Ukraine's battlefields are shaping up to look like a tank time warp.
Russia is thought to have lost more than half its operational tank fleet since the start of the February 2022 invasion and is now "scraping the barrel," according to military analysts.
Images that have emerged in recent weeks show Moscow has started dragging 70-year-old museum pieces into the conflict.
Onlookers have mocked the move, referring to the fleet of T-62 and T-55 tanks — which first appeared in the 1940s — as "dad's army".
Ukraine has also seen its main battle tank supplies dwindle, but is replenishing its stocks with modern Western varieties.
About 230 NATO tanks have now arrived and are expected to play a powerful role in Ukraine's full-blown counteroffensive.
But while Ukraine may have the edge in quality, Russia still — despite its losses — has the upper hand in quantity, a senior NATO official told reporters in Brussels this month.
And with Kyiv unlikely to get its fighter jets "coalition" in the air anytime soon, the conflict could remain bogged down in a war of attrition for months.
Both sides will still be wanting to hold onto every tank they can get.
So what does it take to knock-out a tank, and what tactics are both sides deploying to keep their array of battle beasts in action?
What is Russia working with?
Zeno Leoni, defence studies lecturer at King's College London, said this was a conflict where "quantity really matters," and Russia's older tanks may end up making a difference in the long run.
When it comes to Moscow, "we need to be careful with wishful thinking," he said.
"We have been saying that Russia has been scraping the barrel almost since the beginning ... but actually, Russia is still fighting and has large reserves of hardware and assets."
Recent reports suggest Russia may have as many as 5,000 older tanks it could bring into the conflict, Mr Lenoi added.
Jason Belgrave, assistant manager at the Australian Armour and Artillery Museum and ex-Army tank commander, said it was hard to imagine what kind of combat the older tanks could withstand.
"I'd hate to see what the metal fatigue is like on these vehicles," he told the ABC.
"They [T-55s] have thinner armour and are starting to get into the smaller calibre gun."
The tanks are reportedly being deployed to be used as artillery rather than for tank-on-tank battle.
Russia had roughly 3,000 operational tanks at the start of the campaign, according to the International Institute of Strategic Studies (IISS).
Its fleets included mainly T-72 or T-90 variants, but it still had a large number of T-80s.
The T-90 is essentially an upgraded T-72, with more advanced technological features, increased firepower, mobility and protection.
"They have better electronics and better sights, but they are essentially the same vehicle hull-wise and turret development wise," Mr Belgrave said.
The T-90 has been Russia's strongest tank on the battlefield so far, but last month it debuted its highly-touted T-14 Armata
Some military analysts argue the 2018 Armata is a better tank than the US Abrams.
"But they have not yet participated in direct assault operations," Russia's RIA state news agency reported.
And it is uncertain they ever will at scale.
Any deployment of the T-14 would likely be "a high-risk decision" for Moscow and "production is probably only in the low tens," according to the British military.
Most of Russia's tanks have undergone several upgrades in recent years, with Defence Minister Sergei Shoigu boasting in 2020 that the T-72B3M had new modifications that "outshined foreign rivals".
But bad tactics and advanced anti-missile weapons are seeing even the T-90 getting taken out "quite easily," Mr Belgrave said.
Dutch open-source verification outlet Oryx has counted around 1,900 Russian tanks have been destroyed so far.
However, researchers from the IISS told Reuters in February that Russia's estimated tank losses could be as much as 2,300 and Ukraine's at up to 700.
Ukraine is estimated to have gone into the war with a tank fleet around half the size of Russia's.
Prior to gaining Western supplies, it had been offsetting losses with donations of Soviet tanks from allies like Poland and with hundreds of tanks captured from Russian forces, according to IISS analysts.
Why are T-72s 'easily' taken out?
In March, Oryx "visually confirmed" Russia had lost more than 1,000 of its T-72s — the tank which has formed the backbone of its armoured units.
Technically, the latest T-72 is comparable to Western tanks, Mr Belgrave said.
But a crucial design flaw makes it vulnerable to complete destruction.
Videos have frequently circulated showing strikes that blow the tanks' turret spectacularly into the air.
And often it's not even a powerful weapon that is causing the devastating effect.
Earlier this month, footage reportedly showed a T-72B being taken out by a cheap R18 bomber drone.
Both the T-72 and T-90 use an autoloader and store ammunition in a ring directly under the turret.
If an explosion punches through the turret it can explode an entire ammunition store of up to 40 shells.
"You've got ammunition exploding and literally blowing the turrets off," Mr Belgrave said.
Western tanks such as Germany's Leopard 2 don't use an autoloader, which is why they have a crew of four.
Ammunition is stored outside the turret and there is less danger of rounds detonating if the turret is hit.
Analysts say a lot of the tanks were also being lost due to lack of infantry support and protection.
"Tactics wise, we see this a lot where the Russians literally drive into a town with their tanks and they get hit by all these anti-armour weapons," Mr Belgrave said.
"So that's where Russia is lacking at the moment, with that integral infantry support they need to clear anti-armour weapons."
Western tanks will 'almost certainly' be destroyed
Ukraine has most commonly been using the locally-made older T-64s — which have undergone several upgrades and modifications — followed by T-72s.
But it is hoping to move away from its reliance on Soviet tanks now that it has begun receiving an array of highly sought-after heavy Western weapons.
Last month, NATO Secretary-General Jens Stoltenberg said the alliance's allies and partner countries had delivered more than 98 per cent of the combat vehicles promised to Ukraine.
So far, this includes about 230 tanks, among them Germany's Leopard 2s and the British Challenger 2s.
A delivery of 31 Abrams tanks is expected after spring, with the US opting to send a refurbished older model that can be ready faster.
John Amble, editorial director at the US Modern War Institute at West Point, said Ukraine would need a steady flow of Western tanks to shift the military balance substantially.
But he warned "there is no such thing as a tank that can't be killed".
"The Leopard 2A6 has fewer vulnerabilities than most T-72 variants — certainly those that have received fewer upgrades — and better survivability, which means the type of catastrophic kill seen in the videos is less likely," he said.
"But it isn't impossible ... There will almost certainly be Leopards destroyed in action."
Mr Leoni said if Russia decided to use its air power "more effectively" it would be a "huge game changer".
"Tanks will always be vulnerable to air power, especially if Russia manages to integrate more intelligence on the ground with air power in order to be able to target these Ukrainian tanks," he said.
However, Russia has realised there is a cost in using air power and wouldn't want to risk losing its sophisticated assets, he added.
Protecting tanks with exploding 'bricks'
There are many ways both sides are modifying their vehicles for better protection.
A common tactic, which has Soviet origins, is to cover tanks in Explosive Reactive Armour (ERA).
The ERA "bricks" are made-up explosives sandwiched between two metal plates, which detonate and reduce the penetrating power of a missile before it hits the tank.
ERA adds another layer of protection against anti-tank weapons, but have varying capabilities depending on the type.
Mr Belgrave said all types of ERA only work to a certain point.
Russia's latest Relikt ERA was designed to better protect against tandem warheads like the Javelin, but "it's just not holding up," he said.
Another protective add-on is "bar armour", which is essentially a metal exoskeleton that attaches to the side of a tank to trap an incoming warhead.
"It either captures the round so it gets stuck, or it'll pre-detonate that round before it gets to the vehicle," Mr Belgrave said.
Screens or "cope cages" have also been seen covering turrets, which have the weakest armour thickness.
A recent video released by Russia's ministry of defence showed a T-72B3 protected by a cope cage covered in what appears to be a layer of Kontakt-1 ERA.
Success is in smart tank tactics
Ukraine's modern tank fleets may have more solid armour, sophisticated sensors, and powerful guns, but tanks alone can't win a battle, Mr Amble said.
"They need to be paired with smart tactics and employed by flexible leaders who not only use them, but protect them," he said.
"That's the case no matter how capable or modern the tank is."
The Western tanks' battle power potential will be on display in the coming weeks if Ukraine launches its expected counteroffensive.
"If they're incorporated into combined arms approaches — meaning they support and are supported by infantry — they will certainly have an impact," Mr Amble said.
But whether a tank like Leopard 2s will be able to stay in the fight will come down to how well crews have learned to operate them and whether the necessary logistics and mechanics systems are in place, he added.
In the longer term, manpower may become an issue and there will be the need for continued weapons support, Mr Leoni said.
"[It's] not just who has more tanks or who has better tanks, but what other assets the two countries have," he said.
"In warfare that will last for a long time, there will be an issue of manpower, especially for Ukraine ... which the West clearly cannot resolve."
