Any rules of thumb or tables for sizing hearts?

[Tim Holt]

I've seen tables of sizes for blocks and line, as well as some rules of thumb (ratio of line size to sheave size).  Is there such a thing for determining the size of a heart?

 

And a related question...

 

When the size of a heart is given, it's often just a single dimension.  What exactly is this dimension?  Is it the widest point of the opening?  Outer width?  Inner or outer height?

[allanyed]

Hi Tim,

 

What is the circumference of the line?  (not kit supplied rope, the contemporary size that it should be?)   If you do not have this, but have the size of the vessel (for English ships) and the year it was built you can calculate the size of every mast, spar and rope.  Once you get the size of of the rope itself you can then calculate the size of the heart.   Sorry it is not very straightforward, but if you want accuracy this is possibly the best way to do so.   If you have the size and year of the vessel, (and it is English) you can you use the spread sheet calculations developed by Dan Vadas here at MSW.  It is very accurate except for a period between 1670 and 1711 for which it is incorrect from the first calculation thus through all calculations that follow for that time period.  These are based on James Lees ratios (again, except for the 1670-1711 period)  

 

Allan

[Tim Holt]

8 minutes ago, allanyed said:

Once you get the size of of the rope itself you can then calculate the size of the heart.

 

I'm not sure if you mean "calculate the size" based on a table, or if there is a formula for that calculation. 

 

I have looked at a few tables (back of Biddlecombe , The Art of Rigging for example) that reference hearts at times for some things, but then some references (Chapelle's Search For Speed) I recall occasionally say "heart or deadeye" for some rigging.

 

Let's say a table says deadeye and gives a diameter, and I wanted to use a heart instead.  What size would I use?  Perhaps that's the case I'm looking for. 

 

So far the only thing I've thought of is to take the lanyard rope diameter, multiply by 5 (seems typical number side by side in heart), and use that as my internal wide dimension.  Then use the "typical" heart shape and work out the size from that.

 

Additionally, when tables do reference hearts, they only give a single dimension.  Which relates to my secondary question:  what does this dimension mean?

[allanyed]

Tim,

I know it sounds complex, and in fact it is for most of us.    (Caveat, if you are talking about the whaler Swift  that the Royal Navy purchased in 1804, some things may not apply) 

The size of a heart, as are all masts, spars, ropes and blocks, is related to the size of the ship and year.   If you take the Vadas spread sheet and enter the extreme beam and length of the lower deck in the appropriate year segments in the  spreadsheet, you will get the size of the masts, spars and ropes.  From the size of the rope you can then calculate the length of the heart, which, according to James Lees, is 1.45 times the circumference of the stay for which it is intended.  Each stay and collar is a different circumference so each heart is different in size as well.    He makes no mention of the number of turns inside the heart, but David Steel states there is to be room for four or more turns for the lanyard in The Elements of Rigging (1794) on page 158 which can be found on-line for free.  He gives not other dimensional information that I could find.  

 

As to whether a heart or deadeye is to be used, it depends on what stay or collar and sometimes which year.    

 

Note that Biddlecombe is 1848 so probably not applicable to Swift and while I love Chapelle's work, it is not very detailed for this kind of thing.  

If you want to try the Vadas spread sheet go to https://thenrg.org/resource/articles and scroll down to his spreadsheet in the rigging section of these many fine articles.  You will have to have the extreme beam and lower deck length for this or the formulas in Lees' book.

Allan

[Tim Holt]

Thanks Allan!  Good info. 

Edited July 12, 2021 by Tim Holt

[Tim Holt]

  

On 7/9/2021 at 6:03 PM, allanyed said:

From the size of the rope you can then calculate the length of the heart, which, according to James Lees, is 1.45 times the circumference of the stay for which it is intended. 

 

So to be clear, this dimension is the same one that I see listed in tables and the spreadsheet, plus the dimension that vendors of pre-made hearts use, correct?

Edited July 12, 2021 by Tim Holt

[allanyed]

Hi Tim,

Forgive me but I  am not sure I understand your question.   If you have the circumference of the stay or collar (from Lees or Vadas or contemporary sources tables) you can size the heart.  Once you figure the size, check that against the hearts you find to see if they are the right size. 

 

Example  HMS Bristol, a 4th rate ship launched in 1775    

Length of the ship on the gun deck: 148 feet

Breadth:  40 feet 7 inches  

For 1775, only the breadth was used in the initial calculation for the length of the masts. 

Length of the main mast - 2.23 X 40.583 =90' 6"

Diameter of the main mast - 0.9" per three feet of length  --  0.9X30.2 = 27.18"

Lower stay circumference- 0.5 X 27.18= 13.59"   (diameter  4.32")

The heart would be 1.45X 13.59= 19.7" long (and about the same width at the widest point.)

1:48 scale    19.7"/48= 0.41 inches long

If your ship had preventer stays, a quick calculation is that they would be 0.7 X the size of the stays so the hearts would be proportionately smaller as well.  Based on the scale of your model and having figured out the proper stays' circumferences at scale size, you will be able to check if the hearts that you are looking at are the right size for any give stay.  I doubt that kit or after sales suppliers are able to offer enough sizes to help everyone what with various years, rates, scales, &c. but they may be close.   If they do not have the various sizes that you need, you might consider making your own. 

I hope someone checks these numbers in case I missed something  🤪    

I hope this was of some help to you

Allan

[Tim Holt]

Sorry to be so ignorant.  I see them for sale with dimensions like "12mm heart".  I'm trying to figure out if that is 12mm long, 12mm across, 12mm on the inside, or what.  From your post I assume that 12mm is the equivalent of the 0.41 inches long you mention in your example.

 

I guess the question I had was extremely basic, but for someone not used to dimensions it’s not basic. I've already ordered the wrong sized blocks once out of ignorance of what the single dimension meant for blocks - and I'm trying to not do that again with hearts.

Edited July 16, 2021 by Tim Holt

[Mark P]

Good Evening Tim;

 

If you are not sure what size something is which you intend to buy, the best course to follow would seem to be to ask the seller for clarification. Members of this forum can advise you on the various sizes of what the heart should be, but only the seller can tell you if this is the width or length. I would expect it to be the largest dimension, which would make the heart 12mm long. Its width would then be around 9-10mm (for closed hearts)

 

All the best,

 

Mark P

[allanyed]

Tim,

No apologies necessary, we are all short of knowledge in this hobby of ours, just depends on the specific subject that we are encountering.   I just did some more searching and found the following information that might be of more help.      From Lees'   .................  

As before, the heart is 1.45 X the circumference of the stay.  The diameter (width?) is .075 X the length at the widest point and the thickness is twice the DIAMETER of the stay.  The inside opening where the lanyard lies is 0.33 the widest dimension of the width and the smallest part of the opening was 0.25 the widest dimension of the width.  I cannot find anything regarding the circumference of the lanyard, but assuming five passes, it would be the widest portion of the inside opening divided by five.   Unfortunately there does not seem to be anything straight forward so most of us are without total knowledge (I hate to say ignorant 😄)   As Mark suggests, once you have the sizes you need, confirm with the supplier the dimensions, at least the length and width outside.    

Allan