0005892: BMP-3 autoloader for ATGM

Notes
(0011064) partypidgeon (reporter) 2020-10-06 16:45	BMP-3 Early reloading time was 30 seconds for the ATGM

(0011065) partypidgeon (reporter) 2020-10-06 16:52	Cannon Loading and Firing. https://thesovietarmourblog.blogspot.com/2014/10/bmp-3-underappreciated-prodigy.html [^] The GIF below shows most of the loading process, excluding the lowering of the elevator rail back to its standby position. The mechanism in the video clip appears to be moving rather slowly and more deliberately than in reality, most likely because it is set up for demonstration purposes and is probably running on the vehicle's batteries only. https://1.bp.blogspot.com/-PgCloX69BRc/Xbc0_6pEM9I/AAAAAAAAPhQ/yzT9enltkUQIa59CttiSpVq08b_jEe-owCLcBGAsYHQ/s400/autoloader%2Bloading.gif [^] A normal loading cycle takes 4 to 5 seconds to complete, putting the theoretical maximum rate of fire for HE-Frag shells at 12 to 15 rounds per minute. However, this figure is based entirely on the loading speed of the autoloader mechanism and not the actual achievable rate of fire. In reality, the maximum rate of fire is only 10 to 12 rounds per minute because the ejection process takes some time to complete, adding a short delay between each loading cycle. When loading the 2A70 manually, the BMP-3 manual states that it takes 15-20 seconds to load each round. The maximum rate of fire when loading the cannon manually would therefore be approximately 3-4 rounds per minute. After the first shot is fired, the cannon must eject the casing of the previous cartridge before the loading process for the next shot can begin. After a shot is fired and the 2A70 has reached the end of its recoil stroke, it is locked in its recoiled position and it is automatically depressed to a predetermined angle while the ejection chute is lowered from the ceiling and the ejection port hatch is opened. Once all of these components are in their proper positions, the spent shell casing is ejected from the 2A70. The spent shell casing is thrown into the ejection chute and its trajectory is diverted upwards and out of the ejection port. The ejection chute is retracted and the ejection port is sealed, and then the cannon is returned to battery by the recoil mechanism. The cannon automatically returns to the previous point of aim. https://1.bp.blogspot.com/-ENTEh6mEgYY/XbF8UwcnmvI/AAAAAAAAPdY/BNAPaLOU0RcYa5eFUdjXOo7PgnOX5uvBgCLcBGAsYHQ/s1600/ejection.gif [^]

(0011066) partypidgeon (reporter) 2020-10-06 16:55	ATGM Loading and firing ATGM LOADING One of the firepower advantages that the BMP-3 held over its predecessors was its larger quantity of ATGMs and the increased ease of loading them. In a BMP-2, the commander or gunner had to open their hatches to manually remove an expended missile container from the external launcher and replace it with a new one. This could be done under armour protection thanks to an innovative missile mounting system, but it still forced either the gunner or commander to lose overhead protection with the opening of their hatch and also depressurize the vehicle and breach its hermetic seal, thus exposing all of the occupants to an NBC-contaminated environment. The American M2 Bradley was unique, but not more sophisticated in this regard even though it had two ATGMs ready to be fired in its launch pod rather than just one. This is because it still had to be loaded manually by a passenger and it could only be done from the roof hatch of the passenger's compartment. Still, the BMP-2 and M2 Bradley were certainly more sophisticated than the BMP-1P as the gunner had to exit his hatch in order to fire as well as to reload the ATGM launcher. This shortcoming was shared by foreign IFVs like the German Marder 1, the British FV510 Warrior and the French AMX-10P, and it was brought about by the use of the least costly and most expedient solution of simply mounting an existing man-portable launcher on the turret roof. In the BMP-3, the use of a gun-launched ATGM system instead an external launcher gave it the ability to maintain its pressurization and thus remain sealed from an NBC-contaminated environment during the reloading process while having a larger supply of ATGMs than a comparable vehicle with external launchers. The loading of ATGMs was primarily the responsibility of the gunner but depending on the BMP-3 model, it may be done using an assisted manual loading system with the participation of the commander and a passenger, or it may be done by a full autoloader system. All BMP-3 models with the original turret had three missiles stowed in the turret basket behind the gunner's seat backrest. Besides that, all BMP-3 models carried five additional missiles stowed in a rack on the port side of the vehicle hull as a reserve supply.

(0011067) partypidgeon (reporter) 2020-10-06 17:18	ATGM Ramming Mechanism RAMMING MECHANISM In the original BMP-3 model, known internally under the product code of Object 688-sb.6, the loading of ATGMs was done manually but the convenience of the process was enhanced by a special loading mechanism. It is described as such in practically all publicly available sources but with varying levels of specificity. In page 30 of the book "Боевые машины пехоты БМП-1, БМП-2 и БМП-3" (Infantry Fighting Vehicles BMP-1, BMP-2 and BMP-3), Sergey Suvorov writes that the loading of missiles was carried out manually with a ramming mechanism. Aleksandr Kurochkin simply writes in "Famous BMP-3: New Capabilities" that prior to the introduction of an autoloader, a passenger assisted the gunner to load the ATGMs quickly. http://btvt.info/5library/vbtt_1991_bmp-3_100.htm [^]

(0011069) reyhard (administrator) 2020-10-06 17:56	just a note, it's not possible to achieve without scripting so it's rather low priority thing

(0011070) nevalashkarus (reporter) 2020-10-07 14:03 edited on: 2020-10-07 14:04	but is it possible to make longer reloading time for atgm on earlier versions?

(0011074) reyhard (administrator) 2020-10-07 16:36	"but is it possible to make longer reloading time for atgm on earlier versions?" no, not without scripting. there is relodTime & reloadTimeMagazine property which is assigned to a weapon and applies to ALL magazines. BMP-3 would need similar autoloader system as on T tanks, but since I want to rewrite it one day, there is no point to implement it right now there.

(0011078) partypidgeon (reporter) 2020-10-08 01:51	:D

Issue History
Date Modified	Username	Field	Change
2020-09-21 23:08	nevalashkarus	New Issue
2020-10-06 16:45	partypidgeon	Note Added: 0011064
2020-10-06 16:52	partypidgeon	Note Added: 0011065
2020-10-06 16:55	partypidgeon	Note Added: 0011066
2020-10-06 17:18	partypidgeon	Note Added: 0011067
2020-10-06 17:56	reyhard	Note Added: 0011069
2020-10-07 14:03	nevalashkarus	Note Added: 0011070
2020-10-07 14:04	nevalashkarus	Note Edited: 0011070	View Revisions
2020-10-07 16:36	reyhard	Note Added: 0011074
2020-10-08 01:51	partypidgeon	Note Added: 0011078

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