China - the not so sleeping giant.

[willedoo]

Came across these photos of the third Chinese amphibious assault ship/landing helicopter dock (LHD) under construction. Work started on it this year and it doesn't look too far off launch date. Another photo shows the first of it's class alongside the Shandong, China's first domestically built carrier. It gives an indication of how big the LHD is.

 

Other photo from earlier in the year shows nine new destroyer class vessels in the water and being fitted out. To put it in context, the RN has 9 destroyers total compared to 52 for the PLAN. I remember reading an article this year by one of the defence commentators (not Janes), who estimated that the PLAN would equal the U.S. Navy in 10-20 years in tonnage, if not capability. My money would be on 10 years if the Chinese economy holds up. The article discussed the construction aspect, noting the large number of Chinese shipyards building Naval vessels, compared to America's rapidly declining shipbuilding capacity. The Chinese seem to be pumping them out.

 

 

[Old Koreelah]

 

China has built massive ships before.

It is rapidly returning to its position dominating the world economy, as it did 500 years ago.

The problem for us is how far they want their power to reach. 

 

https://en.wikipedia.org/wiki/Chinese_treasure_ship.\

 

 

 

 

[old man emu]

We shouldn't be amazed at the speed of the Chinese shipping build up. Just look at the production of Liberty ships during WWII. 

 

Mass-produced on an unprecedented scale, the Liberty ship came to symbolize U.S. wartime industrial output. The class was developed to meet British orders for transports to replace ships that had been lost. Eighteen American shipyards built 2,710 Liberty ships between 1941 and 1945 (an average of three ships every two days), easily the largest number of ships ever produced to a single design.

[facthunter]

The  Liberty ships were JUNK really and built with the whole structure welded and many broke up because of internal stresses. The technique wasn't fully proven. Bit like the "consolidated ' Liberators. Had plenty of faults but the numbers won the day..  I bought a 1942 Chevrolet and spent a lot of time and money on it but it was poor quality of production. Porous castings in the steering box and crook rivets in the wishbones amongst other things.  Way down on prewar build quality . Cut corners. Make more dollars.. Nev. 

[onetrack]

The Liberty ships suffered from serious structural failures because of a combination of the poor weldability of American steel, unrecognised stresses caused by fully welded hulls, and a knowledge failure as regards steel toughness vs temperature.

 

The Liberty ships suffered from brittle fracture of their hulls at low temperatures and ductile fractures at higher (typically, tropical) temperatures, aided by weld stresses. One Liberty ship snapped in two, and sank at its mooring!

 

But the Americans didn't care too much about the problem - there was a war on, and in the best American Gung-ho fashion, "there's plenty more where they came from!"

 

However, the engineers studied the problem and realised where the basis of it lay, and Fracture Mechanics as a specific engineering subject came into being.

 

More importantly, after WW2, better steels were produced with improved weldability and notch toughness. It was important that Fracture Mechanics came into being, otherwise we'd have a lot more bridge and building construction failures.

 

A Japanese bloke has written up an excellent analysis of the Liberty Ship failures.

 

http://www.shippai.org/fkd/en/cfen/CB1011020.html

[old man emu]

Sure, Liberty ships were not of the quality of the Clydebank or Belfast shipyards, but they were built to fulfill a short term need. They were only expected to last for five years. It's also true that they brought out previously unknown metallurgical conditions. At least they provided the impetus for new areas of study - a bit like the de Havilland Comet and cabin pressurisation cycles.

 

My point was that when a strong government wants a lot of something quickly, it will get what it wants, when it wants it.

[Old Koreelah]

Not all welded ships were crap; the heroic Ohio proved to be almost unsinkable, surviving numerous air and submarine attacks to deliver crucial fuel to Malta

https://en.wikipedia.org/wiki/SS_Ohio

 

[Marty_d]

A lot of things in WWII were produced with a very short design life.  I read somewhere (think it was in an autobiography of a Spitfire pilot) that the venerable Spit had a TBO of 20 hours.  Absolutely amazing that some are still flying now (albeit totally rebuilt and lovingly nurtured!)

[spacesailor]

Marty_d,

During the London blitz, pilots averaged 6 yes six minutes for their life.

spacesailor

[old man emu]

There's a big difference between the RAF 20 hour TBO and a Rotax-powered puddle jumper's TBO. The engine of the Spitfire probably could be removed and replaced by a fresh one in a few hours, so the plane might be out of action only over night when it wasn't likely to be used for fighting at night.

 

The Time Before Overhaul (TBO) on the Merlin used to be 250 hours when the engines were in combat mode. Nowadays with more gentle use that figure is closer to 500 hours. However the cost of said overhaul is £120,000, which is a lot when you consider that a complete, ready-to-fly Merlin should cost in the region of £170,000.

 

https://www.goodwood.com/flying/latest-news/so-youre-thinking-of-buying-a-spitfire/

[Old Koreelah]

9 hours ago, old man emu said:

...The engine of the Spitfire probably could be removed and replaced by a fresh one in a few hours...

The Bf-109 engine could be swapped in 12 minutes. The German designers placed a high priority on ease of maintenance.

[facthunter]

The highest "TBO" for the Merlin in civilian use was 650 hours in some "converted" airliners. In the war, (military outputs) it was about 200, but most never reached that. Many countries NEVER allowed the Merlin on the civil register as the magneto drive wasn't duplicated and has a skew gear that had a habit of shearing off then NO sparks whatever.. They had a name for it (the failure mode) amongst the Hurricane Pilots which I can't recall at the moment. Nev

[old man emu]

3 hours ago, Old Koreelah said:

The Bf-109 engine could be swapped in 12 minutes.

But those damned Jerries didn't stop for a brew from the NAAFI truck.

[Marty_d]

Maybe they had a stein delivered by Helga.

[facthunter]

The speed of an engine swap depends on the level of black marketing going on. Nev

[willedoo]

PLAAF recruitment video showing a few aircraft.

 

 

[willedoo]

A video showing the new Chinese passive exoskeletons. It makes you wonder how they would work in practice, in regards to possible chafing and comfort, but they look good for carrying heavy packs. No doubt production models will come in various camo patterns.

 

 

Edited February 14, 2021 by willedoo

[onetrack]

They're Made in China. They won't last for 5 mins in front-line conditions. I could well imagine how well they work after crawling through mud, then having the mud dry out.

That's a standard test for a lot of military firearms, and why the 7.62 SLR was so good. 

[willedoo]

17 hours ago, onetrack said:

They're Made in China. They won't last for 5 mins in front-line conditions. I could well imagine how well they work after crawling through mud, then having the mud dry out.

Good point. Maybe they could forget about a camo version and issue duct tape in olive drab instead. The end result would be the same.

[willedoo]

17 hours ago, onetrack said:

They're Made in China. They won't last for 5 mins in front-line conditions. I could well imagine how well they work after crawling through mud, then having the mud dry out.

Another issue would be the practicality of them in situations like an extended infantry patrol. If you had say, platoon or company strength infantry on patrol in the bush for weeks or even days without motorized backup. In that situation, you would have to either wear the exoskeleton all the time or carry it. Because of the backpack frame, you would have to remove it to sleep. At sparrow fart, the enemy would get the jump on you while you're still trying to strap the contraption on. Either that or everyone bugs out and leaves a pile of exoskeletons behind. On an extended hike, they would save the back with a full pack, but the problem is they are there all the time and what do you do with them when they're not needed immediately.

[spacesailor]

send the surplus to the " vets " Who need them when paralysed. to walk again.

could be the " bee's knee's for Paraplegics.

spacesailor 

[old man emu]

I was reading the War Diary of my father's Battalion in WWII. As Part of the 6th Division he took part in the initial taking of Tobruk in early 1941. (Not the 7th Battalion "Rats"). Amongst those diaries and records were reports of how the Italian POWs were managed. There were about 30,000 POWs to look after, and it fell to the battalions of the 6th Div to look after them in the first few days after the battle. Can you imagine the logistical problems that entailed? The very first thing was disease prevention. A man's gotta do what a man's gotta do, and 30,000 men do a lot of doing. Secondly there is the need to at least provide water. Water supply at Tobruk was a big problem even for the Italian army before the War. Thirdly, it was February - winter. Not only was it the colder season, but records show that it rained heavily, when there weren't howling winds kicking up dust.

 

What's that got to go with China?

 

All China has to do is declare war on South Korea and invade from North Korea. Then it waits until the USA and its hangers-on set up a defensive front line. Once that is done, China starts sending battalion after battalion across No-Mans-Land under white flags. The USA & Co would capitulate by the end of the week under due to the strain on resources needed to look after POWs under the Geneva Convention rules.

[Bruce Tuncks]

On 31/12/2020 at 10:16 AM, facthunter said:

The highest "TBO" for the Merlin in civilian use was 650 hours in some "converted" airliners. In the war, (military outputs) it was about 200, but most never reached that. Many countries NEVER allowed the Merlin on the civil register as the magneto drive wasn't duplicated and has a skew gear that had a habit of shearing off then NO sparks whatever.. They had a name for it (the failure mode) amongst the Hurricane Pilots which I can't recall at the moment. Nev

Very interesting Nev. My Jabiru engine is now 700 hours and running well. Good thing that CASA were not active during the war, they would have grounded all the Merlins for sure.

How did the Merlin compare to enemy engines ?

[nomadpete]

OME, I wish you hadn't told them that. Now we're done for!

[old man emu]

1 hour ago, Bruce Tuncks said:

How did the Merlin compare to enemy engines ?

It's hard to tell since the only records we are likely to have are those of the Allies. I watch a video series by a young German bloke who seems to be able to access records in the German archives. He might be able to dig out that information.

 

Given the state of the Art of engine component metallurgy in the 1930s I doubt if the quality of the raw materials was as good as that of modern engines. I've just finished reading a book about the 8th American Army Air Force. It seems that engine failures were the cause of turning back by many aircraft. When you consider that for those operations regularly involving over 1000 aircraft, that's 4000 engines. Statistics will tell you how many failures you could expect per operation.

 

In wartime, nobody really looks to preserving a particula engine. If it fails, fling it. It is more efficient to replace than rebuild, especially when manufacturers are turning out engines faster than they can be fitted to new aircraft, or replaced in existing ones.