Cornish beam engines - understand continued use

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Richard Smith

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Dec 29, 2021, 3:39:42 AM12/29/21
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Hello all

Can you help me understand something about Cornish beam engines?

Studying about Cornish beam engines.
I was working in Cornwall this year, so the interest gripped me.
As you'll be knowing, there's abandoned engine-houses everywhere there
was mining in Cornwall.

I've done a lot of "steam nostalgia", but now as a welder and
technologist, looking at it going forward on then the world leading
edge of engine development.
The mines were hundreds of metres (~ yards) deep chasing the lodes and
there is no coal in Cornwall.
Driving an intense competition for efficiency ("duty") - world leading
edge from 1800 to 1850.

The "Cornish engine" using steam at significantly above atmospheric
pressure - 45psi (3 atmospheres) was daring searing thrilling
technology of its day.
By 1850 advancing technology and accumulated skill had moved the
baseline and 45psi was generally achievable and exceeded. Seems
Cornish beam engines "hit a wall" at about 45psi to 50psi possibly
60psi - apparently literally the walls of the house-built engine can't
take more force. Plus is explained the cast-iron beam of the day was
vulnerable to the jerking force of higher-pressure / short cut-off for
greater steam expansion. Etc.
So they were stuck about about 45psi.

Yet the use continued and there were even new Cornish beam engines for
municipal waterworks up to 1900.
The very last beam engines went out of service in the 1950's - so they
couldn't have been that bad even by standards then.

Why?

Higher pressure is usually higher efficiency.

If I estimate right, about 1/3rd of the power came from condensing the
steam and the vacuum it created under the piston.
Given you've got a big slowly-cycling stationary engine where a
condenser can be part of the overall engine concept.
So you are getting that 1/3 "for free" compared to an engine
exhausting to atmosphere...

My conjecture is...

Apart from the efficiency of few parts as the engine directly gave the
oscillating motion working the pumps with long pump-rods direct down
the shafts - that the "extra 1/3rd for free" from condensing
compensated for the loss of efficiency from not being able to go above
50psi?

I'm adding detail to this thought that, with this being direct
condensing by water spraying into a chamber with the steam it must
condense - much cheaper and simpler than "indirect condensers" used on
eg. current nuclear power stations - that the mix of water, condensed
steam and some lubricating oil (?) tipped back into the boiler to gain
some fuel economy from heat in the "hotwell" - the oil and
contamination is tolerable in a Cornish boiler at max. 50psi?

Where it would be totally intolerable to the much more sophisticated
"then modern" boilers developing which gave >>50psi and much higher
steam-making ("evaporative") capacity...?

Where Cornish boilers with their all-cylindrical shape - a
cutting-edge technology and a huge leap forward in 1800 - had become
very simple by 1850, with their single large furnace/flue tube and no
"firetubes" of the later "locomotive" and "marine" boilers - no nooks
and crannies for contaminants to come out doing nasty things?

I'm also seeing that "not simple harmonic motion" of the beam engine -
with a passive slow pumping stoke driven by the weight of the pump rod
and a rapid steam-driven return-stroke - with pumping rate being
controlled by how often you "triggered" the engine to cycle - gave
some efficiency advantage over a rotative engine for pumping...

Added all together...

So I'm conjecturing a status-quo where all advantages of higher
pressure where negated for mine-pumping by inherent advantages
retained by the Cornish engine???

Thanks for indulging me and my interest.
Hoping some of you can offer knowledge, wisdom and guidance on this.

Best wishes,
Rich Smith

PS - I'm hoping to estimate efficiency % for a "duty" of
eg. 100million (the "magic" top figure) - work out what weight of coal
and therefore the energy in Joules was in that "bushel" of coal which
lifted those 100million foot-pounds of water...
When I'm out of Christmas mode and have my technical head back on :-)

Jim Wilkins

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Dec 29, 2021, 8:45:44 AM12/29/21
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"Richard Smith" wrote in message news:lyy243k...@void.com...
------------------------
Steam engine efficiency could be below 5% for locomotives without
condensers, which were too fragile to withstand the engine and track
vibration.
https://en.wikipedia.org/wiki/Hammer_blow

Wrought iron's random weld weakness imposed severe limits on pressure
vessels, both boilers and cannon. Look up Armstrong's rifled cannon for more
info. Despite being a softer and weaker metal, bronze cannon cast in one
piece were considered safer. Bessemer steel began replacing wrought iron in
1864, though use of wrought iron continued through the 1887 construction of
the Eiffel Tower.

A notable failure of wrought and cast iron:
https://en.wikipedia.org/wiki/Tay_Bridge_disaster
The investigation revealed how common foundry practice degraded the strength
of the metal.

Savery's 1698 steam engine used pressure to force water upward, but the
workmanship of the time was inadequate to contain the stress. Newcomen's
1712 engine and others for the next hundred years avoided pressure for
safety reasons. Boiler operation was a very uncertain art until Bourdon
introduced a practical pressure gage in 1849.

Trevithick in England and especially Oliver Evans in America advocated the
greater efficiency of high pressure steam in opposition to Watt who feared
the bad publicity of boiler explosions. Being further away, Evans was less
inhibited and created lighter and more efficient high pressure engines that
enabled American river steamboats. Since the Cornish engine was stationary
it could be built of a great mass of cheap material.
https://en.wikipedia.org/wiki/Oliver_Evans
Evans even experimented with supercharging the firebox but concluded that it
would demand far too much of blacksmiths.

This describes early marine steam engines which needed to be fairly light
weight and fit into confined hull spaces, resulting in some clever but
strange designs.
https://www.naval-history.net/WW0Book-Sennett-MarineSteamEngine.htm
-jsw



Jim Wilkins

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Dec 29, 2021, 9:04:15 AM12/29/21
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"Richard Smith" wrote in message news:lyy243k...@void.com...


I'm adding detail to this thought that, with this being direct
condensing by water spraying into a chamber with the steam it must
condense - much cheaper and simpler than "indirect condensers" used on
eg. current nuclear power stations - that the mix of water, condensed
steam and some lubricating oil (?) tipped back into the boiler to gain
some fuel economy from heat in the "hotwell" - the oil and
contamination is tolerable in a Cornish boiler at max. 50psi?

--------------------------

Spraying water into the cylinder cooled it, so on the next stroke the steam
had to first reheat the cylinder.
Watt's external condenser eliminated that considerable loss.
The tradeoff was cost of fuel versus the skill and wages of the operator,
who if good enough could work for the railroads.
https://www.gutenberg.org/files/62609/62609-h/62609-h.htm

Richard Smith

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Dec 29, 2021, 11:04:44 AM12/29/21
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"Jim Wilkins" <murat...@gmail.com> writes:

>> ...

> Wrought iron's random weld weakness imposed severe limits on pressure
> vessels, both boilers and cannon.

Not random - strong in direction of grain, but totally unreliable in
any other direction?

You could work around that with plates [in-plane design stresses
resulting from boiler pressure] and riveted structures with lapped
joints [clamped together and no forces trying to delaminate the metal]
?


> ... Look up Armstrong's rifled cannon
> for more info.

There's Woolwich Arsenal (and other?) rifled muzzle loaders all over the
place where I am working in Portland.
"Effective" range in kilometres compared to a couple of hundred metres
(?) with smooth-bore cast-iron canons.
Their concentric shrink-fit (?) structure of machined cylinders is
totally obvious to see. I'd seen them in books when I was a kid and
now for the first time in this job I'm doing I am walking past them
all the time.
Wrought iron would perform well by reason of stresses in the
direction of the grain of the metal given by forging.

> A notable failure of wrought and cast iron:
> https://en.wikipedia.org/wiki/Tay_Bridge_disaster
> The investigation revealed how common foundry practice degraded the
> strength of the metal.

I think it was only the cast iron which failed - and the engineer knew
and explained the limitations of the then achievable design.
I understand there were two things which were the undoing of the Tay
bridge
* wind-loadings weren't correctly assessed then (but were after this
experience) - not Bouch's fault really
* the railway operators got blase/ and had a flexible relation to the
severe speed limits specified



> Savery's 1698 steam engine used pressure to force water upward, but
> the workmanship of the time was inadequate to contain the
> stress.

Yes, but it had other limitations - particularly it could not lift
more than the about 10 metres of a "Toricelli" (sic.) vacuum with
water. As I understand it. So it was a first for applying fossil
fuel at a demonstrable level, but didn't have what it took to be a
usable device.
?


> ... Newcomen's 1712 engine and others for the next hundred years
> avoided pressure for safety reasons.

Yes - Newcomen's engines the boilers had no pressure at all -
apparently you could seal leaks with clay.

Boulton and Watt's engines operated at about 5psi - barely any pressure
at all.

The Newcomen engine was a "coal guzzler" and almost infeasible in
Cornwall, which has no coal.
It endured a long time at collieries, where it could consume waste
fines of no saleable value.
Apparently the "duty" of the generation of engines
* Newcomen - about 4~1/2million, rising to about 12million with
vastly improved mechanical detail (precision cylinder boring, etc.)
* Boulton and Watt - maximum about 30million
* "Cornish cycle" - maximum about 100million, but "blunted" back to
about 70million to 80million to lower peak forces giving the unfailing
reliability needed.
All according to
"The Cornish Beam Engine"
D.B Barton

> ... Boiler operation was a very
> uncertain art until Bourdon introduced a practical pressure gage in
> 1849.

You only had to have a feedwater water head of a few feet above the
boiler to keep it filled, and if it went over pressure it would push
water back up into the header and blow off steam - impossible to
over-pressurise. However - even that bare puff of pressure was
enought to burst boilers as they corroded, with horrible consequences.

Plug for a the book of a friend of a friend - both boilermakers by
Trade:
https://www.sledgehammerengineeringpress.co.uk/publications/historic-steam-boiler-explosions/
Alan McEwen
Historic Steam Boiler Explosions
Sledgehammer Engineering Press Limited (his own publishing house)

But come Cornish engine pressures of then "astronomical" 45psi
pressure - yes you would do well to have a safety-valve and
pressure-gauge...

> Trevithick in England and especially Oliver Evans in America advocated
> the greater efficiency of high pressure steam in opposition to Watt
> who feared the bad publicity of boiler explosions. Being further away,
> Evans was less inhibited and created lighter and more efficient high
> pressure engines that enabled American river steamboats. Since the
> Cornish engine was stationary it could be built of a great mass of
> cheap material.
> https://en.wikipedia.org/wiki/Oliver_Evans
> Evans even experimented with supercharging the firebox but concluded
> that it would demand far too much of blacksmiths.
>
> This describes early marine steam engines which needed to be fairly
> light weight and fit into confined hull spaces, resulting in some
> clever but strange designs.
> https://www.naval-history.net/WW0Book-Sennett-MarineSteamEngine.htm
> -jsw

Trevithick yes.
Apparently one of a number of talented Cornish engineers of the time.
One interpretation is that the Cornish cycle engine was the
combination of a Trevithick high-pressure engine "front-end" feeding a
Boulton&Watt separate-condenser "back-end" all on / in one cylinder...

The North American connection / steam-boats is a lead I must follow.


Efficiency - I have found this in the interim time

https://www.asme.org/wwwasmeorg/media/resourcefiles/aboutasme/who%20we%20are/engineering%20history/landmarks/194-kew-bridge-cornish-beam-engines.pdf

"Kew Bridge Beam Engines"

"...
One important side effect of the Cornish engine’s intermittent action
is that each up and down stroke is a separate power entity. So its
high efficiency – an 80-inch engine in Cornwall attained 11% overall
in 1835, a staggering figure for the time – is virtually unaffected by
the pumping rate. Maintaining efficiency over a wide range of load
factors is a problem with prime movers even today.
..."

The maximum for a single-stage high-pressure steam engine exhausting
to atmosphere peaked at about 12% maximum - if you got everything as
optimum as could be ?! - so that 11% 150years before and that
maintains over all loadings deserves serious respect.

Best wishes,
Rich Smith

Bob La Londe

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Dec 29, 2021, 2:25:06 PM12/29/21
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Perhaps it was just that they knew how to make them and they were tooled
up for it. Perhaps when manufacturing time and costs were factored in
it was cheaper and easier to go with what you know.

As a parallel in my contracting business. When the price of fuel peaked
during the Obamma administration here in the US I looked at replacing
all my 3/4 ton service trucks (except 1) with compact pickups. When
push came to shove the net savings on fuel didn't dent acquisition cost.
It was far cheaper even if fuel stayed that price to keep my 3/4 ton
trucks through their normal service life. Load that compact pickup
with tools and materials and the net fuel savings was even less.

Sometimes its about inertia, but usually its about money.

--
This email has been checked for viruses by AVG.
https://www.avg.com

Richard Smith

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Dec 29, 2021, 4:59:55 PM12/29/21
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Bob La Londe <no...@none.com99> writes:

> On 12/29/2021 1:39 AM, Richard Smith wrote:
>> ...

>
> Perhaps it was just that they knew how to make them and they were
> tooled up for it. Perhaps when manufacturing time and costs were
> factored in it was cheaper and easier to go with what you know.
>
> As a parallel in my contracting business. When the price of fuel
> peaked during the Obamma administration here in the US I looked at
> replacing all my 3/4 ton service trucks (except 1) with compact
> pickups. When push came to shove the net savings on fuel didn't dent
> acquisition cost. It was far cheaper even if fuel stayed that price to
> keep my 3/4 ton trucks through their normal service life. Load that
> compact pickup with tools and materials and the net fuel savings was
> even less.
>
> Sometimes its about inertia, but usually its about money.

Your "expensive" and our "expensive" for fuel are two different
things!
Anyway...

The amount of fuel used by mine pumping engines apparently made an
enormous difference to what was practicable.

Well, I am relying on reading from not many sources.

I'm mainly challenging whether my "condenser" conjecture is correct -
the a "free extra 1/3 of power" compensates for inherently lower
efficiency through low pressure...

Jim Wilkins

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Dec 29, 2021, 6:42:43 PM12/29/21
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"Richard Smith" wrote in message news:lyczlf3...@void.com...

Bob La Londe <no...@none.com99> writes:
...

Your "expensive" and our "expensive" for fuel are two different
things!
Anyway...

The amount of fuel used by mine pumping engines apparently made an
enormous difference to what was practicable.

Well, I am relying on reading from not many sources.

I'm mainly challenging whether my "condenser" conjecture is correct -
the a "free extra 1/3 of power" compensates for inherently lower
efficiency through low pressure...

----------------------
Watt introduced condensers on atmospheric (no pressure) engines. Their use
depended on availability of cooling water, not steam pressure.

Search for a downloadable .pdf of "Technical Choice, Innovation and British
Steam Engineering, 1800-1850", by Nuvolari_and_Verspagen.
I didn't get it from a quotable link.

"Second, since improvements in designs and operating procedures had been
attained by extrapolation and
guesswork, the actual performance of an engine remained surrounded by a good
deal of uncertainty."

"By the mid 1840s the Cornish engine had probably reached its practical
limits. Carried to the
extreme with pressures reaching 50 p.s.i., the expansion of steam produced
an extremely powerful
shock on the piston and the pitwork. Such an operating cycle increased the
probability of breakages
in the pitwork accelerating the wear and tear of the engine."

The extremely well documented RMS Titanic provides a view of nearly the
ultimate development of coal-fired marine reciprocating steam engines,
before Diesels and turbines took over. Titanic was optimized for fuel
efficiency rather than speed, and consumed only about 70% of the coal of the
slightly faster and considerably smaller Lusitania and Mauretania.
http://www.titanicology.com/Titanica/TitanicsPrimeMover.htm

Richard Smith

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Dec 30, 2021, 3:04:25 AM12/30/21
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Jim - you various links
"Titanic"
"locomotives 1880's" (a contemporaneous writing)
"essay 'Technical Choice, Innovation and British Steam Engineering, 1800-1850'"
are amazing.

The locomotives 1880 by Angus Sinclair is notable for being
contemporaneous by someone involved in the then experience of running
locomotives.

Best wishes,

Jim Wilkins

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Dec 30, 2021, 7:07:32 AM12/30/21
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"Richard Smith" wrote in message news:lysfuab...@void.com...
----------------------

https://www.gutenberg.org/files/55428/55428-h/55428-h.htm

Richard Smith

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Jan 17, 2022, 5:00:11 PMJan 17
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I've calculated thermal efficiency for a Cornish beam engine.

The best was a "duty" of about 100Million - foot-pounds of work
to a bushel of coal.

For a "duty" of 100million - ft-lb to a bushel of coal
94lb of coal per bushel
0.4536 kg per lb (pound)
30e6 J/kg calorific value of coal
9.81 Earth's gravity, N/kg
12 inches per foot
25.4 mm per inch
1e-3 mm to m (convert to SI units)

(/
(* 94 0.4536 30e6) ;; 1279152000.0
(* 100e6 0.4536 9.81 12 25.4 1e-3) ;; 135630391.68
)
9.431160554471974

9.4% efficiency

That is quite remarkable.

More than 100 years later by 1950 steam railway locomotives couldn't
realistically match that (?).

That "work" in the "duty" is a measure of the amount and height of
water lifted from the mine? (what else could they be measuring?!
What else would be possible to measure!!)
If so, that answer is very "final".

Comment is made in well-regarded books that that efficiency does not
change over all intended pumping rates.
Which is the cause of envy, to this day.
With the amount of water being adjusted by how many strokes per minute
the engine performed.

Richard Smith

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Jan 18, 2022, 1:23:04 AMJan 18
to
Belay this - I got the maths the wrong way around.
Sorry - I was wilting by then. Had quite a day at work welding in the
void spaces in an aluminum boat...

It's

work-done
-----------
energy-used

and answer is a fraction of 1

I will leave it for now. The answer could be 10.6% efficient...

Jim Wilkins

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Jan 18, 2022, 7:21:16 AMJan 18
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"Richard Smith" wrote in message news:lyv8yig...@void.com...
...
More than 100 years later by 1950 steam railway locomotives couldn't
realistically match that (?).
...
---------------------

Locomotives couldn't realistically employ bulky and fragile condensers or
tall smokestacks to improve draft, so they used the cylinder exhaust steam
to increase air flow through the firebox.

When condensing the steam was required they usually lost overall efficiency.
https://en.wikipedia.org/wiki/Condensing_steam_locomotive

Richard Smith

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Jan 19, 2022, 1:22:23 AMJan 19
to
Hi there

I think this is the correct calculation for the thermal efficiency of
a Cornish beam engine.

For a "duty" of 100million - ft-lb to a bushel of coal
94lb of coal per bushel
0.4536kg per lb (pound)
30e6 J/kg calorific value of coal (used good Welsh coal)
9.81 Earth's gravity, N/kg
12 inches per foot
25.4 mm per inch
1e-3 mm to m (convert to SI units)

Work done
(* 100e6 0.4536 9.81 12 25.4 1e-3) ;; 135630391.68
(message "%e" (* 100e6 0.4536 9.81 12 25.4 1e-3)) ;; "1.356304e+08" ;; J

Energy used
(* 94 0.4536 30e6) ;; 1279152000.0
(message "%e" (* 94 0.4536 30e6)) ;; "1.279152e+09" ;; J


(/
(* 100e6 0.4536 9.81 12 25.4 1e-3)
(* 94 0.4536 30e6)
)
0.10603148936170213

Efficiency of 0.106 = 10.6%

Comment as from previous message:

That is quite remarkable.

More than 100 years later by 1950 steam railway locomotives couldn't
realistically match that (?).

It's the condenser on this slow-cycling stationary engine which makes
the difference, it seems.
Boiler pressures approaching 20Bar (300psi) but exhausting to
atmosphere could not overcome the advantage of condensing despite the
Cornish engine hitting a practical limit at 50psi (just over 3Bar).
Unimaginably high when first done in around 1800, but "left behind"
after 1850.

Jim Wilkins

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Jan 19, 2022, 7:14:41 AMJan 19
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"Richard Smith" wrote in message news:lyczkos...@void.com...
....
------------------
The Cornish engine is an example of maximizing efficiency at the expense of
size and weight, which were more important in other applications.
Particularly in Britain the "loading gauge" or bridge and tunnel clearance
restricted the dimensions of steam locomotives.
https://en.wikipedia.org/wiki/Loading_gauge
"Great Britain has (in general) the most restrictive loading gauge (relative
to track gauge) in the world."

David Billington

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Jan 19, 2022, 9:18:42 AMJan 19
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I think much of that was down to penny pinching investors that didn't
want to pay for the larger loading gauge costs. I live less than a mile
from a GWR branch line that was originally broad gauge and the loading
gauge is huge in comparison to many other locations, Brunel had some
foresight, you could probably double the width and height of the current
trains and they would still pass through. My neighbour does miniature 
steam locos and many of his drawings I've seen have the loading gauge
shown for various rail companies and yes as you mention the clearance is
minimal in many cases.

Jim Wilkins

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Jan 19, 2022, 12:16:19 PMJan 19
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"David Billington" wrote in message news:ss96k0$snd$1...@dont-email.me...

...My neighbour does miniature
steam locos and many of his drawings I've seen have the loading gauge
shown for various rail companies and yes as you mention the clearance is
minimal in many cases.

Why did Britain change from inside to outside cylinders?

Richard Smith

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Jan 19, 2022, 12:44:19 PMJan 19
to
Yes, small crowded island. Lots of convoluted routes.

The power-to-weight of some good British locos - eg. the Stanier 8F's,
the Great Western Railway "Castles", etc - all with tapered boilers
and other features which are hard work to make and not normally worth
it but allow it to "pack a punch" when size is limited.

In most countries you would not make an engine more powerful that
would break traction on the rails if unskillfully driven.

In Britain with the good locos - skilled driving needed to know how
much punch to apply.

Videos of 8F's in Turkey - they snort along with a fiesty blast
despite being half the size of "Continental loading gauge" main-route
engines. It's quite a sight to see. Apparently the Turks called the
8F's "Churchills" and it part influenced them to stay strictly neutral
in the WW2 - sense of be careful juding how much strength-in-depth
Britain might have...

Richard Smith

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Jan 19, 2022, 12:48:36 PMJan 19
to
Good question.
Well informed answers looked forward to.
I conjecture that inside cylinders gave smoother running - but the
simplicity and easy maintainability of outside cylinders and motion
became the rational choice as technology developed and labour became
more expensive.
Anyone???

Jim Wilkins

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Jan 20, 2022, 7:22:22 AMJan 20
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"Richard Smith" wrote in message news:lylezbs...@void.com...
--------------------
One explanation that I read for retaining inside cylinders amounted to NOT
being like the USA, where locos rudely exposed their private parts.

Jim Wilkins

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Jan 20, 2022, 8:17:15 AMJan 20
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"Jim Wilkins" wrote in message news:ssbk5q$u0b$1...@dont-email.me...
...
One explanation that I read for retaining inside cylinders amounted to NOT
being like the USA, where locos rudely exposed their private parts.

------------------------

British resentment of US advances appeared strongly during WW2, largely in
the differing capabilities in air power. The RAF firmly advised us that
daylight bombing was impossible, then fumed and sputtered when we forged
ahead and succeeded with heavily armed bombers and long range escort
fighters. Though an excellent dogfighter, the Spitfire had an endurance of
barely two hours, even less for the otherwise superb XIV model, while the
Mustang could stay up for eight and protect the bombers to Berlin, Prague
or Vienna. German fighters also had relatively little endurance.

British designers tended to maximize performance in one area at the expense
of others while US ones sought a wider balance with no exploitable
weaknesses. An example is the 17-pounder gun fitted to British Sherman
"Firefly" tanks. It was a superior antitank gun but inferior against
infantry, so we kept our 75mm gun for most of our tanks.
https://warfarehistorynetwork.com/2019/01/01/michael-wittmann-how-the-legendary-panzer-ace-died-in-world-war-ii/

We aren't bothered at all that the computer chip in our cell phones is a
British ARM instead of a US product.


Leon Fisk

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Jan 20, 2022, 10:14:06 AMJan 20
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On Wed, 19 Jan 2022 17:44:15 +0000
Richard Smith <nu...@void.com> wrote:

<snip>
>The power-to-weight of some good British locos - eg. the Stanier 8F's,
>the Great Western Railway "Castles", etc - all with tapered boilers
>and other features which are hard work to make and not normally worth
>it but allow it to "pack a punch" when size is limited.
>
>In most countries you would not make an engine more powerful that
>would break traction on the rails if unskillfully driven.
>
>In Britain with the good locos - skilled driving needed to know how
>much punch to apply...

If you haven't found them yet... you should check out the Shay
Locomotives ;-)

https://en.wikipedia.org/wiki/Shay_locomotive



--
Leon Fisk
Grand Rapids MI

Richard Smith

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Jan 20, 2022, 4:12:29 PMJan 20
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Shays - "Iron Dinosaurs" Colin Garratt - journey of the imagination as kid

Richard Smith

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Jan 20, 2022, 4:15:00 PMJan 20
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"Jim Wilkins" <murat...@gmail.com> writes:
> ...
> We aren't bothered at all that the computer chip in our cell phones is
> a British ARM instead of a US product.

ARM - Cambridge - "silicon fen" - one of the few upbeat
research-and-manufacturing places in the UK.

Richard Smith

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Jan 20, 2022, 4:20:16 PMJan 20
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"Jim Wilkins" <murat...@gmail.com> writes:

> ... while the Mustang could stay
> up for eight and protect the bombers to Berlin, Prague or
> Vienna. German fighters also had relatively little endurance.

Total digression, but...

Are you able to explain?
A Mustang over eg. Berlin has to have enough fuel to get home -
several hours flying. Yes it's emptied its drop-tanks, but its wing
tanks are full to the brim (?)
I meets the then Luftwaffe planes which are on a splash-and-dash.
How come the Mustangs prevailed?
Is it that they only had to "tie-down" (fully occupy) the German
fighters? Leaving the bombers to do their work?

Leon Fisk

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Jan 20, 2022, 4:34:19 PMJan 20
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On Thu, 20 Jan 2022 21:12:29 +0000
Richard Smith <nu...@void.com> wrote:

>Shays - "Iron Dinosaurs" Colin Garratt - journey of the imagination as kid

Somewhat recent article that ran in our local paper:

https://www.mlive.com/news/2021/10/historic-logging-locomotive-to-be-restored-for-display-in-michigan-inventors-hometown.html

Shay was an interesting guy...

Jim Wilkins

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Jan 20, 2022, 5:44:45 PMJan 20
to
"Richard Smith" wrote in message news:ly1r12p...@void.com...
---------------------

During the Luftwaffe debates on rec.aviation.military I concentrated on
technology and left tactics and organization to British expert Keith
Willshaw. He's still active in the group and may know something about
welding.
keithw...@gmail.com

Jim Wilkins

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Jan 20, 2022, 5:52:08 PMJan 20
to
"Leon Fisk" wrote in message news:ssbu7q$41i$1...@dont-email.me...

If you haven't found them yet... you should check out the Shay
Locomotives ;-)

https://en.wikipedia.org/wiki/Shay_locomotive

-------------------------

We have one locally:
https://www.shaylocomotives.com/data/factsheet/sn-3066.htm
Maximum Safe Speed: 17.2

Richard Smith

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Feb 6, 2022, 5:23:19 AMFeb 6
to
for what it's worth - the "duty" as keenly measured in Cornwall (UK)
from 1800-ish to 1910-ish
ft-lb of work done per bushel of coal (either 94lb or 100lb of coal -
not "got to the bottom of that").

How is the work done measured or estimated for a pumping engine
keeping a mine clear of water?
I found the answer in
On the Steam Engine In Cornwall
Thomas Lean
1839
(reprint from the late 1960's)

I've previously calculated
for a "duty" of 100million
10.6% thermal efficiency if 94lb of coal per bushel
10.0% thermal efficiency if 100lb of coal per bushel

The work done is a close estimate.
They know the diameter and stroke of the water pumps.
(there's a "lift" over several stages from a mine 100's of metres deep
- but water being an incompressible fluid it follows (and is the case
that (?)) each pump in the rising sequence has the same diameter, and
the stroke certainly is the same, given all pumps are driven by the
same pump-rod)
So the volume per stroke can be calculated.
There is the critism that there may (will be to some extent) leakage
past the piston, valves, etc.
However, there is good reason for that to be kept minimal.
The mine owner doesn't want to pay for coal whose water pumped leaks
back to the bottom of the mine.
The owners probably also want to know "duty" as accurately as possible
to make good business decisions - about the mine at that moment and
future equipment acquisitions.
So for a combination of reasons, it is "a good bet" to use the swept
volume of the pump(s).
There was then no good way to measure the rate of water (cu-ft per
hour, or whatever) going into the adit from the pump shaft,
anticipating that thought / query.
So yes, there we have it.

But that 10.6% / 10.0% efficiency - that's the efficiency all the way
from coal going into the boiler at the start of the "pumping process"
to water spilling into the adit at the end of the "pumping process".
It's "the big number overall number which counts". Impressive.

Regards,
Rich Smith

Jim Wilkins

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Feb 6, 2022, 11:40:31 AMFeb 6
to
"Richard Smith" wrote in message news:ly5yps5...@void.com...

There was then no good way to measure the rate of water (cu-ft per
hour, or whatever) going into the adit from the pump shaft,
anticipating that thought / query.
So yes, there we have it.

-----------------------
For those who don't know, an Adit is the opposite of an Exit.

If you care enough the flow rate can be measured by timing the filling of a
measured volume, perhaps the cistern that stores water for the steam engine
boiler. The answer can be as accurate as your timepiece, which can be
calibrated within a few seconds per day by determining the local noon
(maximum sun height) with a sextant and pan of water.

If you care. Also, how wet is that bushel of coal? As a chemist I would
weigh it, bake it dry and weigh it again, then subtract the weight of the
ash and clinker afterwards. Those measurements could be done on samples of
new coal deliveries, without measuring the water flow.

Thanks to clock and instrument makers length could be measured quite
accurately by 1800, we still use the original 1793 French definition of the
metre as one ten-millionth of the distance from the equator to the north
pole, as registered by marks on a bar, or currently by wavelengths of light.
The result was and still is wrong by 0.2mm or two standard hair's widths.

France qualified to set the world standard because they previously had the
worst measurement system in Europe, nearly every town was different.
https://www.mysciencework.com/omniscience/measuring-the-meter-an-error-that-changed-the-world

Accurate measurement has always been a limitation on the advance of science.
Experimental uncertainty permitted incorrect alternate explanations like the
Sun revolving around the Earth, earth, air, fire and water being the four
elements, and the Caloric theory of heat as a physical substance. Without
accurate measurement the correct answer was just one of many possibilities.
Einstein's Relativity was only a conjecture until measurements of star
position displacements during an eclipse confirmed it.
https://earthsky.org/human-world/may-29-1919-solar-eclipse-einstein-relativity/

https://www.vox.com/science-and-health/2018/11/14/18072368/kilogram-kibble-redefine-weight-science
jsw

Richard Smith

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Feb 7, 2022, 12:29:01 AMFeb 7
to
"Jim Wilkins" <murat...@gmail.com> writes:

> "Richard Smith" wrote in message news:ly5yps5...@void.com...
>
> ...
>
> -----------------------
> ...
>
> If you care enough the flow rate can be measured by timing the filling
> of a measured volume, perhaps the cistern that stores water for the
> steam engine boiler. ...
>
> ...

The water from the mines was is too full of minerals to be much use.
It apparently welled-up at quite high temperatures in the 30's or 40's
Celsius in the deeper mines. One observation revived now is that the
mine water could have a lot of lithium in it - and effort is being
made to "mine" lithium with boreholes.
That added to the reason it discharged down the adit, rather than
being brought to surface. I'm finding many mine depths being "below
adit" rather than "below surface".

For the mining, leats were constructed to bring water.
Devon and Cornwall are very green - for good reason - it rains
frequently.
For the boilers and condensers yes, but also for the mineral dressing.
Apparently where there was a shortage of water and they had to bring
mine water to the surface and use that, boilers only lasted a couple
of years, or something like that.

Jim Wilkins

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Feb 7, 2022, 9:16:51 AMFeb 7
to
"Richard Smith" wrote in message news:lya6f35...@void.com...

"Jim Wilkins" <murat...@gmail.com> writes:

> "Richard Smith" wrote in message news:ly5yps5...@void.com...
>
> ...
>
> -----------------------
> ...
>
> If you care enough the flow rate can be measured by timing the filling
> of a measured volume, perhaps the cistern that stores water for the
> steam engine boiler. ...
>
> ...

The water from the mines was is too full of minerals to be much use...

---------------------

It was technically possible for them to measure flow rate though probably
not worth the effort if the results wouldn't lead to cost-effective
improvements.
https://proteusind.com/history-of-flow-meters/
"Due to the limitations of technology and economy up to and during the
1950s, only Orifice plate flow meters were being used in all industries,
including the rotate flow and pilot tube."

Ancient Roman water meters weren't much different. They installed bronze
flow restriction tubes and billed according to their size.

I found some of these second-hand to measure and improve the draft of my
wood stove chimney and the air pressure drop (heat transfer rate) through a
transistor heatsink.
https://www.terrauniversal.com/differential-pressure-gauge-magnehelic-uninstalled-2625-09.html

The result of my measurements and improvements is burning less than half as
much firewood as others with similar houses. They were built with electric
heat and though well insulated are difficult and expensive to retrofit with
anything beyond a single wood or gas stove in the cellar, so I have a fuel
problem similar to Cornwall's. At least I have a 240V 200A electric service
able to support any welding or plasma cutting I could want, and a neighbor
with undeveloped (hilly) land who let me cut dead trees.

Richard Smith

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Feb 7, 2022, 4:24:47 PMFeb 7
to
"Jim Wilkins" <murat...@gmail.com> writes:

> "Richard Smith" wrote in message news:lya6f35...@void.com...
>
> "Jim Wilkins" <murat...@gmail.com> writes:
>
>> "Richard Smith" wrote in message news:ly5yps5...@void.com...
>>
>> ...
>>
>> -----------------------
>> ...
>>
>> If you care enough the flow rate can be measured by timing the filling
>> of a measured volume, perhaps the cistern that stores water for the
>> steam engine boiler. ...
>>
>> ...
>
> The water from the mines was is too full of minerals to be much use...
>
> ---------------------
>
> It was technically possible for them to measure flow rate though
> probably not worth the effort if the results wouldn't lead to
> cost-effective improvements.
> https://proteusind.com/history-of-flow-meters/
> ...

"Not worth the effort" is surely the answer.
The pump's swept-volume (piston-area x stroke) will give a very
accurate estimate of water volume pumped.
Measuring water flow directly - at each mine you'd have to get down to
the adit carrying your equipment down a small twisting shaft then have
some space to deploy it - big "ask".
The readings would have to be the same for the same water-flow at
each mine - so whatever direct measurement you use would have to be
very consistent.
Rich Smith

Jim Wilkins

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Feb 7, 2022, 6:44:55 PMFeb 7
to
"Richard Smith" wrote in message news:ly4k5ae...@void.com...

"Jim Wilkins" <murat...@gmail.com> writes:

"Not worth the effort" is surely the answer.
The pump's swept-volume (piston-area x stroke) will give a very
accurate estimate of water volume pumped.
Measuring water flow directly - at each mine you'd have to get down to
the adit carrying your equipment down a small twisting shaft then have
some space to deploy it - big "ask".
The readings would have to be the same for the same water-flow at
each mine - so whatever direct measurement you use would have to be
very consistent.
Rich Smith

-----------------

Accurate measurement wasn't a priority until recently. Consider that the
steam engine had been in use for 150 years before someone bothered to invent
the boiler pressure gauge. Previously stokers shoveled in coal until the
weighted safety valve opened.

When I was a kid learning to use a lathe the size measurement tool was still
friction calipers, set by eye to a wooden ruler.

John B.

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Feb 7, 2022, 7:17:03 PMFeb 7
to
Gee, you must be a really old geezer as, I read, the first hand held
micrometer dates back to about 1848
https://www.alliancecalibration.com/blog/history-of-the-micrometer
(:-)
--
Cheers,

John B.

Richard Smith

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Feb 8, 2022, 1:25:26 AMFeb 8
to
"Jim Wilkins" <murat...@gmail.com> writes:

> "Richard Smith" wrote in message news:ly4k5ae...@void.com...
>
> "Jim Wilkins" <murat...@gmail.com> writes:
>
> ...
>
> Accurate measurement wasn't a priority until recently. Consider that
> the steam engine had been in use for 150 years before someone bothered
> to invent the boiler pressure gauge. Previously stokers shoveled in
> coal until the weighted safety valve opened.

Reading

Historic Steam Boiler Explosions
by Alan McEwen (Author)
Sledgehammer Engineering Press Limited
(Mr McEwen is the friend of a friend)

(title sounds gruesome and in many ways it is, but the insights are
notable)

in Boulton&Watt's day, with boiler pressures around 5psi (1/3Bar), the
pressure was retained and limited by a water-column of a few feet
(very few metres) tall.
Over-pressure, and you'd "blow" water and steam into the header tank.

Richard Smith

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Feb 8, 2022, 1:26:17 AMFeb 8
to
"Jim Wilkins" <murat...@gmail.com> writes:

> ...
>
> When I was a kid learning to use a lathe the size measurement tool was
> still friction calipers, set by eye to a wooden ruler.

Sounds quite a pragmatic start!

Jim Wilkins

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Feb 8, 2022, 7:01:58 AMFeb 8
to
"John B." wrote in message
news:4dd30h5o2rnrt3jc9...@4ax.com...
----------------------------

Verniers date from 1631.

https://en.wikipedia.org/wiki/Pierre_Vernier

Over 100 years later Watt used the thickness of an old shilling to quantify
a measurement.

Wood lathe work still uses ancient measuring tools:
https://www.woodturnerscatalog.com/t/86/Calipers

Jim Wilkins

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Feb 8, 2022, 7:43:15 AMFeb 8
to
"Richard Smith" wrote in message news:lytud9y...@void.com...
-------------------------

Our Jr High (age 13-14) shop teacher was a retired Swedish cabinet maker who
first taught us the old skills like sharpening saws with files and squaring
cuts with a plane and try square before introducing us to newer methods. My
friends and I were ambitious and competitive enough to try to outdo each
other so we learned quite well.

I still use what I learned to make press-fit joints in timber framed
woodsheds at the back end of my property, beyond the reach of electricity,
and have even used them for hand fitting parts in electronic equipment,
including a prototype of the Segway balance sensor.

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