Looking for scale reference for block sizes expressed in inches

[Simon Martin]

Hi,

I am busy building a model of the Bluenose and in Jenson's book the blocks use in the running rigging are all listed as "13-inch triple", "12-inch double", etc.

I would like to know which dimension the 13-inch refers to: sheave diameter? Something else?

Also what proportions should I use to determine shell height, width and thickness for each type of block? Are Monfeld's proportions also applicable to blocks from the early 20th-century, or is there a better resources for that era?

Thanks in advance for your help!

Cheers,

Simon

[druxey]

Usually the size is expressed by the length of the block. I haven't the Mondfeld reference handy, but don't think block proportions changed much over time.

[Gregory]

This might help from a recent discussion:

 

 

[Simon Martin]

Thank you Gregory, I saw this reference as well during my research, but the block size I am looking for is expressed in inches, not in rope diameter or circumference.

So even if I use the excel tool I end up not knowing which size block I should pick from the results. I just want to make sure I start off a good base before I go on and make 144 blocks by hand!

Cheers,

Simon

[Simon Martin]

Thank you druxey, will try with that and see how it compares to what I initially got. When I superimposed the blocks I had with a rigging plan mine were almost twice as big: 

Cheers,

Simon

[Gregory]

43 minutes ago, Simon Martin said:

block size I am looking for is expressed in inches, not in rope diameter or circumference.

The size of the blocks are based on the rope size being used, not the other way around.

 

You find the rope size you are using then find the block for that size rope.

[allanyed]

There are block size charts for several similar schooners in Chapelle's American Fishing Schooners that will give you all the block sizes on pages 341-347 along with many other details you may find useful for the Bluenose.  I would post these but there is far too much to copy here without possibly violating copyrights.  Those vessels Chapelle lists regarding blocks include Dunton, Ed Bosley, Grampus, and Columbia.  There is a used copy on line at Abe Books for $17.

 

Allan

Edited February 21, 2023 by allanyed

[Gregory]

2 hours ago, allanyed said:

will give you all the block sizes

Allan, do you disagree that block size is determined by rope size?   The type of ship shouldn't matter..

 

Here is a basic table from Mondfeld

 

Edited February 21, 2023 by Gregory

[allanyed]

Hi Gregory

I agree with you that the block sizes for many/most ships, are based on the size of the rope.  But, in the case of the Bluenose, the only thing I could find were block sizes in Chapelle's book on schooners as he does not give the line sizes.   Different tack, but that is all I could find for these vessels.  If he had listed line sizes instead, it should be the same for finding the block sizes as we are used to doing.  

Allan

Edited February 21, 2023 by allanyed

[Simon Martin]

allanyed, I had checked Chapelle's previously but too quick perhaps: at p.347 it says: "(From Merriman table of vessel blocks)". A search online for that caption led directly to Merriman Bros. 1928 catalog, which listed sheave dimensions for various sizes, from which I am going to try Monfeld's proportions. We'll see what comes out of it. Will post the results here in case anyone's interested.

A big thank you to all of you!

Cheers,

Simon

[Simon Martin]

Using the designated inch value as the shell height and applying Monfeld's proportions to the sheave diameter provided in the catalog, I had to scale my block model down by 23%!

It now looks much more plausible, doesn't it?

I think I'll go with that.

Thank you very much!

Cheers,

Simon

[Roger Pellett]

Something to consider-  In the later years of the Nineteenth Century the design of blocks changed.  The earlier blocks can be described as “wooden shell” as they were carved or more properly machined from a solid block of wood.  The block had to be strong enough to withstand loads from the sheave transmitted by its axle through the wooden shell to the rope strop.

 

The later blocks are called metal or internally stropped.  These feature a metal frame within the wooden shell that transmits loads from the sheave directly to the block’s attachment point.  The block’s wooden shell does not bear loads from the rigging.

 

I am unfamiliar with Mondfeld’s book but if he is referring to Eighteenth/ early Nineteenth Century practice the block’s in his table would be the earlier wooden shell variety.  Chapelle, on the other hand is providing dimensions for the later internally stropped variety that would have been used on the Twentieth Century fishing Schooner.  Dimensions for these might have been different.  Use the Chapelle dimensions.

 

Roger

[allanyed]

2 hours ago, Roger Pellett said:

internally stropped variety that would have been used on the Twentieth Century fishing Schooner.  Dimensions for these might have been different.  Use the Chapelle dimensions.

Great advice.  He did his research so if he is giving block dimensions, I would not question them without contrary information from other contemporary sources.

 

Allan

[Simon Martin]

Roger's comment triggered further photo browsing and the thickness proportions provided by Mondfeld (sorry for misspelling his name in my sketches) are different from what appears on the pictures I found showing Bluenose blocks. The internally stropped blocks have a thinner outer shell and also look thinner in between the sheaves when there are many of them. Attached are the proportions I guessed by looking at pictures. Note that the drawing provided at p.243 of Mondfeld's book are out of proportions. When drawn using the numbers he provides, the blocks are much thicker than they look on the drawing, owing to the thicker cheeks. Again thank you all for your willingness to share knowledge and resources! Cheers, Simon

 

[Hsae]

For what it’s worth, the bloc dimensions for Bluenose II (Bluenose II, Saga of the great fishing schooners, by L.B. Jenson)

 

 

 

 

Edited February 22, 2023 by Hsae