Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length.

[TCC]

I'm having a 'discussion' about the main hull armour along the ships side. When a capital ship is launched, its sans armour and whatever is required seems to be sat in a armur-shaped indentation right along the hull..the lower edge of the belt sitting upon a little 'shelf' at the bottom of the indentaion.

The debate is whether water can get behind he plates?

Od do they 'caulk' the seems between the plates with something?

Somethi ng else, how did the fix the armour tot he hull? Theer's no bolts or rivets that can be seen. I'm thinking that they used te physical shape of the armour in some way,  as LIOn had her amour 'dislodged', not broken away or sheered off. I can think of several ways to fix the armour without bolts or rivets.

[dreadnought72]

Once again, full explanations are in the AoTS Dreadnought book.

Armour plates are bolted from behind to the plates in the indent. In between both there's a wood filler. The internal bolt heads are often covered to prevent them sheering off (with lethal consequences) in action.

Andy

[Colin Bishop]

The armour was usually fitted with "blind bolts" taken through the shell plating from the inside and screwed into the the thickness of the armour. I think that a teak or hardwood backing was used to seat the armour on the hull. Of course that applies only to those ships with "external" armour belts. In some ships, such as Nelson and Rodney the armour belt was carried inside the hull and the external plating served to detonate shells before they reached it. Warship armour is a very interesting and complex subject. There is a lot of information in Oscar Parkes' book "British Battleships" now out of print but obtainable secondhand (at a price!) and more recently D.K. Brown's series of books on 19th and 20th century warships.

Colin

[RickF]

What follows is part of the specification for the breastwork monitor HMVS Cerberus. A bit earlier than the Hood (completed in 1870), but of interest.

The Armour Plates are to fastened with conical-headed Iron Bolts, those in the 8- and 9-inch plating to be 3 inches in diameter, and those in the 6-inch plating 21/z inches in diameter.

The counter-sinking in the plates to receive the heads of the bolts is to extend one half through the plates; the bolts are to pass through the Backing and Skin, and their points are to be secured with Nuts and Elastic washers, in accordance with a sketch which will be furnished; or the Bolts are to be formed on Major Palliser's Plan, if so directed. There are to be two bolts in each plate between every two frames, and three in each butt; they are to be placed 9 inches from the edges, and the two outer ones 1 foot, and the inner one 16 inches from the butts.

The above description as to the number of bolts between every two frames is for the plates of 6 inches and above, where the plates are thinner the bolts are to reduce in diameter, as the Overseer may direct.

The Armour Bolts to be of Bowling, Lowmoor, Farnley, or other iron approved by the Controller of the Navy.

All the Butts in the Armour Plates are to be on the frames, not between them, and the edges and butts are to be well planed and fitted to the satisfaction of the Overseer.......

......Great care is to be taken that the wood backing is well fitted to the sides of the ship, and all faying surfaces are to be thickly coated with Red Lead, Waterproof Glue, or other approved materials as may be directed. All the joints are also to be caulked and made water-tight to the satisfaction of the Overseer, the number of threads of Oakum and Spun Yarn being as is usual in H.M. Service for similar thicknesses. The outer surface of the Backing is to be completely coated with Hayt Waterproof Glue before the armour plating is put on.

As more than ordinary care will be required to prevent leakage between the Shelf Plate to recess and the wood backing, the Overseer will have authority to introduce additional means for effecting this object without additional charge......

Below are two pictures of a turret today, showing the sections of armour.

All the above from http://www.cerberus.com.au/

Rick

[TCC]

Thanks... I'm still not sold on the idea that they used 'bolts' through the armour... they may have in Victorian and early Edwardian times but during WW1 and up to WW2? I had thought they'd have used 'keys' or shaped armour that held the adjoining plate it... sort of like tongue-and-groove or laminate flooring where you clip one end in and nail (bolt) the other, and so on, and so on.

I'm prepared to be wrong about it but that's my gut instinct.

[Colin Bishop]

After Victorian times they used the "blind bolt" system i have described above. Keyed armour was tried out, before 1900, but the problem was that it was very, very difficult to repair if damaged and it was decided that the expense could not be justified. (imagine trying to replace a single plank in the middle of your laminate floor!).

What you can't see on the outside is that usually either the upper or lower edge of the belt butted against the edge of the main armoured deck which gave it support. The damage to Lion in WW1 was caused by the shock of the shell's impact literally driving the whole supporting structure in causing the hull to leak. I have a book called "Jutland, an Anaysis of the Fighting" by John Campbell which graphically describes the effects of many individual shell hits on both the British and German ships using data and diagrams recorded immediately after the battle. It makes very interesting reading indeed and give you some idea of just what happens when a heavy calibre shell impacts on a ship's structure. Very sobering!

Colin

[TCC]

Blind bolts? I had to google them. These are like 'metal' rawl plugs? Yes I could 'see' that as it's only the reverse face of the armour that's getting drilled. Them drilling holes right through just seemed unlikely to me as they're introducing weak points. I knew there'd have been a better way.

I had imagined it being like on some of the german big (read: late war) ww2 tanks.. they tended to have 'keys' or interlocking edges that held the plates against each other..

That said, I've just remembered I have an image of LION of the inside 'face' of the armour... well the framing. This was the damage at Dogger Bank where the plating was 'dislodged'. Are they (the 2 'studs') the 'blind bolts' system?

That cambell book has been on my radar for a while now. Is there any images or drawings of any of the LION class in there? After Jtland, someone went round and did a 'census' of all the battle damage on all the ships and drew each hit/area of damage for Jellicoe/admiralty.  I have some of them.

Agree about it being an interesting subject. It's like the main armament blast bags or 'ensigns' or 'paying off pennants' or 'coaling', they are all interesting little articles waiting to be written.

Cheers

[TCC]

Colin
Does the Cambell: 'Fighting at Jutland' describe the hit on Q Turret at Jutland and what actually happened to the fore roof when it was blew off? Specifically, does it say where it landed?

Cheers

[Colin Bishop]

Yes, quite a lot of detail plus a diagram. The front roof plate was blown off and lay upside down on the port side of the deck about 12 feet from the turret while the centre face plate was also dislodged and came to rest 15 feet abaft the turret and close to the ship's side. The turret was trained to port at the time. There is a picture of the damage turret here: http://en.wikipedia.org/wiki/HMS_Lion_(1910)

Colin

[TCC]

Thanks.. that's a great help. I'll have to actually get off my backside and actually make efforts to get a copy now.

I ask as someone helped me making LION so I thought I'd make a bit of a 'vignette' model of LION's Q turret 'at 4PM on the 31st May, 1916' sort of thing. [or was it 4:01 or 4:02 pm? Anyway... ]

I'd just do a bit of deck around the turret, some grey bulkheads under it an model the actual turret with the damage and mount it on a certain hardwod base he'd left with me. But I didn't know where that top plate had gone... what is the 'diagram' you mention of? I don't suppose it shows this plate and the centre face plate? [by the way, I'd always understood it that the centre face plate stayed in situ except for a small area on the top left which was punched through by the shell? I'll have to recheck that.]

Cheers, it's a great help

[Colin Bishop]

It's just a rough sketch really - see below. I do seem to remember seeing a picture somewhere showing the turret roof plate on the deck but no idea where!

Colin

[dreadnought72]

I do seem to remember seeing a picture somewhere showing the turret roof plate on the deck but no idea where!

Ditto! 

Andy

[TCC]

I do seem to remember seeing a picture somewhere showing the turret roof plate on the deck but no idea where!

Ditto! 

Andy

Yes, isn't it the middle plate? They took both front and middle roof plates off and there's an image of q turret taken from the 3rd funnel, looking fore, that shows the middle roof plate 'behind' Q and on the starboard.

There's a drawing above shows the front roof plate.

There's also this photo from the book 'The Fighting At Jutland' that supposedly shows this front face plate but that looks to me more like the front roof plate. Why? I don't think it's thick enough for a 9 inch front plate compared to it's size. Yet it's thin enough to be a 3½-4½ roof plate.

The front face plate was a narrow rectangle of thick 9 inch armour between both guns, the shell hit this plate in the top left corner and punched through knocking a chunk off the reverse face and then exploding over the left gun. (Is that what you have Colin?) But it hit next to the joint between it and the front roof plate and contemporary reports say the FRP 'rolled back like a sardine tin'. You're image (sincere thanks) shows that. There's no mention of the face plate being 'rolled back', all reports say the roof was 'rolled back' and the face 'knocked through'. [edit: actually, if you look at the drawing posted above, you can see it's actually the same image as this photo but 'drawn'... and then you realise that there's indeed a sighting hood opening in the photo on extreme left.  ]

My last reason why I think the caption is wrong is look at the shadow under the plate, you can see one of the rectangular holes for the sighting hoods. Likewse, you can just discern a hood opening on our right hand side as we look at the image.

Is this the image you mean?

cheers

I think that caption is wrong and that shows the front roof plate, not the face plate.