Sail design for 18th-century longboat?

[Justin P.]

The contemporary evidence supports both scenarios, though I would say that there are two types of contemporary evidence and they support two accurate scenarios.   However dubious we might be with regard to the practicality of a below-tiller arrangment, Chucks research is sound.  

 

It seems like there is a bit of reinventing the wheel here, let us not forget that these are 18th century models.   Of course it was "impossible" to sail with that arrangment, thats why it was changed.  Read Lavery's book as was suggested.  It was also impossible to build pyramids, until they did.  Now we do it differently, and cannot concieve of how they did it then.  Its impossible without cranes.

 

The detractors it would seem are making the very same discovery that mid-18th century sailors made: tacking and gybing the boat is difficult if not impossible with the traveller located below the tiller.   That does not mean that wasnt done or that models reflecting it are inaccurate.   I for one appreciate the level of detail and research and can see (without being expert) that the contemporary evidence and primary sources support Chucks original schematic as possible if not likely.  I actually appreciate that, with regard to model making, this particular model represents an interesting historic anamoly. 

 

I am reminded that we dont fully understand how such things like the Pyramids, Stone Henge could have been built with primitive technology, YET they were, though probably with great difficulty.   Likewise, though it seems impossible to sail a boat with a below-tiller-traveler arrangement, it actually was likely quite possible, though probably very difficult.    Not an expert sailor by any means, but I do sail and I do have a boat, and I can concieve of a way to sail the boat (though not gracefully, and not sharply) with this arrangment.   If I just needed to sail in a straight line, say from my ship to shore and wouldnt be doing a great deal of tacking... well...  its possible.

 

 

[thibaultron]

Recently a study of the pyramids using some type (I forget the tech name), of deep scanning equipment, they found that there appears to be a ramp spiraling around the outside of the structure, just under the present surfaces. So they used the ramps for most of the construction, then covered them over when they finished the outside. At least that is the latest theory.

[Gregory]

On 7/12/2017 at 9:38 AM, Chuck said:

Gregory...because that was the way it was done.

.............................

 

Chuck

 

I realized after re-reading a couple of times, that I may have not made my thoughts clear on this;  being that, if this was not the practice at the time, why would a professional

model builder do such a thing?

My opinion was/is, that they would not.  Leading me to believe the model is accurate..

 

 

 

[Dowmer]

On ‎7‎/‎12‎/‎2017 at 11:14 AM, Chuck said:

That is correct.   It is a very faithful representation of the tiller horse arrangement but just a little later than the contemporary model I used as inspiration.  Both are correct.  I guess at some point they said to themselves...."this arrangement with the sheet and tiller is stupid.  Why do we insist on using it when all we have to do it make it go over the tiller"   One can only speculate why they used it in the first place and why for so long when it seems pretty clear it was in fact not a smart thing to do. 

 

 

I know this is an old thread, and there was a very heated debate about the working of the tiller with the strange horse arrangement, but i just could pass this sail plan up when I saw it on the NMM website.  I know both travelers are correct as we have discussed, and I agree with Chuck on his version, but perhaps the comment about "they learned later to change it" never happened everywhere.  Here's another example of the impossible version below the tiller in a drawing as late as 1910 from Scotland!!! This impossibly difficult sailing rig still baffles me, but here it is again.

Someone must like it?

 

 

 

Another point that I would like to bring up that I don't think anyone has addressed.  It's the absence of a bobstay for the jib.  You would thing that there would be considerable pressure on the jib pulling it up and something would be needed to hold it down. I read in Lees Masting and Rigging that mentions that longboats carried a bobstay.  But the models don't seem to show one.

 

Then I looked closer at the picture of the Medway model that Chuck shows for the inspiration for the 18th century longboat.  See below, it has what appears to be a sheave attached to the stem for rigging a possible bobstay or jib tack..

 

 

 

And then I found a sail plan in the NMM (albeit a slightly later plan circa 1800) of a cutter/longboat with what appears to be a bobstay or possibly the sail rigging through something similar on the stem.  Perhaps a bobstay could have been rigged on the Medway model but was damaged and fell off over the centuries.  Better yet, I think the rigging from the sail is supposed to reeve through the block on the stem thus acting like a bobstay holding the bowsprit down when it is pulled tight. I think the line on the Medway probably reeved through this block on its stem.  If not, then why would they put it on?   Who knows, but I find it interesting nonetheless.  Just more options to consider.

 

 

 

  

 

 

 

 

 

[Chuck]

For all interested and who may also have Mays book on the "boats of men of war".  Just turn to page 90.   That is all the evidence you will need.  It reproduces exactly a sail plan (contemporary draft) that shows the exact rigging arrangement.  The prevailing theory is that prior to 1750 or so they used the tiller/sheet arrangement shown on the model. It doesnt make sense but it is 100% accurate for the time period.  

 

And yes the fixed block on the stem is for the outhaul.  I dont understand why it isnt rigged that way on teh contemporary model.   One end is fixed to the traveler ring and then run through a sheave in the end of the bowsprit.  Then its taken through the fixed block and belayed inboard to a thwart.   There is other contemporary evidence of this.  

[druxey]

Two more cents' worth: In a contemporary model of a hoy, there is no bobstay. However, a block was hooked in the same position as your longboat sheave for the jib traveller outhaul line. Might I suggest that what you see on the plan of c1800 is similar, but for the jibstay?

[druxey]

Also, regarding the sheet/horse arrangement: is it possible that the horse rounds aft at the center, providing clearance for the tiller? (Think of an arc, like a tiller sweep.) Does the illustration show the sheet in the boom hard over position?

[Chuck]

I dont think so but who knows???   Is it also possible that the tiller wasnt permanent?  How feasible would it be for someone to remove the tiller as they swung the boom to the other side and then quickly reposition it into its slot.  Just spit-balling.

 

[Dowmer]

1 hour ago, druxey said:

Two more cents' worth: In a contemporary model of a hoy, there is no bobstay. However, a block was hooked in the same position as your longboat sheave for the jib traveller outhaul line. Might I suggest that what you see on the plan of c1800 is similar, but for the jibstay?

Druxey,

I think you, Chuck and me have the same opinion. Perhaps I didn’t explain myself very well. That the outhaul is rigged through the stem block. As it is hove taught it probably acts similar to a bobstay, holding the end of the jib boom down.  Remember, the jib probably isn’t used in anything but light to medium breeze anyway.  Like chuck says, there is other evidence and he doesn’t know why the Medway model isn’t rigged that way. Lots of stuff happens to models over centuries. If you look closely it appears there is damage. The metal work has come loose holding the bowsprit to the stem. The bowsprit probably came loose at some point. They put it back on and didn’t reeve the outhaul through the stem block. That’s my guess anyway. 

 

 

 

Edited August 1, 2018 by Dowmer

[Dowmer]

32 minutes ago, Chuck said:

I dont think so but who knows???   Is it also possible that the tiller wasnt permanent?  How feasible would it be for someone to remove the tiller as they swung the boom to the other side and then quickly reposition it into its slot.  Just spit-balling.

 

 

Interesting hypothesis Chuck. I believe the tiller arm is designed to slip in and out of the rudder head. So it is possible, but I would think tacking or jibing while essentially unshipping your rudder control is a recipe for disaster. But stranger things have been done. 

 

If I was in a boat rigged in this confounded way, since the boat is relatively small,  I would probably start the turn, as the wind comes off, loosen the sheet with enough slack to pull it around the tiller with one hand, then snug it up again as it passes through and catches the wind again. But that’s just me “spit balling”  😬 😀

 

 

[Roger Pellett]

I have commented on this subject before, but since someone else resurrected it I will add my two cents worth.  For what it’s worth I am scratch building a model of the longboat shown on page 90 of May’s book so this topic is of considerable interest to me.

 

First of all as an active small boat sailor, pulling the tiller out of it’s socket during tacking in any kind of a breeze will likely cause the boat to broach and capsize. -Personal experience!

 

The Scottish boat shown on the drawing posted in the drawing is not gaff rigged with a long boom like the longboat.  It is rigged with a dipping or standing lug sail.  Dipping lug sails are actually dropped and rehoisted during tacking.  This past May I watched a pair of lug rigged boats doing just that while tacking into the harbor of St Ives, Cornwall.  If a standing lug rig, the sail’s boom is short enough for the sheet to be pushed forward around the tiller during tacking.  This drawing, therefore does not apply.

 

These longboats were once rigged with a gaff sail without boom.  The foot of these  sails was much shorter than the boomed sails shown on the Medway longboat model.  May includes a picture of a longboat rigged with this boom less gaff sail in his book.  It would have been awkward but perhaps possible to pull the clew of a boomless sail forward enough during tacking to keep the sheet from fouling the tiller.  This would have been impossible with a sail attached to a long boom overhanging the transom.

 

Cutter rigged boats in Britain sailed into the 1900’s with unstayed bowsprits.  Tom Cunliffe’s Pilot Cutters Under Sail includes photos of unstayed bowsprits bending in a stiff breeze.

 

For other mysteries relating to the way that gaff rigged cutters actually worked. see Tom Cunliffe’s Hand Reef and Steer recently reviewed in the book section of the forum below.

 

Roger

 

[Dowmer]

Thanks Roger. I think we all agree that there are issues with the way the gaff is rigged, for better or worse but there is historical precedence for whatever insanity drove them to it. 

 

I agree there probably wasn't a dedicated bobstay for the bowsprit. We covered that already, but there is a block on the stem for a purpose and it’s documented in other plans as well. So do you agree that the outhaul should reeve through this and provide some stability to the bowsprit like in the plan shown?

 

By the way Roger, do you have a build thread of your longboat. I’d love to see a picture or a thread for it?

 

cheers

 

 

 

 

[druxey]

I would not wish to lose rudder control at a crucial moment of going about either! It does seem like an odd arrangement.

[thibaultron]

Abe Books has several reasonably priced copies of Mays book "The Boats Of Men Of War"

[Mark P]

Hi Everyone;

 

Just a few thoughts to throw into this bubbling mixture!

 

I am not a sailor,  and I cannot be sure if what I am about to suggest is realistic or not,  so other people's opinions will be needed here.

 

However,  one point which is being not mentioned here is that the tiller on all such boats was removable. 

 

with the boat on either tack,  or with a following wind,  the sail would be out over one or other quarter,  or broad over the beam.  In all cases here,  the sheet block would be at one end of the horse,  closest to the sail,  and away from the central point where the tiller pivots.

 

It is only when going about that the sheet block needs to traverse the horse,  thereby crossing the centre zone.  I believe that the prime mover in going about is the headsails,  once the rudder has started the initial turn.  What is the likelihood that while the ship was turning through the eye of the wind the rudder is,  for a very short period,  in a dead zone,  and the tiller can be un-shipped,  allowing the sheet block to run past,  before the tiller is re-shipped. 

 

Would this be a true possibility?  Over to those more nautical than me.

 

All the best,

 

Mark

[Dowmer]

1 hour ago, Mark P said:

What is the likelihood that while the ship was turning through the eye of the wind the rudder is,  for a very short period,  in a dead zone,  and the tiller can be un-shipped,  allowing the sheet block to run past,  before the tiller is re-shipped.  

 

Would this be a true possibility?  Over to those more nautical than me.

 

All the best,

Mark

 

Mark,

This was already discussed a few posts back.  Possible but not advisable, with potential disastrous consequences (going swimming).  But no one knows exactly how they actually sailed 250 years ago.

 

Brian,

I don't think there is any historical precedence for modern adaptations such as this. Not for the 18th century anyway.

 

Cheers

Edited August 2, 2018 by Dowmer

[Mark P]

Hi Dowmer; 

 

Thanks for letting me know.  I think that when I clicked on this topic,  I was taken to an earlier point in the discussions,  and missed some of the latest posts.

 

Has a sailor commented on the practicality of this,  rather than only landlubbers.  The boat's momentum would keep it moving ahead,  and the wind on the headsails turns the bows in the direction that they need to go.  For a brief while,  the rudder does nothing.

 

All the best,

 

Mark P

[Roger Pellett]

I love to sail and for 10 years as a young man owned a 17ft Thistle Class sailboat. Since moving to Duluth almost 30 years ago I have both raced and sailed for pleasure most summers. For the last 15 years or so I have sailed several times each summer on a friend’s Flying Scot 19ft sailboat.  I believe that I qualify as a sailor.

 

I also suffer from peripheral neropathy in my feet and hands.  Fortunately I can still do good work in my shop but my grip is not what it should be.

 

My friend and I were sailing his Flying Scot in the Duluth Harbor in a 10-12 knot breeze with stronger gusts. As I was tacking the boat in a gust, the tiller slipped from my hand.  In an instant, she broached sidewise to the wind and over she went.   Attempting to unship and reship the tiller of a longboat would lead to capsize and loss of crew members who could not swim.

 

A boat under sail can be visualized as a lever pivoting about an imaginary point called the center of lateral resistance (CLR).  Sails aft of the CLR pivot the boat into the wind.  Sails forward of the CLR pivot the boat away from the wind.  When tacking the mainsail pushes the boat up into the wind and momentum swings the boats head through the eye of the wind on to its new tack.  The head sails are luffing until they fill on the new tack.  The jib on a poorly balanced boat or on a boat tacked with insufficient momentum can be backwinded to push the boat’s bow around but the jib on a well balanced, well sailed boat just goes “along for the ride.”

 

Roger

 

 

[Mark P]

Thanks Roger;

 

I guess that blows my theory out of the water then!  Good to hear the facts from someone who knows through experience.

 

All the best,

 

Mark

[xAlpha]

I'm not a sailor (I just pretend to be one on weekends), but how often would a small boat like this tack and jibe? Was it not mostly used as a ferry for going back and forth (rather directly) to a larger vessel?

[Dowmer]

It depends on the direction of the wind.  Yes, they were a general utility boat ferrying supplies, equipment and people back and forth.  They were also used for exploring shallow waters and depth soundings.

 

so the answer which I’m sure you will love is......”It depends”  on the winds, current etc.

[Nirvana]

I am very confident that the long boat was an excellent sailing boat, has the right shape and the rigging is right in my opinion.

It was probably not as efficient in tacking as a modern sailing boat, but still able head towards wind.

[Brandajz]

Hello to all.

This is my contribution to sail design for 18^th -century longboat.

Original boat model does not have sails. When I almost finish the longboat

I have decided to tray to add a sails but only two of them.

For sails material I used old white shirt. Using a paper sheet I found a proper

shape and size of sails. I have made a fabric stiffener from 2 Tbsp white flour dissolved in 1 liter of water. Sails size was 4 mm wider on every side for fold down edges. Material was stiffened and ironed. Than I mark a line 4 mm from

edge and initially folded it by using a metal ruler. I brushed Elmer’s white glue on 4 mm edge area and fold each down. When the glue dried the sails where pretty stiff.

Using a CA glue I glued main sail edges on boom, mast and gaff and finish the rigging of gaff. On jib sail front edge top and bottom corners I attached an eye with hook and finish the rigging.

Here are several pictures of longboat with sails. I do not have experience of posting the pictures so I do not know what will be on the screen.

Regards, Brian

 

[shipman]

Ok, this post is a year old now. Ah, well, hear I go.......what mystifies me with this type of ships boat is the bottom location fittings for the stays and deadeye straps. The above model has 'nails' just banged into the hull. This is a typical modelling feature; but it leaves me unconvinced. When these boats are depicted with masts and rigging unshipped there is never any evidence of these fittings. Surely if a 'nail' had been there before there should be one there after.

The sides of these hulls aren't that strong anyway, the stresses on these 'nails' must be substantial.

I'm simply curious about this feature which surely demands some justification. I've raised this issue before, to no avail.

I have an extensive library of my own, yet I find no answers. The horse and tiller debate worked itself into a frenzy. Perhaps my issue could highlight a similar controversy?

[Roger Pellett]

In the 1700’s bolts were not threaded, but were locked in place with a wedge driven through a slot in the bolt’s end.  The deadeye strap could be easily secured with such a bolt that would appear as a nail on a model.  The bolt and deadeye could be removed by driving the wedge from the bolt.

 

These boats were built with a heavy strake that would be called a “bend” on a larger vessel.  The bolt passes through this heavier strake.  The drawing of the longboat shown on page 90 of May’s book also shows a heavy short reinforcing timber between the bend and cap rail in way of the deadeyes.

 

Roger

[shipman]

That's new to me Roger, thanks for that. So, the 'bolt' should still be evident on unrigged boats(?)

Happy New Year to you and everyone else.

[Roger Pellett]

No, when the boat was not rigged, the bolt would have been withdrawn.

 

Roger

[shipman]

Roger, this is getting silly. No doubt you're correct and I'll go with that. However, all evidence of the fitting just disappears when the bolt is withdrawn? Why would the bolt (a relatively minor bit of kit) have to be withdrawn anyway?

Just pulled down May's book and agree the p90 illustration depicts the deadeye chain is (sensibly) attached to the sheer 'strake'.

Other than your welcome assertion, I maintain my original question. Could you kindly direct me to your source describing this bolt withdrawal business? I will then enter the New Year with my fevered mind at rest.

[Roger Pellett]

Murphy's law applies on sea as well as on land, and can be rephrased as "whatever you can get your self caught on you will."  Any fitting unnecessary to the boat's unrigged function that could have been removed would logically have been.  Furthermore, removal of the deadeye would have required the bolt to be extracted, so why put it back into its hole until it was needed to secure the dead eye again.

 

Roger

[shipman]

Not one of the contemporary models of ships boats I've ever seen has any indication or evidence that there was any provision in the hull for these 'dissapearing' bolts. Not even the lovely and comprehensive  NMM collection, including their drawings which have every conceivable detail portrayed.

An additional use for these bolts could have been utilised to lash the boat down on board ship: but no evidence of that either. But it would have been plausible.

What you say makes practical sense, Roger; but why is this (important) feature not evident on the models?

 

Returning to my original question:- 'I'm simply curious about this feature which surely demands some justification.'

 

I'd be happy if someone could show me some contemporary evidence of the detail we've been discussing.