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Posted: 6/2/2023 11:55:54 PM EDT
[#1]
Quote HistoryOriginally Posted By SoCalExile: This thread is snail atm, time to post a vid about historic Russian shenanigans:  https://www.youtube.com/watch?v=yzGqp3R4Mx4That’s hilarious. Apparently Russia is upholding a fine tradition of throwing masses of men with little training into the heat of battle. With equally “impressive” results. |
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Posted: 6/3/2023 12:09:27 AM EDT
[#2]
Twitter thread about Russia's mobilization efforts.
Wow. Russian MOD published a report on mobilisation in Russia and deleted it shortly after. But web archives still has it. Key takeaways: 1. MOD was able to form 280 new unites with mobilized men. 2. Russian army is experiencing problems with "unpreparedness of part of society to perform military duties" and blames it on "the information pressure of the online blogging community" 3. RU Armed Forces have problems with provision of weapons and equipment, and state corporations and private companies help with the supply of equipment. 4. MOD began involving employees of security companies in the war efforts (as in private security companies) 5. Military registration and enlistment offices compiled a database of 31.6 million people, 2.9 million of them are people of military age. The authorities also collect up-to-date mobile phone numbers and email addresses of those eligible for military service. 6. Government's reserve fund allocated 5 billion rubles to "stimulate" military enlistment office employees working on mobilization and conscription. 7. In 2023, the General Staff plans to create a new combined arms and RAF, one army corps, five divisions, 26 brigades, and also form new Azov naval military district. 8. In 2023, the military registration and enlistment offices will conduct organized raids on conscripts together with the Ministry of Internal Affairs. |
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Posted: 6/3/2023 12:21:08 AM EDT
[#3]
Quote HistoryOriginally Posted By MKSheppard: Here's why I think the Kerch Bridge is not long(ish) for this world. https://www.engineering.com/story/europes-longest-bridge-spans-troubled-waters tl;dr -- the Kerch Straits is a terrible place to build a bridge; everything is against it: Foundational -- you have to drive piles down 200 feet through silty mud into solid bedrock, and then a further 100 feet into the bedrock for stability concerns. Currents -- Because of the extremely strong currents; the bridge piers are actually suspended in mid-water over dozens of individual piles to let the currents flow through as shown in the image below. https://i.imgur.com/XhCcKXy.png Fault-Line -- It passes over an active fault.  Mud Volcanoes -- Yes, these are a thing. "Further complicating matters is that the strait’s seismic activity can make mud volcanoes from the silt. Mud volcanoes are formed when water heated deep in the Earth’s crust mixes with underground mineral deposits, and the mixture is forced upward through a geological fault." Ice -- Ice in the winter beats the hell out of piers and other structures. A lot of smart people think that any span over 200 meters (700+ feet) is safe from ice. The longest span is 227m, but most spans on the bridge are shorter than that. In short, the bridge is an engineering feat in itself that would require the services of a top grade general contractor (of which there are only a few in the world) as well as a sustained development/planning process. The reality is... In early 2015, the Russian government awarded the 228billion-ruble ($3.7 billion) bridge contract to infrastructure construction firm Stroygazmontazh Ltd. (SGM), a company that specialized in pipelines but which had not previously built any major bridges. Basically, the company is/was owned by a Putin crony/friend. Even under construction, the thing was already cracking -- this image is from 2017: https://i.imgur.com/AhoHIsy.jpg Theoretically, it was designed for a 100 year lifespan. Applying a "corruption" factor; it probably only has a 40 year lifespan. But here's where it gets tricky. These lifespans are calculated using a set rate of tonnage moving over the bridge (i.e. so many 3 ton vehicles and 15 ton vehicles per day). As a vital logistics link; I believe the Russians have been shoving a massive amount of tonnage over the bridge since the war started; because it's an all weather connection, unlike ferries which can't run if the waves get too rough. I would not be surprised if thanks to the overloading during this war, the actual lifespan is now down to about 10 or 15 years... Maybe less, depending on how drunk the inspector(s) were each day. Great info. Amazing it was cracking during construction! The nominal load bearing strength of a structural member with in-line force is proportional to the the area of the cross section of the member for the given material. The rebar is mainly for tensile strength in bending/side forces. The concrete carries most of the compression load. A significant crack on the surface breaks the integrity of that affected ring (depth of crack). And since the outer diameter has the greatest cross sectional area for a given depth of crack it is hugely more damaging than the same size crack internally closer to the center. Then add in that exterior cracks allow infiltration of salt water!!! Besides the swelling from rust and further cracking, you have a similar reduction in tensile strength of the rebar as the outer diameter is eroded. And seismic activity will greatly stress the tensile strength of the rebar with lateral and uneven uplift motions or even ground waves. TL:DR Kerch Bridge is fucked. But I would still love to see it a smoking ruin! |
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Posted: 6/3/2023 12:22:23 AM EDT
[#4]
Quote HistoryOriginally Posted By m35ben: I think the90 is just fine. More HE Very limited range and magazine capacity. |
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Posted: 6/3/2023 12:24:57 AM EDT
[#5]
Quote HistoryOriginally Posted By Ryan_Scott: Very limited range and magazine capacity. |
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Posted: 6/3/2023 12:27:25 AM EDT
[#6]
Quote HistoryOriginally Posted By fadedsun: Basically an 1151 HMMWV with a 20mm? The French and Taiwanese do something like that. |
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Posted: 6/3/2023 12:29:38 AM EDT
[#7]
Quote HistoryOriginally Posted By GTLandser: If you can bend a prop shaft or disconnect a reduction gear from all the other fiddly bits, then you don't have to sink her, you'll just consign her to dry dock for 10 years.  Source: Naval Engineering Night School for Kids Who Want to Read Good, and Do Other Stuff Too Quote HistoryOriginally Posted By GTLandser: Originally Posted By AlmightyTallest:
If you can bend a prop shaft or disconnect a reduction gear from all the other fiddly bits, then you don't have to sink her, you'll just consign her to dry dock for 10 years. Source: Naval Engineering Night School for Kids Who Want to Read Good, and Do Other Stuff Too Too much technical jargon but sounds bad! 
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Posted: 6/3/2023 12:32:05 AM EDT
[#8]
Quote HistoryOriginally Posted By RockNwood: Too much technical jargon but sounds bad! |
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Posted: 6/3/2023 12:35:54 AM EDT
[#9]
Quote HistoryOriginally Posted By m35ben: That is true but France thought it was enough. And it was, in the 1960s. Now that you can’t kill a tank with it, you might as well have 200 ready rounds and link feed. |
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Posted: 6/3/2023 12:42:39 AM EDT
[#10]
Quote HistoryOriginally Posted By m35ben: We should take bets on how many times the ship sinks or catches fire in dry dock over the next few years. Quote HistoryOriginally Posted By m35ben: Originally Posted By RockNwood: Too much technical jargon but sounds bad! 
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Posted: 6/3/2023 12:44:29 AM EDT
[#11]
Quote HistoryOriginally Posted By Ryan_Scott: And it was, in the 1960s. Now that you can't kill a tank with it, you might as well have 200 ready rounds and link feed. |
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USA
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Posted: 6/3/2023 12:46:52 AM EDT
[#12]
Quote HistoryOriginally Posted By ArmyInfantryVet: I think it may be best to cut the land bridge off. Hit the supply ships with Neptunes or whatever. Make it so they either leave or starve. Quote HistoryOriginally Posted By ArmyInfantryVet: Originally Posted By Zam18th: I'm not so sure I agree with that. Russian troops will never evacuate Crimea. The Kremlin/Putin will fall before that happens, IMO. And the fewer civilians, the easier it'll be to keep it supplied with food, water, fuel. When is the rail bridge supposed to be repaired? I see 3 options 1. Starve them logistically until they are combat ineffective. 2. Take high casualties liberating it conventionally. 3. Cede Crimea That said, I expect Hodges knows better than me.  ETA: maybe the plan is to force russia to blow the bridge to prevent retreat. I think it may be best to cut the land bridge off. Hit the supply ships with Neptunes or whatever. Make it so they either leave or starve. Maybe. I'm just skeptical that they can cut deep enough into their logistics without taking out the bridge in addition to the land bridge and attritting air and sea resupply operations. Moscow will throw everything they have at the problem. |
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Posted: 6/3/2023 12:53:45 AM EDT
[#13]
Quote HistoryOriginally Posted By m35ben: We should take bets on how many times the ship sinks or catches fire in dry dock over the next few years. Quote HistoryOriginally Posted By m35ben: Originally Posted By RockNwood: Too much technical jargon but sounds bad! On most ships the “No Smoking” sign announces a restricted activity. On a Russian ship “No Smoking” is the day’s damage control report! Could change at any moment though. |
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Posted: 6/3/2023 12:56:23 AM EDT
[#14]
Quote HistoryOriginally Posted By RockNwood: On most ships the "No Smoking" sign announces a restricted activity. On a Russian ship "No Smoking" is the day's damage control report! Could change at any moment though. |
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AZ, USA
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Posted: 6/3/2023 1:01:59 AM EDT
[#15]
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IRL
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Posted: 6/3/2023 2:15:03 AM EDT
[#16]
Another big day.
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Posted: 6/3/2023 2:31:30 AM EDT
[Last Edit: mancow]
[#17]
Anyone else still amazed at what we are seeing? It's our entire lives of growing up during the cold war and all the threatened conventional forces battles played out in real time and we can watch in near real time in HD. Of course, like everything else nobody I know seems to care but to me this is the single most interesting thing I've witnessed in my entire life. FINALLY, the curtain is pulled back and we can see what is really there and we know now for sure t isn't 'shit. They must have been paralyzed in fear all those years seeing what we have.
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Posted: 6/3/2023 2:51:47 AM EDT
[Last Edit: m35ben]
[#18]
 Yuriy Sak - West Needs to Arm Ukraine to Win the War and Bring Prosecutions Against War Criminals |
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Posted: 6/3/2023 3:06:39 AM EDT
[#19]
Quote HistoryOriginally Posted By iggy1337: This was only one component of the total Dutch tank package (I think about 15%) but still a dick move. Despite GD's bitching NL owned 0 tanks at the start of the war1 but have been buying them all round to send. (1) NL sucks in the tank department becuase it's not in the NATO mission. Dutch for a smal country already do navy/subs and airforce Quote HistoryOriginally Posted By iggy1337: Originally Posted By m35ben: Originally Posted By iggy1337: Swiss block sale of Leopard tanks to the Netherlands. In short NL was trying to buy tanks to send to Ukraine but that transaction has been blocked. Apparently by the Green party and a right wing party citing concerns about neutrality. Dutch news but just posted for reference This was only one component of the total Dutch tank package (I think about 15%) but still a dick move. Despite GD's bitching NL owned 0 tanks at the start of the war1 but have been buying them all round to send. (1) NL sucks in the tank department becuase it's not in the NATO mission. Dutch for a smal country already do navy/subs and airforce I said it before, but I will gladly repeat it. What do you think the swiss will do when the dutch decide to not care about a swiss permission and just hand the tanks over to Ukraine. They will bitch for 2 seconds and then cave. Switzerland has less spine than a overcooked worm and everyone in europe knows it. Fuck the green and SVP wankers. |
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CA, USA
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Posted: 6/3/2023 3:41:58 AM EDT
[Last Edit: Shistavan]
[#20]
Quote HistoryOriginally Posted By m35ben: We should take bets on how many times the ship sinks or catches fire in dry dock over the next few years. Quote HistoryOriginally Posted By m35ben: Originally Posted By RockNwood: Too much technical jargon but sounds bad! Sinking while in dry dock would be quite a feat! However the Russians have come very close before: https://en.wikipedia.org/wiki/PD-50 |
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Posted: 6/3/2023 4:14:31 AM EDT
[#21]
Quote HistoryOriginally Posted By Schmigs: Another big day. https://pbs.twimg.com/media/FxrI-nfWwAACfuC?format=jpg&name=large How the hell did they do that? Have they fielded a large force of new medium range drones? New tactics with counter battery radar and precision guided artillery hunter/killer teams? HIMARS going cyclic? |
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USA
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Posted: 6/3/2023 4:26:39 AM EDT
[#22]
An interview with Petraeus that's worth a read
https://kyivindependent.com/retired-us-general-petraeus-this-is-ukraines-own-greatest-generation/ |
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USA
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Posted: 6/3/2023 4:28:57 AM EDT
[Last Edit: Zam18th]
[#23]
Not sure how I missed this
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Posted: 6/3/2023 5:26:05 AM EDT
[#24]
Quote HistoryFantastic interview with Yuri. Lots of good background and comprehensive understanding. I liked what he said about the quick start for F16 training will shorten it even more by having different groups dedicated to different mission so they only need that one tactics block I stead of waiting for all of them. One group focus on ground attack, another on air to air superiority and a third on missile interception. For instance. |
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NY, USA
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Posted: 6/3/2023 5:51:57 AM EDT
[#25]
Quote HistoryOriginally Posted By Prime: https://pbs.twimg.com/media/FxpLhLrXsAEafTM?format=jpg&name=medium
The russians better look out, those guys have a trombone...
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Posted: 6/3/2023 5:59:15 AM EDT
[#26]
Interesting panel discussion in Russia. One analyst is saying you have to be insane to start a widespread confrontation with the west. He is very calm and objecting comparing the economy and military of the west versus Russia. Another panel member just keeps claiming he is lying. 😂😂😂
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Posted: 6/3/2023 6:05:20 AM EDT
[#27]
With all the talk we’ve done about Russian ships burning at the dock and Russian “maintenance”, I thought a MiG-31 burning up mid flight was pretty funny😂
OK who on the crew filled my internal tanks with vodka instead of JP5??
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Posted: 6/3/2023 6:15:50 AM EDT
[#28]
Quote HistoryOriginally Posted By Saltwater-Hillbilly: The problem is that an M109 turret has relatively thin aluminum alloy armor. There is also a huge difference between 155mm Artillery Ammo and 120mm Tank ammo, as in the Arty ammo comes with the projectile, fuse, charge, and primer separate and they have to be loaded in stages during every mission. Plus, the 155mm projectile alone weighs more than a complete 120mm tank round. Even with the rounds pre-fused, it takes at least twice as long (and usually a lot longer) to load and fire a 155mm of any type than a tank round. Though you CAN do direct fire with an M109, it is generally not advisable; sort of like conducting a close combat engagement with a bolt-action .338 Lapua sniper rifle and a 4x scope. Quote HistoryOriginally Posted By Saltwater-Hillbilly: Originally Posted By maddmatt: Originally Posted By PolarBear416: Originally Posted By voyager3: Dumb civilian's observation: artillery rounds seem to have much easier job destroying tanks than main guns of other tanks. Is this because artillery shoots HEAT munitions that attack from the top? Why even bother with the flat-shooting tank guns of ever larger calibers firing sabot rounds with ever more exotic penetrator designs then? This is why some people think tanks are obsolete. Artillery has a longer range, fires over hills, and can now be guided accurately by drones. That said infantry who encounter a tank that starts firing those big rounds at the building they were using for cover may not feel like tanks are all that obsolete What about a self-propelled howitzer firing at that same building? Thats what I'm having a hard time wrapping my head around. With the advances to 155 mm munitions, and how effective they seem to be, plus the prevalence of small anti armor missile, I'm wondering what the ultimate effect would be if you took something M109 and had it bang an M1. Keep sensors and data links, armor, but a 155 mm turret The problem is that an M109 turret has relatively thin aluminum alloy armor. There is also a huge difference between 155mm Artillery Ammo and 120mm Tank ammo, as in the Arty ammo comes with the projectile, fuse, charge, and primer separate and they have to be loaded in stages during every mission. Plus, the 155mm projectile alone weighs more than a complete 120mm tank round. Even with the rounds pre-fused, it takes at least twice as long (and usually a lot longer) to load and fire a 155mm of any type than a tank round. Though you CAN do direct fire with an M109, it is generally not advisable; sort of like conducting a close combat engagement with a bolt-action .338 Lapua sniper rifle and a 4x scope. The fancy new automated SPAGs can do direct fire and even fire accurately on the move, |
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USA
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Posted: 6/3/2023 6:30:42 AM EDT
[#29]
Zelensky told the WSJ that Ukraine is ready to start the counter offensive.
https://www.wsj.com/articles/ukraines-zelensky-we-are-ready-for-counteroffensive-22f4f3f2 Several other things he said: Would have liked more Patriots and Russian air power will cost a lot of soldiers in the counter-offensive; can't understand why the West is drip-feeding advanced weapons instead of giving what's needed all at once; said he doesn't understand why Trump thinks he can end the war given that he didn't end it when he was in power; wants Ukraine to be part of NATO once the fighting ends. |
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Posted: 6/3/2023 6:38:25 AM EDT
[#30]
Quote HistoryOriginally Posted By Capta: The fancy new automated SPAGs can do direct fire and even fire accurately on the move, Quote HistoryOriginally Posted By Capta: Originally Posted By Saltwater-Hillbilly: Originally Posted By maddmatt: Originally Posted By PolarBear416: Originally Posted By voyager3: Dumb civilian's observation: artillery rounds seem to have much easier job destroying tanks than main guns of other tanks. Is this because artillery shoots HEAT munitions that attack from the top? Why even bother with the flat-shooting tank guns of ever larger calibers firing sabot rounds with ever more exotic penetrator designs then? This is why some people think tanks are obsolete. Artillery has a longer range, fires over hills, and can now be guided accurately by drones. That said infantry who encounter a tank that starts firing those big rounds at the building they were using for cover may not feel like tanks are all that obsolete What about a self-propelled howitzer firing at that same building? Thats what I'm having a hard time wrapping my head around. With the advances to 155 mm munitions, and how effective they seem to be, plus the prevalence of small anti armor missile, I'm wondering what the ultimate effect would be if you took something M109 and had it bang an M1. Keep sensors and data links, armor, but a 155 mm turret The problem is that an M109 turret has relatively thin aluminum alloy armor. There is also a huge difference between 155mm Artillery Ammo and 120mm Tank ammo, as in the Arty ammo comes with the projectile, fuse, charge, and primer separate and they have to be loaded in stages during every mission. Plus, the 155mm projectile alone weighs more than a complete 120mm tank round. Even with the rounds pre-fused, it takes at least twice as long (and usually a lot longer) to load and fire a 155mm of any type than a tank round. Though you CAN do direct fire with an M109, it is generally not advisable; sort of like conducting a close combat engagement with a bolt-action .338 Lapua sniper rifle and a 4x scope. The fancy new automated SPAGs can do direct fire and even fire accurately on the move, Panzerhaubitze 2000 got no gun stabilisation because it would be counted as a tank.  Direkt fire on Leopard 1 wrecks:  Panzerhaubitze mutiert zum gefährlichen Kampfpanzer - Bundeswehr |
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Posted: 6/3/2023 7:16:43 AM EDT
[#31]
Quote HistoryFor perspective, a ruble is roughly equal to a penny. |
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Posted: 6/3/2023 7:19:13 AM EDT
[#32]
Quote HistoryOriginally Posted By GTLandser: If you can bend a prop shaft or disconnect a reduction gear from all the other fiddly bits, then you don't have to sink her, you'll just consign her to dry dock for 10 years. Source: Naval Engineering Night School for Kids Who Want to Read Good, and Do Other Stuff Too Quote HistoryOriginally Posted By GTLandser: Originally Posted By AlmightyTallest:
If you can bend a prop shaft or disconnect a reduction gear from all the other fiddly bits, then you don't have to sink her, you'll just consign her to dry dock for 10 years. Source: Naval Engineering Night School for Kids Who Want to Read Good, and Do Other Stuff Too lol, good points and life lessons. 
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Posted: 6/3/2023 7:24:21 AM EDT
[#33]
Quote HistoryOriginally Posted By mancow: Anyone else still amazed at what we are seeing? It's our entire lives of growing up during the cold war and all the threatened conventional forces battles played out in real time and we can watch in near real time in HD. Of course, like everything else nobody I know seems to care but to me this is the single most interesting thing I've witnessed in my entire life. FINALLY, the curtain is pulled back and we can see what is really there and we know now for sure t isn't 'shit. They must have been paralyzed in fear all those years seeing what we have. I agree, I'm just as fascinated by all this, seeing what equipment of theirs and ours works, and what doesn't and why. The tactics being used, etc. A lot to learn from in many various fields of study. |
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Posted: 6/3/2023 7:30:40 AM EDT
[Last Edit: AlmightyTallest]
[#34]
Spot the turret.
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Posted: 6/3/2023 7:32:00 AM EDT
[#35]
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Posted: 6/3/2023 7:32:46 AM EDT
[#36]
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Posted: 6/3/2023 7:34:51 AM EDT
[#37]
lol, that's one way of looking at it, but that tank is f'ed up.
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Posted: 6/3/2023 7:38:41 AM EDT
[#38]
https://warontherocks.com/2023/06/what-the-ukrainian-armed-forces-need-to-do-to-win/ |
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Posted: 6/3/2023 7:40:57 AM EDT
[#39]
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Posted: 6/3/2023 7:42:37 AM EDT
[#40]
https://twitter.com/TheDeadDistrict/status/1664877294484062212 Germany pledges 66 FFG APC (GER version of US BATT UMG). The deliverey was announced earlier this week, but it was unspecified which vehicles would be delivered. 
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Posted: 6/3/2023 7:47:41 AM EDT
[#41]
Quote HistoryOriginally Posted By AlmightyTallest: lol, that's one way of looking at it, but that tank is f'ed up.
Keep an eye out for the uncropped version of that video, I've been looking for it. In the original video you can see a guy pop up out of his hole CLOSE to take the shot. You can see the puff from the launch along the border. They cropped it out because it's awesome. |
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Posted: 6/3/2023 7:47:49 AM EDT
[#42]
UK centric lessons learned from Ukraine article regarding MLRS.
https://wavellroom.com/2023/04/26/rise-of-the-rocket-launcher-2/?utm_content=buffer4c174&utm_medium=social&utm_source=twitter.com&utm_campaign=buffer A focus point of Rise of the Rocket Launcher was the modern family of munitions for the HIMARS family. Whilst briefly mentioned, the alternative warhead (AW) was not given its dues. Capable of firing 84km and covering an area of up to 400m squared with 160,000 tungsten fragments, the AW accounts for any micro displacements in enemy locations and inaccuracies in the targeting. This helps quicken the targeting process and ultimately leads to more enemy casualties. One AW missile can achieve the same effect as firing a large open sheath of GMLRS-Unitary missiles, without driving up the cost of war and further burdening the logistics chains. The British Army must remain at the forefront of technological advances and missile development to truly be able to strike high value depth targets as precisely as possible. It must also, as recently warned by Tobias Ellwood MP, upgrade its stockpiles of ammunition to meet NATO commitments. |
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Posted: 6/3/2023 7:49:09 AM EDT
[#43]
Quote HistoryOriginally Posted By Prime: Keep an eye out for the uncropped version of that video, I've been looking for it. In the original video you can see a guy pop up out of his hole CLOSE to take the shot. You can see the puff from the launch along the border. They cropped it out because it's awesome. Quote HistoryOriginally Posted By Prime: Originally Posted By AlmightyTallest: lol, that's one way of looking at it, but that tank is f'ed up.
Keep an eye out for the uncropped version of that video, I've been looking for it. In the original video you can see a guy pop up out of his hole CLOSE to take the shot. You can see the puff from the launch along the border. They cropped it out because it's awesome. Thanks for that, I'll keep a lookout for the full version. I wondered what that smoke on the right hand side was from when the tank got hit. |
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Posted: 6/3/2023 7:52:19 AM EDT
[#44]
 
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Posted: 6/3/2023 8:04:35 AM EDT
[Last Edit: AlmightyTallest]
[#45]
 Reference, F-18 not included.  Same sentiments as here.
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Posted: 6/3/2023 8:06:56 AM EDT
[Last Edit: AlmightyTallest]
[#46]
Reference, ATACMS coming out of the fake 6 round launcher.
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Posted: 6/3/2023 8:08:06 AM EDT
[#47]
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USA
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Posted: 6/3/2023 8:08:21 AM EDT
[#48]
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PA, USA
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Posted: 6/3/2023 8:15:50 AM EDT
[#49]
Quote HistoryOriginally Posted By RockNwood: Great info. Amazing it was cracking during construction! The nominal load bearing strength of a structural member with in-line force is proportional to the the area of the cross section of the member for the given material. The rebar is mainly for tensile strength in bending/side forces. The concrete carries most of the compression load. A significant crack on the surface breaks the integrity of that affected ring (depth of crack). And since the outer diameter has the greatest cross sectional area for a given depth of crack it is hugely more damaging than the same size crack internally closer to the center. Then add in that exterior cracks allow infiltration of salt water!!! Besides the swelling from rust and further cracking, you have a similar reduction in tensile strength of the rebar as the outer diameter is eroded. And seismic activity will greatly stress the tensile strength of the rebar with lateral and uneven uplift motions or even ground waves. TL:DR Kerch Bridge is fucked. But I would still love to see it a smoking ruin! Quote HistoryOriginally Posted By RockNwood: Originally Posted By MKSheppard: Here's why I think the Kerch Bridge is not long(ish) for this world. https://www.engineering.com/story/europes-longest-bridge-spans-troubled-waters tl;dr -- the Kerch Straits is a terrible place to build a bridge; everything is against it: Foundational -- you have to drive piles down 200 feet through silty mud into solid bedrock, and then a further 100 feet into the bedrock for stability concerns. Currents -- Because of the extremely strong currents; the bridge piers are actually suspended in mid-water over dozens of individual piles to let the currents flow through as shown in the image below. https://i.imgur.com/XhCcKXy.png Fault-Line -- It passes over an active fault. Mud Volcanoes -- Yes, these are a thing. "Further complicating matters is that the strait’s seismic activity can make mud volcanoes from the silt. Mud volcanoes are formed when water heated deep in the Earth’s crust mixes with underground mineral deposits, and the mixture is forced upward through a geological fault." Ice -- Ice in the winter beats the hell out of piers and other structures. A lot of smart people think that any span over 200 meters (700+ feet) is safe from ice. The longest span is 227m, but most spans on the bridge are shorter than that. In short, the bridge is an engineering feat in itself that would require the services of a top grade general contractor (of which there are only a few in the world) as well as a sustained development/planning process. The reality is... In early 2015, the Russian government awarded the 228billion-ruble ($3.7 billion) bridge contract to infrastructure construction firm Stroygazmontazh Ltd. (SGM), a company that specialized in pipelines but which had not previously built any major bridges. Basically, the company is/was owned by a Putin crony/friend. Even under construction, the thing was already cracking -- this image is from 2017: https://i.imgur.com/AhoHIsy.jpg Theoretically, it was designed for a 100 year lifespan. Applying a "corruption" factor; it probably only has a 40 year lifespan. But here's where it gets tricky. These lifespans are calculated using a set rate of tonnage moving over the bridge (i.e. so many 3 ton vehicles and 15 ton vehicles per day). As a vital logistics link; I believe the Russians have been shoving a massive amount of tonnage over the bridge since the war started; because it's an all weather connection, unlike ferries which can't run if the waves get too rough. I would not be surprised if thanks to the overloading during this war, the actual lifespan is now down to about 10 or 15 years... Maybe less, depending on how drunk the inspector(s) were each day. Great info. Amazing it was cracking during construction! The nominal load bearing strength of a structural member with in-line force is proportional to the the area of the cross section of the member for the given material. The rebar is mainly for tensile strength in bending/side forces. The concrete carries most of the compression load. A significant crack on the surface breaks the integrity of that affected ring (depth of crack). And since the outer diameter has the greatest cross sectional area for a given depth of crack it is hugely more damaging than the same size crack internally closer to the center. Then add in that exterior cracks allow infiltration of salt water!!! Besides the swelling from rust and further cracking, you have a similar reduction in tensile strength of the rebar as the outer diameter is eroded. And seismic activity will greatly stress the tensile strength of the rebar with lateral and uneven uplift motions or even ground waves. TL:DR Kerch Bridge is fucked. But I would still love to see it a smoking ruin! They could have used coated rebar to limit corrosion but this is Russia. Does anyone have pictures of that phase of construction? |
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Posted: 6/3/2023 8:17:00 AM EDT
[#50]
Quote HistoryOriginally Posted By ArmyInfantryVet: Lt General Ben Hodges doesn't think Ukraine is going to target the Kerch bridge. Makes a fair argument that the Ukrainians would want to keep it open so the Russian troops and civilians can evacuate on it after the land bridge and ship supplies to Crimea are cut off. I agree and have said the same thing. But it's an old Russian tradition NOT to allow civilians to evacuate (until it's too late). So it will be fun to watch. |
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