Period Scale Model Masting and Rigging Tables

[DaveBaxt]

Hoping this is the correct place to post this question

I tried to use this excel spread sheet a few years ago but unfortunately I was unable to get this to work on my chrome book at all. In the hope that things had moved on a bit, I decided to give this another go. When opening up the spreadsheet, unlike before everything looked to be in its correct place. After adding the scale 1:64 in the appropriate box I moved onto  the dimension input boxes required, Trying both imperial and metric tabs for the inputs. On both occations the data for the main masts look to be way out. 

        Being the proud owner of lees book' the Masting and Rigging of English ships of war' I was able to carry out the same calculations as the spread sheet and compare the Main mast using Lees formulae of the length of the lower deck plus the extreme breadth divided by two. This is given for calculating the main mast for 1794 . I also own the book AOTS Diana a 38 gun Frigate but unsure if this is a Class 4 or 5 ship.but tried both boxes isn the spread sheet . The measurements  for the ship are given in ft and are as built are follows. length of lower deck 146 .25ft and Breadth extreme 39.29ft . My calculations work the main mast length to be 92.77ft. and the the diameter 1" for every 3 ft = 30.9 " . At a scale of 1:64 =0.4828" metric this equals 12.24mm. The Caldercraft kit has supplied 10mm dowel but do not intend to use this but have some 13mm square boxwood stock to make the lower masts .When adding the appropriate dimensions into the spread sheets I am getting ridiculous numbers for both the actual and model size masts. Where am I going wrong, Is it my calculations or is the excel spreadsheet still not compatable with my chrome book. Sorry for asking such an awkward question, but if I can resolve this issue it would save me a lot of time and I would therefore be very grateful for any input.Best regards Dave

    

      

 

[GGibson]

Hi Dave.  Did you intend on sharing/attaching the Excel spreadsheet for people to check calculations? Don't see anything attached.

[AON]

What you explained seems correct. If we could see the "ridiculous numbers" and how they come up it might help.

You also have to calculate the mast dimensions for the quarter lengths as it tapers some above and below a specific point in its length.

Edited March 24 by AON

[DaveBaxt]

Thak you guys for your help and quick response. I would give you a link if I could . I am trying to copy and paste the file  but isn,t happening for me. Neither is using the choose files option either. As you can tell I am no tech wizzard. For the record according to the AOTS Diana the main mast should have a diameter of 27.75 " the model main mast  should therfore be 27.75 x 25.4 divided by 64 =  11.01mm on the model and I am assuming this will be the largest diameter. When inputting a 4th rate vessel in 1794 with a beam of 39.29ft and the length of 146.25ft the  model mast diameter in metric is coming up as 2.6mm.? I am only trying to then work out the diameter of the stays and other rigging so I can order up what I need for the rigging etc.I had this problem last time and gave up in the end and just worked it out using Lees book as reference, but its a lot of hard work. 

Length chart.xlsx

Edited March 24 by DaveBaxt

[AON]

This sheet has cannon barrel lengths. Nothing to do with masts.

 

Try this spread sheet (attached) by Danny Vadas

 

It will take a moment to open so be patient.

 

At the upper left side of your screen may be a Security Warning saying some content has been disabled.

 

Pick Options, pick Enable the content, then pick OK.

enter your build scale  in the box at the bottom and then pick Enter Data at the top.

scroll down to the year (1794)  and across from 5th rate 40 guns enter your Beam (39.29) and Length (146.25) info.

At the top pick View Results

Now pick Masts and Tops- view results in Inches

 

Main mast 92.770 feet long and 2.354 feet diameter or 17.39" long and 0.44" diameter at 1:64 scale

 

MastingandRiggingSpreadsheet.xlsm

Edited March 24 by AON

[DaveBaxt]

8 hours ago, AON said:

This sheet has cannon barrel lengths. Nothing to do with masts.

 

Try this spread sheet (attached) by Danny Vadas

 

It will take a moment to open so be patient.

 

At the upper left side of your screen may be a Security Warning saying some content has been disabled.

 

Pick Options, pick Enable the content, then pick OK.

enter your build scale  in the box at the bottom and then pick Enter Data at the top.

scroll down to the year (1794)  and across from 5th rate 40 guns enter your Beam (39.29) and Length (146.25) info.

At the top pick View Results

Now pick Masts and Tops- view results in Inches

 

Main mast 92.770 feet long and 2.354 feet diameter or 17.39" long and 0.44" diameter at 1:64 scale

 

MastingandRiggingSpreadsheet.xlsm 1.4 MB · 1 download

Thank you for your valued imput and for the great spreadsheet by Danny Vadas, which at first had apeared to work fine. There was no warning message but I did have to transfer it over to google speadsheet called sheets. Anyway all seemedto be  fine and the data for the mast came up ok  but I was unable to use the buttons on the front of the sheet and had to use the tabs along the bottom. All great and the main mast diameter calc came up 11.2mm . So all good. I then went to the standing rigging using the tab along the bottom marked standing. Again all calcs came up for the Bowsprit and I assumed these would be correct, why wouldn,t they be as the mast dimenstions were fine.I have tried the button on the front marked 'Next Yard'  and nothing happens as non of the buttons on the front apear to work. I am ony able to navgate the spreadsheet using the tabs along the bottom, even when I click on the tab list (the arrow at the side of the tab)I can,t see anything to move me to another mast or yard.It is the same with the running tigging tab too. 

        Once again I think there are issues running this type of spreadsheets on google sheets  and I might need to use a Windows  excel spereadsheet to work. I hope I am wrong, as my eyes lit up when I saw the mast sizes for the model in metric are correct. I apologise for giving you the incorrect file .I have now attached the correct file but unsre if you can see it.I do like That Danny Vadas spread sheet as it looks a very profession job. I am prepaired to use  the Microsoft excel spreadsheet if it will run on a Chromebook  and I am prepared to pay a fee if this is the  only way forward. 

                 I appreciate your help and for your time and patience but I could be wrong ( hopefully I am not) but I am beginning to think there are compatibility issues at play.

Period Ship Scale Tables (1).xlsx

[Bob Fraser]

4 hours ago, DaveBaxt said:

but I was unable to use the buttons on the front of the sheet

Hi Dave.

This is because Dannys sheet uses active-x controls to do some of the calculations.  Google sheets doesn't alow the use of active-x.

I don't think it will run on a Chromebook, Office 365 on line also doesn't use active-x controls.

You'll need you use Excel on a PC to open the spreadsheet to get it to work as it should. 

I just ran a quick check (Dannys) and measured the results against an NMM print I have which came out exact to the drawing.

 

[allanyed]

While the program saves a ton of time and is a great tool for the most part, keep in mind the Danny Vadas program is based on James Lees ratios EXCEPT for the period 1670-1710.  It is completely wrong for this time period and really should not be used.  The math that Lees uses for his period is extremely accurate but would have been difficult, maybe impossible, for Danny to duplicate in his program.

Allan

[DaveBaxt]

Thank you Bob and Allan for your valued replies Bob, I was beginning to think that would be the case but it at lease I got the mast sizes from the program which seem to ceheck out ok. Looks like I will have to dig out an old windows lap top and see if I can get it going. It worked fine as long as it was still plugged into the mains electrical supply. Unfortunatetly it is quite old and probably wont run any programs these days but who knows.

Allan thank you for letting me know the data is incorrect for between the dates you have mentioned. For the record I have a copy of James Lees book so will be able to work out the mast and rigging sizes from Lees instruction and least I will know I am correct for the date of the Diana was built.1794. Best regards Dave 

[AON]

Dave

I had a quick look at your sheet.

If I look at the data for the main mast in cell C13 that reads 48.94 feet the formula for that cell is =AG136

Cell AG136 is hidden.

If I scroll to where it should be (down to line 136 and across to row AG and unhide it I see all the calculation cells.

Cell AF103 hasn't populated the length of the deck properly.

It populated the beam so the formula should be (Beam + Deck Length)/2= main mast length but the cell is telling it to add (Beam + Beam)/2

[Bob Fraser]

Hi Allan, Dave.

Allan - I'd seen that comment about the dates before, but couldn't remember it fully. Thanks for the reminder.

As you say, a fantastic resource.

I'm no expert or have extensive experience in these calculations, and my use has only been with this one ship.

The ship I based my comment on was a RN sloop built 1756/57 and would most likely have been built to the 1745 Establishment, quick mast drawing measurements taken with a brass caliper.

I would imagine that you are aware of all the different calculations over the 18th Century 🤣  I wasn't at all except for the 1745 Establishment, and was surprised by the variations 🤯

 

I was hospitalised last year for 10 days with covid and while I was there I did a little research on the sloop to give some working mast dimensions. but only from 1711 to 1794, and came up with the following table of authors.

Purely for my own benefit!

--------------------------

Dimensions for Bonetta 1756 as designed -

Deck 85’10”, Breadth 24’ 4”, Depth in Hold 10’ 10”, Keel 78’ (as per Ollivier)¹, 220 ^40/94 tons (profile plan ZAZ4368 RMG)

Dimensions for Bonetta as built -

Deck 86ft 4in, Breadth 24’ 6”, Depth in Hold 10’ 10”, calculated Keel 78’5”, 227^60/94 tons (Winfield, 2007)

 

RD is Range of Lower Gun Deck or upper deck on a single deck, EB is Extreme Breadth, DIH is Depth in Hold, K is Keel length, BMF is Beam Multiplication Factor.

 

Calculation Information			Main Mast Length (Ft In)		Beam Multiplication Factor
Date	Name	Formula	As Designed	As Built	As Designed	As Built	Reference
	Davis	EB*BMF			2.66	-------------	(Marquardt, 1986)
1711	Establishment	(RD + EB) / 2					(Lees, 1979)
1719	Establishment	No Change to 1711	-------------	-------------	-------------	-------------	(Lees, 1979)
1723	Anderson	EB*BMF			2.25	-------------	(Marquardt, 1986)
1726	William Sutherland**	(((EB + DIH) * 3) / 5)*3					(Marquardt, 1986), (Sutherland, 1726)
1735	James Love	((K + EB) * 2) / 3					(Marquardt, 1986), (Love, 1705)
1737	Blaise Ollivier	EB*BMF			2.33	-------------	(Ollivier, 1737)
1745	Establishment	EB*BMF	55.479  55'7 3/4"		2.28	-------------	(Lees, 1979)
1752	Duhamel Monceau 1	EB*BMF			2.5	-------------	(Marquardt, 1986), (Monceau, 1752)
1752	Duhamel Monceau 2	(EB*2) + DIH					(Marquardt, 1986), (Monceau, 1752)
1756	William Mountaine	(K + EB) / 2					(Marquardt, 1986),(Mountaine, 1767)
1768	Chapman	EB*BMF			2.43	------------	(Marquardt, 1986)
1794	Steel	(RD + EB) / 2	55.083 55'1"			-------------	(Steel, 1794)

** EB+DIH in feet, multiply by 2 and then divide by 5 = length in yards. Multiply by 3 = feet and part.

------------------------

Hoping my calculations above are right, Dannys spreadsheet first entry for a sloop is 1794, and his calculations came out as 55' 7" to 3 decimal places, 55' 6" to 2 decimals for the inches part as input.

Looks like the 1745 Establishment is used up to at least that date in the spreadsheet, as per Lees. Steels dimensions come out smaller.

 

I have the Lees and Marquardt books, Love, Monceau, Mountaine, Sutherland are available as Google books.

 

Dave - I think even an XP based laptop with Excel on it will run the spreadsheet.

BTW, a distant cousin of mine captained Diana in 1799!

 

 

[DaveBaxt]

Having looked more closely at the results of the masting sizes on Danny's masting sheet and looking at the diameter of both the main mast and the fore mast as the same 11.2mm on the model. I believe this to be incorrect but I could be wrong. I have taken my calculations from Lees book'The masting and rigging of English ships of War ' and as the lower fore mast is shorter than the main mast by 0.9 x the main mast = the fore mast then I assumed that as the diameter of the mast is calculated for 1" for every 3 ft of masting , then if the fore mast is shorter than the main mast then the diameter must be smaller. There is some ambiguity concerning Lees wording on this which perhaps I may have got wrong . In the Proportionate Diameters of the Mast section in Lees book FORE equates to 'The same proportions as given for the Main' My take on this would be for the same proportions as to the length of the fore mast and not main mast. I Hope I am making sense and wonder if it is possible to change the formulae in the spread sheet without too much trouble but beginning to think Allan is correct and we are just better off just working all this out for ourselves. There is however the possibility that it might be another incompatibility issue. However it is my hope to borrow a windows office 123 lap top installed  and try this out for my own curiosity.Thanks again for all your help and patience. Best regards Dave 

[Bob Fraser]

Hi Dave.

This is the DV spreadsheet on Windows view of the masting sizes for Diana as per the contract - available at the nmm here Artois Contract

Using Extreme Breadth as 39' and length of lower deck as 146'

 

Steel gives the same main mast length as the spreadsheet, 1745 Establishment as 88.92'

There were amendments to the 1745 Establishment for larger ships in the intervening times.

Using Lees the 1/64 diameter comes to 10.80mm

Does the same for my little sloop, too!

You'd need to do the math for the other given sizes of the fore to work out if there are any other differences.

The spreadsheet is protected from editing, and I'm not a genius with spreadsheets.

 

[DaveBaxt]

My working out is different than the spread sheet. for a main mast length of 92.5 ft . According to Steel the diameter is 9/10 th an inch for every 3 ft  for 1794 gives me 30.8x9/10=27.75" change to metric x 25.4 and divide by 64 =11.01mm        

Fore mast is 0.9 the length of the main mast after 1773= 83.25 ft /3ft = 27.25 x 9/10 = 24.975" x 25.4 then divide by 64  = 9.91mm. 

According to the book AOTS Diana they also have the main mast at 11.01mm but the fore mast diameter at 9.77mm . So another discrepancy. Any idea where I am going wrong???

[AON]

Dave

You are going to chase your tail on this one.

These are rules of thumb they worked to in that age... but they weren't chiselled in stone if you get my drift.

Also, getting it dead nuts on seems really important right now, it took me about two years to get comfortable with working to a reduced scale and the "close enough" concept.

The difference between the two calculations at 1:64 scale is indistinguishable to look at and absolutely no one is going to take a vernier to you model but you.

If you can actually make your mast exactly to scale your better than me.

 

It is akin to a ship build contract stating what length and breadth the vessel was to be built to... and when done they wrote in the actual dimensions on the drawing.

 

Edited March 28 by AON

[allanyed]

7 hours ago, DaveBaxt said:

The same proportions as given for the Main' My take on this would be for the same proportions as to the length of the fore mast and not main mast

That is my take as well.  Proportions of the foremast are the same proportions as the main mast.  For example if the diameter of the main mast is one inch for every three feet of length of the main mast the diameter of the foremast is one  inch for every three feet of length of the foremast.

 

FWIW regarding accuracy the human eye can only perceive a dimension difference of about 0.1mm if the objects are within the same field of view.   

 

Allan

[DaveBaxt]

Phew I am glad I got that one sorted. So for my masting and spars I think I am pretty well sorted then. However apart from the breeching rope and the gun tackle I think I will leave the rest of the rigging for another day. But  a huge thanks for walking me through this. Best regards Dave

[DaveBaxt]

May I be so bold as to ask one more question regarding mast dimensions if I may. I see from the AOTS Diana was launched on march the 3 1794. I also notice that 1794 is a fairly important year for the subsequent change in mast dimensions and how to work them out. I f there is a change of dimensions in this year I am assuming if the ship is launched without masts and perhaps not made yet. In this case would we take the formula given for before 1794 or for after that year and after. Once again I am not sure if this would be much different other than a slight difference in the diameters. So really just a matter of interest and  perhaps the diameters increased due to the increase in the amount of sail carried as time progressed. Just a thought so could be wrong. Best regards Dave

[AON]

I honestly do not know. How quickly did people receive the information and actually implement it?

[Bob Fraser]

Dave asked earlier if the spreadsheet could be re-written to account for the foremast discrepancy.

I've managed to get the spreadsheet so it's unprotected, made it so you can see the rows/columns and sheet tabs.  Also frozen some headers so they don't get lost.

The calculations can now be seen and followed, but they seem to go round in circles to me (probably just me not seeing it right).

Would an Excel wizz like to have a go?

Masting and Rigging - Danny Vadas - open.xlsm

 

Forgot to mention you'll likely get some warnings about active code. These will need to be allowed to run it properly.

Edited March 29 by Bob Fraser

[DaveBaxt]

17 hours ago, Bob Fraser said:

Dave asked earlier if the spreadsheet could be re-written to account for the foremast discrepancy.

I've managed to get the spreadsheet so it's unprotected, made it so you can see the rows/columns and sheet tabs.  Also frozen some headers so they don't get lost.

The calculations can now be seen and followed, but they seem to go round in circles to me (probably just me not seeing it right).

Would an Excel wizz like to have a go?

Masting and Rigging - Danny Vadas - open.xlsm 1.38 MB · 5 downloads

 

Forgot to mention you'll likely get some warnings about active code. These will need to be allowed to run it properly.

Bob thank you for finding that spread sheet. Now that I have borrowed a PC with windows 11 and excel on I can have a proper look at it. I have  managed to down load Danny's spreadsheet and the one I downloaded origonally onto a  Chromebook , I was able access the calculations page but as it is many years since I did any spreadsheet work and only fairly small ones, I got lost off a bit and could not make any sense and some of the commands were lost on  me, such as the 'If.............. ' command.. It made me a bit dizzy if I am honest.

I will take another look at your link, but I think jumping into a spread sheet of someone else work and this large is probabaly beyond my apprehension. I must thank you again Bob for sticking with me on this one. Your patience holds no bound. 

Edited March 30 by DaveBaxt

[allanyed]

19 hours ago, Bob Fraser said:

to account for the foremast discrepancy.

  In Danny's quest to make the Lees ratios available to everyone for free and easy to use it appears he may have some ratios wrong.  In addition to the 1670-1710 period which is not useable, he may have misinterpreted the ratios in other time periods for the foremast diameters, therefore his diameters for the foremast are wrong so it may be best not to use his system for the foremasts diameters.  Lees states that the diameter of the foremast is the same proportion as the main mast.   I believe this means proportion to the foremast length, not the main mast length.  If not, why not just writer the diameter of the foremast is the same as the main mast, which it was not.  For example, for the Artois class, 1794.

 

                     Main Mast   Length   Diameter

Lees                                   92.645'     27.79"

Vadas                                 92.645'    28.236" 

          

                       Foremast   Length   Diameter

 Lees                                  83.38'     25"

 Vadas                                83.38'     28.236"       

 

For possible confirmation that the foremasts were smaller in both length and diameter, at least for the approximate period in question, I looked at some contemporary plans of masts.  The foremasts are smaller in diameter than the main masts.  An  example are plans J7801 and J 7796 at RMG and on the Wiki Commons site in high resolution. for a 74 gun ship .  The main mast maximum diameter is 37" and length is 111.6'   The foremast maximum  diameter is 32" and has a length of 95' 8"   

 

From David Steel's The Elements and Practice of Rigging 1794

The diameters in proportion to the length, in the royal navy, are as follow: viz.

The main and foremasts of ships of 100 to 64 guns inclusive, are one inch in diameter at the partners to every yard in length. Ships of 50 to 32 guns inclusive, 9/10 of an inch to every yard in length. And ships of 28 guns and under, 7/8 a of an inch to every yard in the length.  

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

 

Allan

 

 

 

 

Edited March 30 by allanyed

[DaveBaxt]

On 3/29/2024 at 4:29 PM, Bob Fraser said:

21 hours ago, allanyed said:

  In Danny's quest to make the Lees ratios available to everyone for free and easy to use it appears he may have some ratios wrong.  In addition to the 1670-1710 period which is not useable, he may have misinterpreted the ratios in other time periods for the foremast diameters, therefore his diameters for the foremast are wrong so it may be best not to use his system for the foremasts diameters.  Lees states that the diameter of the foremast is the same proportion as the main mast.   I believe this means proportion to the foremast length, not the main mast length.  If not, why not just writer the diameter of the foremast is the same as the main mast, which it was not.  For example, for the Artois class, 1794.

 

                     Main Mast   Length   Diameter

Lees                                   92.645'     27.79"

Vadas                                 92.645'    28.236" 

          

                       Foremast   Length   Diameter

 Lees                                  83.38'     25"

 Vadas                                83.38'     28.236"       

 

For possible confirmation that the foremasts were smaller in both length and diameter, at least for the approximate period in question, I looked at some contemporary plans of masts.  The foremasts are smaller in diameter than the main masts.  An  example are plans J7801 and J 7796 at RMG and on the Wiki Commons site in high resolution. for a 74 gun ship .  The main mast maximum diameter is 37" and length is 111.6'   The foremast maximum  diameter is 32" and has a length of 95' 8"   

 

From David Steel's The Elements and Practice of Rigging 1794

The diameters in proportion to the length, in the royal navy, are as follow: viz.

The main and foremasts of ships of 100 to 64 guns inclusive, are one inch in diameter at the partners to every yard in length. Ships of 50 to 32 guns inclusive, 9/10 of an inch to every yard in length. And ships of 28 guns and under, 7/8 a of an inch to every yard in the length.  

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

 

Allan

 

 

 

 

 

Thank you Allan for keeping me going with this and not giving up on me and also for your patience. I was told ages ago that Lees book,' The Masting and Rigging of English ships of war 1625 to 1860 ' is the holy grail for masts and rigging and when I first started doing this hobby not so long ago,I have always used his book. Thanks also for sshowing us  the difference in the mast calculations between Danny Vadas and Lees book, which are very similar to what I came up with. Yes it looks like I will use Lees book for calculating the Fore mast dimensions  together with the fore mast rigging. I think it should be ok to use the tables for the standing & running minus what is needed for the fore mast but  I will compare rhe two resorurces for the Masts & yards . If anything seems to be out of wack I can check again with Lees.Once again I big thank you to Allan and Bob and for that matter anyone else and not forgelling all the likes  I have recieved too. best ragrds Dave

[DaveBaxt]

 Incorrect content Sorry

Edited March 31 by DaveBaxt

[DaveBaxt]

Another Dept to you Alan in an attempt to educate me , so I thank you kindly for the Link to Steels Document The Elements and Practice of Rigging 1794. Best regards Dave

[Kris Avonts]

Hello,

I found this topic while searching for mast and rope dimensions and I also already downloaded the spreadsheet made by Danny Vadas from the Articles Database. It's a well appreciated effort by Bob Fraser to provide this spreadsheet in an open form so one can look at the calculations done under the cover.

That is why I’m reacting in this topic. I think that almost all masts diameter calculations are slightly under the value that results from the rules given in the book of James Lees.

Let me explain a bit more in detail what I think is the problem.

I entered a beam of 46.83 ft for a 3rd rate 74 gun ship in the 1769 section.

According to Lees rules for that period ‘main mast to length of beam is 2.27’ and from that length, its diameter is ‘15/16 inch per 3 feet in length’.

That gives me: 46.83 ft * 2.27 = 106.304 ft for head to heel length of the main mast and (15 / 16) * (106.304 / 3) = 33.22 in = 2.768 ft for its diameter.

The results from the Danny Vadas spreadsheet are shown in the next screenshot.

 

 

The mast length is spot on but the diameter is about 3 inch shorter.

Then I looked at the spreadsheet formula for the diameter: ‘=(Z89*($AR$2*(15/16)))’.

The Z89 is a cell with the calculated mast length value and $AR$2 refers to the cell AR2 that is preceded in the spreadsheet by the explanation ‘Inch to 3 Feet in Metres’ and has the value 0.0254.

I expected this to be (1 / 3) * (1 / 12) = 0.0278, the combined division by 3 for the mast length and by 12 to get the result in feet like it is displayed in the Masts and Tops page.

The strange thing is that cell AS2 has that constant 0.0278 but is not used.

 

The next image shows a graph where the value of cell AR2 is used.

 

 

So that is about everywhere.

And this one is for the use of AS2.

 

 

No graph could be shown because there are no formulas using that value (in Dutch in the image).

 

To me it is now clear that we can only get the correct diameters (and all other proportions derived from the diameters) when we switch AR2 and AS2.

 

That is what I have done in this excel sheet.

 

Masting and Rigging-DV-open-corrected-KA.xlsm

 

Because the error made in the original spreadsheet is less than 10%, I think it was overlooked.

In any case, the Danny Vadas effort is a massive help to every modelship-builder.

 

The Masts and Tops result page now looks like this.

 

 

I hope this helps for all who are looking for masting and rigging dimensions.

Best regards,

   Kris

[Kris Avonts]

Just an addition: do not use the above provided excel, it has no correction for the fore mast diameters. I will provide an update of the excel file soon.

 

best regards,

   Kris

[Kris Avonts]

As promised this morning, I can now provide you with an updated version of the Danny Vadas spreadsheet.

Masting and Rigging-DV-open-corrected-KA.xlsm

This version should produce correct diameters for all masts.

Next I will also do a check on the 1670 - 1710 period that was warned about by Greg.

Hopefully I can find some issue there and make a correction.

It would be of great help if anyone could provide me with real data (beam, length of keel and depth of ship) of a ship from that period.

 

best regards,

   Kris

[Kris Avonts]

Hello,

 

Because the Danny Vadas spreadsheet is so helpful, it deserves to be fixed for the period 1670 to 1710 that was mentioned by Allan (not Greg of course, as I wrote in a previous reply).

 

Going over the formulas for that period I encountered the constant 8.2296 that was used in a comparison with a value expressed in feet. Now 8.2296 is 27 feet in metres and that is strange because mixing feet and metres can never give you a correct result. The subsequent addition or subtraction to the mast length in feet also used the constant in metres.

That can explain why the results are judged way-off by the experts here on this forum.

 

So, lets fix that and check if the results are more in line with expected dimensions. To do that I need some data the enter in the spreadsheet. A Wikipedia search delivered me the following data for 3 ships in that period to cover all cases that need to be handled in the spreadsheet (beam > 27 ft, < 27 ft and = 27 ft).

 

These are the selected ships:

 

 

The Royal James will be used to check the case ‘beam > 27 ft’, the Greyhound for case ‘beam < 27 ft’ and for Sapphire I will cheat and set the Beam to 27 feet to check the last case.

 

These are the results from the original uncorrected spreadsheet:

 

 

And these are the results from the corrected spreadsheet (except sprit topmast diameter, see later):

 

 

I have no data on the mast dimensions of the 3 ships I used as a test but if someone here on MSW can evaluate these figures, I like to hear your comments.

 

The original spreadsheet did produce the correct mast length if you set the ‘Metric Entry?’ input to ‘Yes’, and you entered all values in metres. The mast diameters are however always a little under the correct value, as I did explain earlier in this thread (see #26).

 

Another issue I see for ships of the time period 1627 to 1719, is the diameter of the sprit topmast. According Lees, it should be in relation to the sprit topmast length but the formula in the original spreadsheet references the AU column which has the fore topmast diameter. So that was also corrected.

 

Here is the corrected spreadsheet:

 

Masting and Rigging-DV-open-corrected-KA.xlsm

 

I did not take a look at the tops, yards, stays and all the other ropes, so be careful and check if you can.

 

Best regards,

Kris

[tlevine]

The updated version has been added to the Resources section.