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[TurboTyne]

I'm dismayed to see that 10 years have passed since I asked for and received advice about the design of an R-class destroyer in the topic "Advice re: WW1 destroyer, scale displacement etc." ( https://www.modelboatmayhem.co.uk/forum/index.php/topic,48047.0.html )

Since then I did make a start on the project but then became side-tracked on other projects. I'm now back on the model ship again. Since I received excellent advice at the time I thought I'd show that it was not all in vain - although the model is still very far from finished. The model in question is a 1:48 scale model of the R-class destroyer HMS Rigorous. I obtained copies of the original drawings prepared by John Brown from the National Maritime Museum. The model is to be made of soldered tinplate as pioneered by Norman Ough and described in two excellent articles written later authors. So the first stage involved construction of a wooden former over which to assemble the tinplate shell. From the drawings  I made a set of aluminium templates of the sections across the hull and these were used to shape the former. One complication for the model is that the hull shows a degree of tumblehome in the midship region and that means that it will not be possible to simply lift the completed shell off of the former. Therefore I made the former out of a large number of wooden blocks which were initially all rectangular and arranged in 4 and 6 layers. They were all screwed together in a way that the screwheads can be accessed from the upper deck level so it can be removed in pieces. It took quite a lot of head scratching to be sure that the blocks were suitably sized, overlapped at the vertical joints and the screws were positioned so that they secured the blocks well without being at the surface after the former had been shaped.

This photo shows the initial former before shaping.

[TurboTyne]

These photos show the former after it was shaped. The gantry shown over the inverted former was used to guide the position of the aluminium templates and can be moved along the board to the relevant positions. This was all completed a couple of years ago. The two colours of wood just reflect the wood that I had available at the time - mahogany and some knot-free pine that had been in my garage for about 15 years.Next stage is the actual plating.

[derekwarner]

Hullo Mike.......I had always considered the complexity  and frustration of soft soldered tin-plate model, together with the lofting of the hull expansion plate shapes as a near-lost Trade

So look forward to the build.....

Derek

[John R Haynes]

I have been building a w/line 1916 HMS Restless  at 1/192 for a few months now , nearly finished

[TurboTyne]

Thanks for your interest Derek. As I’ll explain below, this project has developed into a very interesting (well, it’s interesting to me anyway) investigation into shipbuilding practice back in the WW1 era.

John, was there a particular reason for choosing HMS Restless for your model? I gather it was also built by John Brown, but a year earlier than the Rigorous. I'd be interested to see photos.

The technique of shaping and soldering tinplate was bound to be challenging so before starting on the hull of a 5ft long model destroyer I decided to make a much smaller practice hull, and I’m very glad I did so because I have learnt a lot in the process. Apart from just getting practice at the task of soldering the plates together I have had to investigate certain details of riveted ship construction in the WW1 era. Although I’m not attempting to replicte all aspects of a riveted hull, some features seem important for the model.

The wooden former for the practice hull has a very basic and unrealistic shape. The main thing is that it has features found in the R-class destroyer which seemed likely to pose particular problems:  These are: 1. The stem; 2. The vertical rudder bearing fixed securely to a sloping undersurface of the hull; 3. The exits for twin stern tubes through the sloping undersurface and 4. Secure fixing for the two A frames that support the propeller shafts.

Regarding the stem, I was wondering how to join the plating onto this and how to finish the leading edge. I had been able to take photos of the pages of the ships covers at the NMM. These included detailed specifications for the M-class hull upon which the R-class hull was closely based. The specification for the stem is shown in this image.

[TurboTyne]

 I am allowed to show details of the ships cover documents, unlike the drawings which I am not allowed to copy.
The expression “4¹/₂ inches moulded” in the specification is key to understanding the design but I did not know if that measurement referred to the thickness or the depth of the stem. Eventually I found the book ‘Modern shipbuilding terms’, by F.F. Pease, published 1918 ( Lippincott Co., Philadelphia). This stated:
 “Molding of a stem: The fore-and-aft dimension”.
From the profile drawing of HMS Rigorous it appears that the plating extended about halfway across the upper (narrow) part of the stem. Drawings in a book by E.J. Reed (1869) called 'Shipbuilding in iron and steel'  (John Murray, London) show several examples of stems with rabbets down each side. It was stated that this required much more work than a plain stem but was considered worthwhile for warships.
I conclude that the stem was forged into the shape shown in the following diagram.

[TurboTyne]

Having the rebates makes for a very neat leading edge but at 1:48 scale the model stem would have a maximum thickness of about 3/64” or about 1mm and a moulded depth of about 3/32” (2.4mm). This seems very flimsy for the model. The stem for the practice hull is of brass and is much thicker than that, as will be the stem for the destroyer.

[TurboTyne]

 The trial hull was basically made from a 4 in. square timber off-cut plus a couple of smaller pieces. The assembly was crudely shaped as shown. Overall length is 19.25 in. The former needs to be a pale colour to allow the strakes of plating to be easily marked. Tests on all the usual types of paint showed them to be unsuitable for this because the heat of soldering while pressing the plates onto the painted surface made the paint tacky so it adhered to the metal. That would probably have made it impossible to remove the finished shell without serious distortion. In the end I used a home-made mixture of wallpaper paste and powdered chalk (whiting). This formed a distemper-type mixture. Wallpaper paste is made from substances that do not soften with heat and, when dry, the surface could be easily drawn on. If mistakes were made, it could be coated over or removed with a damp cloth. The only disadvantage is that it is less robust than paint. However, it does not need to withstand much abrasion in its current role.
The steel rods projecting from the stern tube locations were just to allow the wood rods to be aligned properly while the glue set

[TurboTyne]

 The crudely shaped and kinked piece of tinplate shown in the photo was not used and was replaced before any soldering was undertaken. The stem was inserted in a slot in the former. The main part of the stem was made from sheet brass. Another strip of brass was then silver-brazed onto its leading edge and filed to give a very rough rounded shape so the overall result was rebated on both sides.  This is a very crude stem but only for this rather hastily made practice hull. A different approach will be used for the stem of the destroyer itself.
Plating thickness

The destroyer hull is very narrow and so its displacement is small bearing in mind its length. Therefore the weight of the hull of the actual ship was made as light as possible. The shell plating varied in thickness depending on its location in the hull but was as thin as was sensible, varying from 15 lb/sq ft (0.375 in. thick) down to 7 lb/sq.ft (0.175 in. thick) and even as thin as 5 lb/sq.ft (0.125 in. thick) in some places. The 15 lb plating was mainly the keel and the garboard strakes (i.e. the strakes adjacent to the keel). Where maximum strength was needed the plating was high tensile steel.
The trial hull was made from 0.2mm thick tinplate. If used for the model destroyer that will be equivalent in thickness to the 15 lb/sq. in plating.
The next aspect to be decided upon was the structure of the keel.

[TurboTyne]

 As was common at that time, the M and R-class destroyers had flat plate keels and a continuous vertical keel. The latter was attached to the flat keel by steel angle bars and above, by more angle bars to the lower deck plating. This is shown in the following diagram. Thus the keel was a very strong I beam
The M-class specification is also shown below and states that the flat keel plates should be butt jointed and the edges should be planed.
The garboard strakes were IN strakes and were overlapped by the flat keel plates.
Obviously the hull of a model is not going to experience the same bending stresses as a full-size ship in a rough sea but with a thin tinplate hull it seems a good idea to include a degree of strengthening to the keel. My design is to have a flat plate keel attached to a double row of tinplate strips bent as angle bars. This is shown in the following diagram.

[TurboTyne]

 The following photo shows the pair of keel angles soldered together in the slot that was cut for them in the former. The flat keel was soldered on top later. The photo also shows the arrangement for providing a secure fixing for the A-frames. Slots were cut in the wooden former using one of the small cutting discs in a Dremel-type tool. The slots were positioned where the A-frame attachment points will be. Then, for each A-frame a bracket with each end bent at right angles was prepared from thin brass sheet. This was tinned with solder and placed with its ends in the slots. Next the piece of shell plating was positioned and clamped in place over the bracket, having first placed a small thin piece of solder on the bracket. The soldering iron was then applied so as to join the plate and the bracket together in their correct positions. The plate with the attached bracket was then removed and a small cutting disc used to cut slots through the tinplate right next to each end of the bracket. The plate and bracket were then replaced on the former ready for soldering.

[John W E]

hi ya there Turbo


it intrigues me to know, are you a member of one of the North East Clubs?   The reason I ask this is Heaton and South Shields followed by Tynemouth have a long history of tin plate home made hulls.   I do know there are one or two models in the South Shields club which date from (I believe the 1930s) and I do know Bob Kirtley is presently renovating a model of HMS Newcastle - that model was originally built in the late 1940's/1950's by someone from Heaton Club.


The reason I am mentioning that is that I can see you are progressing reasonably well with your build - however, between the 3 aforesaid Clubs there is a lot of knowledge that can be 'tapped' into that would help you along.   If you do wish.


Here is a photograph of one of Bob Kirtley's previous renovations which he converted to radio control and I know this liner was built before Co-op Store pies  .


John

[TurboTyne]

Hi John,
Thanks for that suggestion. Yes, I've met Bob Kirtley a couple of times - mainly to discuss his impressive flashsteam hydroplane and a steam turbine that he made. I did not know he was working on a tinplate hulled boat. I'm near Paddy Freeman's  pond and know a couple of people from that club, although I'm not a member myself. They've not mentioned anything about tinplate models at Heaton but your message prompts me to drop Bob an e.mail to ask about the models at South Shields.
I'm sure Bob will have some wise words of advice.
Cheers
Mike

[TurboTyne]

 This photo shows the flat keel soldered in place. It covers over the keel angle strips and overlaps the garboard strakes. The plate being clamped in place is part of another IN strake. It had to remain clamped until the OUT strake was soldered onto it.

[TurboTyne]

 This photo shows the completed IN strake being clamped in position while the OUT strake is being soldered. As with the actual ship, all plates in the same strake were butt jointed and have butt straps soldered across them on the inside of the hull. Small recesses were cut in the former to accomodate the butt straps so as not to cause a bump in the surface - there are more than enough bumps already.

[ballastanksian]

I was intrigued to read a chapter on tin plate hull making in a building model ships book of some forty five years vintage where the chap mentioned soaking everything in fluxite rather than acid based fluxes as they tend to eat the hull away over time. I don't know what flux you are using but it seemed to be the friendliest flux to the modeller. Your project looks amazing Turbo!!

[TurboTyne]

Thanks very much Ballastanksian.
yes, I am using Fluxite and I think I have the book you are thinking of - Scale model warships by Bowen. It contains an extremely informative chapter by Lt. Col. H.T.N Batchelor. Another very helpful article is Model shipbuilding in steel by John Purvis. It is made  freely available on-line by the publishers of "Model Boats" magazine at: https://www.modelboats.co.uk/688/model-shipbuilding-in-steel/?page
One worrying aspect of this is that both these authors prepared draft articles but died before the articles were published. In both cases the articles were considered so useful that they were edited and published posthumously.
Metal plated hulls seem to be very rare these days which is why I've described my methods a little and its definitely not because I am particularly pleased with the result so far. I hope the actual destroyer will be finished more carefully with the benefit of what I've learnt making the trial hull.
There is another current project about a metal hulled Clyde puffer but I can't find the link just now.
Mike

[TurboTyne]

This is the link to a series on the 'Model Boats' forum describing a very impressive model Clyde puffer built on metal frames rather than a wooden former.
 
https://www.modelboats.co.uk/forums/topic/tin-plate-clyde-puffer/


Somewhere I'm sure I came across another model puffer being built with plating of thin phosphor bronze. Since that has a high tensile strength it cn be used in very thin sheets just like tinplate but it has the distinct advantages over steel of being easier to solder and not subject to corrosion in water. But, a big disadvantage is the price of that material.

I've searched but cannot  find the web address for that report so if anyone knows I'd be grateful to hear about it.
Mike

[Geoff]

A fascinating blog which do please contine as this is very interesting. I have a "barn find" which is a 70" brass destroyer hull all solderd together of the J class destroyer Javelin. I think it was built in the 50's because some of the superstructure, which is in tin still has faint old logos on the sides.


I have done some research and the plans came frrom MAP so are not at all acurate. The hull is either 2" too wide or 8" too short for a J class and the plans are very simple. I suspect it was designed for those engineers who were building steam engines/boilers and wanted something to put them in.


Keep up the excellemt work amnd I look forward to the next episode!


Cheeras


Geoff

[TurboTyne]

Many thanks for the thumbs up Geoff. Is your brass hull soldered together in small pieces like original plating or bent up from a few large sheets?
 
The following photos are of the completed practice hull. When I first tried to remove it from the former it soon became clear that I could not simply lift the hull off. I only managed to separate them by dismantling the former and removing part at a time. The main problem was that excess flux acted as a glue because, after heating during the soldering process, it became more viscous. The presence of several small butt straps in recesses in the former did not help but they were very shallow and the hull was sufficiently flexible for them not to prevent removal. However, this experience highlighted an additional advantage of making the former for the destroyer in many small parts that can be removed one at a time. One problem with the Fluxite is that it's stickiness after soldering makes it difficult to remove from all the nooks and crannies. The dark patches on the surfaces in the photos are partly due to flux remains since I've not done a thorough clean-up. But also they are due to some sort of discolouration in the tin surface.

The hull feels pleasingly light weight but I have no idea how much a fibre glass hull of the same size would weigh. It is 19.25 in. long, 4 in. beam, 3.5 in. high and weighs 13 oz (376 g).
If I were intending to use this hull for a model I would need to plug a few small unintentional holes. Also I’d solder some frames inside to hold the plating in shape and solder in place some decking. These should improve its rigidity and will probably be even more important for the destroyer hull.
 
Hopefully the destroyer will look neater since my soldering technique and methods for cutting / shaping the tinplate have all improved during the construction of this practice piece.

Mike

[ballastanksian]

That is the book indeed! I was very interested in how he went about the process of building his hull (to the point at which the officer passed on to his next command) This will have given you so much knowledge on how to progress on your destroyer Turbo!  [size=78%]The test hull is a superb structure in its own right so do practice some priming and painting on it.[/size]



I did learn from a model engineer friend that some physical joining methods such as pinning etc can help if you need to add parts to already soldered saving some issues with the phasing of different melting point solders.

[TurboTyne]

Thanks Ballastanksian for your kind comment. Also for the advice about pinning parts together etc. I have obtained some low m.p. solder but have not tried using it yet. From your comment it seems like there may be issues regarding the low mp solders on top of 60:40 tin:lead solder. That is something i've wondered about. Pinning hull plates in place may be tricky because, in addition to lateral alignment it is also important to press the overlaps together. Holding the plates onto the stem by bending fine wire through fine holes drilled through plates and stem could work well.
Mike

[Geoff]

Mike,


Its all plated in small plates albeit the underside is moisly large flat plates, where is doesn't show. Please see attached.


Cheers


Geoff

[TurboTyne]

Geoff
Thanks for posting those photos. It looks a very impressive model.
Is it built on internal frames? If not, do you think it was built over a wooden former of some kind?
Do you plan to finish it, install power etc?
Being made of brass, is the hull very heavy?
Regards
Mike

[Geoff]

Mike,


It appears to have been built on flat frames (brass strips bent to shape) but its hard to tell. Its quote a heavy hull because its 70" long but its very boyant so no issues as such. As a scale modeler it gives me a conundrum because there is some deformation in the hull as it slopes downwards at the stern and its also either 2" too wide or 8" too short for a J class but as a stand off scale model it would be fine. I have seen another example completed as such and it looked very good on the water.


Whether I'll ever get around to completing the model to be honest I don't know as Ive sat on it for over 10 years!!


I look forward to seeing updates on your model.


Cheers