The Ship Model Forum

Yes, Pgollin perhaps misunderstood Church's comments. One careful look at the pic and you can clearly see canning effect on the freeboard that is references. And it cannot be mistaken for plates overlapping. I would refer you to the pic he posted and ask to zoom in on the white hull portions that would be above water. I dont know why actually they appear there, however. Those usually developed after sailing in rough seas over time (or just after sailing for long time). So it remains to be understood why it is there, but it is on the non-armorered part of the hull, it would seem...




Yes what Mr. Church refers to at least appears very much as oil-canning. You are not wrong when you talk about overlapping plates, but this is NOT what Church talks above. Look again - the hull freeboard above the antifouling paint (which is red black or grey, have fun with that one separately). You can see, clearly, a lot of vertical ridges running close to each other, with that distinct oil canning effect.

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It might not be classic "oil canning". There is another possibility to consider. It could be temperature related. In this view of the USS Barton (DD-722) (https://destroyerhistory.org/assets/sum ... als_01.jpg), you can see the framing because the temp outboard of steel beams was different from that outboard of the interior air spaces. What was the air temp when PoW launched? Could it be condensation in the photo rather than oil canning?

The dished-in plating appearance is very common on today's warships, even those that have yet to touch water. I agree with Dick that it may have to do with temperature, whether from the welding process as the metal heats and cools, or from the general atmosphere.

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De quoi s'agit-il?

As far as I'm aware, it's the welding process that's primarily responsible for this effect. It's more prevalant today due to the universal use of thin plate instead of armour. All of the KGVs were rivetted hulls, but if the ships were hot-rivetted you might expect a more subtle effect as a result on the thinner plates, such as the top of the hull there.

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King George V class Battleships in 3D

Yes indeed it is these areas I was referring to:



And not the lower hull plating below the waterline. As I outlined in my initial post it is obviously not 'oil canning', as the hull has not been to sea yet and not been subject to wave action that would be necessary to cause 'oil canning'. But what else does one call it? It looks like oil canning even if it is obviously not really.

It's the hull framing showing through the exterior hull plating. She was launched in May 1939 which would be late springtime in Liverpool when you might still have warm days but cold nights. That might account for the effect?

In any event, it is very subtle and not at all apparent in any other photos I have seen of King George V Class battleships.

And I couldnt see the forest for the trees.

Given previous discussion I was looking below the waterline. But when pointed out in photo, it stands out like the proverbial dogs.............Interesting 'effect' whatever may have caused it.

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“We are off to look for trouble. I expect we shall find it.” Capt. Tennant, HMS Repulse. 8 December 1941
“A review of the situation at about 1100 was not encouraging.” Capt. Gordon, HMS Exeter. 1 March 1942

Hi All,

Hello Mr Church, as far as I know from memory the hull plates were 40lbs at that point, the frames were joggled to follow the "in and out" plate construction.

The plates were overlapping in most areas and butt strapped in others each plate being riveted to the framing behind. Some plate joints, mostly below the waterline were treated with Aranbee composition designed to seal and streamline the joints.

I would guess that the D steel used in the hull could be made to form a series of flex areas either in the riveting process, causing the visible distortion (but there are also longitudinal frames for decks and intercostal frames too). A temperature difference (I have launch details so I'll check if there's temp data) may cause a similar effect which as DavidP says the paint enables us to see. The effect does seem to go down the hull side.

Prince of Wales was, as far as I can tell, the only KGV with the knuckle at upper deck level forward. If you look at KGV you see the hull side at the bow rise into the flare and meet the upper deck with a sharp edge. On PoW this doesn't happen (the pic shows it wonderfully) the hull rises into the flare at the bow, but doesn't form a sharp edge, it flattens and forms a small flat knuckle that meets the upper deck edge. This starts at the stem and fades out just before A turret, I don't think Duke of York, Howe, or Anson had this feature?

There are pics of other riveted Battleships showing similar "canning" but as you say most have seen sea time.

I will try dig out the plating drawing and launch particulars if that might help.

Best wishes
Cag.

Wave-action as a driver for the oil can effect is a bit of a modeller's myth, I think. As can be seen in numerous photos, brand new ships that have never seen water yet exhibit the effect strongly. It is caused by the expansion and subsequent contraction of the hull plates due to the intense heat of the welding process. The outside of the plate will cool slightly faster than the inside due to being in open air, so they almost uniformly become concave. I don't think wave action plays a significant part in this. (I'm a mechanical engineer)

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King George V class Battleships in 3D

At the risk of leaving the battleship navigable channel and going off-topic, I definitely agree the effect is present to an extent on new hulls that have never been to sea. But I would respectfully disagree that wave action plays no part whatsoever and that it is a mere modeller's myth.

I took this photo of the 1981 built car ferry Stena Europe the other week. Look at the oil canning effect in the lower reaches of the bow opposite the rust streaks. The effect is worst nearer the waterline, which will likely receive more wave impacts than the upper reaches of the bow. Of course the lower hull form and the shape of the bow, and how it rides or pierces the waves will be a factor here in where the effect occurs more strongly:



Naturally a battleship will be of sturdier construction than a mere car ferry. But the idea remains the same. The USS Iowa Museum has a short video posted on Youtube about repairs to her hull. It is filmed from water level from a small boat on a high resolution camera so you can really see the 'oil canning' effect around her bow. I doubt it has all been exactly like that since she left the shipyard in 1943. Though the effect probably was there to an extent in 1943. Heavy seas in the meantime must have had an impact on it. Screenshot still showing 'oil canning' to her bow and a link to the video:



https://www.youtube.com/watch?v=O2oE7TkfpkY

Finally to try and drag things back onto the topic of the King George V Class Battleships again, here is some footage of the Home Fleet from 1942, including King George v and Victorious. Some heavy seas shown towards the end, I would have to think these would 'oil can' the ship's hulls over time:

https://www.youtube.com/watch?v=6iXqM630DD4&t=61s

Hi All,

Hello Mr Church, as promised I have taken a look in my files and the plates did vary in thickness but at upper deck level they were about 40lbs but I'll dig a bit further as there are other drawings I need to look at.

The launch details don't give much temp detail, her weight on launching was 18,414 tons of which 34 tons was paint/compositions. She was launched at 11 am in fine sunny weather with a light SSE wind and took 45 seconds to launch.

Hope that helps a wee bit, but I can imagine that due to construction processes and stresses "oil canning" like patterns are present on new ships and are created by numerous factors on ships that have seen sea time.

Unfortunately PoW also had hull damage from bombing in mid 1940 (I think I have the damage report on that somewhere) and later from damage during the Bismarck action and of course from her sinking.

Best wishes
Cag.

It seems irrefutable that 'oil canning' was/is present on new ships, but it's not hard to believe that the areas of the hull subject to the greatest water pressure showed further distortion. Wave impacts will have a huge amount of pressure and force, and many ships, particularly in the treaty era when there was a major push to reduce hull weight, suffered significant distortion, cracking and buckling when driven hard in heavy seas.

There is a photo in Nelson to Vanguard of HMS Glorious (as an aircraft carrier) in which the horizontal hull plating of the lower flight deck at the bow is literally caved in due to wave impact.

Hi All

Hi JC_4130, yes no doubt, we must also remember hulls of ships expand and contract (sometimes called panting) due to pressure and heat etc etc, just because a ship is on the stocks doesn't mean the same effect won't occur?

Best wishes
Cag.

I didn't mean to suggest the sea has no effect - of course, if the plates are thin enough then wave action is clearly going to press the plates inwards. Presumably if it's thin enough to receive some oil-can effect from hot rivetting prior to launch, wave action can reinforce the effect at sea. Bad choice of words from me.

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King George V class Battleships in 3D

Thanks Cag, appreciate you taking the time and trouble to go looking.

The new book on H.M.S. Duke of York from Seaforth Publishing has some photos of her under construction in John Brown's in Clydebank which show the hull framing in the process of being plated.

Battleship Duke of York (Hardback)
An Anatomy from Building to Breaking

https://www.pen-and-sword.co.uk/Battleship-Duke-of-York-Hardback/p/19034

Again I have no connection with the publisher or authors bar having bought a copy of the book.

"Again I have no connection with the publisher or the authors bar having bought a copy of the book"

No matter Mr C: with those authors, it can be guaranteed that it is a very fine book and well-illustrated.

81542

Of course, I have some of their other works too, all excellent stuff.

My earlier comment was solely intended to clarify that my opinion of the book is purely my own opinion and that I am not advertising it on behalf of anyone or getting free samples or anything.

The book really does have some lovely photos in it. Absolutely great for model detailing. Thoroughly recommended.

I have followed the matter of the apparent distortion (oil-canning if you wish) of the plating in the sheer strake of HMS PRINCE OF WALES with interest. To really get to the root of the subject would require the opinion of a ship builder; which I am not, versed in both riveting and welding techniques, however, I have spoken to a retired naval architect on this thread who did an apprentice-ship in a well-known British ship-yard and some of his information is included here.

First, let's deal with welding. The distortion of shell plating using this technique is caused by contraction of the weld as it cools. This is shown in diagrams on Page 37 of the first edition of RN Newton's "Practical Construction of Warships" printed by Longmans in 1941.
This will clearly occur whilst the ship is under construction. In PRINCE OF WALE's case, this now begs the question, was any part of her constructed using welding techniques? Cag might be able to answer this from his References. If not then the only Reference still open that might, will be the Ship's Cover in the National Maritime Museum. Whatever the case, "Newton" does mention that Messrs Cammel Laird did construct approximately 75% of the aircraft carrier HMS ARK ROYAL by welding. If this technique was applied to PRINCE OF WALES's sheer strake, then it might well explain the apparent distortion in it. Let's "assume" for the purposes of the rest of this post, however, that it was riveted.

"Newton" mentions nothing about distortion in riveted plates while a ship was under construction that I can find in a quick perusal of his content on the subject. Theoretically, it should not therefore have occurred therefore unless the scantling of the plate specified was too light and the distortion was caused by the heat of rivets contracting or the distortion was caused by something else. In which case, what?

Cag has pointed out that PRINCE OF WALES was the only member of the class to be built with a "knuckle" in the sheer strake close to the Upper Deck. The question is "Why?" It must have been approved by the Director of Naval Construction (DNC), so there may well be information about this matter in the Ship's Cover. The next question is "Why did the three members of the class laid down later not have a "knuckle?" For what my opinion is worth, it may have been that Messrs Cammel Laird experienced some trouble in fitting the plates that had this feature; which may have caused the observed distortion and having reported it to DNC, orders were given to the builders of the follow-on ships not to include it in their ships.

It may beg the question in some minds, "Why would such a "knuckle" cause such a problem in a plate?" Well, plates with two and more bends had to be appropriately "smithed" (hammered under heat) to shape and in the case of the bow sheer strake plates in PRINCE OF WALES I can see three if the "knuckle" is included. Fitting such a plate in place may have necessitated some local heat being applied to get it in place before the rivets were closed up. However, some will say "All right, you have a point but what about the "smithing" of the plates having "knuckles" in British cruisers of the period?" Good point, so we would need to look at the bow plates in these ships.

With that I will end there, except to say that the plate distortion in the sheer strake of PRINCE OF WALES, does not appear to have resulted in any adverse comment in the "big name" References so in her case it is only discussion-worthy on this site. However, I do consider it extremely unlikely that changes in the shades of the paint will have caused this effect seen: it is more likely to have been high-lighted by the angle of the sun at the time the photograph was taken.

I look forward to seeing a clear answer to the matter: if it can be found.

81542

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Hi All,

Firstly I must apologise as I'm in error as regards hull plating thicknesses, my basic plan shows 10lbs, now I've got home to check the shell plating plans which show the shell plating at upper deck level (Row 'O') to be between 25 to 30lbs, the one below this (Row 'N') to have been 20 to 25lbs D steel.

The 10lbs were bulkhead thicknesses, so once again apologies. I will go through my copy of the foremans build diary to see if welding is mentioned, but I do know from the ships purchasing record that the use of welding was promoted, however it was to be used in non load bearing structures and unstressed areas only. I believe that a number of the portholes were traditional brass, but some were aluminium to aid weight saving.

On the shell plating however there are areas at the bow that show internal welding, and on the upper deck there are 4"×3" beams cut to 4"×1.5" with the 1.5" portions welded to the deck.

As Mr Foeth says the majority of hull structure was welded, as 81542 says the individual plates were formed in the shop using heat over formers. The plans of PoW do show the knuckle, interestingly her lines plan says an Admiralty letter of 1937 contained modifications.

I shall continue looking, and will measure the distance between frames to see if it is possible to use that info together with the image to see if they correspond which may indicate whate these indentations are.

Sorry again for the mix up
Best wishes
Cag.

Hi All,

As promised more detail, in tender sheets Cammel Laird state £60,000 has been spent on welding facilities to enable slipway and workshop welding. The Admiralty respond citing clause 8 of their specs sheet 1a regarding welding equipment and skills.

The only mention of welding in the build diary is rudder construction being both riveted and welded and that prior to launch temporary stiffening beams were welded to the upper deck alongside A and Y turrets and those alongside B turret were riveted.

From the forepeak to the start of the lower tier of armour there were 57 frames and using the quarter inch to the foot scale equate to 3 to 4 foot spacings, this would seem to match the indents on both sides of PoW hull in the image.

Excluding the hold there were 5 deck longitudinals with 5 intercostal stringers between, these were either tee or channel bar and it does say in some areas "direct welded".
The stringer behind the plating concerned was channel bar and parts just after the hause openings were welded.

Painting of the shell started on the 13th March 1939 and by the 01st of April the grey topside paint was applied and final coats begun on the 17th April.

Mr Foeth has correctly pointed out in the past that PoW had square cutouts in her stern for the square ports as seen on KGV, in PoW build diary it does mention the square ports were examined in store and found to be "incapable of watertightness" and condemned. This may be why PoW completed with round ports at her stern?

Hope this helps a wee bit more
Best wishes
Cag.