M551 "Sheridan" AR/AAV | DESIGN DISASTER!

[Music] [Music] [Music] welcome back everyone it's me Matt Smith and thank you for joining me today we are going back to talking about tracked vehicles thank god it's been a while since we've talked about tanks really isn't it and today we are talking about the Sheridan the m551 the cute ditzy little tank that you think isn't really much in terms of capability but overall it has quite a powerful little bite to it and it's not something you would really want to mess with back in its era when it was actually deployed so we're gonna talk about the vehicle overall and there's quite a bit of history this vehicle so please bear with me following three years of budget negotiations and roughly one year of preparations limited production of the m551 was produced in 1966 with the production variant more or less based on the 12th prototype the earlier prototypes served mostly to verify various technical solutions the m551 was officially accepted in service in May of 1966 and was the first vehicle to arrive on an operational unit christened General Frank s Besson jr. the commander of the Army Materiel Command as m551 general Sheridan named after the famous Civil War General Philip Henry Sheridan the vehicle was mass-produced between 1962 and 1970 with [Music] 1662 made in total there are a lot of these things for hopes the tank was immediately submitted to a series of tests in various different climates and it was found out that even in a human environment the shillelagh missile was actually quite functional the same however could not be said about the semi combustible casings of the 152 millimeter shells they often got damp which resulted in many failures another issue was the fact that since the barrel was actually quite short it had no fume extractor and the crew compartment often became filled with gunpowder residue and gases regardless of the fact that the turret ventilation intake was located straight above the breech I can tell you this much taking in gunpowder fumes is just not a good time it makes you dizzy sick and will reduce the capability of the crew very quickly to make things even worse hot remnants of the semi combustible casings remained in the barrel and there was always a danger of the loaded ammunition spontaneously combusting as you loaded it to remedy this last issue sheridan's were equipped from February 1967 with the so-called open breech scavenger system the purpose of which was to flush the inside of the barrel with the compressed air removing all the residue potentially left insight from the last firing the compressed air was stored in a laminate pressure container installed on the front of the driver's seat and they were pressurized for about 3,100 psi which is a ton of pressure folks this was produced by a compressor located under the seat itself three different versions of the system existed in production and to the amusement of maintenance crews it was generate not a very efficient solution anyway and didn't even work some of the sparks would still stay inside there even if you blow 3100 psi at it the worst testing results came from the trials that took place in 1967 in the human environment of Panama during one of the tests one loaded shell exploded while the gun breech was open the explosion was the result of the above-mentioned issue with the hot residue staying inside the bowel and as a result the crews and workers were now forbidden to store ammunition in the tanks themselves and the production was temporarily stopped this happened after the OB SS system was installed leading to its replacement by the closed breech scavenger system in 1968 which improved the safety of the whole firing mechanism significantly there were tests performed in Australia which showed pretty much similar results and the general conclusion was that while the vehicle was not suitable for human environments and drying coal environments it still works just fine these warnings however were not disregarded and the first combat use of the Sheridan would indeed take place in Vietnam the Sheridan deployed in Vietnam was a chapter onto itself the vehicle was actually designed for the battlefields of Europe and to fight the Soviets and their mechanized infantry tactics the Soviet IFES carrying infantry were to be the primary targets basically will be a case by case event where a BMP would take on a Sheridan because that's primarily what they would be used for dropping off infantry and engaging with their anti-tank missiles and the Sheridan should be the one that should go and take them out it has the shillelagh it has the 152 millimeter heat gun it would be perfect for taking out these vehicles however in Vietnam these just want a thing the tactic was not suitable for the asymmetric warfare in Vietnam and the new shell was required in order to deal with enemy foot soldiers the result was the need for the XM 65 beehive fourchette round filled with 9900 nail sized needle shards it could quite literally tear any in caught in the open in two pieces another modification for the 't nam battlefields where the commander's post on top of the turret this received an additional protection and the 50 caliber m2 browning machine gun which provided a protective gun shield as a result the commander was somewhat protected from the front by that shield but from the sides where the open parts were it was really no additional protection for them some vehicles were modified even further by adding an additional machine gun for the loader or even a mortar or grenade launcher the deployment to Vietnam uncovered further issues of the vehicle had some of which took years to remedy the transmission for example was insufficient for the weight and power of the vehicle and the drivers had to be very careful with the clutch otherwise there was a real danger of completely ruining the transmission this was especially a problem in two specific cases funnily enough the first instance is with the drivers they were used to the m48 Patton tank where they could treat the clutch very roughly unfortunately not so much in this vehicle the second instance is when the transmission was under unusual stresses or high workloads example prime example was that the Sheridan's were leading the way through the jungles and the amount of foliage that they were churning through in the mud made it very difficult for the transmissions to last unlike the following m113s behind them they could deal with it quite well the fragile and improper construction of the RPM limiter led to various failures as well stalling the engine or allowing the rpm to run too high and damaging it the turret was also a nightmare and to this day it still currently considered to be one of the worst weapon systems ever to be used in the US Army and in my personal opinion I can't really agree with that I think it had a great concept but I think from a design perspective for those who used it it was not the greatest describing the pleasure of fighting in a real Sheridan hardly does it justice so let's just talk a little bit about the examples of issues that turret crews used to face in regular tanks overpressure in the recoil hydraulics usually resulted in busted seals which were not really that too hard to replace in the Sheridan however such overpressure was theoretically prevented by a valve screw that however quite failed often resulting in the turret being pretty much showered by red hydraulic fluid which to me is hilarious and they nicknamed it being cherry juice another source of constant irritation Cruz was the wiring of the turret the main circuits were distributed to ten removable separate circuit boards the problem was that the violent recoil of the gun often shook them out of their beds resulting in various electrical failures in short circuits given the fact that the gun was fired by an electric mechanism such a failure was possibly disastrous for the vehicle especially in a combat situation this is very very scary stuff other things like carbon residue from the semi combustible casings got stuck to the electrical wiring in the gun firing mechanism significantly reducing its reliability these issues were far from rare that sometimes appeared even after two or three shots and the average Sheraton crews reported one gun failure per 50 shots that's pretty much one failure per half the ammo storage that you have available to your vehicle the proverbial cherry on the top was the firing of the full charge high explosive and high-explosive anti-tank ammunition from the gun The Beehive rounds although sounded fantastic were relatively fine because they used a reduced charge but when firing the full heo heat rounds the vehicle shook so violently and it's front road wheels were actually thrown up in the air by the recoil while the tank was temporarily covered by a thick cloud of smoke because the barrel was so close to the vehicle this negatively influenced the shillelagh missile targeting system and after firing a few regular rounds it was problematic to actually launch the missile or really hit anything the loader had the possibility of being the worst in crew position operating the breech itself was not exactly easy as the electric part of the breech failed for reasons mentioned that I already said and it had to be opened manually using a crank operating this crank was difficult to say the least in a cramped turret like the Sheridan and the loaders hated it with a passion it was also very important for the load and not to forget to switch to gun mode when firing a regular round if the last round was fired as a missile if he forgot to do that the missile launch mechanism would rip the side of the shell combustible case open and the gunpowder granules would spill on the turret and would pretty much cover the floor of course the missile rounds were no better either they were large and extremely difficult to manipulate inside the turret as well there were issues with unfired rounds getting sometimes stuck inside the barrel literally getting stuck halfway down the barrel finally a rather nasty flaw was when the gun was elevated to its maximum position for some reason the turret just started randomly rotating left to the undisclosed floor the Gunners were really not amused most of these issues were solved and fixed throughout its service but it's really detrimental for a vehicle like this to have so many problems coming out as release to trace the roots of the vehicle the Sheridan lineage can be brought back to the m41 Walker bulldog and needed to be replaced very quickly the Bulldog was a solid American light tank but as much more of a Soviet heavy tank started appearing in the mist in terms of this vehicles history the Sheridan lineage can be traced back to the m41 Walker Bulldogs that needed to be replaced the Bulldog was a solid American light tank but as more Soviet heavier tanks started appearing in America reports it was clear that the 76 millimeter gun was no longer capable of dealing with the newest Soviet medium tanks the Bulldog insets service in 1953 but soon after in 1954 the US army started developing many different replacements some of these vehicles were rather interesting including the t92 light tank a 17-ton experimental vehicle it was equipped with a 76 millimeter high-power gun and a 340 horsepower engine it was tested a lot between 1956 and 58 but ultimately the design was not successful it had two major Falls for one it was undergunned and the 76 millimeter gun was no longer considered sufficient to deal with the threats of vehicles that it may encounter the second major flaw was the vehicle was not in phidias it could not be modified to swim there even looking at potential for these vehicles to be thrown out the back of aircraft which as you know the Sheridan was something quite prominent in the late 50s it was clear that the 76 millimeter gun would no longer do any of the frontal sloped armor of Soviet designs ever since in 1958 the Ford Company was developing a new weapon system considering that there was a hundred and fifty-two millimeter gun on the drawing boards there m81 gun launcher capable of firing the MGM 151 shillelagh missile the entire launcher was very light since the charge needed to be launching the missile was quite small and they thought there was no real need for mechanisms that were too the recall was supposed to be very low as allowing the system to be used on a relatively light chassis at that point the missile warhead offered enough firepower to destroy any many vehicles that it would encounter on the battlefield up to around four kilometers which meant that the light tank equipped could actually destroy enemy tanks at distances far beyond their own gun ranges the theoretical minimal range for this missile was somewhere between 75 and a hundred meters with the minimal truly effective range being estimated at 1,000 metres but that was at least in theory not a problem as shootouts with enemy or medium tanks at less than one kilometer were considered pretty much suicidal anyway but the missile was of course only effective against armored targets the gun had to be capable of firing high-explosive rounds as well fortunately it wasn't a huge problem considering that the H Iran's needed less muzzle velocity than anything else it was completely fine to simply fire them with reduced charges just like the missiles once the US Army had a gun selected they started looking for something to put the gun on as usual for most different procurements the army had a contradictory set of demands that included frontal hull protection against Soviet vehicles from fourteen point five millimeter shells frontal turret protection against Soviet twenty millimeter shells amphibious capability gas protection night fighting capability transportation by air and maximum mobility in terrain that's a pretty heavy Christmas list right there folks there are a couple more demands and in the end Cadillac GM proposed as one of the best at going for the contract in addition to the project viability Cadillac also had tank production plants in Cleveland where 600 qualified workers were assembling the last of the Walker Bulldogs the Cadillac proposed was powered by a Detroit Diesel 6v 53 t engine the engine code basically means six cylinders v-shaped cylinder configuration 53 is the volume of one cylinder and cubic inches and the t means turbocharged which produced 300 horsepower at 2,800 rpm in order to keep the power-to-weight ratio at sufficient levels the developers opted for an aluminum hole instead of the classic steel to save weight the dimensions of the vehicle were further constrained by the maximum allowable dimensions that could be carried by army transport planes and therefore unfortunately made it completely impossible for the vehicle to be amphibious it just didn't have the displacement so did not take that objective they would have to put rubber floaters on it to make it float the project received its designation the armored reconnaissance airborne assault vehicle or AR AAV in 1960 in 1961 and the turret was given with the prototype with the 152 millimeter X M 81 gun which was trialed on the m41 Walker bulldog with the suspension for the shillelagh firing trials the X M 81 development was actually delayed as well due to the mbt-70 debacle and the cleveland plant was actually under threat of closing for some time the gap between the m 41 and the future vehicle was very difficult for them to maintain before was saved by the contract to produce the m1 one for howitzers luckily the plant did not close the army ordered six prototypes in 1960 and the vehicle was actually prepared quite quickly for the project at that point it was the first prototype that was ready later that year arriving for tests at Fort Knox they ordered prototypes and increased from six to twelve and then finally to twenty the XM 551 as it's called was a completely new design and built from scratch and it caused a lot of issues during its initial prototype assembly as every prototype does yes there were flaws many flaws that I already mentioned the cooling system was also very poor the engine was constantly overheating and some of the internal aluminum parts were very fragile and completely breaking apart this vehicle was just desperate for a new designer despite the issues related to the entire Sheridan development the turret design the combat results of the vehicle were actually not that bad mixed would be the correct word really for describing the first impressions of the vehicle from Vietnam funnily enough though due to the amount of vehicles that they produced the Sheridan's were also deployed in Europe by the time the Vietnam War raged on and surprisingly the mild climate saw the Sheridan performance improved by quite a bit especially when it came to reliability the Sheridan units developed quite effective tactics to deal with the perceived danger of hordes of Soviet armored hit-and-run style shooting scoop using superior range of the shillelagh missile the m551 would fire two or three of the missiles at long ranges at around 2,000 meters and it could really not be threatened by the Soviet tank guns at the time retreat quickly leaving the enemy confused and reeling in 1971 the Sheridan's were with a new Ruby laser anv vg1 rangefinder sucks vehicles bore the m551 a one designation this posed a slight problem for European Sheridan's as during the exercises the friendly soldiers playing the bad guys could have their site damaged by the lasers but this issue was remedied by some rules directions when training and for live use this would obviously not really matter anymore from 1978 onwards the phasing out of the Sheridan's slowly started with the active vehicles being replaced either by the m60a1 and the m60a3 tanks or the m113 APC s temporarily with the final replacement being the bradley vehicle family in the end the only unit with these vehicles still in service was the 4th battalion of the 68th Regiment 82nd Airborne Division the rest of the Sheridan's ended up on military scrap yards or on repair plants as the spare parts were sourced for the ones they still had firing before its final retirement in 1996 the m551 saw two more conflicts operation just caused the invasion of Panama and Operation Desert Storm in Panama the Sheridan's of the 82nd airborne were first used to capture the airfield and where air dropped from around the area due to bad weather some Sheridan's actually ended up in a swamp their crews were quite obviously not amused the combat use itself however was satisfactory the vehicles were agile and the 152 millimeter Hg shells had sufficient demolition power in the city to combat and get rid of entrenched troops it was however the desert storm operation that proved to be the final war for the Sheridan the first 55 vehicles were deployed in the Persian Gulf by 1991 and until the Abrams tanks arrived they represented the most American firepower on the battlefield at the time it was here that the missile was used operationally for the first and final time knocking out an Iraqi type 59 main battle tank the vehicles also proved to be quite reliable though with the proper maintenance here and there didn't really save it so much but it kept it going for the most part after the war the Sheridan's were also used up for a while as optimal vehicles training units represented them for Soviets on the battlefield during military exercises which is just a kick in the teeth to the designers you make a tank that's purely designed to be an enemy and that was really the role and end for this career of the tank which ended in 1998 that's it for today folks I hope you enjoyed your little history lesson about the Sheridan m551 really a vehicle that was kind of doomed from the start and I feel really sad because I think in terms of its concept it was really trying to think outside the box a different kind of weapon system that provided a capability that should of should off being very very effective at being able to knock out tanks and infantry fortified positions the like sad to see that it did have such a rough time but hey you know that's what happens when you design things that are really really intricate thank you again for joining me today folks I really appreciate you stopping by hopefully you enjoyed the footage and my little discussion about this vehicle if you've ever served on it I'll know much more about this vehicle your own experiences I would love to hear from you this is one of those vehicles that has had so many problems mechanically and sort of weapons system wise that I'd love to hear your own experiences if you've been around them or you know people who have please let me know in the comments section below guys if you wish to support my channel I'd really appreciate you check out my patreon page you're more than welcome to look in the description box there and click on the link you'll be able to be sent there I also have my discord channel if you want to come hang out in there and have a chat and of course Facebook and all that good stuff if you want to be notified of upcoming videos please hit the little bell button by the subscribe button so you can be notified of upcoming videos in the future all the best folks have a great day and bye bye [Music] [Music] you

Channel: Matsimus

Views: 258,584

Rating: 4.9243808 out of 5

Keywords: M551, Sheridan, M551 Sheridan, XM551, Armored Reconnaissance/Airborne Assault Vehicle, light tank, United States, MGM-51 Shillelagh, Amphibious light tank, M551 Sheridan AR/AAV, Operation Just Cause, Gulf War, anti-tank missile, Shillelagh, MGM-51, M41 Walker Bulldog, US Army, MBT-70, Vietnam War, sheridan tank, sheridan light tank, airborne tank, airborne armor, M48 Patton, M551A1

Id: f-LRsRamBjc

Length: 20min 10sec (1210 seconds)

Published: Mon Dec 24 2018

Reddit Comments

[u/SaperPL]

I just thought this belonged here.

Usually Matsimus talks about newer, modern equipment (I think), but this time he picked up some historical stuff. Enjoy :)

[u/rcvj8]

Yeah Matsimus is great and quite unbiased to whatever he takes a look at, from what I’ve seen so far that is. Looking forward to watching more of his reviews in the future!