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I have come across some old plans for HMB Endeavour which show an arch shaped object under the tiller. Can anyone explain what this is? I'm guessing it could have been marked with degrees for steering and or a supporting run for the tiller?

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That's a wooden arc hung from the quarterdeck beams.  It both supports the end of the tiller and carries the tiller lines around its circumference so the fleet angle of the lines to the tiller remains efficient.

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Thanks for this Joel. Do you or anyone have photos of this on a replica or more detailed technical drawings of it?

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Hi Dash have a look in here

 

https://www.flickr.com/photos/endeavourvoyages/albums/with/72157634081735926

 

Only 3729 photos, but the Albany to  Port Lincoln album has a few not quite complete pics

Chris

 

And a few photos here

 

http://www.modelships.de/Museums_and_replicas/Endeavour/Photos%20HMB%20Endeavor.htm

 

PS, if someone could remove the people it would be much better for us

Edited by Cabbie

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Thanks guys but my curiosity is still not satisfied.

 

I just rotated the drawings and discovered that the woolwich yard comments of 16 October 1771 are written on the drawing upside down relevant to the drawing and scale at it's bottom. So the rotation of the drawing is correct as uploaded and the top drawing appears to show the above deck fittings including the tiller and arc as you wouldn't include the odd below deck fitting on a technical drawing in a solid line, but instead it would be drawn in a dotted line which is the case for the main deck beams below the quarterdeck on the same drawing. The 1768 drawing doesn't even show the tiller or bumpkins, so with these details omitted then is it likely that the arc detail has been also omitted from the drawing? The tiller with iron end attachment on the woolwich yard drawings of 1771 matches the tiller with iron end attachment on the Navy refit build draught of 1768 further suggesting this is the same tiller in the same position above decks. 

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Edited by dashicat

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The drawing certainly shows a quadrant for the tiller.  Perhaps this was done after the voyage, or for some reason the replica was done differently.  The wheel is there in the photos, as is the tiller, but there are no tiller ropes on the wheel, though apparently there were at one time as there are grooves worn in the drum of the wheel.  I also don't see any ropes on the tiller so maybe that whole system has been taken down, to reeve new ropes?  If you're going by the replica that is what you go by, certainly.

Underway pics show the ropes hooked up and apparently used in the normal way.  Where the quadrant came from is a mystery.

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Dashicat: Dashed lines used as you suggest (for hidden or underlying items) is a modern drafting convention. Back then dashed lines indicated retrofitted items. Usually internal fixtures were drawn in red ink. 

 

So, the quadrant is above the quarter deck (unusual) and on the sheer and profile there is a cranked gooseneck on the end the tiller. This suggests some form of block and tackle arrangement above deck.

Edited by druxey

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Thanks Druxey this is helpful.

 

The dotted lines I was referring to are on the top drawing where the quarter deck overlaps the main deck. You can see the main deck beams are drawn in solid where exposed and change to broken when passing under the quarter deck structure and beams.

 

You refer to the 'quadrant', is this the term for the arched tiller support? Thinking about it, whether below or above decks a long heavy tiller would require an arched support at around 2/3rds of its length. So I'm guessing it's uncommon to have such a large tiller above decks, but maybe not unheard of? It might help to see the tiller arrangement of other ships of this era and size.

 

The iron cranked goose neck on the tiller was to clear the flu from the captains cabin fire. It would have been rigged via blocks to the ships wheel which is shown just forward of the mizzen. Maybe the tiller tackle on the replica is removed when parked so visitors won't trip over it? I also notice the replica tiller has a metal brace to help support its weight where it connects to the rudder.

 

Another consideration is the steering tackle would pull down on the tiller as it clears above the bulwark height. Having a quadrant under the tiller would counter these downward stresses from the tackle.

Edited by dashicat

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Thanks Robin and everyone. Ok a little progress, it appears that our 'quadrant' is in fact called a 'sweep' and has a metal strip where the tiller arm rides on it which was kept greased. Sweeps were in use since the days of the whipstaff to support the weight of the tiller and give it a smooth sweep.

 

So until I'm convinced otherwise, at this stage the evidence is in favour for the use of a sweep as shown positioned on the quarterdeck under the tiller to be historically and technically correct. Why it has been overlooked in recent years is a mystery as it would have been a critical component for this design. Without it the stresses on the 18ft (21ft with the metal gooseneck) long tiller where it connects with the rudder post would I imagine be a cause for frequent catastrophic failures, not to mention it's bounce would frequently slacken or break it's tackle.

 

I am almost up to the rudder on my Endeavour build so unless I come across information to the contrary I will attempt to bash a tiller sweep on the quarterdeck.

 

I've had a closer look at the 1768 profile and while the forward cooks oven and flu are shown there is no flu coming out under the tiller gooseneck from the great cabin? Another mystery or was the fire part of the 1768 navy refit, but if it was then what is the reason for the gooseneck on the tiller in the original build?

 

Thanks again for everyone's input and if anyone finds any more information regarding the use and design of 18 ft quarterdeck tiller and wheel steering then please share it here.

 

Cheers Dash

Edited by dashicat

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Here is a shot from the link provided above of the replica. By all accounts a VERY faithful replica. By my reckoning the portion of the tiller cantilevered from the Rudder Head is about 15'and that IS a lot of wood with presumably a very strong levering force constantly stressing the Rudder Head. But it appears to be fine in the photo. Also I have never seen any sort of arc shaped structure above decks associated with any tiller on any ship or model that I can recall. Its true that large ships with rudders set under an upper deck do have an arc shaped shelf the tiller hangs from, but in this case the tiller HANGS from it. The conjectural structure above deck would be below the tiller and then what is it doing for you? A wooden truck or roller would do the same job and I will say I have never seen provision for any such roller or guide of any kind on ships that I can remember. Maybe I am wrong. What I can NOT imagine is a guide or Tiller Sweep set ABOVE a tiller on an exposed deck, that is just too much stuff getting in the way of everything on the crowded small space aft. But the drawing is clearly showing a Tiller Sweep and this is a mystery. To me it suggests evidence the tiller was relocated to the underside of the deck and then it could have a Tiller Sweep that would be useful.

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So, if I understand things correctly, the sweep or brace was raised above deck to the height of the underside of the tiller. I presume this would have been supported on pedestals or stanchions of some sort. (It appears to be about 2' 0" above deck at the midline in the sheer and profile.) As the rudder is hung at the angle of the stern post, the tiller arc will not be horizontal, so this sweep must be arc-shaped as seen from forward or aft, as well as transversally.

 

The gooseneck at the fore end of the tiller must be there for a reason. Is it simply to raise the end to a convenient height for the steersman? And lastly, what kind of tackle or relieving tackle was fitted to the eye at the end of the gooseneck?

Edited by druxey

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Frankie. According to the AOTS book the tiller measures 21 ft including the bent iron extension if I've read their scale of 1/8" to 1ft correctly. Is the replica tiller made from the same timber and therefore the same weight? What we are referring to as an arch, quadrant or sweep may in fact be the tiller brace Cook is referring which broke twice on his voyage and it would have been positioned 2/3rds the length of the tiller from the rudder post. If it were below decks then it would be drawn as a broken line following the way the draughtsman as drawn main deck beams where they pass under the quarter deck if you look closely at the Woolwich drawings. Also if the tiller were move to below decks then it would move forward on the drawings as the rudder angles under the keel which is clearly not the case with were it is drawn. It is drawn on the quarter deck fitted to the rudder post as it clears this deck with what I will refer to as an arched tiller brace supporting it. I'd imagine this brace would have stops to prevent over steerage and if a stop broke then this would require repair but wouldn't prevent the tiller from working.

Druxey. I'm also thinking about the method of attaching this 21 ft tiller to the rudder post. If an arched tiller brace were used to bear the weight and considering the angle of the stern and rudder post then I'd imagine the simplest, most reliable and logical method of attachment to be floating. That is via means of a metal bracket and pin allowing for the tiller to ride smoothly along it's brace while only the steering stresses are at it's attachment to the rudder post. If it were a fixed attachment to the rudder post then the tiller would ride up in an arch over the deck like you say, adding undue stresses where it connects to the rudder post and also to the steering tackle. As for the height of this tiller brace that would also be influenced by deck camber and tiller bend but its ends are well clear of the bulwarks allowing for easy passage around it.

According to the AOTS book the great cabin had a fire who's flu came up through the quarter deck right under the bend in the attached metal tiller extension which is just to the rear of the mizzen mast. This possible explains this bent metal tiller extension. As for the tackle I'm not sure but I'd imagine it could be hooked into the ring following the steering gear layout in the AOTS book or I see on the replica it is lashed to loops in the helm robe? But having a 21 foot tiller would reduce the strain on the steering gear and helm (but only if the tiller were well braced) making for a light helm. Also can you see which side of the drum the wheel is on? According to AOTS it is aft of the drum but in the above drawing dated 1771 it appears to be forward of the drum just to the rear of the skylight which makes more sense keeping it clear of the mizzen mast belaying?

Edited by dashicat

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Greetings everyone;

 

A few thoughts strike me on studying the draughts. 

 

Firstly,  the tiller and sweep are above deck,  else they would be drawn in red.  Secondly,  by virtue of its being located only two-thirds of the length of the tiller,  the sweep does not extend the full width of the quarter-deck,  allowing free passage past it on the outer part of the deck. 

 

With the helm hard over,  the tiller would reach the end of the sweep,  and the gooseneck would be tight to the bulwarks.  It would seem to me,  therefore,  that the function of the sweep was to support the tiller from below,  with the tiller riding along the top of its curve for the full length of its travel.  There was probably a lug fitted to the underside of the tiller,  and passing below the sweep to aid in keeping it in place against any force from the steering ropes,  or the effect of waves on the rudder. 

 

The curvature of the sweep would need to be steeper than the camber of the deck,  with the outer ends of the sweep probably very close to the level of the deck planking,  whilst being higher above it in the mid-ships position.  The camber of the deck would allow the tiller to extend beyond the sweep,  even if the end of the sweep was quite close to the deck.  As Druxey says above,  it was curved in two planes.

 

The steering ropes must have passed along the deck planking,  probably through fixed sheaves at deck level,  both below the wheel and at the ship's sides.  Any location at a higher level would have caused an intolerable nuisance to anyone attempting to pass.

 

I am afraid I cannot think of any reason why the iron gooseneck should need to be cranked;  not from any feature shown on the draught,  anyway.  My only thought on this is that if its end is higher than the end of the tiller,  it would serve to keep the tensioning blocks,  located at the end of the tiller ropes,  a little aloft,  thereby keeping them from bouncing along the deck and chafing both the ropes and the deck as they swung. 

 

All the best,

 

Mark P

Edited by Mark P

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The photos linked above show blocks either side of the wheel, directing the tiller ropes to the bulwarks, then another block each side directing the ropes aft, then another block on the bulwarks inboard to the tiller.  Three pairs of blocks.

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Hi JB;

 

Yes,  it would need three blocks or sheaves per side to work.  The use of blocks in a replica vessel does not point to their use in the vessel being copied,  unless based on good evidence.  From what I have seen in the writings and illustrations about steering ropes,  the use of sheaves was common to guide them.  This can be seen in surviving vessels:  both Victory and Foudroyant are fitted with sheaves.  We obviously cannot know for certain either way,  unless there is some description or mention in the logs or journals.

 

All the best,

 

Mark P

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Thanks Cabbie for those links as I haven't seen these photos and they give some very clear shots to work from. Have you found any shots of the rudder post under it's little hood?

 

I'm left wondering how much information is given in the Admiralty draughts and how much was just left out and presumed up to the shipwright and shipyard? But then I suppose a Navy refit would be a fairly structured affair and from the logs included some experimental kit such as the 'white stuff' on the pinnace.

 

And thanks again to everyone I'm really getting a lot of useful information from this discussion even though there are still unanswered questions. 

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Look what I just found...

 

It is dated 1768 and shows what I assume to be the Navy refit drawn in red. What is interesting is I think I can just make out a line going from the top of the rudder post down at 45deg to the tiller drawn in red along with a curving red tiller. If this is the case then it might support the metal tiller brace on the replica which is in this position and could in fact be the broken tiller brace Cook is referring too and not the sweep which I thought also possible. I cannot make out if there is or isn't a sweep under the tiller as the picture isn't clear enough. But I can also make out the orientation of the helm wheel aft of the drum drawn in red also. It seem the steering gear is all part of the navy refit. I wonder if somewhere there is a more detailed draught of the steering gear?

 

post-8909-0-22430200-1459069633_thumb.jpg

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HI Dash I kept this one, of the rudder.

 

https://www.flickr.com/photos/49614558@N02/5672239356/in/album-72157626613240438/

 

And this album Of The Endeavour in dry dock has a couple looking up.

 

https://www.flickr.com/photos/endeavourvoyages/sets/72157634081735926

 

I think you are right about the brace it looks like it on the drawing.

 

I opened the image in photo viewer and enlarged it and the brace line is there.

It doesn't seem to show the tiller support you are asking about though.

 

Something else about that drawing it has 2 steps in the gunwales, so i don't

know if any ones knows what's correct.

Chris

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Dashicat

I'm intrigued by that last sheer plan you put up showing the Endeavour as she was before refit and the proposed changes. I have a copy of plan 3814b and it is different, on mine the badge window shows the carving details and a few other details are different.

Anyway this pic of the draught shows the bracket where the tiller joins the rudder, a slight upward curve of the tiller. but nothing to suggest what that arc is on the original plan you put up.

That plan with the arc is the a planmade after Cook's voyage with different cabin arrangements proposed, it also has an extra scuttle on the forecastle. It also has the drum aft of the helm.

 

Cheers

Steve

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post-819-0-65274700-1459077957_thumb.jpg

Edited by shipaholic

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Cabbie thats a great bunch of photos on that website you linked to. I'm taking the liberty of cutting and pasting the relevant shot of the tiller. Also the HMB Endeavour replica has a facebook page which has a very large number of photos taken over many years and I found some tiler photos there too. In these photos I see a wooden tiller with iron features bolted to each end. In some of the photos the wood is revealed to be laminated of several pieces, which makes perfect sense for such a crucial part of the ship.  The initial mystery of "what is this arc shaped object on this drawing" is no closer to being solved though. Again I wonder if any tiller on any exposed deck on any ship or model has ever exhibited such an arc shaped object? I have never seen one.

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Cheers Robin, you are a champion for opening up your studio for us and providing that info.

 

Steve I'm intrigued by the top close up which shows some good detail of the tiller and especially how it connects to the rudder post with a brace like on the replica. Interestingly the tiller seems to leave the post close to the deck and curve upwards to the gooseneck which looks to have two small holes through the nob on it's end (I could be mistaken). And importantly there is no sign of a sweep on this draught.

 

Thanks Cabbie and Frankie for find those good shots of the replica tiller and the info that it is composit laminated wood which could explain why it dosn't curve and why it inturn connects to the rudder post slightly higher than in the draught of 1768 put up by Steve.

 

I feel like we are getting somewhere with this. Some more 1768 draughts showing different profiles and detail would be helpful if they are out there. The evidence we have uncovered so far is in my opinion now leaning in favour of the replica steering gear being the most accurate with the exception of the uncurving laminated tiller with the possibility of sheeves instead of blocks as has been suggested earlier. Possibly due to two noted breakages of the tiller brace a redesign was prompted for the 1771 refit which replaced the tiller brace with a sweep two thirds down it's length as shown on the 1771 Woolrich draught?

 

I'm interested in what others make of this, cheers dash.

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Morning Dash

Looking at the tiller pic, I think that there is a metal cap on top of the rudder post

to which the brace is attached to. I wonder if they added any more hinging under the canopy

to make it stronger.

 

I was just thinking too, I wonder if they hid a steel bar inside the laminated timber?

 

Also that pic also shows a very clear view of the inside of the stern

which will help for our models.

Edited by Cabbie

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Hi again

In answer to one of Cabbie's comments, if you have a close look at the pic I posted previously there is a hinge at the top of the rudder post level with the deck.

Here is pic of how I set up the tiller on my Endeavour if it helps. I would ignore that arc on the plan, doesn't make sense.

 

Cheers

Steve

post-819-0-51027000-1459121623_thumb.jpg

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My two cents about the shown ark on the 1768 drawing makes sense to me, if it was placed between the deck and tiller arm as it appears to be. Think about the moment arm acting on the rudder post just from the weight of that heavy tiller, then add the iron work at the end. Because of the location and height of the steering gear attachment point above the deck in the 1768 drawing  would also add some more downward force to the load on the tiller that the rudder post would need to support, the rudder post would soon snap off. The reinforcing iron and bolts between the rudder post and tiller aboard the replica will not save the rudder post from damage, it would quicken it by making the joint stiffer, they must have lots of problems with the steering gear. Suspect the ark in question and shown on the 1768 drawing lies on the main deck for the tiller arm to rest and run along, probably the arc device was topped with a well greased iron cap and a iron pad attached to the bottom of tiller arm to ease movement and stop excessive wear.

jud

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I'm always hesitant to take anything in the AOTS series as gospel truth. Perhaps building a mock-up of the presumed arrangement might shed some light on things.

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Hmmm. If the iron brace is used at the rudder post as drawn in red on a 1768 draft then the tiller wouldn't be able to ride along a sweep because it would be rigid along its vertical axis at a fixed angle relative to the rudder. Therefore if a sweep were used to support the tiller then the tiller to post joint would need to swivel on its vertical axis so the tiller can ride the sweep making the iron brace redundant and the sweep would then be the tiller brace... I think?

Edited by dashicat

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