NB width.

[b0atman]

I believe on the south pennines there is a roman wagon track with ruts still to be seen.

 

[Athy]

8 minutes ago, Mike the Boilerman said:

 

Either they were unusually narrow narrow boats or the 13' 3" locks are actually a bit wider than 13' 3"!

(Or they wouldn't have got in to jam in the first place...)

 

Yes, a five-inch discrepancy. But let us not forget that narrowboats are tapered, so the second one will start to draw alongside the first one but will get stuck when its widest part reaches that of the first boat.

[MtB]

1 hour ago, alan_fincher said:

Everybody quotes Brunel's broad gauge as 7 feet, as if it is somehow a nice round number unlike 4 ft 8.5".

However the gauge was actually 7 feet and a quarter of an inch.

 

I'd say part of the reason for the lack of consensus is the way people are quoting exact dimensions rather than using the engineering convention of including the manufacturing tolerance which needs to be known in order to successfully make something. E.G 7' 0.125"" +/- 0.125"

The gap between two rails is likely to need quite a large tolerance in order to accommodate the coarse conditions in laying them over long distances, temperature changes, wear, and the equivalent tolerances specified in the width between the wheels of the rolling stock.

I wouldn't be surprised if the gauge tolerance on early railways was as much as +/- 0.5"

[bizzard]

13 minutes ago, Mike the Boilerman said:

 

Either they were unusually narrow narrow boats or the 13' 3" locks are actually a bit wider than 13' 3"!

(Or they wouldn't have got in to jam in the first place...)

 

Tapering bows on one and stern on the other, inertia of the boat at about 2mph or so following in, they stuck absolutely fast, couldn't rock them or anything.

[bizzard]

10 minutes ago, Mike the Boilerman said:

 

I'd say part of the reason for the lack of consensus is the way people are quoting exact dimensions rather than using the engineering convention of including the manufacturing tolerance which needs to be known in order to successfully make something. E.G 7' 0.125"" +/- 0.125"

The gap between two rails is likely to need quite a large tolerance in order to accommodate the coarse conditions in laying them over long distances, temperature changes, wear, and the equivalent tolerances specified in the width between the wheels of the rolling stock.

I wouldn't be surprised if the gauge tolerance on early railways was as much as +/- 0.5"

Train wheel tyres were flat in those days and the flanges bound and wore the sides of the track badly. Cast iron track at first, which cast iron being quite trecherous broke regularly, then wrought iron track which was much better, but still wore away quite quickly and then the Bessemer steel process was perfected which solved most of the problems.  Modern railway rolling stock wheels have tapered tyres which roll along the tracks with the flanges hardly touching, much less rolling resistance and much smoother.

[alan_fincher]

24 minutes ago, Mike the Boilerman said:

 

I'd say part of the reason for the lack of consensus is the way people are quoting exact dimensions rather than using the engineering convention of including the manufacturing tolerance which needs to be known in order to successfully make something. E.G 7' 0.125"" +/- 0.125"

The gap between two rails is likely to need quite a large tolerance in order to accommodate the coarse conditions in laying them over long distances, temperature changes, wear, and the equivalent tolerances specified in the width between the wheels of the rolling stock.

I wouldn't be surprised if the gauge tolerance on early railways was as much as +/- 0.5"

If I remember correctly, when the preservationists took on the Talyllyn Railway in the early 1950s, they acquired two much needed locomotives from the then long closed Corris Railway, having the same unusual gauge of 2' 3", (luckily the GWR has put these into storage, rather than scrapping them).  However when they started operating one of the Corris locomotives, it regularly dropped between the rails on the rather run down Talyllyn.  They discovered the actual gauge was more of the order of 2' 3.5", so as they improved and relaid track they set about reinstating it to the quoted 2' 3", assuming simply it had spread with old age over the years.  However as they tried to use the locos that were originally built for the line, they found they then got in trouble because the re-gauged track was too narrow on some of the bends.  The over-gauging was deliberate to accommodate locos, which (by narrow gauge standards) had a long wheelbase.

I would need to look up what gauge they eventually decided to standardise to, but suspect the 2' 3", is probably  now what is used, with everything adapted to fit.

Edited April 18, 2018 by alan_fincher
Spelling

[Athy]

23 minutes ago, alan_fincher said:

 the same unusual gauge of 2' 3", 

This approximates to 70 cm, a gauge used for industrial railways in France and possibly elsewhere. The C.F. d'Abreschviller, which may be the correct spelling, a former forestry line, is probably the only one extant over there. I wonder if there is a connection, especially as 70cm is exactly 2'3 1'2", the actual gauge which you mentioned for the original Tally line.

Edited April 18, 2018 by Athy

[bizzard]

Together with tapered tyres on wheels, transition curves with super elevated track made the rolling resistance much less and higher speeds could be attained around them.

[dmr]

12 hours ago, Mike the Boilerman said:

 

It's not though, is it? 4ft 7 3/4in springs to mind...

 

I think it connects into an artificial cut, part of the Wey Navigation canal. Then the WNC connects to the River Wey. 

Checking the googlymap however, it connects int the River Wey. A suspiciously long and straight section of waterway for a river.  

Actually 4' 8" and a bit. I fear that last night alcohol hybridized the railways (4' 8") and narrowboats (6' 11" and a bit in my case). It wasn't even cider,just a couple of bottles of Proper Job.

But the Basingstoke would still be taking craft that came up the Thames rather than craft designed for just shuffling up and down that canal?????

............Dave

[furnessvale]

4 hours ago, Mike the Boilerman said:

 

I'd say part of the reason for the lack of consensus is the way people are quoting exact dimensions rather than using the engineering convention of including the manufacturing tolerance which needs to be known in order to successfully make something. E.G 7' 0.125"" +/- 0.125"

The gap between two rails is likely to need quite a large tolerance in order to accommodate the coarse conditions in laying them over long distances, temperature changes, wear, and the equivalent tolerances specified in the width between the wheels of the rolling stock.

I wouldn't be surprised if the gauge tolerance on early railways was as much as +/- 0.5"

As a former perway engineer, I once had access to the track standards for railways in the USA.

The requirements for gauge on a class 1 railroad astounded me.  For speeds up to 110mph, gauge was set at 4' 8.5" +/- 0.5".  In other words, anything between 4'8" and 4'9" will do!  At the time, the equivalent UK standard was +/- 0.125".

I hope the USA has tightened its standards since!

George

[Boat&Bikes]

So. Back on topic it seems my wife may well be right......Again! 

[Horace42]

Apologies if something along the lines of my theory have already been posted, but reading through them, I did not see any.

I think the width of a narrowboat is traceable to the width of typical road carts, typical 7ft wide with a 5ft wheel base to fit the basic roads and tracks of the day, with loads able to be pulled by a single horse.

Larger carts for heavy loads needing two or more horses were much  less common, not just the cost of keeping horses, but also because the roads were not strong enough to carry the weight.

So for very heavy loads in special cases (eg. stone and coal, etc) they came up with the idea of iron tracks laid on the ground, but to keep the steel (iron ?) to a minimum width, and to keep the wheels on the narrow rail, they used a rail with an upward external flange - that just happened to be 5ft (a nice round figure).
Eventually it occurred to them that it would be better to have  flanged wheels running on flat tracks - and if to fit the existing tracks - the gauge would have to be the same as the innermost edges of the standard track.

A little bit of math will show how two  2" x 1/4" angle irons laid flange-up with a 5ft external gauge between inner faces of the flange, will also have innermost edge of  4ft 8.5 inch - which would be the gauge of the flanged wheels designed to run on it.

The narrow boats designed to carry the same sort of cargo copied the typical overall width of the carts of the day.

 

[Athy]

Not sure if it's true, but very convincingly argued.

[furnessvale]

27 minutes ago, Horace42 said:

Apologies if something along the lines of my theory have already been posted, but reading through them, I did not see any.

I think the width of a narrowboat is traceable to the width of typical road carts, typical 7ft wide with a 5ft wheel base to fit the basic roads and tracks of the day, with loads able to be pulled by a single horse.

Larger carts for heavy loads needing two or more horses were much  less common, not just the cost of keeping horses, but also because the roads were not strong enough to carry the weight.

So for very heavy loads in special cases (eg. stone and coal, etc) they came up with the idea of iron tracks laid on the ground, but to keep the steel (iron ?) to a minimum width, and to keep the wheels on the narrow rail, they used a rail with an upward external flange - that just happened to be 5ft (a nice round figure).
Eventually it occurred to them that it would be better to have  flanged wheels running on flat tracks - and if to fit the existing tracks - the gauge would have to be the same as the innermost edges of the standard track.

A little bit of math will show how two  2" x 1/4" angle irons laid flange-up with a 5ft external gauge between inner faces of the flange, will also have innermost edge of  4ft 8.5 inch - which would be the gauge of the flanged wheels designed to run on it.

The narrow boats designed to carry the same sort of cargo copied the typical overall width of the carts of the day.

 

Given that canals, such as the Bridgewater, predate the narrow canal system, it seems unlikely that the builder would arbitrarily reduce the width of later builds without good reason.   The main driver being the Harecastle tunnel, which was an immense undertaking in its day, and the quadrupling of cost and difficulty a doubling of the width would cause, was a step too far.

George

[Jen-in-Wellies]

20 minutes ago, furnessvale said:

Given that canals, such as the Bridgewater, predate the narrow canal system, it seems unlikely that the builder would arbitrarily reduce the width of later builds without good reason.   The main driver being the Harecastle tunnel, which was an immense undertaking in its day, and the quadrupling of cost and difficulty a doubling of the width would cause, was a step too far.

George

I think the Harecastle tunnel is key to the decision. At the time it was probably one of the most challenging civil engineering projects in Britain since the Roman empire collapsed. They would have wanted to minimise the amount of rock removed. Another long Brindley tunnel, Norwood on the Chesterfield was also narrow beam only. Anyone know when the first long (>1000 yards) broad beam, or two way traffic narrow beam tunnel was started? I suspect it would be after the completion of these two narrow, one way traffic tunnels. Brindley's Irwell Aquaduct on the Bridgewater was also going beyond what had been done in Britain at that time. With the rapid advance of civil engineering in just a few decades in the late 18th and early 19th century we forget just how radical these 1760's and 1770's constructions were to the people living at the time.

Jen

[magpie patrick]

52 minutes ago, Jen-in-Wellies said:

I think the Harecastle tunnel is key to the decision. At the time it was probably one of the most challenging civil engineering projects in Britain since the Roman empire collapsed. They would have wanted to minimise the amount of rock removed. Another long Brindley tunnel, Norwood on the Chesterfield was also narrow beam only. Anyone know when the first long (>1000 yards) broad beam, or two way traffic narrow beam tunnel was started? I suspect it would be after the completion of these two narrow, one way traffic tunnels. Brindley's Irwell Aquaduct on the Bridgewater was also going beyond what had been done in Britain at that time. With the rapid advance of civil engineering in just a few decades in the late 18th and early 19th century we forget just how radical these 1760's and 1770's constructions were to the people living at the time.

Jen

I concur - Harecastle was what set the gauge , and as it was at a pivotal point on the system the rest followed.

The longest wide beam tunnel was Sapperton, and that didn't open until 12 years after Harecastle. Also, whilst it was difficult, I seem to recall that the geology of Harecastle is so bad that it would present issues building a tunnel today - certainly the railway now goes round and over rather than through

[Horace42]

1 hour ago, furnessvale said:

Given that canals, such as the Bridgewater, predate the narrow canal system, it seems unlikely that the builder would arbitrarily reduce the width of later builds without good reason.   The main driver being the Harecastle tunnel, which was an immense undertaking in its day, and the quadrupling of cost and difficulty a doubling of the width would cause, was a step too far.

George

You might be right, why not!. My attention was focused on the reasons behind a 4ft 8.1/2" railway gauge - which tended to introduce the need for a standard width...leading to the narrowboats boats...albeit the railways came much later once the standard was adopted and got under way.

[beerbeerbeerbeerbeer]

2 hours ago, Horace42 said:

Apologies if something along the lines of my theory have already been posted, but reading through them, I did not see any.

I think the width of a narrowboat is traceable to the width of typical road carts, typical 7ft wide with a 5ft wheel base to fit the basic roads and tracks of the day, with loads able to be pulled by a single horse.

Larger carts for heavy loads needing two or more horses were much  less common, not just the cost of keeping horses, but also because the roads were not strong enough to carry the weight.

So for very heavy loads in special cases (eg. stone and coal, etc) they came up with the idea of iron tracks laid on the ground, but to keep the steel (iron ?) to a minimum width, and to keep the wheels on the narrow rail, they used a rail with an upward external flange - that just happened to be 5ft (a nice round figure).
Eventually it occurred to them that it would be better to have  flanged wheels running on flat tracks - and if to fit the existing tracks - the gauge would have to be the same as the innermost edges of the standard track.

A little bit of math will show how two  2" x 1/4" angle irons laid flange-up with a 5ft external gauge between inner faces of the flange, will also have innermost edge of  4ft 8.5 inch - which would be the gauge of the flanged wheels designed to run on it.

The narrow boats designed to carry the same sort of cargo copied the typical overall width of the carts of the day.

 

Yep, I agree. I said something similar regarding width of carts but not as well put as you.  

[Pluto]

There were conflicts over whether to build wide, 14 foot, or narrow, 7 foot, locks on many canals. Early mid-18th century canals, such as the T&M and L&L, were originally promoted as wide, which would have allowed the coastal craft of the time to use them.The short L&LC locks were built to suit the Humber keels of the time, the longer Liverpool length locks being built for Mersey flats. The Bridgewater was built for wide boats, though narrow boats were also used, particularly those which entered the mines at Worsley. I have also come across records of narrow boats being built for the Liverpool section of the L&LC before it was connected to other waterways.

The economic benefit and return from canal building was completely unknown at the time these early canals were being promoted, and it is noticeable that the first investors, in the 1760s and 1770s, were mainly local people, often those associated with the industries which would be supported by canal transport. There was virtually no money from the London financial institutions as the returns were unknown, and the London markets continued to have little interest in investing in canals. As the early canal investors also had to finance their industries, some sought to reduce the cost of construction. Building canals to the same size as the narrow boats used in the Worsley mines, half the width of the established coastal craft, was considered to reduce the cost by about one third over the cost for a wide, 14 foot, waterway. This was accounted for mainly by land purchase costs, and slightly lower building costs for locks, bridges, etc. The water supply would be virtually the same for equal tonnages of goods carried, so nothing was saved on water supply.

The arguments for and against wide or narrow canals were brought out again in the 1790s, with the Rochdale being a particularly good example, for which many records survive, including Rennie's discussion of the problem. The result depended upon the foresight of the industrialists who were investing, with Lancashire and Yorkshire merchants and mill owners seeming to understand the longterm implications of narrow versus wide canals than those in the Midlands.

Standardised measurement was in its infancy when canals were first built, so dimensions could be a little generous to ensure clearance. By the 1790s, measurement had become a more exact technology, so canals from this era are sometimes tight, with minimum clearance, possibly in an effort to keep down costs. This cost reduction was shown to be insignificant by 1800, so subsequent canals have more generous dimensions. I have not researched this idea fully, so it could be challenged, but there certainly seems to be some significance in the variation in lock chamber dimensions and the date of their construction.

The London finance markets were possibly wise in not investing in canals, or transport generally, as few made money in the longterm. It was over 100 years after construction of the L&LC began before the investment produced a return, if compound interest is added to the investment. However, those who invested did make money from the industries which the canals supported. It does suggest that we should be making investment decisions at a local level if we want to provide employment for local people, rather than rely upon the investment decisions of London financial markets, who are only interested in a return for a few large investors.