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Yarwoods steel quality


jenevers

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Not on their canal craft - as a rule - I think that the Royalty and Middle boats were copper bearing steel, the Large boats were all steel and the Small boats were iron sided with wooded bottoms. No idea about their sea and river going craft.

I think that the copper bearing steel boats were much more expense.

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Not on their canal craft - as a rule - I think that the Royalty and Middle boats were copper bearing steel, the Large boats were all steel and the Small boats were iron sided with wooded bottoms. No idea about their sea and river going craft.

I think that the copper bearing steel boats were much more expense.

 

The drawings that exist for the "middle" boats, (a detailed cross section), certainly specify it.

 

As an aside, the sides (but not the bottom) of a "middle" boat are only specified as 4/20", which is only about 5mm - 1mm less than most modern leisure boats.

 

I haven't seen drawings for a "large" boat yet.

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Can we assume the term Copper Bearing refers not to copper plating but to the fact that copper was included in the steel "mix" as part of the manufacturing process. I can only guess that the inclusion of cooper un some way improves the physical properties of the steel, maybe makes it easier to bend?

Not heard of copper used foe this purpose before but have used a lead bearing steel called Leadalloy where the machineability is greatly improved with faster cutting speeds etc but the inclusion of lead did have an adverse effect on the material strength, hence limiting the use of this particular alloy.

Phil

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I can only guess that the inclusion of cooper un some way improves the physical properties of the steel,

 

Not so

 

 

Abstract—Copper being one of the major intrinsic residual impurities in steel possesses the tendency to induce severe microstructural distortions if not controlled within certain limits.

 

http://waset.org/publications/9999677/effect-of-copper-on-microstructure-and-mechanical-properties-of-construction-steel

 

From memory, copper has become a contaminant in steel due to leaving copper in the scrap used in production. It's removal isn't easy

 

Richard

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Copper bearing steel is a 'High Strength Low Alloy' (HSLA) steel use by the shipbuilding industry. Just what it's specification was back in the 1920-30's would take a bit of research.

 

That's helpful. Between 0.2% and 0.5%. PDF document: http://www.asminternational.org/documents/10192/3466171/06117_Chapter%203B.pdf/a764507a-3499-4d23-b348-5536d31c0ba2

 

Richard

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When I was a junior on a steel firm I was instructed on how to use the spark spectrometer, we would buy offcut rolls and non spec steel coils from Corby or another BS steel mill and Id be tasked with analysing the content. When I found copper in the mix the coils would be put aside and kept for specific customers, intervening years have clouded the reasons for this but I know we couldnt send them to any of our automotive customers as they would be rejected off bat, they tended to go to the 'less picky' customers with no stress critical specifications.

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The drawings that exist for the "middle" boats, (a detailed cross section), certainly specify it.

 

As an aside, the sides (but not the bottom) of a "middle" boat are only specified as 4/20", which is only about 5mm - 1mm less than most modern leisure boats.

 

I haven't seen drawings for a "large" boat yet.

 

No mention of it on the Large Northwich drawings I've got.

Edited by IanM
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Not on their canal craft - as a rule - I think that the Royalty and Middle boats were copper bearing steel, the Large boats were all steel and the Small boats were iron sided with wooded bottoms. No idea about their sea and river going craft.

I think that the copper bearing steel boats were much more expense.

Presumably the logic is increased corrosion resistance rather than mechanical advantage so it's probably not coincidence that it's the boats with rounded chines that used copper bearing steel given that someone posted the other day that the rounded chines were do with intended use in estuarial waters.

 

JP

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Presumably the logic is increased corrosion resistance rather than mechanical advantage so it's probably not coincidence that it's the boats with rounded chines that used copper bearing steel given that someone posted the other day that the rounded chines were do with intended use in estuarial waters.

 

JP

 

To me this seems quite a reasonable assumption.

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That spec is dated 2001. It may still be correct for prewar steel but have failed to find a spec for the era. Copper bearing is nothing to do with corrosion or antifouling it is all in relation to it's strength.

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That spec is dated 2001. It may still be correct for prewar steel but have failed to find a spec for the era.

 

Likewise

 

My 1971 Machinery's Handbook mentions HSLA, but nothing about it's composition

 

Incidentally, HSLA is very misleading as it seems to cover a whole range of low alloy steels, not all of which are about the copper content

 

Richard

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I have been digging through my stuff and found in a list of steels for boat building......

 

examples of special steels

Steel with Copper

Incrasteel40

50-58 Kgfmm sq

possible for round bilge craft

excellent for chine craft

type of welding possible gas shielded arc

type of welding recommended gas shielded arc

distortion after welding very small

Edited by John V
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Presumably the logic is increased corrosion resistance rather than mechanical advantage so it's probably not coincidence that it's the boats with rounded chines that used copper bearing steel given that someone posted the other day that the rounded chines were do with intended use in estuarial waters.

JP

That's interesting.

I wonder if the British Isles Transprt "A" Shortboats and the Longboats (Ambush etc) on the L&L, were built using copper bearing steel, as they worked across the Mersey and had round Chines.

Edited by jenevers
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That spec is dated 2001. It may still be correct for prewar steel but have failed to find a spec for the era. Copper bearing is nothing to do with corrosion or antifouling it is all in relation to it's strength.

I have been digging through my stuff and found in a list of steels for boat building......

 

examples of special steels

Steel with Copper

Incrasteel40

50-58 Kgfmm sq

possible for round bilge craft

excellent for chine craft

type of welding possible gas shielded arc

type of welding recommended gas shielded arc

distortion after welding very small

Increased levels of copper in steel will increase tensile strength and reduce Young's modulus. Therefore the resulting steel will be more workable and stronger.

 

There was also plenty of research done in the early 20th century demonstrating the corrosion resistant properties - both in water and polluted atmospheres - of copper-bearing steels.

 

We will quite likely never know the real reason it was used but all three suggestions we have come up with are potentially valid.

 

JP

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Likewise

 

My 1971 Machinery's Handbook mentions HSLA, but nothing about it's composition

 

Incidentally, HSLA is very misleading as it seems to cover a whole range of low alloy steels, not all of which are about the copper content

 

Richard

That is so. Generic steel families are 'carbon', 'alloy' and 'stainless'. Those terms can be misleading because all steel is technically an alloy and all of those steels contain carbon. Just to demonstrate the point the primary alloying elements in rail steels are carbon and manganese. Copper is not part of the mix.

 

JP

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Increased levels of copper in steel will increase tensile strength and reduce Young's modulus. Therefore the resulting steel will be more workable and stronger.

 

There was also plenty of research done in the early 20th century demonstrating the corrosion resistant properties - both in water and polluted atmospheres - of copper-bearing steels.

 

We will quite likely never know the real reason it was used but all three suggestions we have come up with are potentially valid.

 

JP

Hmm interesting, this is the complete opposite of the info given by Richard when I suggested copper was added to improve the material characteristics'

Phil

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Hmm interesting, this is the complete opposite of the info given by Richard when I suggested copper was added to improve the material characteristics'

Phil

We are all learning as well as inputting our own knowledge.

 

I am not sure Richard wasn't right in terms of why this steel was used in this particular instance but generically copper-bearing steels do have increased strength, workability and corrosion resistance compared to standard low carbon mild steel.

 

It is entirely possible the use of copper-bearing steel was an empirical decision based on all three factors but if I had to put a fiver on any one of those singularly, based on the discussion above I would go with workability. Which means I don't necessarily agree with my own initial post on this subject!

 

JP

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