The quality of steel in war production no4s

[WarPig1976]

bob4wd I think your wrong on only one point, our friends up north say they have the BEST beer and hockey players!!!
Oh, Aussies can brag about their food,,,,I just love Outback steak house!!.....

[Rumpelhardt]

Surface ships dont dive often....not more than once anyway.

This is very true but 9,000 ton ships traveling at 20+ knots for hours and some times days at a time in all sorts of sea conditions will impart some severe stresses of its own.

[bob4wd]

bob4wd I think your wrong on only one point, our friends up north say they have the BEST beer and hockey players!!!
Oh, Aussies can brag about their food,,,,I just love Outback steak house!!.....

I can't argue with any of that!

[breakeyp]

regarding how heat treat was done in the day might be very informative if someone can expand on it. I have been told that some work was done by reading the heat colors of the part as it was heated and cooled. It it was done in batches of parts, I can see that part location during the process and how the heat was evenly distributed would affect how the heat treat proceeded. I don't know when temperatures could be read by instruments. I don't know when they started heating parts in molten sulfur baths.

[bigduke6]

This is very true but 9,000 ton ships traveling at 20+ knots for hours and some times days at a time in all sorts of sea conditions will impart some severe stresses of its own.

An old Esso tanker I was on (270,000 Tons DWT) you could see the whole deck flex, from the cargo control room, (to the none seafaring types) this happens on all ships and is called hogging and sagging, this is one of the main stresses on any vessel, I,m not going to copy from my Naval architecture notes mainly because I cant read my own writing, but see link below, regarding the steel etc.

I cant remember the steel used on the hulls of the Trafalger, and Trident class subs but is on the high side for yeald strength going off memory.

Strength of ships - Wikipedia, the free encyclopedia

[ssj]

This is very true but 9,000 ton ships traveling at 20+ knots for hours and some times days at a time in all sorts of sea conditions will impart some severe stresses of its own.

This was the first sub I worked on at the yard as a test and commisioning engineer.

HMS Trafalgar (S107) - Wikipedia, the free encyclopedia

I worked on all of that class, plus the hull of the first Trident and I think also the first 2400 class hull sections. So 26 years active about what I remember from the hull design criteria.

Now it quite possible surface ships have issues, but cutting out a bit and putting in new is pretty easy, on an aging pressure hull, no. It also doesnt mean that such a sub is OK one day and not the next, it means as she ages her operational depth is reduced and it was policy not to dive deep unless needed to lengthen its service life. The main thing is quietness and its passive detection capability, which was about the best in the world.

---------- Post added at 11:24 AM ---------- Previous post was at 11:21 AM ----------

I cant remember the steel used on the hulls of the Trafalger, and Trident class subs but is on the high side for yeald strength going off memory.

HY80 or the british equiv.

---------- Post added at 11:33 AM ---------- Previous post was at 11:24 AM ----------

I wonder how they determine metal fatigue other than looking for cracks? .

As the hulls were made they were xray'd.

[jmoore]

I wonder how they determine metal fatigue other than looking for cracks?

All sorts of NDT methods. Visual, penetrant, ultrasonic, magnetic particle, eddy current, Xray, just to name a few. Aluminum has no lower stress limits at which cracks will not propagate under cyclic loads, unlike steel, so that complicates things a bit. But as far as predicting failures, experience and testing seem to be the usual methods of catching drams before it's too late. Life limits and all that.

ETA:For powerplants, that's about it as far as approved methods go, except for Thermographic NDI (used for composites), but that's not something with which I'm familiar.

[bigduke6]

As the hulls were made they were xray'd.

ssj, I only remember the hull sections getting x rayed after each section was welded, I worked on HMS Trenchant , HMS Talant, And HMS Vanguard, on Vanguard was mainly involved with the the missile section and the deck sections when I was in the MAS shop.
When were you in Barrow ?

[ssj]

Cool, how is old barrow? I was so glad to leave, loved the Lake district though, I was there 83 to 86 or 87. Welds yes that is correct, should have been more specific I guess, though I thought they did a bit more, I didnt go near the xray stuff much. Ssn17 was hull sections, Vanguard was hull sections I think but might have been ssn18, or both not sure now, one curved piece of steel looked like another after a bit when testing the lifting eyes. I was on ssn16 for its launch, think it was 16, did work for 14 and 15, weapons on one, dont remember which it was 25~30 years ago. I left before they did the new huge building / hall with the lift.

[bigduke6]

I started in the training school in 86 (next to the bridge) first sub was HMS Trenchant was in propulsion and hull services from training school.
lived outside Barrow, small village (Kirkby-in-furness)and after apprenticeship went off to sea. Like you say lakes was nice, to me the Best thing about Barrow was the road out....