Sherbourne blocks

[cotrecerf]

Help needed: I am about to start making blocks for my af Chapman English Cutter and due to the lack of original block dimensions given for this special cutter I make use of the rigging list for Sherbourne 1763 (same period): There I find some blocks noted which are absolutely unknown to me so far:

 

block, single, QUARTERED?? and 

block, single, ironbound, iron, PINED?? and

block, double, brass, COAKED??

 

For the  2 latter ones I assume the sheave is either Iron or Brass and coaked seems to be brass rods inserted in the sheave to act like a ball bearing in connection with the brass sheave.

 

If someone has got a description and favourably some drawings of pics, these ar most welcome.

 

Thanks in advance for your expert help.

 

Joachim

 

 

[Thukydides]

Not an expert by any means, but here would be my interpretation:

• I would guess a quarter  may be referring to a thin single block. According to steel a quarter block (also called thick and thin) was a double block with one sheave thicker than the other. So maybe in this case it is just the thin part.
• The pins for the blocks were made of wood so an iron pinned one had an iron pin instead of a wooden one.
• Coaking was the process layering the inside of the sheave with a cylindrical piece of metal into which the pin would be placed. I would guess this was to increase the strength of the block or perhaps to make is spin easier.

https://maritime.org/doc/steel/part5.php

Edited May 27 by Thukydides

[Ferrus Manus]

@Isaiah you should check this out. 

[cotrecerf]

Thukydides,

many thanks for your input, whioch gave me some ideas of what the blocks might look like. I'll keep on searching for quartered block to know for sure. That's part of the fascination of our hobby, that there always pops up a new topic to looking closer into.

I'll post the results, if any.

 

Best regards

 

Joachim

[cotrecerf]

Ferrus Manus,

 

thanks a lot for your answer. Alas, I don't seem to be a good checker as I have not found any enlightening answers to my block questions under Isaiah's content. He is working on Sherbourne but now busy with planking.

 

best regards

 

Joachim

[Ferrus Manus]

6 hours ago, cotrecerf said:

thanks a lot for your answer.

I was actually referring Isaiah to your question, in hopes that he would learn more about the Sherbourne's blocks. He and I already had this discussion about blocks. I also referred him to the specific table used above. I was hoping he could glean some information from this topic. 

[cotrecerf]

Ferrus Manus = Ironhand,

 

thanks for your action towards Isaiah, now I understand. Hopefully he can shed some light onto the matter. Thanks again.

 

greetings

 

Joachim

[Isaiah]

17 hours ago, cotrecerf said:

Ferrus Manus = Ironhand,

 

thanks for your action towards Isaiah, now I understand. Hopefully he can shed some light onto the matter. Thanks again.

 

greetings

 

Joachim

I’m afraid that whatever you know, I probably know less than half. I’m still a beginner and don’t know much so I can’t really help with a lot.

 

I think you’re gonna have to help me out! 🙂

[Isaiah]

On the block chart above, what measuring system does it use? Is this in a certain scale or is it life size? 

[Thukydides]

1 minute ago, Isaiah said:

On the block chart above, what measuring system does it use? Is this in a certain scale or is it life size? 

It is real life, this is a table from the 1700s for an actual ship.

 

Block sizes are the length of the block and rope sizes are the circumference of the rope. In both cases the size is in inches.

[Isaiah]

1 hour ago, Thukydides said:

It is real life, this is a table from the 1700s for an actual ship.

 

Block sizes are the length of the block and rope sizes are the circumference of the rope. In both cases the size is in inches.

Ok thanks for clarifying.

[cotrecerf]

Gentlemen,

thanks for your efforts so far. I've transduced that original Sherbourne Inventory into a xls-sheet showing in the end all measurements in metric in my preferred scale 1:50.

 

Yet there still remains my need for illustrations or descriptions of a quartered block as mentioned in the inventory.

 

Best regards

 

Joachim

Sherbourne 1763 Mast Rahen Rigging Blocks.xlsx

[Isaiah]

Wow this is amazing info, this is going to be very helpful.

 

Do we know where the plans and/or dimensions are for the gun tackles and blocks?

[Gregory]

10 hours ago, Isaiah said:

Do we know where the plans and/or dimensions are for the gun tackles and blocks?

We have this information from a recent discussion.

https://modelshipworld.com/topic/36354-gun-positions-and-their-associated-tackle/?do=findComment&comment=1042700

[Mark P]

Good Morning Joachim;

 

Re your original query, a quarter block had a small projection worked on it, so that it would not be pulled flat against the yard-arm causing the rope inside to bind against the yard, preventing movement. Typically used for sheet blocks at the yard-arm. 

 

An iron-bound block has a strap of iron around it, rather than a rope strop. It also has an iron pin, which is set into holes in the strap each side of the block.

 

A coak is a metal plate of iron or brass, set into the outside surface of the shell of the block, to form a bearing for the pin through the sheave. This prevents the pin bearing on the wood, which would wear out more quickly than the iron will.

 

All the best,

 

Mark P

Edited May 31 by Mark P

[cotrecerf]

Hello Mark,

thank you very much for your detailed answer, very helpful for me! So, there is no general difference between a Quarter block and a QuarterED block ?

 

All the best

 

Joachim

[Mark P]

Good Evening Joachim;

 

I cannot think that there is any difference between the two. I note two points from the list shown above: 

 

Firstly, the sheets pass through a shoulder block. This is the same as a quarter block, yet the inventory also lists shoulder blocks separately. However, as the quarter blocks are for the bowlines, they must be located on the bowsprit, near its outer end, with the running end coming inboard over the bowsprit. When the rope is hauled, this could cause the block to be pulled down against the bowsprit, with the rope being compressed between the two, and becoming jammed.  For this reason a shoulder block is needed here, and has been listed using an alternative name for the same item. 

 

As evidence of this, I have checked my images of the rigging warrant for the cutter 'Kite', of 1762. This lists the blocks for both the bowlines and the sheets as 'shoulder blocks'. They are both the same size, as they are on the list you show above. 

 

Below is a picture of a shoulder block, from Steel's Elements of Rigging. 

 

 

All the best,

 

Mark P

[cotrecerf]

Hello Mark,

thank you very much. I now understand the the inventory in some details much better avoiding any  ambiguiance in the block matter. The pic helps too.

I haven't been aware of the Kite's rigging warrant. I guess it can be found via NMM's homepage.

 

Have a nice weekend

 

Joachim