the road and ramps put in place in a manner which a 4wd vehicle would have difficulty navigating, let alone the normal traffic on the road.

 

Disclaimer: though I hope to be avoiding those pitfalls on my layout, the rest of it is a rivet counter's nightmare

[Il Grifone]

I always understood that a 'whisker' referred to a 'gnat's whisker', which is an euphemism for the part of the creature that is really intended.

 

I was taught that feeler gauges should be used so that the size smaller would fit and the size larger not.

 

From the above "Half of the last figure", I would assume that a decimal tolerance for (say) 0.8 would be 0.75 - 0.85, but perhaps I'm wrong?

 

Likewise, I would assume 16mm is a rounded off metric equivalent of 5/8" (15.875), which was the original H0 gauge (half of 1¼" which was the 0 gauge at the time - itself a rounding off of Märklin's 35mm (IIRC) measured to the rail centres). It was then found that a little more clearance was needed, hence 16.5mm.