Denny Steam Gunboat

[Steve D]

Finally, I've got some time to start the post on my next scratch build, a 1:48th scale Denny SGB, actually S304 Grey Fox, IWM picture below, at 145ft, the model will be ~36 inches long in old money.  Warning, I expect this build to take a year or so.  This time I really will try to make everything (apart from the split-pin stanchions), but some complex components will be 3d printed, though to my own drawings.  I'm also going to have a go at the propellers, printed in wax and then cast, may as well go for it...

 

My aim is to produce full drawings, components and etchings so others could build the same model if they wish.  I will document it all here, mistakes and all

 

 

I have two professional plans, one available on line by G Stone in 1:48th scale and one from model shipwright no 87 (March 1994)

 

 

But as I do with all major builds, I also contacted the maritime Museum in Greenwich (actually the old brass foundry in Woolwich) who have the archive of all naval vessels since the 18th century.  They claim to have an example of every type that served in the navy and they have a number of drawings of SGB's.  I chose three drawings of SGB303 (the sister of S304), which include the GA and the shell expansion, a vital piece of the puzzle for plated models.  At 36 inches long, the model is too large for my block infill so I'm going to plank it on frames and then plate the outside with aluminium sheet to the shell expansion drawing, rivets included.

 

Shell expansions show stuff other drawings omit, like the water intake and outlet for instance.  A section of the drawing is shown below and on it you can see the inlet is rectangular and on the centre line, I've not seen that detail before.  This section also shows the layout of the outlet with the doubler plate etc.  In other parts of the drawing is it clear that the portholes on port and starboard where not in the same place, again, where else could you find that sort of detail?

 

 

From a scan of the lines (actually from the model shipwright drawing which looks a higher quality piece of work) I prepared a cutting drawing of the keel and frames. The frames have been set back by 2mm to allow for the planking.  The keel is 5mm ply but the stem and the docking keel will be made of brass, inset in the ply as the former is sharp and the latter much thinner than the ply (poor quality copy below

 

I started yesterday by cutting out the keel and setting in the brass, seen below on a temporary building board to keep everything straight.  Keeping hulls straight is a real challenge as the planking can frames can easily end up twisted (I know this from experience) so I make a lot of fuss at this stage, sometimes it pays off...  The hull will have a large slot in the deck for the deck-house.  I'm not going to build a working model, but this could easily be done and then the slot would allow access to the motors battery etc.  For me is helps to keep the deck house separate until very late in the build, then is will just slot in

 

 

The frames were printed and mounted to 3 mm ply for cutting out

 

 

Much later today...

 

 

More timber to keep things straight.  I've had to slot the build board as the boat does not have an exposed keel apart from the small docking keel at the back.  I'll be planking it upside down, more detail later.  The platform at the back holds the alignment holes for the rudders, you can also see the holes for the prop shafts (5" dia)

 

 

After much fettling, I glued it up, tape is holding everything straight (I have a phobia about straightness....)

 

 

So, we're off and running, sheer strakes going in tomorrow

[Jerry L]

Following with great interest. Can not agree with you more concerning the 'straightness' phobia.

[robgizlu]

That is Super fast work - Really looking forward to this.  

They were very graceful boats

Rob

[Steve D]

Thanks Rob, speed is deceptive at this stage, but I agree, the frames went together quite quickly.  I just hope this time my drawings are OK, less ability to fudge things with plank on frame 🤞

[Courageous]

Impressive work Steve.

 

Stuart

[Steve D]

23 minutes ago, Courageous said:

Impressive work Steve.

 

Stuart

Its a start, thanks

[mollythedog]

Good luck with this,a handful but the subject merits the commitment,

[JohnWS]

Nice!  I'll be following closely.  

 

John

[dnl42]

I'm in!

 

I'm particularly interested in seeing the cast propellers as that might best suit a project I have in mind.

[Steve D]

9 hours ago, mollythedog said:

Good luck with this,a handful but the subject merits the commitment,

I've had that Model Shipwright plan for 20+ years, its always been on my mind to do, will make a nice companion to the Fairmile

5 hours ago, JohnWS said:

Nice!  I'll be following closely.  

 

John

Cheers, John, any comments most welcome

4 hours ago, dnl42 said:

I'm in!

 

I'm particularly interested in seeing the cast propellers as that might best suit a project I have in mind.

Shapeways offer this service and the propellers are quite distinctive so its a good one to try

[stevehnz]

Liking the look of this, I'd love to do one in  1/72, so if I'm seen to be peering into hidden corners, I'm just being nosy. Take no notice.

Steve.

[Steve D]

22 minutes ago, stevehnz said:

Liking the look of this, I'd love to do one in  1/72, so if I'm seen to be peering into hidden corners, I'm just being nosy. Take no notice.

Steve.

Peer away Steve, I'm already asking plenty of questions myself so if I can help in any  way, that's great

[Bandsaw Steve]

This is going to be awesome! I’m going to watch this closely. 👁 👁 

[beefy66]

3 hours ago, Steve D said:

I'm already asking plenty of questions myself so if I can help in any  way, that's great

You may regret that statement Steve I will be also hoping to gather some information from your build as I will be doing GREY GOOSE in the near future but in the much smaller scale of 1/350.

 

 

Best Wishes

 

beefy

[Steve D]

23 minutes ago, Bandsaw Steve said:

This is going to be awesome! I’m going to watch this closely. 👁 👁 

Any suggestions or questions, please go ahead

17 minutes ago, beefy66 said:

You may regret that statement Steve I will be also hoping to gather some information from your build as I will be doing GREY GOOSE in the near future but in the much smaller scale of 1/350.

 

 

Best Wishes

 

beefy

Wow, that's tiny, rather you than me  🔭, still it has the advantage of not taking up so much room I guess, I won't say what  my wife thinks of all the cases for fear of being banned

[Steve D]

Quick update, the sheer strakes went in OK and the deck is now on

 

But I managed to loose the alignment slightly on the opening, which is a bit of a (expletive replaced) shame  

Cleaned up now, the curves look OK (hard to sort) and I can sort the hole with the deck house.  The hole in the forecastle is for the 20mm Oelikon mounting which sits below the deck level, thanks to G Stone for that detail, not shown on the other two drawings and I'd have missed it otherwise, you cannot have too many drawings....

 

 

I love the 3 dimensional curvature of a deck, its a really interesting hull form, sweeping up from a shallow stern to a raised bow, cool

[Steve D]

Having three drawings is great, except when they don't agree...  If you only have one drawing, that's the truth, if you have three, the truth gets confused.  This is the case for the desk house arrangement, three quite distinctly different drawings.  The two commercial plan show it narrower behind the torpedo tubes, the actual GA from the design office makes is clear that is is parallel to the rear, I went for that version.  The heights are also different as are the slopes.  The torpedo tubes really get in the way of this and none of the drawings have the sections you expect to clarify things.  It seems to me that the rear upper deck and the funnel housing deck are parallel to the keel, but the lower forward deck and the bridge follow the deck rise (somewhat...)  All of this makes a simple looking structure actually quite intricate, plus is has those curved bridge wings to add to the challenge that are right angles to the keel so sit on a slope to the deck and a different slope to the bridge floor.  

 

And of course, it didn't quite fit in the hole I'd so carefully made for it, ungrateful object...

 

This is of course really a buck as it will be plated in aluminium, though for the bridge, I'll probably go for copper as it will be structural above the bridge floor.  Forward chart house still to be added, but at least I have the actual dimensioned drawing of that from the Maritime Museum so no doubt there

 

 

The reason to fit it into a hole is now apparent, there are curves everywhere in every direction and so making one that sits down on the deck (I know from experience) is just about impossible.  This whole assembly will remain removable up to nearly the end, makes working on it so much easier, after a lot of sanding, it is a tight snug sliding fit now

 

 

Hard to see but the upper surfaces are curved to the deck camber apart from the bridge floor and funnel housing roof which are flat, the wonders of working at this scale is you have the opportunity to care about such stuff

 

No matter how careful, it will need some filler before plating, but its square, upright (where it needs to be), on the centre line and as good as I can get it...

 

Interestingly, the sloping flanks of the funnel housing are shown on the builders GA as bosun's lockers, which makes more sense that the skylights shown on the War Thunder 3D model and the two random bolted openings shown on the model shipwright drawing

 

You'll see I've cut out the engine room skylights, not sure how this will end up, but cutting them out later is a nightmare and I can always cover them up

 

In case you are wondering, I'm still considering the planking.  I've been debating double diagonal because the bow is so flared, but the wood I've bought is for normal fore and aft planking, more complex to taper but actually quicker....  The challenge is where to start....

[Courageous]

1 hour ago, Steve D said:

All of this makes a simple looking structure actually quite intricate,

You are the man, you'll sort it.

 

Stuart

[Steve D]

Warning, planking purists turn away now, this post may be upsetting...

 

Basically, this planking will sit under the plating after being smoothed out with filler so there is little point in perfection and this is a way aways from that...  The bow will be carved from a block of Jelutong, too hard to taper in to that tight.  Still, what I've done will work with a lot of sanding, it just doesn't look too pretty at this stage

 

 

I've also made the chart house which manages to combine angles in various impossible ways, this will be straight painted as the actual chart house was made of plywood with the roof covered in cloth (I can do this...)

 

The observant will notice the rear deckhouse roof is lower, this is not due to subsidence, it was of course a stupid mistake.  The line I'd taken was the top of a cowl vent casing, not the roof.  The more I looked at it, the less sense it made so more careful examination of the drawings, in spite of the torpedo tubes being in the way) and the real line became apparent.  20 seconds in the band-saw and a new back was made, as ever I rework mistakes as I go along...

 

 

That cylinder is the gun mounting base for the midships gun, the deck extends over it, that's just resting while I think about the framing and plating.  If anyone has a picture of a gun platform like this one, I'd love to see the deck detail around the gun.  On Grey Fox, this position mounted a 20mm Oerlikon

[Jerry L]

Great work! Beyond my capabilities, really enjoying and learning. Can you let us in on that hull that you have stored on the shelf above the gunboat?

[Steve D]

45 minutes ago, Jerry L said:

Great work! Beyond my capabilities, really enjoying and learning. Can you let us in on that hull that you have stored on the shelf above the gunboat?

The hull is a year's work on HMS Jason, a torpedo boat chaser from the 1890's  I started it 20 years ago but got tired, it has immense amount of detail left to do (probably 2 years worth) and I just decided that it is a project for when I retire (if ever...).  It's moved twice with us and has acquired a lot of dust.  If it becomes a chore, then it's no longer a hobby.  I switched to smaller projects that need smaller cases...

 

Also, I was not happy with the bilge keel, now I think I could do better....

 

This is a better picture, its similar to the boat in the middle picture in the background (HMS Speedy)

 

 

What you can see in this picture is the aluminium plating technique I will be using on the SGB, though with rivet detail.  These torpedo boat destroyers were flush riveted (very slow and expensive to build) to get the most speed from triple expansion engines of the day. Once they put turbines in, they left the rivets exposed because the parasite drag of the rivet heads ceased to be material.  The SGB is mostly normal rivets according to the shell expansion drawing notes

 

Steve

[Jerry L]

Steve, thank you. Your level of craftsmanship is extremely evident in the quality of your work. And yes if a model becomes a millstone then the enjoyment is lost. Thanks again for starting this build, I am really enjoying it.  

[JohnWS]

She's looking very fine, Steve.  Another awesome project to watch & learn from.

 

You're setting the bar pretty high again for the rest of us. 

 

3 hours ago, Steve D said:

... I've also made the chart house which manages to combine angles in various impossible ways, ...

Your chart house is similar to the one on my old Fairmile 'D' build.  I remember the number the attempts I made using paper card before I got it all those angles 'just right'.  I can't imagine having gone through the same exercise building it out of wood. 

 

John

[Steve D]

12 hours ago, JohnWS said:

Your chart house is similar to the one on my old Fairmile 'D' build.  I remember the number the attempts I made using paper card before I got it all those angles 'just right'.  I can't imagine having gone through the same exercise building it out of wood. 

 

John

You're right, there is a lot of similarity between the D and the SGB, the more I look at Lambert's anatomy of the ship book, the more help I find supplementing the outline drawings I have.  I appreciate your comments as ever, it counts more from other modellers

[robgizlu]

Wow - that Torpedo boat chaser really does look an epic build 

Wonderful progress on Grey fox

Rob