Inside the Chieftain's Hatch - AC I Sentinel Part 2

The second part of two videos taking us on the tour of the lesser-known Australian Cruiser Mk 1.
NA Forum discussion thread: forum.worldofta...
Asia/Australian: forum.worldofta...

[@Phatman2167]

That slot in the turret is a chimney. the heat from the metal at the top creates and updraft. With a constant draft of air blowing up through it the air coming in from the bottom will be cooler and will actually pull heat through the armor from inside the tank, helping it cool off in there. It's the same as old houses with a hollow center. cool air from the basement/under the house gets pulled up the center by the warm air nearer the top. Instant 19th Century air conditioning.

[@gone547]

TFT.

[@eliwatson7936]

It’s an absolutely fantastic first tank design, they just forgot they had to put people in there

[@neilwilson5785]

They really did lol

[@pavarottiaardvark3431]

The Aussies did the "this is mediocre but it's amazing that you managed it at all" no less than THREE times during the war: the Sentinel, the CAC Boomerang and the Owen Gun (and arguably the Owen gun was actually pretty good).

[@Goatboysminion]

The Owen was a bloody sight better than "...mediocre.."!

[@trevorlong3003]

I fired the Owen and it’s replacements the F1 they were good guns but the experience in Vietnam was not good!

[@aymonfoxc1442]

@@trevorlong3003 Did you serve in Vietnam? I only ask because the veteran accounts that I've heard were quite to the contrary (reportedly owing to the Owen Gun's reliability, ease of maintenance and ease of handling).

[@sebastiancarrall117]

Owen gun was the best smg of ww2

[@thefantasyreview8709]

Owen was a great smg, in use right up until the Vietnam war.

[@forbeshutton5487]

The slot/chute: a coin operated tank?

[@LastAvailableAlias]

It took tokens. You had to go back to the token supply vehicle for more.

[@theflyinghetzer4335]

Lol

[@theflyinghetzer4335]

Sentinel tsv, token supply vehicle

[@neilwilson5785]

The rear angle is like a jukebox to be honest.

[@korbetthein3072]

@@LastAvailableAlias Probably needed to do daily rewards missions to get more tokens.

[@eurobeatbandit]

There are going to be gifs of "machinegun elevation" in no time, I can guarantee you that :^)

[@TheChieftainsHatch]

+Noodles They beat you. i.imgur.com/Ho75l1u.gif

[@eurobeatbandit]

Thank you good sir, my sides have left the orbit.

[@tahunkwai5979]

+TheChieftainWoT the real question is how many Viagra does it need

[@PhillipAtherton]

+Yao Wang lol nice one he he he

[@panzerabwerkanone]

+Noodles I find machine gun elevation mildly erotic.

[@agarestretiak8925]

When on the interior of the vehicle, I noticed the housing for the mystery chute on the loader side of the turret. It seemed like there might be a vent there, on the metal housing. So, I propose it might be some sort of passive ventilation device for the turret or other sort of vent.

[@TheMalevolentSpoon]

"You just unscrew it, and all of a sudden, your tank is now happy to see you."

[@mudcrab3420]

If my RAAC history is correct Australia was the proud owner of ONE M4 medium, making us possibly the only Western Ally to NOT operate the Sherman during WW2. M3 Mediums we got a bucket of, as well as M3 lights. The lights were used in PNG were they were mostly functional, but it was found that the engine and transmission didn't really like crawling around in 1st gear the entire time. The Matilda, as well as having thicker armour, handled the low speeds of close jungle support better and hence the Matilda was tank we finished the war with during operations against the Japanese.

[@carlwesternut2434]

Matilda... my favourite infantry tank.

[@larrythorn4715]

I imagine you could call the Matilda the Pacific Tiger. Did the Japanese have anything deployed off the home island that could take on a Matilda?

[@fulcrum2951]

@@larrythorn4715 they have the chi nu in the works or equivalents

[@Ocker3]

@@fulcrum2951 although the Navy took all of the resources that would have been necessary for making larger tanks I believe. Apparently the Japanese Army and Navy competed to overthrow the Gov and put their own person in as PM, and inter-branch rivalry was responsible for an incredible number of problems they had.

[@willburns9399]

There is a Sentinel in the tank garden of Texas Military Forces Museum at Camp Mabry, Austin TX. Cast armor was done extensively in France and the story I heard was refugee French armor designers were sent to Australia to help in the build effort, their skills were not needed in England. The Somua had cast armor as did many of the small infantry tanks. The bogies have a french appearance with the improvement of volute springs from USA. It is an amazing vehicle, thank you for the video!

[@TheChieftainsHatch]

That tank has been in Australia for at least eight years. It's on display in Cairns

[@stephenwarhurst6615]

Is that Sentinel happy to see you or is it just hull Machine gun elevation

[@captainseyepatch3879]

Am I the only one that does not think it looks like a penis?

[@crazyafrican9955]

CaptainsEyePatch really we all know that

[@1337flite]

Yes CaptainsEyePatch - everyone else thinks it looks like a penis. Because it looks like a penis.

[@machinenkanone9358]

This is a very gay thread

[@raymoney6503]

@@machinenkanone9358 are you jealous of the hull machine gun’s size

[@andywagner212]

This guy deserves way more views. Interesting stuff to watch. In depth looks into pieces of history

[@TheKalkalash]

I guess the turret chute could still be some sort of a ventilation system. Even if the duct doesn't go inside the turret, the amount of metal between air on the outside and air on the inside is going to be thinner, thus heat is transferred faster. Still a pretty far fetched idea though.

[@Colinpark]

+TheKalkalash My thought as well

[@con_boy]

+TheKalkalash my gut feeling is that it is to do with fast water cooling. Australia is incredibly hot. This tank would have been impossible to physially function in I suspect. My gut feeling is you can dump buckets of water down there, and recapture it in a bucket at the bottom, in an an emergency, to quickly bring the temperature down inside the crew compartment

[@Voyager989]

+TheKalkalash I'm pretty sure that's an air vent. You can see it behind his right shoulder when he's in the gunner's seat, and what looks to be a handle and cover plate. Given the gases produced by the gun and two water-cooled MGs, you'd want as much ventilation as you could get, and without fans, natural ventilation would require one front-ish. There's two more air vents on either side of the turret bustle as well.

[@b1laxson]

+TheKalkalash My theory goes like this: Heat rises. So a vent in the top would let heat out. There are other openings possibly vents at the back. If these rear ones were height wise lower it would be where outside cooler air would enter. So with both rear and a top vent you get an ongoing air flow with outside cooler air coming in at the back, passing through the compartment to wick sweat off the crew and then go up the hot air vent on the top. Plus this air flow would also assist in venting gases. My theory anyway.

[@b1laxson]

+Conrad Bate Pouring water down the top opening is unlikely an in combat action. Outside of combat you could easily afford having the commander's hatch open. So would you just pass the water through the larger open hatch. IMHO it seems the water pour method for the small opening is unlikely. That is an "In my humble opinion"

[@FairladyS130]

Let's get a bit of perspective here, the AC1 was never accepted by the Army as being fit for service, they had a list a foot long of problems to be sorted before that would happen. The good thing about the turret was it's size, internal space and ballistic shape, the interior arrangements were obviously never satisfactorily designed and completed to a suitable standard so it's pretty ridiculous to infer that this was a done and dusted product. The water cooled MG and the inside cooling arrangement it required is just another example of what necessity can result in when your 'allies' suddenly find they have nothing suitable to spare, like engines and gearboxes as well. Nothing at all to do with some cheeky country building a tank that was a rival for theirs at all lol. Lots of other stuff that invites critical comment, one will do and that concerns the 17pdr gun and the comment doubting it would fit. Perhaps a look at the modified gun and the larger Thunderbolt turret would be a good starting point for the making of such a comment. The important thing to note is that the need for such a Tiger killer was recognised, something that not everyone understood.

[@bruceinoz8002]

Regarding the turret and armaments: I vaguely recall reading, years ago, that to test the sturdiness of the turret, with an eye to squeezing a 17 pounder into that turret, ring, etc., the boffins fitted one and then TWO 25 Pounder guns to a new mantlet and let fly on the range with BOTH guns fired simultaneously. It held together. I suspect that the turret team were OUTSIDE the turret when this was done). That would have made a serious bunker buster in the islands, where the dinky, agile but fragile M3 light tanks were being chewed up by the Japanese 90mm AA guns . (It was "dual-purpose", very like the German "88"). The 37mm gun on the light M3 was OK for shooting up earth bunkers reinforced with coconut-palm logs, but like the 2 pounder on the Matildas, also roaming the coastal flats and swamps of New Guinea, not much use against reinforced concrete. As for the use of water-cooled Vickers MGs, I guess that the army had been using them since the previous great unpleasantness and making them at Lithgow since the early 1930s. Having yards of empty cloth belts floating about loose in the fighting compartment would have been "interesting". There's a LOT to be said in favour of disintegrating link and "catcher" bins. If they insisted on a .303 MG for ammo logistics reasons,, the logical choice would have been the .303 Browning guns, as widely used in many RAAF aircraft at the time. Whether the RAAF could spare them would have been a matter of inter-service politics and "budget constraints". As far as I know, ALL of the .303 Brownings and spares were imported, not made in Oz. It was all a bit late, because a swag of M3 Medium tanks, in the process of becoming "obsolete" in the US system, were available for a song (probably "Waltzing Matilda"), and Sentinel just faded away.

[@xGxPhantomZzz]

Ironic the ChieftainWoT has no vid about the Chieftain

[@ultimo36]

actually he did do a snapshot vid of it but whatever

[@robertguttman1487]

That chute from the top of the turret though to the right side of the turret: It's an ashtray for the tank commander to enable him to smoke while his head is sticking up out of the hatch. Very clever, these Australians, nobody else ever thought of that.

[@shawnamericanrebel5676]

😏🤣

[@paspax]

On the subject of railways.. It was a bigger issue than you mention.. The Islington rail maintenance yards were making bren carriers. My dad was a lad at the time and he recalls convoys of them running up Churchill road to get to Port road to go to the docks.Likely similar situations across the country.

[@VaucluseVanguard]

Nearly 80 years on and our procurement processes are not a lot better!

[@matthewwadwell6100]

11:31 onwards - you can see the rectangular tube that connects the top and bottom opening on the side of the turret. If you look closely, it appears to be welded on afterwards (as other components in the turret are NOT welded on like this). My _guess_ is that the rectangular tube is not originally there, and these openings were vents. In fact, the vent on the top of the turret is very similar to the ones on the bottom of the rear of the turret. Later, Matt

[@MrMenefrego1]

That odd chute on the right rear of the turret is obviously to aid the various females in the towns and villages they pass through on the way to beautiful downtown Berlin in getting their phone numbers to the Aussies in the tank itself... mystery solved!

[@justforever96]

But it doesnt go into the tank. Does no one actually listen? It opens on top of the turret, outside, and exits on the side of the turret, outside. Whatever you drop in there falls out and off the side of the hull. Just like if you simply dropped it off the side of the turret. Yes, I know 'it was a joke', but the premise of a joke should at least make some sense.

[@WildBillCox13]

Old habits die hard, if they die at all. Some of mine are my love of the Sentinel and Ram projects. Thanks for covering this icon from the M3 Medium Tank Evolutionary Tree. The Sentinel was a wonderful work of designing a racehorse by means of Industrial Heads shaking their heads at your proposals and requirements, lamenting their absolute lack of potential for enlargement and improvement of their support in the matter of producing new arms or materiel in the extreme short term. I am again and again impressed by the rapidity with which this project was promoted to fruition. Adapting, shoe-horning, amalgamating, squeezing, forgetting your gunner has a left leg, casting armor in large sections . . . Until you slid into the turret I really thought that amateurs had made better of a bad situation than the professionals. Subsequent to your arduous journey, therefore, I would be interested to know how the ergonomics (and the pointy and knobby bits that stab or club you when you try to move around inside) changed for the "slightly" enlarged turret for the S3 and S4. With the 24pdr(Aus) main gun, which was used as an AT gun in the desert (at need) and had a useful AP performance for its time and place, not much tweaking would be needed to make the S3 so much better than the much taller Stuart looming over it in the display. I agree that two piece ammo is a debit . . . unless your turret space is limited (and/or your loader can't stand up). Then it might be useful to have two small, easier to handle components, instead of one long single piece round. Indeed, for the '42-'44 period, the 25pdr would've been a great choice for any CS tank; with well developed ammunition, greater effect on target, AP duality; a Tommy "Good 88" to oppose (figuratively speaking, of course) Jerry's "Bad 88".

[@GeneralJackRipper]

I must say, going from making absolutely no tanks, to arrive at Sentinel as a first effort is pretty impressive. Yeah, the crew ergonomics are appalling, and it was essentially obsolete the moment it entered production, but the armor protection and firepower seem typical of 1940's tanks.

[@brucelamberton8819]

Actually it was better armoured than most other tanks of the time

[@warhawk3719]

16:40 - The AC 1 Sentinal Hull Gunner's position: It's ribbed for your pleasure!

[@lukeskywalker3329]

Thank you Chieftain. That was a very practical and pragmatic honest look . Even your sarcasm is informative . ☺ Thank you from down under .

[@RailfanDownunder]

Superb work again.... I assume your attempt to photograph the Sentinel at Puckapunyal coincided with the security lockdown and/or closing of the RAAC Museum...? Still closed as there is a plan to build a new museum outside the base for greater Public access but that may be delayed as the Army budget has been slashed so we can but nuclear subs .. strange to think that by 1944, we had three armoured divisions in Australia but none would see service as either divisional or brigade units nor would they go to Europe? M3 Stuarts were utilised as Infantry Tanks at the battles of Buna and Gona after Universal Carriers were tried - no wonder Matilda tanks were then deployed in New Guinea and the Dutch East Indies and Borneo afterwards.... Keep up with the good work Sir

[@KOS762]

the Roof Vent..... Like a german bunker vent.. .the top is where the air goes in and the bottom is where the enemies bullets exit.... the function is to get air into the turret, without allowing the enemy to use it to harm the crew....... think of the entire port shaped like the letter "T" on its side.....nothing falls sideways, so they stay pretty safe, even if the enemy is on roof, shooting into the openings.

[@willburns9399]

The turret air shaft is obviously a cable raceway for a Canal Defense Light, making turret weapon ergonomics superfluous, 3 engines gave a clever design feature to declutch and run generators to spit out 70 million candlepower to blind and mesmerize enemies. With the enemy stunned, the next step would be to charge them with the hull weapon in the "angry" position.

[@SickocrowAU]

In the words of Luke Skywalker 'What a piece of junk!', but I'm still proud of our first home grown tank even if it is shite.

[@ZGryphon]

Hey, it's better than your neighbors managed. en.wikipedia.org/wiki/Bob_Semple_tank

[@davidgreen5099]

It looks great!!

[@SportbikerNZ]

@@ZGryphon Haha, thanks for the link. That's our classic No8 wire mentality right there, but not the finest example.

[@ZGryphon]

@@SportbikerNZ Upon reflection, I'm pretty impressed with it. I mean, when all you have is a shed and some machine guns, you make it work, right? It probably would've worked reasonably well for what they expected to need it for.

[@johnd2058]

@@ZGryphon As Chieftain said, Japanese tanks, which themselves worked reasonably well against the Chinese.

[@BillHalliwell]

Could it be that the swivel seat in the TC,s position should have been the gunner's seat and that they mixed them up during the renovation? It makes far more sense to have the gunner swivel around to fire and traverse the gun rather than bend like a pretzel on a static seat. Thanks, Nicholas, another great video. I'm ex-RAAF and had zero interest in tanks until I saw your vids! I thought some aircraft positions were cramped... wow! I also discovered my inner claustrophobia thanks to your videos! Cheers, from Downunder! BH

[@Ocker3]

Well there were other things in the way of the gunner swinging forward, but you make a good point. I wonder if the AC3 turret had better ergonomics, Mk 1 anything almost invariably needs work!

[@BillHalliwell]

@@Ocker3 G'day Ocker3, You're absolutely right. You never see an aircraft or tank or anything retire as a Mk 1. It is really scary how many aircraft were 'flown off the drawings' during WW2, that is where a design was approved at the drawing and, if they were lucky, wind tunnel tests, and then went right into production without extensive prototype flight testing. This, of course, pushed the envelope of development but it was significantly deadly for military and civilian test pilots at the time. Test pilots really are the last unsung heroes of the WW2 story. I believe the greatest and bravest of them all was Lt. (later Captain) Eric 'Winkle' Brown RN. He became the Royal Navy's most successful test pilot, so good he was farmed out to the RAF and Farnborough. His log books confirm he flew 487 different types of aircraft in his relatively brief military career. This is a record that will never be beaten as these days aircraft are 'flown' first in computer modelling and some still with air tunnel testing. Then groups of test pilots are rotated through airframe testing these days. It is still a dicey job but nowhere near as dangerous as it was in 'Winkles' time. Eric was awarded many medals and decorations and passed away several years back of natural causes. In aviation terms he was a true hero. His book, 'Wings On My Sleeve' is a great read. Cheers, and all the best, BH

[@EssentialPedagogy]

Mate, you made a mistake. Australia didn't use the M4 except for a few (like 4 I think) that were acquired for testing purposes. It was decided to just use the Stuarts. The M4s were considered not up to purpose for jungle warfare. Australia was one of the few countries to reject the M4.

[@TheChieftainsHatch]

+EssentialPedagogy You are quite correct. The availability of M4 was part of the argument against, but yes, I spoke in error. I'll make the annotation.

[@hart-of-gold]

Hello Chieftain, I reckon the chute covered an overflow for the machine gun coolant, otherwise the turret would fill with stream after sustained firing.

[@Maus5000]

+Hart Poole That's a great idea. Most likely explanation I've seen, for sure

[@mudcrab3420]

My understanding was we got one M4 for evaluation. Open to correction. We did get enough M3 Mediums that we ended up doing most of the conversions everyone else did on Sherman hulls using M3s. At Pucka they have a lot of them. At Keswick they have a M3 Medium used to support the atomic tests. Not THE Atomic Tank (which was a Cent and I believe now lives in Darwin) but they wanted a camera vehicle to film the tests so they removed the guns and used the space to mount movie cameras.

[@aaronleverton4221]

I can imagine that someone who has never designed a tank before might think it useful for the commander to be able to reference the direction of travel versus his direction of vision occasionally and thus he can swivel his seat to give himself a very broad baring of "difference" for whatever reason. A bit like the MBT70 fitting everyone inside the turret, but keeping their direction of facing true to the direction of travel no matter where the turret was pointing, while the commander is separate from the all, facing wherever he wishes.

[@coalhearted4823]

Ok, just saw this one and gotta say I busted a gut seeing the bow gun, that had to be deaigned on purpose, someone back then had a bent sense of humor, just had to be, really enjoyed this one!

[@DimoB8]

Just Aussies!

[@selcukkaynak1642]

that mg nest haunts me in my nightmares....

[@selcukkaynak1642]

+xGxPhantom Zzz shit happens

[@SolyomSzava]

+Selcuk Kaynak After that thing rapes someone... shit doesn't really happen anymore. The stuff just slides out on its own, no effort needed.

[@xGxPhantomZzz]

***** ( ͡° ͜ʖ ͡°)

[@Crimsonedge1]

+Sólyom Csaba Speaking from experience? :D

[@neurofiedyamato8763]

The Sentinel has always been one of my favorite tanks but this interior kind of ruined the image for me. On paper, it seems like a real good tank except lack of 360 vision cupola. Its also Australia's first tank yet seems to be quite top notch so I really liked it. Sad it never got to see service and that Australia stopped designing tanks entirely.

[@donaldhill3823]

My guess on the mesh covered slot is that maybe it was a simple attempt at passive ventilation to keep the outer turret which would help keep the inside cool. Air enters from bottom and exits through the top. The faster the tank would go the better the air flow. mesh would simply be for personnel safety. Same idea as the vents for the roof of a house.

[@gleggett3817]

When he's on the loader position you can see the sheet metal.chute that joins the two holes in the casting. It looks like it would line up with the breech of the turret Vickers MG when installed. Perhaps it was a means for casings (belt) and gases from the MG to leave the turret interior.

[@justindunlap1235]

as a 6'3" tall man who is caver, I definitely agree that you develop a sixth sense for when you're about to smack your head. the trick is learning how to listen to that feeling.

[@mo45327]

Could you do an episode on one of the Japanese WW2 tanks?

[@GamebossUKB]

Most of them didn't exist or are all in Japan so prob not

[@mo45327]

There is one right there in Bovington tank museum next to him xD The only other one in Europe is in a Dutch museum. Also there a couple in the USA and in Russia.

[@RedShocktrooperRST]

+mihajlo olujic Look how tight of a fit Sentinel was and remember how tiny the Matilda was. It'd be an instance of Outside the Hatch because the Chieftain would be physically incapable of going into the vehicle.

[@mo45327]

+RedShocktrooper That is true but still, even Outside of the Hatch would be nice.

[@suryanshgupta7195]

+mihajlo olujic 1 hago in India too

[@NewDemocraticMan]

Thanks for yet another great 'In the Hatch' Chieftain! I have to ask, you spent the effort on the AC series, when are we Canadians going to get some insight into the RAM series of tanks? I'd love to hear your take on them! I know most were transformed to Kangaroos by late-war, but I know of at least 3 in Canada that are in one piece. There has to be some museums pieces as well (1900+ production run suggests there should be more hanging around at any rate!)

[@thefantasyreview8709]

I'd say those chutes are air vents... or something to deal with heat. We Aussies are very prone to trying to keep vehicles cool because its very hot. The sentinel design spec was actually for it to operate in hot temperatures, and it was stated that it wasn't to operate in cold climates, so the designers didn't have to worry about dealing with cold climate issues (like snow) or heating. When the design started, we were hard at war with Germany and the Italians in North Africa, and if the tank was to be used in Australia, it needed to deal with heat.

[@niclyx7970]

Comments drinking game: Drink every time someone makes a "armored housing standing at attention" joke.

[@MilesStratton]

How in God's good name did Australia think it was a good idea to put a 17 pounder in that thing.

[@Ray-lf1eo]

#YOLO

[@ShadowFalcon]

Goodness, you're right. I mean if the turret is that cramped with a piddling 2Pdr, the breach of the 17Pdr would surely "interface" with The_Chieftains chest.

[@RedShocktrooperRST]

+Many Miles Away I believe he said the AC3 had a larger turret for the 25-pounder so they just switched the 25-pounder out. Granted I'd honestly question why they needed it. Not like they'd be deployed to Sicily or France.

[@MilesStratton]

true

[@MagzGTV]

+Many Miles Away Fear, At the time very little was known about Japans tank development. The military knew of the light tanks japan had available as we had seen some of them but we had never seen if they had anything larger as the island hopping that was the Pacific theater at the time didn't necessitate japan deploying heavy armor if they had any. Also at the time there was a very real worry of a Japanese invasion of the Australian mainland. The 17 pounder was Australia's answer to a potential Japanese invasion of the Australian mainland involving potential unseen heavy tank designs armored well enough to survive the 2 pounder. One thing to also remember is the name, Sentinel. It wasn't chosen at random. Sentinel wasn't built to fight outside of Australia. She was built to guard and defend only against an enemy with unknown capabilities. Of course knowing what we know today it was overkill but that is the beauty of hindsight.

[@knightmarex13]

So we got a hatch for the Comet, Chieftain, and Conqueror. When will we get one for the Centurion?

[@aflappincod]

I'd love to see you do a video on the Ha-Go they jave at Bovington.

[@bartekt6690]

Hi, In my opinion the mysterious chute in the turret is cooling chute for coax machine gun coolant - the air flow is driven only by gravity air inside as get het from coolantdrafts to the top and cooler air from bottom comes cooler. Best regards

[@lilkobabunga]

Will there be episodes about Japanese tanks?

[@gr0use350]

Japanese tanks where fucking terrible

[@majordbag2]

+Declan Merrick To be fair, they really didn't have any need for good tanks, their main foe was China, which had practically no armor and tanks have relatively little use on the island campaigns in the pacific.

[@fireshorts5789]

+Zoltán Vári Unfortunately there are very, very few surviving examples left to do an episode about. There is at least one Chi-Nu in Japan but I believe it's on display in an active military base, so probably no access. Outside of that I believe I remember seeing a video of a running Type 95 Ha-Go or Type 97 Chi-Ha somewhere on here but they're very tiny tanks so there wouldn't even be much to do the video on.

[@MadnerKami]

+Declan Merrick Can't be as bad as Sentinel vOv

[@RedShocktrooperRST]

+MadnerKami OH YES THEY COULD. A few Japanese tanks had one man turrets. I don't think the Chieftain would be able to fit inside of a Japanese tank.

[@goetzliedtke]

Interesting, the hull was cast without a floorplate. That makes me wonder if the casting company was originally a bell casting foundry or black-powder naval gun casting foundry (or both).

[@allangibson8494]

Try steam engines...

[@TrueCanad1an]

To pass smokes to the guys in the turret

[@jum0213]

awesome vid ! super interesting have been looking for more info in the sentinel, not easy to find :\

[@jayfelsberg1931]

Not perfect but actually a pretty impressive accomplishment for the time and situation. It's a shame it never saw service; it could have handled most Japanese tanks.

[@AgentTasmania]

Jay Felsberg And the disaster of turret ergonomics seems fixable

[@Ocker3]

@@AgentTasmania exactly, it seems to be internal stowage, etc., that's mostly the problem. One of the advantages of this hull is that it's large enough to take a much larger turret ring to handle the recoil from a much larger gun. Larger turret ring implies larger turret.

[@Walaki]

I almost died laughing at the part where he moved the front MG up....X'DDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDD

[@TheAquarius1978]

+Walaki 16:20 and im fairly sure they did that on purpose lololol

[@Walaki]

+TheAquarius1978 I'm 100% sure it was intentional, but still funny as hell :D :D :D

[@johnmartin4639]

TheAquarius1978 especially seeing as he said "bears a certain resemblance to a certain part of human anatomy" a minute before it

[@drdagonator3544]

The best guess on the chute is it allows air to circulate around the turret without going inside the turret so that the metal has more surface area touching moving air to keep the inside of the turret "cool"

[@TommyStyrvoky]

I wonder if the mesh/chute could be for drainage of water/sand. Looking at the inside, maybe it was for another water tank for cooling the MG, then It would have external access to it for filling, or maybe it was planned to allow ventilation into the turret. It could have been to late in production to change the castings, so it was just covered up.

[@Hokum_Paints]

+Tommy Styrvoky Or it could be a means of cooling the water for the machine gun, forced convection?

[@ryanaegis3544]

A chute between two different elevations immediately makes me think of ventilation. With hot air rising and cold air falling, you naturally get a flow through such a system if there are different air pressures on either end. Granted, such a system would require more of a difference in temperature (or humidity) than the height of the turret would signify. Perhaps there was a way to hook the exhaust from the engine to the bottom side of the chute, and thus warm air would pass through, warming the side of the turret on a cold night. Or perhaps the heat radiating off of the tank body was enough to create a flow up through the chute during the daylight hours. If there is an opening alongside the chute inside the turret, the venturi effect would suck air out of the turret as it flows past. But all of these, again, would have minimal practical effect as the flow of air due to differences in pressure (due to temperature or humidity) generally require more distance to really create a noticeable amount of flow.

[@RobinGlijn]

Could it be that the chute leads to a radiator, to cool the coax machine gun's water? Have you checked the inside of the turret? Checking some photo's of the Mk.III which, as you said, didn't have the coaxial machine gun, it also doesn't seem to have the chute(s).

[@hart-of-gold]

My guess for the chute is it was for a radiator to cool the machine gun water. Is there an aluminium heat sink inside it connected to the coolant tank?

[@hart-of-gold]

Or maybe an overflow so you don't have boiling water and steam spraying round the turret.

[@calvingreene90]

Despite the great problems with the interior it is a good first attempt especially given being on the wrong end of the priorities list.

[@matthewwadwell6100]

I found a couple of sources for what the hole with the grille. www.mheaust.com.au/Aust/Research/Sentinel/sentinelmk.htm - states that "The sides and rear specified as 45mm (1 ¾ inch) thick with an armoured overhang covering air vents that ran along the top sides of the tank." You may also want to check the manual for the AC 1 - commons.wikimedia.org/wiki/File:Tanks-Australian-Cruiser-Mark-1.pdf and see if anyone can find anything...... Later, Matt

[@Anlushac11]

Excellent video. Thanks for your efforts. Have obtained more info on Sentinels than I have ever found elsewhere. Dear God after watching this video Wargaming may feel they were too generous and nerf our Sentinel AC1 in game. As for turret chute would like to know if there is any access to inside of turret through that chute. On side of hull looks to be a air intake for engine somewhat below chute. I could imagine engine running, air is pulled in to top of chute and airflow causes low pressure in turret causing air to be pulled out of turret and down chute and into engine thus constantly recirculating air in turret. This would eliminate need for turret roof mounted ventilators which would require additional components and machining to make and finish the holes in turret roof. Chieftain you also hit on my next question. If 2lbr was that cramped how the heck did they get a 25lbr and 17lbr into that turret but as you stated a larger turret was used. Thanks again

[@MadnerKami]

+Anlushac11 That would only work, if the turret was in a certain and very specific position, which kind of defeats the purpose as the turret is usually going to rotate during combat.

[@davidhobson7652]

There were a few of these tanks allocated to a some actual unit, but not for fighting or training purposes but for a movie "The Rats of Tobruk" they were mocked up to be German tanks

[@proileri]

I would guess the chute was for the coaxial MG spent casings. The MG would throw the spent brass into the chute, and the mesh on top is to ventilate any powder gases.

[@rossnelson8433]

Steam from the vickers upwards, condensation downwards. Otherwise the whole turret turns into a rainforest with two vickers blasting away and the hatches closed...

[@thedesignfarm3826]

Two Guesses: 1. With the turret turned left 30deg, if the commander was unbuttoned, he would be furthest from the driver, and if the driver was un buttoned, this could act as a way to holler at him.. like old ships, tubes down to the engine room… 2.With the ridge line at the front of the turret, and slope from the capola - some sort of water drainage to keep water from running (off the front of the turret) down the mantlet, or right hand drivers barn door style hatch?? I take this back [dropping smoke or other ordinance down the chutes to get a smoke screen from the ground up?]

[@MrSteeleye]

There were 2 versions of the Sentinel Tank. I've tried to attach a photo I took of the other version located at the Australian Armor and Artillery Museum located In Cairns Queensland where they have both versions. However this site wont allow me to do so.

[@alanrogers7090]

Speaking about the gunner's position, What if the seat was able to fold up and the gunner was supposed to sit on the floor? Maybe the controls made more sense in that case. The seat was only for travelling. Could this be a possibility?

[@tanfosbery1153]

Good point - the 2pdr being controlled in elevation by a shoulder stock, facing the direction you were aiming in would be better than being at 45 degrees

[@stuartp2006]

I'm going to say the mesh was a heat management thing, being in that sort of weather in a confined space... Any help is appreciated

[@petethebastard]

We were also learning, but didn't have the close knowledge from Europe! We did OK, for a start...

[@markjames4951]

has he ever done a test kneeling using the shoulder pad (for most of the 2lber equiped tanks) to the right shoulder and seeing just where his hands and head are with relation to the instruments handles and vision ports.the travelling seat folded out of the way? bit like saying a submarine commander finds the periscope difficult when standing in the conning tower.

[@chonslie]

I can’t believe that fit a british 17 pounder in that turret with the ac IV thunderbolt I have no clue how Impossible it must have been to operate in the turret

[@jessewrites3819]

My go to channel. Ahhh sanity.

[@SolyomSzava]

Didn't Wargaming basically buy that Sentinel from the private collection you mentioned, and then later donated it to the Australians? Good guy WG I guess, that is a very nice thing to do.

[@flipdart]

Chute? That's the Beer Can Removal System for the commander, keeps empties clear of the tracks.

[@HDSME]

Many sentinals had a machine gun on the left side i believe that was to vent the hot gas and dump the fired shells out Plus it in itself acts as a cooling jacket as used on other tanks of the comman wealht

[@MrMexiguy]

16:15 GOD DAMMIT

[@eze417]

I'd have liked to see you do a video about the Bob Semple tank from New Zealand, but unfortunately there don't seem to be any surviving examples.

[@blumie006]

The slot is just an air vent some tanks also have a round hole for a periscope next to it

[@interdictr3657]

Thanks, great as always!

[@IgoRAZ12345]

16:19 "...and all of a sudden your gun is now..." (and that MG housing lifts up)... lol ))))))))

[@Steme94]

360 degrees video or picture would be nice :)

[@Bill.Papadakis]

that thing with the mesh could be just a passthrough for any MG that would or could be set on top if there was an MG stick-thingy there...you know....tubelike thing to take the casings from the MG and feed them down the hatch so you dont get any on the drivers head,or into small places and jam the turret?

[@cwtcwt4551]

Yes it looks funny and probably would not have been very useful in the Western Desert or in Europe. However we were somewhat more interested in defending continental Australia at the time. So my point or question is, given the geography of most of Australia, plus actual available Japanese tanks, was the AC Sentinel fit for purpose?

[@Thordious]

Give how bad it is with the 2pdr in there, I can't imagine how bad the 17pdr version was or the 25pdr at that.

[@TheForklifter]

The turret was different on the Mk. IV version if I'm right. It had a removed dick gun for more space.

[@RedShocktrooperRST]

+SovietTenkDestroyer I think he also mentioned it having a larger turret.

[@mudcrab3420]

70inch turret ring was the intent I believe. AC1 had... 52inch?

[@allangibson8494]

Try twin 25 pounders - one was fitted with two 25 pounders as part of the development of the 17 pounder turret to test the turret ring for shock loads.

[@InternetSurfer19]

At last, the long awaited part 2 :)

[@juarezezez]

Maybe the vent is part of some sort of add-on snorkel attachment kit?

[@lachlanchester6323]

with the gunners position could it be that they are expected to be standing instead of sitting due the the free gun elevation? if the gunners seat folds then might get rid of some of the problems with the position

[@hart-of-gold]

A quick question, Can the gunner's seat fold under the commander's seat? If so, then the fighting position of the gunner is on one knee with right leg forward between the traverse and the triggers. Shoulder on the gun's rest, left hand on the traverse and right hand on the trigger. The commander turns forward resting his feet on the stowage next to the gunner or on the gunner himself. Not great but it could work.

[@armedbrit493]

+Hart Poole Works theoretically, the early British cruisers used the knees as biological stabilizers, so why not the Aussies?

[@mudcrab3420]

Makes sense. British tank fighting theory was that you shot from hull down. If you couldn't get hull down you shot from the move. Since you had to shoot on the move the gunner needed to constantly adjust the elevation which was why most of their gun mounts had shoulder driven elevation rather then gears. This also had the side effect that the gun needed to be balanced which brought a lot more of the gun inside the turret. Tanks which used geared elevation could get away with pushing the weapon 'outside' and taking up the balance with springs and hence usually had more practical room inside the turret. Seemed like a good idea at the time I guess... Interestingly as a comparison the German tank theory was also to shoot from hull down. If you couldn't get hull down you stopped firing and moved until you got hull down and THEN started firing again. Firing on the move was a mugs game and a waste of ammo. Or at least that is the theory in the manuals. Lot of evidence from battle reports from both sides of crews ignoring the manuals and just driving at the enemy.

[@bruceinoz8002]

Why the Vickers? Probably because that was an "Army" MG in the required .303. And, they were being made "locally" at the Lithgow factory, alongside (well, in a different, specially constructed building), Bren LMGs The design committee was probably blissfully unaware that the Royal Australian Air Force had substantial numbers of .303 MGs as well for aircraft use. Admittedly, the barrels in these were relatively light, as befits an aircraft gun meant to operate at high cyclic rates and with lots of cool / freezing air rushing around it. It probably never occurred to the "experts" to drop a heavier barrel into one of these aircraft guns to see what happened to cyclic rates and barrel heat dispersion. The disintegrating belts would have been a little less "untidy" inside that cosy turret / hull. as well. Lessons learned and applied,? Not many, I'm afraid.

[@bushyfromoz8834]

If the war department is not going to give locally produced radial engines for a tank program and prioritising aircraft, I doubt they would be providing imported browning machine guns for a tank program....

[@charlescann531]

Could the slot be there to allow airflow over some form of radiator to cool the water for the machine gun.

[@Alexthelion2]

My theory is that mistrey "Chute" is a Air gap to keep the tank cool

[@harrypoon3410]

How tho

[@mancubwwa]

@@harrypoon3410 convection. As air inside the "vent" heats it rises, and lowers pressure, which in turn sucks new air via bottom opening. The constant movement takes some heat away. Such system can be suprisingly effective, and needs no fans, so no noise and no power consumption.

[@harrypoon3410]

@@mancubwwa thx

[@glynnmurdoch6243]

think you will find out the private owned AC1 is owned by a guy called Clive Palmer and he is letting it just rust away and will not sell it to any one

[@adamsteele8768]

sounds like a real clive palmer dick move

[@vksasdgaming9472]

I guess that is privatization in its most crude form: it's mine. It has no value for me, but it's mine. It's rusting away, but it's mine. I'm not selling it because it's mine. It pollutes my property, but it's mine.

[@sissonsk]

"is that an armoured .303 Vickers on the front of your tank or are you just happy to see me?"

[@rossnelson8433]

The Sentinel seems a gallant attempt but a quirky dead end that took too long to deliver. But.... lets alter history just a little bit. Imagine if instead of Midway going 4-1 to the Americans, it goes 0-3 to the Japanese. America is reduced to one operational fleet carrier (being repaired) in the pacific and the Japanese still have 6. This is not a big leap and could have easily happened. At this point from mid-42 to at LEAST mid-43 when the Essex class carriers start to roll out Australia will effectively be cut off from the US and Europe by the IJN. Cargo shipments become a risky venture as the Japanese finish quickly occupying the Solomons, what is now Vanauatu and Fiji. Now the Sentinel doesnt seem so silly. That amusing MG cover has a purpose. Those Vickers MGs are made 100% at the Small Arms Factory at Lithgow in NSW. And the little 2lbr and the whole tank is 100% made in Australia. Suddenly you have a tank that is GOOD ENOUGH to EASILY kill ANY tank or armoured vehicle the Japanese may ever try to land into Australia. And those never ceasing MGs can really cramp the style of your average Banzai charge. Add this to the Boomerang fighter and the Owen gun and you have a range of mediocre emergency weapons that will probably keep you in the game long enough to hold on until the cavalry in the form of the USN and US Army plus its ludicrous equipment levels eventually arrives.

[@thefantasyreview8709]

Completely agree. We didn't end up needing because we started winning the war. That is, the Germans were on the backfoot. If we weren't winning the war, we had a tank that easily could of wiped out Japanese tanks, and 17 pounder could have dealt with most German tanks.

[@fredorman2429]

From the outside it’s a cute little tank. What makes it so cute from the outside is that there’s no room to move on the inside. Oh dear!

[@carlwesternut2434]

With a few upgrades , she'd be good I'd reckon . I would own one if i could.

[@theconvictedquokka]

Could the schutes be for dropping ammunition clips through

[@JohnRodriguesPhotographer]

Not bad for a first try. Just that ergonomics wasn't mentioned in the design specs

[@rparker069]

I imagine that chute is a sand or water escape to aid in safety for the top of the tank

[@con_boy]

+rparker069 I like the sand explanation. It must be to do with the Austrialian climate or conditions: my initial gut feeling was it was a way to rapidly cool the turret with buckets of water - you capture in a bucket below and pour a bucket from above - I suspect the interior of this tank could get into high 50's C with 3 engines running - I bet the metal was litterally possbile to burn your skin on contact - and it may have been that or having to leave the tank

[@1337flite]

In Australian service conditions the outside ambient air temperature in the shade can be 50C. With three motors running, guns firing especially with 2 water cooled Vickers reservoirs inside the tank the temperature would be much higher than 50C in the very hot areas of Australia.

[@tonydeleo3642]

I was looking forward to the "Oh buggers...

[@AgentB7]

I just realized that the chute, being relatively close to the water tanks, might be some kind of _passive cooling system_, basically just allowing the airflow of the naturally lifting hot air from the top vent and with sucking up the slightly cooler air from the turret side. I know that sounds ridiculous but that’s what it looks like.

[@S.A.U.1489]

Great video. could you do a video on the M4 Sherman.

[@martij30]

I think the hole in the turret with the mesh would be used to get papers through? Fold up an order or whatever, you keep comms with runners in the battlefield, may radio comms fail.

[@TheHirokaraka]

+martij30 that's what hatches are for:]

[@martij30]

Well in combat you wouldn't just open up the hatches. If you'd still need a messenger to deliver you a message, he jumps on the back, he doesn't have to get your attention to open your hatch, which may be difficult in combat.

[@TheHirokaraka]

Bwahahahahaha!! If you can't open hatch then you surely can't sit on the top of the turret, exposed, trying to fold a sheet of paper and try to squeeze it into that hole. Did that really sound legit in your head?

[@martij30]

Why couldn't you? It's way less time consuming to run up to a tank, jump on the back, slide the paper in, get the hell out than to run up to that tank, jump on the back, try to get the crew's attention SOMEHOW, and then to deliver a message. Aussies aren't that bad at thinking through plan B's.

[@Shinji_2006]

The Sentinel the out side of the turret by right side the tank is a air hole for breathing because it might be hot and many are cant breathe in the desert its like Panzers variants it has Its been 5 years not discoverd

[@LastAvailableAlias]

I suspect things like the swiveling commander's seat, the turret chute, etc are due to buying outside designs or parts and they just had to take what they got