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[Bunkerbarge]

Please feel free to share your Questions and comments on Bluebirds build in this thread.

(  Build thread:    63 FOOT RAF AIR SEA RESCUE LAUNCH WHALEBACK   )

[bluebird]

John- needless to say that this is an absolutely excellent job you have made there. As I am a bit in that fast-scale-theme I wonder, why you have made it plank on frame. Was it your opinion to catch up the hull, like the origin had been built?
Don`t want to doubt in any way what you have done- just want to come behind the idea.
Thankkyou in advance.
Jörg

Hi there Jorg - to try and answer your above questions:

When I originally thought about building this hull, it was to try and show newcomers to the hobby what diagonal planking was about; so, originally I was only going to 'single plank' the hull and keep it at the scale of 1/2 inch to the foot and in doing so, I was planning on using brushless motors.  This brushless motor field was going to be a new learning curve for me personally - but, due to the expense of the brushless set-up, it wasnt a viable option.   I then began to rethink the build and it was at that stage that I decided to build a double-diagonally planked hull, using the inner planks as semi-scale, which should show the beginner or the 'newby' the basics of the planking method.  It would also show others, by adding the scale planking to the outside, how to commence producing a hull near enough to the original full size hull.

With using light materials, as I did with the very thin ply, this meant keeping the weight down to an extremely light hull.    When I took the hull from the building board, I weighed it, and it came in at 2lb and 8oz this is without any running gear added.   This hull is some 39 1/2 inches long, by 10 1/2 inches beam and I think you will find, you will have to go some, to find a fibre-glass hull as light as that, unless we begin to use carbon fibres.

Hope that helps to answer your question Jorg.   If not, fire away with more queries.    :)

aye
john e
bluebird

[White Ensign]

Hi John,
thankyou for the answer. Well, that explains a lot. Now I have to calculate the imperials into metric....
2lb = 2x453,6 Gramm= 907,2 Gramm
8oz= 8x28,35 Gramm= 226,8 Gramm
Total:                       1134,0 Gramm= 1,134 Kilogramm

Length: 39 1/2 " x 2,542= 100,4 cm
Beam: 10 1/2 " x 2,542= 26,69 cm

That gives me a very good relation to my 70`CMB hull, which is out of fibreglass with a deadweigth of in total 700 Gramm at nearly the same dimensions.
I think, that the most people mould much too thick with too many layers when using fibre and carbon isn`t the final answer.
However, this should not be meant to reduce your quality or skill. An awsome job which I am sure, I`d never reach (or just with very much difficulties.
Your photographs remind me on a shipmate at the SWA. He made a MTB all the same way and won the Duke of Edinborough-Trophy some years ago with it.

Again, thankyou for your information. Great to talk with shipmates about their technics. Go on with it, I`m excited to see some more.

Jörg

[Martin13]

John,

Great build.. Love the double diagonal planking. tried it out on my BB and was surprised by how strong the hull is before fibreglassing.

I.m just a little confused by one matter and that is why have you painted the hull after laying mahogany planking. I thought that the planking was going to be a feature of the model.....or have I missed something.

One other thing - when you were talking about the prop shaft exits and rudder positioning - how does one  do this when your (mine) drawings do not show this detail....I hope I do not install them at the wrong end.


Martin Doon Under

[bluebird]

Hi there Martin - in response to your queries....

I.m just a little confused by one matter and that is why have you painted the hull after laying mahogany planking. I thought that the planking was going to be a feature of the model.....or have I missed something.

One other thing - when you were talking about the prop shaft exits and rudder positioning - how does one  do this when your (mine) drawings do not show this detail....I hope I do not install them at the wrong end.

First of all - painting the planks - I myself would have loved to have left the mahogany showing and just with a coating of Epoxy - because, before I painted her, you would think she had been French Polished (the boat not the Mrs )  :)  but to keep in with authenticity of the model; we have had to paint her.

In certain lighting, looking along the hull, one can make out some individual planks along the side which you sometimes can see in the life sized boats.

With regards to props and rudders - there should be somewhere on your plans mention of position of motors in the hull.        If not, though, will have to look for some photographs/other drawings either on the web or in the books, which we can use and scale up to suit your drawings and take the dimensions from there.   Although, having said that, are you going to make your hull a 'single screw' or are you going to go for the 'triple screw' ??.

Aye
John
Bluebird 

[Martin13]

Hi there Martin - in response to your queries....

First of all - painting the planks - I myself would have loved to have left the mahogany showing and just with a coating of Epoxy - because, before I painted her, you would think she had been French Polished (the boat not the Mrs )  :)  but to keep in with authenticity of the model; we have had to paint her.

In certain lighting, looking along the hull, one can make out some individual planks along the side which you sometimes can see in the life sized boats.

With regards to props and rudders - there should be somewhere on your plans mention of position of motors in the hull.        If not, though, will have to look for some photographs/other drawings either on the web or in the books, which we can use and scale up to suit your drawings and take the dimensions from there.   Although, having said that, are you going to make your hull a 'single screw' or are you going to go for the 'triple screw' ??.

Aye
John
Bluebird 

Hi John,

I new I had missed something about the mahogany being painted.

As for the propshafts and rudders, I intend building as three screws.
The drawings show the location of the gas turbine engines , gearboxes, exhausts etc, but weeing I do not have the technical prowess with the real boat - am a little confused. Don't worry about chasing down pic's as I have about 35 photo's of the beast when she was first laid down with a couple showing props and rudders.

I will send CD with the plans -

Thanks again

Martin doon under

[Martin13]

[boats.

The drawings show the location of the gas turbine engines , gearboxes, exhausts etc, but weeing I do not have the technical prowess with the
Martin doon under
[/quote]

Sorry, early morning finger problems - weeing should have read as "seeing". Now why did the spell checker not pick up that error 

Martin doon under

[Proteus]

The drawings show the location of the gas turbine engines , gearboxes, exhausts etc,
Martin doon under



I did not think the boat Bluebird was building had Gas turbines? or are we talking about Two different boats ?

fredy

[Martin13]

The drawings show the location of the gas turbine engines , gearboxes, exhausts etc,
Martin doon under



I did not think the boat Bluebird was building had Gas turbines? or are we talking about Two different boats ?

fredy

Sorry Proteus,

Yes, I was actually talking about my boat HMS Brave Borderer. apologies for the confusion

Martin doon under

[Proteus]

Yea no problem  Martin , I was just a bit confused (doesent take a lot with me). I kept reading the topic and thought I was missing something, it was as much for you than  me that I posted. no need to apologise

fredy

[bluebird]

Hi there Proteus I admit I am as guilty as Martin for side-tracking the topic  problem is Martin is in the process of a build, and, I am trying to persuade him  to put his build on the Forum.

Come on Martin, let us all see your pics - its a blinking good build of yours.

aye
john e
bluebird

[Martin13]

Come on Martin, let us all see your pics - its a blinking good build of yours.

aye
john e
bluebird

My god your persistent

It's coming, one more day for work then I will set about posting my build.......although spending time sanding my recent attempt at fibreglassing may be the order of the day :(

Martin doon under

[Stavros]

Bluebird are you going to varnish that wonderfull deck planking

Stavros

[bluebird]

hi there, Sadly to say, the deck planking is either going to be a grey or a yellow, depending on which era I build the boat at.

Early on in World War II, some of these boats had bright yellow'ish deck and then later on in hostilities - they modify them to 'just grey' because these Rescue Launches became targets for not only the enemy but BOTH SIDES 

aye
John e
bluebird

[Martin13]

G'Day John,

2 Questions,

Rubbing strake - was this timber of plastic - now if I read the photo's correct, did you pin the strake then glued or the other way around - was this to protect the paint - maybe I am just off the track.

Q2. Prop shaft support - probably got this wrong too - but if I read it right -the outer sleeve, then another to slide inside, then another again, solder, then fit shaft, all of which then fit into "P" bracket  ??? ???
I thought that the bronze bush at the end of the tube supported the shaft beyond the "P" bracket - why all the sleeves, or I'm reading this wrong too

I still think it a shame to paint over the Mahogany - what a beautiful piece of planking, maybe one day when I grow up, I can do it too...

Martin doon under

[bluebird]

Aye aye there Martin doon under

Rubbing strake - was this timber of plastic - now if I read the photo's correct, did you pin the strake then glued or the other way around - was this to protect the paint - maybe I am just off the track.

The rubbing strakes were 1/8 x 1/8 inch Obechi timber - I first held the strake in place with Superglue and then pinned it.   To protect the paint was one of the minor jobs it does; the main function though is to protect the joint between the deck and the hull side.

 

Prop shaft support - probably got this wrong too - but if I read it right -the outer sleeve, then another to slide inside, then another again, solder, then fit shaft, all of which then fit into "P" bracket   
I thought that the bronze bush at the end of the tube supported the shaft beyond the "P" bracket - why all the sleeves?

The 'P' bracket is the bush which is next to the propeller, so, this 'P' bracket takes a percentage of the thrust between the propeller and the stern tube bush.

The reason for all the sleeves is; it is an alternative method of making a 'P' bracket, and, it is for those who do not have the facility to machine one of these on a lathe; for those who do have a lathe - they could produce one of these from a suitable piece of say bronze or brass material.

Hope this helps; if it still needs any clarification, please give me a yell  :)

aye
John e
Bluebird

[Martin13]

Aye aye there Martin doon under

 

The reason for all the sleeves is; it is an alternative method of making a 'P' bracket,

Hope this helps; if it still needs any clarification, please give me a yell  :)

aye
John e
Bluebird

Ahhhh......The penny has dropped...

Martin doon under

[Martin13]

Gee, that Aussie 50 dollar note can't be worth much in the UK?

Question-1 - Re your intermediate stringers -
Your model is about 39" long and I forgot the beam. I have noticed that you have four stringers between the keel and chine. My guess is that by having the stringers closer together, there is less likelihood of hollows in the hull - Am I on the right track?

My build of Brave Borderer 1:16 scale being 72" long and beam of 18", how many stringers would you have placed between the keel and chine - I have three, and now realise it would have been better to install more as I have discovered hollows whilst sanding the glass.

Question-2 Planking
I noticed that when you planked the second layer that you started on the side first then did the bottom so that the end grain of the planks were not facing down. Unfortunately, on my model, I did it the other way around - bottom then side. Is this critical or will the Polyester resin seal the end grain? :-\ :-\

Martin doon under

[bluebird]

Hi Martin and everyone  :)

Question-1 - Re your intermediate stringers -
Your model is about 39" long and I forgot the beam. I have noticed that you have four stringers between the keel and chine. My guess is that by having the stringers closer together, there is less likelihood of hollows in the hull - Am I on the right track?

The beam is roughly 10 1/2 inches.   If you note, the bottom stringers - two of them actually form motor mounts on either side of the keel;  the distance at the widest part of the hull on the bottom is divided roughly equally - into four sections.  This serves three purposes :  As you say prevents hollows and humps as well as adding strength to the build;

Also the more complicated the bottom hull shape is, they help to reproduce the shape - the actual thickness of the stringers (or the dimensions) depend obviously on the size of hull you are building - the larger the hull, the more stringers you would put in.

ooOOooOOooOOooOO

My build of Brave Borderer 1:16 scale being 72" long and beam of 18", how many stringers would you have placed between the keel and chine - I have three, and now realise it would have been better to install more as I have discovered hollows whilst sanding the glass.

Knowing of the complicated shape of the bow, on the Brave Class hull, I would have opted to put at least five stringers in, per side, on the bottom.  However, they would have only been about 3/16 of an inch square and for the sides, I would have gone to about four or five stringers per side.

ooOOooOOooOOooOO

Question-2 Planking
I noticed that when you planked the second layer that you started on the side first then did the bottom so that the end grain of the planks were not facing down. Unfortunately, on my model, I did it the other way around - bottom then side. Is this critical or will the Polyester resin seal the end grain?

On your build it is not critical.   The Polyester will have sealed the end grain.   The drawback of your hull though is that it doesnt have a protective spray rail around the chine, where the Whaleback does.  If we wanted to be truly authentic to a double diagonal build, the planks would have been recessed into a rebate in the chine stringer and I have seen this done on a build before; and when done correctly it looks absolutely beautiful, but, it could be very, very time consuming.

Two pictures attached are what I worked from when I did the planking; and, if you have a close look you may be able to make out the rebate line - these pictures were kindly supplied by CDSC123 - and I am deeply indebted to him as he has helped me a great deal with this build.

Aye
John E
Bluebird

[DickyD]

Wow John worth waiting a fortnight for the cabin, very nice. 

[cdsc123]

Love the opening sick-bay doors with home-made hinges  
How are you planning to make the turret domes?
 

[bluebird]

hello there Christian  do you like this one:

PLAN A:

Hopefully, I am going to produce a 'dummy turret' from solid wood; which can be collapsed inwardly.  Onto this, I will construct a framework similar to that of the real turret from plastistrutt 't' section of the correct scale.  Then glue in clear panels of styrene.   

if this fails....

PLAN B:

Produce the gun turret out of solid timber once again; that will become the male and the female will made up of a flat piece of plywood with a hole drilled in it slightly bigger than the turret.  The clear styrene sheet is then 'clamped' onto the plywood and put into the cooking oven and warmed through   when the styrene is nice and soft and pliable the male former is pushed through the hole forming the Dome shape.    That is if it hasnt all melted and ruined cooker  and then flat styrene stip would be glued on top of the Dome to assimilate the structure.

  To be honest with you, Christian, I am dreading this part of the build

aye
john

[cdsc123]

I look forward to seeing how you do them, I wimped out with my 1/24th Thornycroft HSL and bought them from Deans Marine but that's not an option for you. I have heard people have used the valve out of old radios though..
What did you think of For Those In Peril?

[bluebird]

Hi there Christian

Really good shots of the whalebacks plus Fairmile Bs - anybody building a Fairmile B wants to try and get hold of this film for some of the shots - storyline a bit weak - but worth watching for the shots of the craft alone, just as you said. 

I did try and purchase this film on DVD - but couldnt only manage to get the video.     It would be good on DVD because of I would be able to pause it without damaging the film so I could have a good look at the detail etc.

aye
john e
BLUEBIRD

[cdsc123]

Hi John- VMT for the wonderfully clear explanation on how to tackle the turret domes 
One question, how thick was the clear PVC sheet? I feel much happier about trying it myself now.   

[bluebird]

Hi there Christian

I ended up, and obtained the best results, from PVC that was 0.5 mm in thickness.

The other thing I found was, on the plywood jig, with the hole in - do not tighten the two pieces of plywood together too tightly.  Clamp them so that, with a little effort, you can move the PVC back and forwards.   This allows for movement when you push the mould through the hole and it also gives a uniform thickness around the dome.

If you clamp it too tightly, not allowing the material to move, what you will find is that the finished moulded dome is fairly thick at the top but thins out drastically towards the base.  This makes it unusable or splits which has happened to me once or twice.

Just as a sidenote, have you ever come across two versions of the turrets?  A low profile turret which is supposedly later on in hostilities to the turrets which were added when the vessels were first introduced.   

Of all of the vessels, not only with the Whaleback, but, other Air Sea Rescue Launches with the ball turrets, they all appear to be of the 'rounded type' do you know of any different ones and do you have any reference photographs????

Aye
John e
bluebird

[cdsc123]

Thanks John, I'll give that a try. I agree with you regarding the turrets, as far as I know they were all the Boulton & Paul aircraft type turret, although in some photos of the Hants & Dorsets they do look lower, I always thought this was because of the armour plating around the base though. I will check with the experts and get back to you on this one..

[Martin13]

Now don't forget to show us how you made those hatches and the vents. I have pen and paper ready. This stuff is really important, especially when one decides to build a model where you cannot buy ready-made fittings.

Must admit though, I'm still in awe on how you made those gun turrets - would never have thought it possible..

Bl###y  Amazing  :)

Martin doon under

[Martin13]

Thanks John for the explanation on how you made those hatches and Hinges, this is exactly what I was hoping for. I need to make transom exhaust flaps for Brave Borderer and your method is simple and perfect for the job.

It's amazing how you make your fittings with only one fully functional arm

The Brass channel - was that obtained from a hobby shop? ???

Your model is looking great - keep up the good work and How To's

Martin :)

[marksaab]

Hi Bluebird

just started following your build, wonderful stuff, your write ups are great, how do you find the time to do them!!

I saw you were looking for "For those in peril" on DVD, I just got a copy of ebay, its a buy it now and the seller has one left, actually he makes the dvd copies so I guess he wont run out!

here the item number 360072008936

I guess Christian mentioned that there is a whale back here up in Norfolk!  There is another near my boat in West Mersea, both have the same redesigned superstructure.

Anyway hope this helps.

Mark

[bluebird]

good morning there Mark

I was lucky enough to be supplied with a DVD for those in Peril on the Sea - Christian, in his goodness did that for me (I had purchased a copy on video, but I wanted to pause the video for long periods, so I could examine different aspects of the vessel, and, of course the tape began to deteriorate on the video - as they do)  :-\ .  Thank you to you for the Ebay information Mark.

Christian has been an immense help to me with information throughout the build.   I am very grateful for that.

As far as I am going with the build - it is going rather slowly at the moment - due to the fact I am busy researching some other vessels - for a possible build.

aye
john e
bluebird

[mike64]

Hi Bluebird
I have been reading with great interest the article concerning this build. I purchased the same plans as you about 15 yrs ago, and I hope to star building in the next few weeks. Part of the reason being confidence to tackle this project as I am a relatively inexperienced modeller at this level, but what the hell I have waited 15 yrs lol. I am planning to upscale to 1:12 giving an overall length of 63", I have a couple of questions that have troubled me and you or someone else more knowledgable than me can help with. The first being the power plant, I want a triple screw set up and was looking for recommendations for motors. The other problem I forsee is  the stringers and chine rails where they meet the bow. I have looked at the pictures you have posted but I can quiet see how you completed this. Please forgive me if you feel this is a silly question, but I need help with it. Any help, advice or additional pics of your build would be greatly appreciated.

Mike

[bluebird]

Hi there Mike

welcome to the Forum my friend; one thing I can say straight away always remember no question is a stupid question - the only stupid question is the one - one should have asked 

First off; concerning the whaleback build, can I ask you - are you going to build it true to scale or as near to scale as you can get.   The reason being, the original vessels had all their props turning in the same direction.  (All three were turning anti-clockwise).

This is how I built my model and I have yet to try it out on the Lake - I have a suspicion that the stern will tend to kick to one side.   The other thing is these boats with scale size rudders are notoriously difficult to turn using rudders only.

This is why myself I opted to have independent controls of each motor; through a mixer.  Which is in turn connected to the speed controllers.   This is to aid the turning circle of the vessel.   As for size of motors; the model I am building is roughly about 40 inches long; and I have equipt her with 3 x Graupner 600 motors - I intend to eventually run her on 3 x 7.2 NiCad packs.

So, looking at your intended build; of 1/12 scale - i.e. roughly 63 inches long - I would be looking for something like 700 or 800s motors with NiCads.   

Now for your next part of the question; as far as the build the chine stringers - where they reach the bow, they are notched in to what we will call 'sidecheeks' I have shown these in a small sketch and they are marked in as 'B'.

On the next drawing, you will see how I have made these 'sidecheeks' up out of 1/4 x 1/4 inch Obechi, these are glued either side of the keel at the beginning of the build and shaped when they are fairing the frames in.   You will see these marked as 'D' in the drawing  -  as for the deck stringer/gunnel stringer, when it reaches the last frame or the first frame whichever you want at the bow; it overlaps by about 1 inch past the frame - there is a plywood sub-frame shall we call it; but I normally call it a 'false deck' which is glued flush with the top of the frame and the top of the keel.  It takes the place of the stringer at the bow and is marked as 'C' on the scribble.

Hope this is of some help to you.

aye
john e
bluebird

[mike64]

John
firstly your remark about a stupid question is very much appreciated. I was thinking of running one prop clockwise to negate the effects you are expecting as well as using a proportional motor control which is controlled via the rudder control. I hope to build a near scale model due to my limited experience and progress on more accurate models at a slightly later date. I plan to start marking out sometime in the next week (got a week off work coming up). I have looked at the information and sketches you have provided and really do appreciate the time you have spared to do this. It may be fare to say, I would expect this is not the last time I pose a questions to you and any other forum members.

Mike

[Hagar]

Whilst on the subject of silly questions...

Where can I posibly find a copy of the plans for this boat?
 It does look rather nice, and I am feeling the urge to build sumink.