Mast Lengths and their above deck heights for HMB Endeavour

[trippwj]

Not the mast step but rather the support structure beneath were it stepped to the deck not the keelson. That's alot of weight added to an unstrengthened base. You would expect to see added structure beneath the deck to mitigate collapse.

[dashi]

Not the mast step but rather the support structure beneath were it stepped to the deck not the keelson.  That's alot of weight added to an unstrengthened base.  You would expect to see added structure beneath the deck to mitigate collapse.

Thanks Wayne. Yes I agree that if the mizzen were stepped in the lower deck as opposed to the being keel sepped then you would need a heavy vertical stanchion and other timberwork to support it with out a doubt as you and Druxy have pointed out.

 

I will try to expand my previous answer based on all my experience using technical drawings and draughts from the building industry and in heavy industrial construction and maintenance, plus model ship kits in recent years. In all that time  I have never come across all the technical details necessary for building the project to be drawing on one draught. And unless I'm mistaken I can't see any vertical stanchions drawn in below decks on any of the surviving draughts. Therefore I take this to mean that we don't yet have the draught showing this detail if it did exist.

 

Steve provided a detailed analysis of those dashes or asterisk's marking the masts below deck in his post #28 and found that the mizzen dosn't have these marks in the surving original draught of 1768 which is marked 'as fitted'.

 

The silk draught which is also marked as fitted in 1768 has been proven to be a later compilation because not only does it have the 1771 woolwich measurements on it meaning it's title is misleading and is only reffering to the sheer draught which is not a copy of the original 1768 'as fitted' draught. But I've read that draught silk wasn't used until later (I can't recall the source sorry).

 

Along with this evidence and based on the draughts you provided is the Woolwich Yard measurements indicating a shorter mizzen length which has the diameter for a longer mizzen as druxey has worked out. Along with this evidence is the angle of the mizzen chainplates which supports a taller (not longer) mizzen as Steve has confirmed with his drawing.

 

In a previous post I have already provided a link to the Cruiser plans of 1752 which clearly shows a mizzen stepped in the lowerdeck along with it's supporting timbers which exists at Greenwich museum.

 

So unless I'm mistaken all the evidence that we have to date can only tell us that there exists the possibility of the mizzen to be either stepped into the lower deck or the keelson.

 

I hope I've provided a fair answer.

 

Cheers

[trippwj]

One of the challenges, or perhaps benefits, of the NMM is the abundance of draughts for some vessels.  Here, for your consideration, I offer the following:

 

Object ID     ZAZ6591
Description  Scale: 1:48.

 

Plan showing the after fall (platform) with the great cabin for Endeavour (1768), a purchased collier, prior to final fitting as a ship-rigged Bark for exploration.

 

Date made  April 1768

 

Note the absence of deck beams below the mast - the red lines indicate the additions made to the vessel in the area to support this added level.  The beams are evident.  If the mast were to step here; it is quite likely that at least one beam would be very close to the step.  The absence (and the circle representation) are indicative of the mast passing through the deck, not stepping upon it.

 

 

When we look at the mast heights above deck, all the contemporary representations of the vessel indicate the mizzen was significantly shorter than the main or fore masts.

 

Finally, I would not assume that William Gray [Master Shipwright, Woolwich Dockyard, 1767-1773] would sign off on the dimensions if he had not reviewed them and found them accurate.  If we are willing to accept the other drawings as accurate and indicative of the as-refitted condition, why would you doubt these values?  Remember, Steel was offering guidelines, not rules or requirements.  The captain of a ship still had a great deal of freedom in the masting and rigging. 

 

Running the numbers based on the Woolwich values, I find the following:

 

Fore Mast - closest match is Merchant vessel of 400 tons

Lower Mast Length 65 feet 4 inches with height above deck of 47 feet 4 inches

Steel's Tables for a

Naval sloop of 300 tons - 56 feet 0 inches

Naval 20 gun of 429 tons 64 feet 0 inches

Merchant of 350-360 tons - 63 feet 0 inches

Merchant of 400 tons 65 feet 0 inches

 

Main Mast closest match is a Merchant vessel of 400 tons

Lower Mast length 69 feet 4 inches with height above deck of 48 feet 10 inches

Steel's Tables for a

Naval sloop of 300 tons - 63 feet 0 inches

Naval 20 gun of 429 tons 72 feet 0 inches

Merchant of 350-360 tons - 65 feet 0 inches

Merchant of 400 tons 70 feet 0 inches

 

Mizzen Mast closest match is a Naval sloop of 300 tons, though a poor match.

Lower mast length 50 feet 5 inches with height above deck (stepped to keelson) of 28 feet 5 inches of 20 feet shorter than the Main mast above deck.

Steel's Tables for a

Naval sloop of 300 tons - 48 feet 0 inches

Naval 20 gun of 429 tons 61 feet 0 inches

Merchant of 350-360 tons - 58 feet 0 inches

Merchant of 400 tons 62 feet 0 inches

 

The wide disparity in these between the tables from Steel and the reported for Endeavour are quite eye opening.

 

 

[dashi]

Thanks Wayne. Thats an interesting draught from NMM id ZAZ6591 you put up of what looks to be the orlop deck and while I can see the hole for the main mast forward of the quaterdeck hatch passing through it I can't see the hole for the mizzen? Your arguement seems to be at odds with this draught, are you saying that the mizzen is stepped in this deck because there isn't a hole for it?

 

As to the deck beams as far as I am aware it was the quarter deck that was significantly altered and not the lower deck but I could be wrong so I'm not clear on what you are trying to say here regarding the quaterdeck beams and I am aware of the broken red lines on the proposed refit of 1768. As far as deck beams are concerned they are placed where they need to be and not necessarily placed hard up against a mast if you look at the hole for the main mast in the draught you have provided.

 

You make a good point about the accuracy of the Woolwich yard measurements which I wan't to agree with and am trying to prove here because one of the arguments around the mizzen is that Woolwich made a mistake with the slip of a pen which like you say I also find hard to believe.

 

Parkinson's drawings clearly show the Endeavour with the taller standing mizzen and these were drawn first hand. It is his drawings and the woolwich yard measurements that suggest to me the mizzen was stepped in the lower deck and not the keelson. Here is a link to Parkinsons drawing.

https://www.google.co.nz/search?q=parkinson+endeavour&client=tablet-android-samsung&prmd=inv&source=lnms&tbm=isch&sa=X&ved=0ahUKEwj9qMWV-_rMAhWGn5QKHfIGBVIQ_AUIBygB&biw=1280&bih=800#imgrc=hClazxzzPQr-HM%3A

 

As far as the foremast is concerned I have been rechecking everything and using the Woolwich measurements there is about a 2.5' drop in height from the main to the fore standing masts contrary to what I first thought which might be ok. But this is what I'm asking for help with to check these heights. With the mizzen stepped in the lower deck there is a drop in height of around 8' from the main standing mast to the mizzen standing mast and 5.5' from the fore standing mast to the mizzen standing mast. But if you were to step the 50' mizzen in the keel then this would change to an 18' drop from the main to the mizzen which dosn't agree with any of the figures in any of the charts that you have provided and nor does it agree with Parkinson's drawings.

Edited May 27, 2016 by dashicat

[dashi]

Here is a link to an engraving by William Byrne believed to be done from a lost drawing by Sydney Parkinson of Endeavour being repaired.

http://collections.rmg.co.uk/collections/objects/269382.html

 

If you look closely you will notice two interesting facts. First the angle of the shrouds are identical and second the ratio of differences in height of the standing masts. The mizzen standing mast does not appear to be anywhere near 18 feet shorter than the main standing mast and the fore standing mast height appears to be some where between the main and the mizzen. Comparing the shrouds, they all appear to be at the same angle which the mizzen standing mast shrouds couldn't be if it were 18 feet shorter than the main standing mast.

 

And here is another Parkinson sketch showing the shrouds all at the same angle.

https://www.google.co.nz/search?q=sydney+parkinson+endeavour&client=tablet-android-samsung&prmd=inmv&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjinfvcnvvMAhWEW5QKHQ2FA6sQ_AUIBygB&biw=1280&bih=800#imgrc=2Kjd5xBOBhUSFM%3A

Edited May 27, 2016 by dashicat

[trippwj]

ooops....got disoriented looking through the plans!  You are correct, that is the great cabin not the lower deck.  Disregard that one!  Boy, do I feel silly!

 

Can I offer ZAZ6594 as compensation???

 

 

EDIT:  Links I had added are provided in the post above.

Edited May 27, 2016 by trippwj

[trippwj]

One last item to consider:

 

The following excerpts are from Mountaine, William. 1761. The Seaman’s Vade-Mecum and Defensive War by Sea. http://books.google.com/books?id=a8IzAQAAMAAJ.

 

 

 

 

[dashi]

ooops....got disoriented looking through the plans!  You are correct, that is the great cabin not the lower deck.  Disregard that one!  Boy, do I feel silly!

 

Can I offer ZAZ6594 as compensation???

 

ZAZ6594.jpg

 

EDIT:  Links I had added are provided in the post above.

First I think before dismissing this out of hand we to need review draught zaz6591 of the cabin or orlop deck which you provided and which omits the hole for the mizzen standing mast as I think it raises some interesting questions that need answering. To do this and in the interests of clarity I will attempt to list some of the main points that have been raised in this discussion and possible relationships between them.

 

Point 1 : Draught zaz6691 raises the question that the mizzen was stepped in the orlop deck if Waynes 'no hole' argument is true. 

 

Point 2: Wayne you made the argument that you didn't think the shipwrights would have made mistakes. I'd like to agree with this but the evidence you have provided in draught zaz6691 might not support this argument.

 

Point 3: Draught zaz6594 of the 1771 deck plan provide by Wayne along with other deck draughts disagree with draught zaz6691 and show holes through all the decks for the mizzen.

 

Point 4: Point 3 supports the argument that the missing mizzen hole in draught zaz6691 is in fact very likely a draughting error. If there is no other supporting evidence for the theory of the deck holes or lack of them for determining mast steps on plans then this argument needs to be discounted. 

 

Point 5: Point 4 negates points 1 and 2. 

 

Point 6: The last painting Wayne provided has no reference date or who it is by or what ship it is and so can't be verified as evidence for this discussion.

 

Point 7: Parkinsons sketchs clearly show a taller mizzen inline with contemporary ship building measurements wayne has provided and the shrouds all appear very close at the same angle from their respective channels.

 

Point 8: Steves AL model because of the lower mizzen and the replica Endeavour also because of the lower mizzen have the mizzen shrouds at a lower angle compared to the fore and main shrouds.

 

Point 9: Point 7 negates point 8.

 

Point 10:Wayne in your last post your provided evidence with a link in which it clearly gives two formula for working out the length of the mizzen. If the mizzen is to be stepped on deck then it is to be 2/3 the length of the main mast and if it is to be stepped in the hold then 3/4 the length of the main mast.

 

Point 11: The formula in point 10 is further supporting evidence for the practice of both deck stepped mizzens from at least 1761. Which deck they are referring to it doesn't say. It is proof that other formula were used which isn't in dispute. Working backward none of these formulas appear to support the Woolwich Yard measurements with the exception of a formula  in Steel's compilation which is not listed here and came 30 years later. 

 

Point 12: Druxey worked out the mizzen height from it's diameter which came to 60' which matches one of steel's formula. Referencing points10 and 11 suggests that this is the length if it were stepped in the hold and makes it 10' taller than the Woolwich Yard measurement of 50',5" which it would be if stepped in the lower deck. It would need to keep the diameter proportional to the longer mast of 60' because the stresses from the quarterdeck partners would still be the same regardless of whether hold or lower deck stepped.

 

In conclusion: I feel like we have exhausted all the evidence there is. After careful consideration the theory of a deck stepped mizzen is supported and does explain the Woolwich yard measurements using a formula from Steel's compilation of 30 years later as I originally posited. This is not conclusive but it is valid. Secondly the question of the foremast length: After further research I think the Woolwich yard measurements are ok here, but that it is still possible that there has been an error.

 

As far as I'm concerned this discussion has answered my questions, I really appreciate the efforts of everyone who took the time to provide valid evidence and their respective points of view. Nothing is conclusive and we are each entitled to our own conclusions and points of view so with that in mind I'd like to thank everyone as I have learned a lot that I can now use on my build of the HMB Endeavour. 

Edited May 28, 2016 by dashicat

[druxey]

You wrote: 

 

It would need to keep the diameter proportional to the longer mast of 60' because the stresses from the quarterdeck partners would still be the same regardless of whether hold or lower deck stepped.

 

​Stresses would surely be greater if the mast were stepped on the lower deck, as the leverage exerted on it would be greater? (Proportional length of mast above and below the partners, the latter being the fulcrum.)

[dashi]

You wrote:

 

It would need to keep the diameter proportional to the longer mast of 60' because the stresses from the quarterdeck partners would still be the same regardless of whether hold or lower deck stepped.

 

​Stresses would surely be greater if the mast were stepped on the lower deck, as the leverage exerted on it would be greater? (Proportional length of mast above and below the partners, the latter being the fulcrum.)

I did consider that Druxey but figured in my head that if the formula to work out the diameter of the main and foremasts was the same, then if you take the ratios of their fulcrums and compare it to a lower deck stepped mizzen then this ratio should be proportional and therefore the falcrum forces will be ok. You can check this if you like. But I'm ok with it for now.

 

By the way Wayne you will be pleased to know I found that last painting you posted and its by Samuel Atkins 1794. It appears to be evidence for the taller mizzen because although it is late if you rule a horizontal line parallel to the water line of the bark from the fore top (not the top masts or gallant) it should cross below the main top 3 to 5 feet and then where it crosses the mizzen the top should be around 8 feet below the line. Which looks to be the same as in Parkinsons sketch with the mizzen at the taller height putting the mizzen top around 8-9 feet below the main top. If it were the shorter mizzen mast stepped in the hold then the mizzen top would be 18 feet below the main top which it isn't. So interesting thanks.

 

Anyways I've taken a step back from this discussion as I have an answer I can live with for now. It might not be the answer others want but they are equally free to draw their own answers from the validated evidence presented here. Thanks again everyone.

Edited May 28, 2016 by dashicat

[druxey]

Thanks also to you, Dashicat, for an interesting discussion!

[archnav]

Hello dashicat and all the others,

 

I am also doing researchwork on HMB Endeavour for years now and it is a possibility, that (what K.H. Marquardt explains on his homepage) there is an error (maybe) in the copying of the mast and yard dimensions.  Numbers like 6 and 9 can quickly be misarranged when such a list is written by hand.

 

So, if you change the 6 in 16.29 yards for the mizzen in 9, you`ll get:   19.29 yards !  This is 9 feet more, the missing distance when the mizzen was stepped on the keelson in the hold.

I agree, that there are no signs or drawing changes in the plans, that indicates a stepping on the lower deck. Additional, strong pieces would have been needed in this area and additional stanchions in the hold.

Cook ordered a "complete ship rig" !  So I think, the small Bark was rigged like a Navy Ship !

 

Hope this is of help - also check Marquardt`s homepage for his conclusions on Endeavour.

 

Greets,

 

Tom

Edited June 2, 2016 by archnav

[archnav]

Here are two planes of David R. MacGregor from his book:  Merchant Sailing Ships 1775-1815

 

Showing a merchant ship of 330 tons - redrawn from Steel`s "Shipwrights Vade Mecuum" 1805, where the mizzen is stepped on the lower deck.

 

Greets,   Tom

 

 

 

[Windships]

Looking for contact information for Karl Heinz Marquardt with whom I last corresponded in 1996.

I note your mention of his web site, but I have not found such on the web

 

Thanks for whatever you can provide.

[shipaholic]

Here is his website

 

http://karl-heinz-marquardt.com/

 

Cheers

[Williamo]

It might be useful to contact the builders of the Endeavour replica, which rests at the Australian National Maritime Museum in Sydney Harbour, to see how they resolved this. Just a thought.

[druxey]

Stepping on the lower deck of the mizen mast appears to have started very late in the 18th century: perhaps not as early as 1770. Looking at contemporary draughts of Endeavour, (online at RMG Collections) although the mast steps are omitted in the profile drawings, the distance apart of the lower deck beams aft suggest that the mizen step is on the keelson, not the lower deck.

 

Looking at the replica Endeavour may not be helpful (unless you are building a model of it!), as many modifications were made to meet modern safety standards.

[Williamo]

My point was that they had made a very thorough analysis of all available documentation, and may have a view on how it was built, regardless of how it ended up.

[druxey]

Point well taken, Williamo.

[dashi]

On 3/6/2018 at 6:08 AM, druxey said:

Stepping on the lower deck of the mizen mast appears to have started very late in the 18th century: perhaps not as early as 1770. Looking at contemporary draughts of Endeavour, (online at RMG Collections) although the mast steps are omitted in the profile drawings, the distance apart of the lower deck beams aft suggest that the mizen step is on the keelson, not the lower deck.

 

Looking at the replica Endeavour may not be helpful (unless you are building a model of it!), as many modifications were made to meet modern safety standards.

Royal Museums Greenwich, Object ID ZAZ1355, Essex 1741 shows the mizzen ('edit': without the support timbers shown) stepped in the lower deck http://collections.rmg.co.uk/collections/objects/81146.html

 

Edited November 8, 2018 by dashi
See 'edit' which helps answer previous suggestions regarding support timbers

[dashi]

Quote from "The Ship Builders Assistant 1766 written by William Sutherland"

 

Quote

M I Z O N - M. A. S. T. The Mizon-maſt ought to be (in a third Rate) ſix-ſevenths of the Main-maſt, allowing two-thirds of an Inch Diameter for every Yard in Length. And this Length for the Mizon-maſt. is when it ſteps in the Hold, but if upon the Lower Gun deck, then the two-thirds of the Main-maſt will be ſufficient. Bat in a ſmall Ship five-ſixths of the Length of the Main-maſt: will do for the Mizon-maſt, if it ſteps in the Hold

http://The Ship-builder's Assistant; Or, null. https://play.google.com/store/books/details?id=hwhBd0jiVqAC

[dashi]

On 5/24/2016 at 9:28 AM, druxey said:

The mizen mast was stepped on the keelson until late in the 18th century. I suspect Endeavour was stepped in this earlier style. It is irritating that contemporary draughts all omit showing any mast steps!

'Ship-builder's Assistant by William Sutherland London 1726' 

Quote

M i z o n-M a f t.
The Mizon-maft ought to be (in fuch a Ship as the Figure reprefents) 6/7 of the Main-maft, allowing 2/3 of an Inch Diameter for every Yard in Length. And this Length for the Mizon-maft is when it fteps in the Hold, but if upon the Lower Gun-deck, then then 2/3 of the Main-maft will be fufficient. But in a fmall
Ship 5/6 of the Length of the Main-maft will do for the Mizon-maft, if it fteps in the Hold.

Druxey this pushes the practice of stepping the mizen mast in the lower deck instead of the keelson back to at least 1726, the early 18th century.

 

Therefore IMHO when considering the evidence to hand I don't think it unreasonable to conclude that due to the stated length of Endeavour's standing mizen mast that it was indeed stepped in the lower hold instead of the keelson!

 

Ship builder's assistant by William Sutherland London 1726

 

Cheers Dashi

Edited February 7, 2019 by dashi
Inserted link

[druxey]

Thanks for your recent responses on the subject, Dashi! It is interesting to note the early example of the Essex of 1741 with a mizen stepped on the lower deck, as well as Sutherland's comments. Thanks for bringing these to my attention.

[Mark P]

Good Evening Everyone;

 

I recently visited the Naval Base at Portsmouth, with the kind assistance of the staff of the Library of the National Museum of the Royal Navy and the Librarians of the Admiralty Library, to view a variety of interesting documents. One of these was a draught of 'HM Bark Endeavour', described as 'taken off in the wet dock' and dated 25th April 1768.  This lists her principal dimensions, and there is another word near the date, hard to read, of four letters, but it might say '?rey', which I would take to read 'Grey', as mentioned in previous posts, except that the 'r' looks more like a 'p', which would read '?pey' and I can't make much sense of that.

 

Interestingly, this draught shows a tall, built up companion immediately afore the wheel, and a variety of dashed lines for the position of the rails and lengths of the mizzen channels.

 

I will post a picture of part of her here, as it seems that it is not presently known widely, and it may be of use to modellers of the Endeavour. I don't have time right now to edit the picture, but I will do this tomorrow.

 

All the best,

 

Mark P

[shipaholic]

Hello Mark

Is this the draught you refer to different to this one?

This one is the original draught showing how she was as the Earl of Pembroke, with the proposed alterations. The companion in front of the helm was removed at the refit before Cook's voyage. I didn't know there was another with the writing you describe. I'm eager to see it

 

Cheers

Steve

Edited February 8, 2019 by shipaholic
extra info

[Mark P]

Good Evening All;

 

This is part of the draught referred to. I won't post it all for copyright reasons.

 

I checked, and it actually says 'taken off in the single dock', not the wet dock. Memory plays up a bit, sometimes!

 

It is definitely dated as mentioned, though.

 

All the best,

 

Mark P

 

 

 

 

[shipaholic]

I haven't seen that draught before. Can you post more sections of it please? or send the image in a PM if you don't want to post in on here

[druxey]

Interesting. The partial draught above does not appear to be ZAZ 6588, ZAZ 6587 or ZAZ 7844; the three sheer and profiles listed on the RMG site.

[Mark P]

Good Morning Druxey;

 

Yes, it is not the same, although I think that the details shown are very similar to at least one of the draughts shown in earlier posts.

 

The date is very specific, which is helpful.

 

Shipaholic, I agreed that my visit to the Library was for personal research.  I cannot therefore post more pictures here, as who knows what may then happen to them. The Library staff were extremely helpful, though, and would be willing to take a digital scan and send it. This would avoid the photographic distortion present in my pictures.

 

However, very inconveniently, they are now in the process of moving to different premises, and are very unlikely to reply to any emails, for many months. Which is not helpful.

 

All the best,

 

Mark P

[archnav]

Gentleman,

 

after a long time with health problems, I am back and I´m deep into research again since a few month.

 

I have started a new topic:

Regarding to this topic here:  There are new informations about the question, why the mizzen mast of the ship is given so short in the Gray-List. The answer I found is very simple. Apparently the mast and yards, after the voyage, were measured only by the parts, that were not rotten !

As Cook himself wrote in his Log when coming home, the mast and yards were in very bad condition.....rotten away, and also the rigging in very bad condition, main top-backstays broken etc.

The rotten wood of the masts was no longer usable and was probably sold on cheaply. To do this, however, it had to be measured precisely and this was recorded in the Gray list.

Apparently it was common knowledge that masts that were not built were more susceptible to dry rot than built masts. Cook also mentioned this once in relation to the small merchant ships in the coal trade.

There is testimony from a researcher who has studied Cook and the Endeavour extensively that this was a common practice in the Royal Navy. It certainly seems logical.
This would make all the speculation about why the mizzen mast of the ENDEAVOUR is so short superfluous. I am in the process of contacting this woman and getting one or more sources where this can be read. However, this statement must be true, as it has been published in scientific circles.

I too have done all the possible variations for the calculation of the masts and yards and will publish the results in this topic here.

 

I hope that I could again contribute something to answer the unanswered questions or come close to it.