Timbers of an Elliptical Stern c1855

[BANYAN]

Hi all, I am trying to find some good examples of the timbers (fashion pieces, transoms etc) that would form a typical elliptical stern for a vessel c1855.  I have looked through the NMM files (as best I can) for something that might be suited but have lucked out so far.   I have also done a quick look (not yet complete) in the Danish Digital Library (Museum) and found a contemporary ship the Jylland, but she has a different arrangement.  I have plans for the British Gun Despatch Vessels (Arrow Class 1854) and Vigilance Class (1856) but the plans do not show the framing or timbers.

 

I would appreciate any pointers or suggestions that would allow me to create the framing/timbers used in such a vessel to allow me to draw up the 'probable' stern for HMCSS Victoria (1855).  

 

cheers

 

Pat

[Martes]

https://commons.wikimedia.org/wiki/File:PIQUE_1834_RMG_J5227.png

 

https://commons.wikimedia.org/wiki/File:PIQUE_1834_RMG_J5228.png

[BANYAN]

Many thanks Martes, I will have a closer look at these later.  I think what I need is more aligned with clipper ships though; although for the main timbers these will help me to start understanding them.

 

cheers

 

Pat

[allanyed]

I am not sure this would be any help but RMG Collections has a contract of the Albacore Class (1856).   If it is like earlier contracts, it will at least have scantlings for all the timbers.  Between body plan and scantlings, there may some help for your project.   https://www.rmg.co.uk/collections/objects/rmgc-object-572899

Allan

[Jaager]

from

American-Built Packets and Freighters of the 1850s

Wm Crothers

MacFarland & Co.  2013

 

[mgdawson]

17 hours ago, BANYAN said:

I think what I need is more aligned with clipper ships though; although for the main timbers these will help me to start understanding them.

Perhaps this might be of some use.

 

From 'China Tea Clippers', George Campbell, 1974

 

[BANYAN]

Thanks all, that is exactly the type of thing I am looking for.  Much appreciate the feedback and great info.

 

My real issue now is trying to interpret how the after-cant timbers will have differed as Victoria was built using Diagonal planking (to Oliver Lang's plan) whereby most of the frames (floors IAW the Contract) ended at the round of the hull.  The usual frames were replaced with 'bent timbers' which replaced the temporary 'moulds'.  These were placed midway between the floor timbers from the round to the gunwhale.  When the side planking was put on, the first and second diagonals were actually wrapped under the hull and went up the other side, and the keel (except for 30 feet of it both forward, and aft) was put on after the diagonals and then the outer horizontal layer of planking put on in a more traditional manner once the bent and roughtree timbers had been put in. 

 

From what I can see, I believe I would need at least a 'full' aftermost cant-timber in-situ for the stern timbers to butt onto?  Quite the puzzle for this model builder to get his head around   

 

cheers

 

Pat

 

 

Edited August 6, 2023 by BANYAN

[BANYAN]

Allan, thanks for the suggestion. Unfortunately, if scantlings are given in that Contract, that class of ship was built on different principles to Victoria.

 

I have the Contract and appended Specification for HMCSS Victoria, but unfortunately, the scantlings given only cover the floors, bent timbers and roughtree timbers.  There is absolutely nothing WRT the stem and stern (nor the cant) timbers (or the deck beams unfortunately) - hence my questions here.  With no experience in drawing/lofting of ship framing, and finding nothing online nor in any book about the stern framing used in diagonally planked ships, it is doing my head in .  The best/fullest description for these timbers I have found to date are in "Wooden Shipbuilding" by Charles Desmond (1919).  PDF copies can be found online); but even here the subject is not fully covered. 

 

At this point, I think I will use the stern timber framing shown for British ships of this era supplemented with Desmond's descriptions, then modify all but the most aft of the after cant timbers that may lie forward of 30feet from the sternpost.  the reason for this is that Commander Lockyer (Build Superintendent) in one of his reports to the Governor of Victoria (Hotham) states that about 30 feet forward and aft of the keel was put down along with the shadow moulds, but that the remainder of the keel would not go on until the diagonal planking had been completed.

 

cheers

 

Pat

[Jaager]

1 hour ago, BANYAN said:

The best/fullest description for these timbers I have found to date are in "Wooden Shipbuilding" by Charles Desmond (1919). 

I think that Desmond describes a different species of wooden ships.   The 1850s were the end of a long era of guild style shipwrights.  It seems like there is a wall not too much later.  The main stream changed to composite and then iron and steel.   The generation to generation chain of passing of knowledge about wooden ship building was probably broken - except for minor and independent yards.  The old lofting methods replaced with a translation of iron and steel lofting over to wood.  The lofting of every frame was a new practice - taken from metal methods - metal is not open to variation on the fly. 

The all bends with intervening spaces equal to the bends in width was new.  I would not trust Desmond to be relevant to any ship built before 1900 or so.

[BANYAN]

On 8/7/2023 at 11:35 AM, Jaager said:

I think that Desmond describes a different species of wooden ships.   The 1850s were the end of a long era of guild style shipwrights.  It seems like there is a wall not too much later.  The main stream changed to composite and then iron and steel.   The generation to generation chain of passing of knowledge about wooden ship building was probably broken - except for minor and independent yards.  The old lofting methods replaced with a translation of iron and steel lofting over to wood.  The lofting of every frame was a new practice - taken from metal methods - metal is not open to variation on the fly. 

The all bends with intervening spaces equal to the bends in width was new.  I would not trust Desmond to be relevant to any ship built before 1900 or so.

That is a very interesting point you make.  I will need to reconsider this, but I may be missing a point you are making here.  When designing this ship, Oliver Lang did not conform with the old/traditional methods of building a ship; he was of the new generation (not the Guild I believe - his father certainly was).  For example, for the Victoria he used diagonal planking (to his plan which was based on a system he developed from a Devonport boat builder), he also used an Aberdeen style (clipper) bow, and a non-lifting screw design (first fit of this 'differential screw' design by Maudslay, fitted in any warship).  The hull skeleton, especially aft, I think may have been quite different to the traditional more squared and spaced framing.

 

Desmond, and also ESTEP (1918), describe the building of "Wooden Ships" and, if I recall correctly, do sometimes refer back (within their text) to pre-turn-of-the-century techniques, and their descriptions do not appear to refer to the use of iron and timber in composite form for the stern timbers (that I have found so far at least).   I have not read them extensively yet, but I have not seen any reference to composite, rather than wooden building technique?  

 

All that said, I only raise these points to gain a better understanding, and you are probably right.  I just need to get a better understanding of the points you make to establish whether to use these authors or not.  Certainly, Oliver Lang in designing this one-of-a-kind vessel, used it as an opportunity to show the Admiralty some alternative building principles.  Victoria was certainly unique for her time, and while she looked, and was armed, similar to contemporary Gun Despatch vessels (Arrow and Vigilance Class) she was framed/built on an entirely different principle that made extensive use of iron knees, hangers, etc, but she was not a composite build.  She was also equipped with many different equipment designs such that I am at a loss to try and even make an educated guess of how her stern timbers were arranged and fixed.   From the imagery, and the Builder's Certificate, she certainly had an elliptical stern and the knuckle line also appears more rounded than the traditionally framed sterns. 

 

cheers

 

Pat

Edited August 8, 2023 by BANYAN

[Jaager]

Endsor discusses lofting in his 17thC ship building books.  Everything that I have read about lofting from then until ~1860 indicates that the same process was continuous or this whole range of time.  The process is:  Only the station cross sections from the Body plan were expanded from the design plan -usually 1:48  up to 1:1.  The molds made from the 1:1 pattern contained "sirmarks" for the shape of the frames between each station.  The shipwrights in the yard did not need to have their hands held to shape the intervening frames.  It was master to apprentice - generation to generation.

 

Now, Desmond and Estep  come out of the insanity or scams for wooden merchant ship building because of Uboat losses that the new world of warfare that was  WWI.  They feature at least two practices that are a total break from the pre-1860 tradition. 

 

One is all bends with a space between each bend that is equal in width to be bend.  Now, French and North American ship builders pre-1860 used all bends, often, if not most of the time. But the spaces were smaller.  The most that I have seen is 2/3 timber and 1/3 space.  More often than not it was less.  At the time of the American Revolution the space was ~1" and often a pair of frames in a bend had 1" chocks so that there was a space in the middle of a bend.  

 

Two is that the outline of both faces of every frame was drawn on the loft floor.  Instead of maybe 30 molds - there was a couple a hundred or more. 

 

Why this labor intensive extra work?  

I connected the dots:

iron and steel replacing wood about 1860  

iron and steel requite engineers and engineering precision that wood does not.

the master to apprentice chain is broken because the new tech required different skills

the new mould lofts translated the engineering practices over to the war emergency wooden ship building for lofting the timbers.

 

No references - just speculation.

 

How this applies to ship modeling:

 

Charles Davis introduces POF to model shipbuilding and presents the methods  and styles that he learned in the WWI shipyards as  being the style of the 18thC and early 19thC.  The earlier methods and builds were an entirely different tradition.  He deserves all credit for encouraging POF,  but we must go somewhere else for the proper what to do.

 

Harold Hahn also used an all bends and room = space.  I do not think that he did this because of what Davis wrote.  Hahn was focused on the time of the American Revolution.  The framing at that time had almost all wood.  The spaces were 1-2" air gaps.  There is not much visual interest in showing a POF hull with no below the wale planking if the frames on display are a solid wall of wood.  If every other bend is omitted, the frames are a more interesting display. It also saves half the work and half the wood.   Compared to planking a carved or POB hull, the volume of wood needed for frame timbers is 10 - 20 - 30 times that amount.   The calculation is BF ( board feet ) not the number of strips.

The loss to kerf and strange shapes cut from the stock is maybe 50%.