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When were blocks changed?


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Hi Bob,good question.

 

I think that both types of pin were in use all of the time. Lees quotes wood pins (lignum vitae I would think) for small blocks and Iron or Brass pins for large blocks used in English ships. Marquardt quotes pins being made from Lignum Vitae,Cog-Wood (Laurus chloroxylon),Greenheart and Iron in his book 18th Century Rigs & Rigging which covers other countries as well as Britain. Neither of these books mention anything about dates of change from wood to metal.  

 

Hope this is of help to your question.

 

Dave :dancetl6:

Edited by davyboy
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Are you guys talking of sheaves or really of the axles, i.e. the pins on which the sheaves run ? I have never heard that the axles were made from anything else, but metal. The friction of wood on wood would be rather to high and they would very quickly wear down without constant greasing.

 

I think there has never been a complete shift over from wood to metal as far as blocks for organic and man-made fibres is concerned. The sheaves of blocks for wire rigging to my knowledge have (almost) always been from cast iron. The wire rope would simply saw into wooden sheaves. Also, wire rope requires relatively large sheaves that would be quite expensive to make from wood.

 

wefalck

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Are you guys talking of sheaves or really of the axles, i.e. the pins on which the sheaves run ? I have never heard that the axles were made from anything else, but metal. The friction of wood on wood would be rather to high and they would very quickly wear down without constant greasing.

 

 

wefalck

 

I would tend to agree with you but it is obvious from the pictures the pins were made of wood.

 

http://modelshipworld.com/index.php?/topic/889-gothenborg-by-popeye-the-sailor-billings-1100-scale/page-8

 

Click and scroll down.

 

Bob

Edited by Cap'n'Bob
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I wouldn't doubt the use of lignum vitae, it is an extremely hard wood.

In the late seventies I had a piece of it in my hands and I couldn't find a tool able to score it.

As for friction I can tell you it was part of a propshaft bearing on a 10 000Hp bulk carrier, operating at 122RPM,

so you can figure out the resistance to wear.

In that capacity it was water cooled, but on the other hand it would get more friction in one minute than a block in one

hour, so I believe there would have been no problem

 

All the best

Zeh

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