Stryker Model 2 Update

[frederf 0]

<span style='font-size:27pt;line-height:100%'>Stryker Model 2 Update</span>

Mission

The mission of the Stryker Model 2 Update is to introduce a fully-featured realistic set of Stryker units into Armed Assault that are capable of field and urban infantry transport, infantry support, and TOW weapon utilization operations during day and night in the context of such a unit being deployed to the island of Sahrani. The Model 2 seeks not only to add capabilities missing from the BIS default Strykers but also to remove features not present on the real vehicles. The overall effect should be more effective fire support and improved survivability when used in conjunction with supporting infantry and current US Army tactics. However not all changes are made strictly to improve the Strykers' effectiveness; some will make the vehicle more difficult to use.

Design Decisions

Not all information is straightforward about the Stryker. In current use a myriad of individual unit modifications and continual development mean making a definitive Stryker impossible. The best that can be hoped for is a Stryker that is middle of the road in terms of features and capability, leaning toward the textbook layout, which is both correct in the context of the game, the context of player sophistication and enjoyment (for both those in the Stryker and those facing Stryker opposition), and within the limitations of the AddOn maker(s). Reference to currently active US Army personnel with regards to realism and overall AddOn effect will be made as often as feasible to ensure a real-life focused outcome. Interoperability and compatibility with other mods is important as eventually the Stryker Model 2 should be adopted by a mod with a larger scale and included as a welcome addition.

Currently there are several issues and decision to be made regarding design:

<*> The M151 Protector RWS on the ICV variant of the Stryker appears to have (realistically) at 30x optical zoom. As anyone who's used an M24 SWS (with 10x optical scope) in ArmA will testify, 30x is most likely overkill in terms of magnification. In terms of existing equipment as well as the foreshortened fighting distances that happen because of both the Sahrani terrain's and ArmA's design, a more reasonable 8x magnification limit will be initially adopted (which is the usual maximum used).

<*> The M151 Protector RWS on the ICV (equipped with either the M2 or Mk19 weapons) has an optionally fitted auto-loader which reloads the weapon's linked ammunition belts. The benefit of the autoloader is that the gunner does not need to unbutton and expose himself to enemy fire in order to reload the primary weapon. The drawback of the autoloader is that the weapon's traverse speeds are less than 50% that of a weapon turret without the autoloader. The options for design are to either do one variant, the other, or both based on user opinion, game engine capability to model either mode, reports of prevailing real use of either mode, and balancing/gameplay concerns.

<*> Some currently fielded Strykers are operating with a Vehicle Commander / Driver and a Gunner while the field manuals on the subject dictate a Vehicle Commander / Gunner and a Driver. The eventual setup is probably going to resemble the current BIS system due to ease of use.

<*> Accurate information about a Stryker's resistance to enemy fire (RPG, 7.62mm, AGS-30, etc) is both conflicting and largely irrelevant the the light of ArmA AI accuracy, RPG7 reload times, and ArmA vehicle damage modeling. The goal of the Model 2 is that of crew survivability over vehicle survivability.

<*> Currently in ArmA a vehicle cannot hold more than 12 magazines. Even at the realistic belt size of 200 rounds per belt of M2, a standard loadout of 10x 200rnd 0.50 cal belts leaves only 2 magazine slots free for other ammo. The other magazines possibly needed (laser battery and M6 smoke grenade) have limited room to function. Depending on the nature of how the M6 smoke grenade launcher and/or the laser range finder operate, this may or may not be a problem.

<*> The M6 smoke grenade launchers are attached to the primary weapon turret on all three Stryker variants and are capable of providing an azimuth-controlled smoke screen in the vicinity of the vehicle. My guess is that they are fired in one of many "programs" aboard a real Stryker. The Model 2 will attempt to have 4 shots of 4 smoke grenades each. Each shot will fire an array of smoke grenades from the RWS in a semi circular arc. While such an action could be made as a weapon (cycle able) it is probably easier and less obtrusive to code an AddAction style command.

Priority Key

<span style='color:blue'>High</span>

<span style='color:green'>Medium High</span>

<span style='color:orange'>Medium Low</span>

<span style='color:brown'>Low</span>

Armor performance

<span style='color:green'>1. Improved wheel armor</span>

<span style='color:blue'>2. Improved hull armor</span>

<span style='color:blue'>3. Increase post-disable survivability</span>

<span style='color:green'>4. Adjust disable threshold</span>

<span style='color:orange'>5. Increase chance of weapon disable</span>

<span style='color:green'>6. Add slat armor version with improved RPG resistance</span>

Drivetrain performance

<span style='color:brown'>1. Verify on road speed</span>

<span style='color:brown'>2. Verify off road speed</span>

<span style='color:brown'>3. Verify braking distance</span>

<span style='color:orange'>4. Verify acceleration</span>

<span style='color:orange'>5. Verify turning radius</span>

<span style='color:brown'>6. Verify fuel endurance</span>

<span style='color:brown'>7. 8x4 / 8x8 transfer case switch</span>

Weapon Performance

<span style='color:green'>1. Reload turned out only ICV_M2 and ICV_Mk19</span>

<span style='color:green'>2. Real reload times ICV_M2, ICV_Mk19, and ATGM</span>

<span style='color:green'>3. TOW2A, TOW2B Aero, TOW2B, and "bunker buster" variants</span>

<span style='color:blue'>3. TOW fires with no/minimal smoke and orange glowing "butt"</span>

<span style='color:orange'>4. TOWs reload independently</span>

Ammunition

<span style='color:blue'>1. Standard load 2000 rounds M2 (200x10) to ICV_M2</span>

<span style='color:blue'>2. Standard load 430 rounds Mk19 (48x9) to ICV_Mk19</span>

<span style='color:blue'>3. Standard load X rounds TOW (2+Z) to ATGM</span>

<span style='color:blue'>4. Standard load 16 rounds M6 smoke (4x4) to ICV_M2, ICV_Mk19 and ATGM</span>

Vehicle Commander Station - Common

<span style='color:green'>1. Remove turret stabilization mechanism</span>

<span style='color:blue'>2. Correct, clean optics zoom range (1x to 8x? 30x?)</span>

<span style='color:blue'>3. Correct optics crosshairs (square TV)</span>

<span style='color:blue'>4. Black and white video overlay effect for optics</span>

<span style='color:green'>5. Magazine reload options (partial, non-automatic)</span>

<span style='color:blue'>6. M6 smoke launcher</span>

<span style='color:brown'>7. M45 commander periscopes (x7)</span>

<span style='color:green'>8. ITAS (Improved Target Acquisition System) with Harrier-HUD IR auto-targeting TD boxes for flying / hot objects (missiles, jets)</span>

<span style='color:green'>9. Integrated FLIR</span>

<span style='color:green'>10. Integrated night vision</span>

<span style='color:blue'>11. Laser range finder</span>

Vehicle Commander Station - ICV_M2 and ICV_Mk19

<span style='color:blue'>1. M151 traverse rate (15 sec for 360? depending on autoloader yes/no)</span>

Vehicle Commander Station - ATGM

<span style='color:brown'>1. ATGM mast traverse rate (???)</span>

<span style='color:orange'>2. Raising/lowering of ATGM mast</span>

<span style='color:green'>3. M240B MG external fire / reload</span>

<span style='color:brown'>4. Correct TOW reload parameter (Mast down, traverse specific)</span>

Driver Station - Common

<span style='color:blue'>1. Turn out hatch slightly open</span>

<span style='color:green'>2. Rear hatch raise / lower option</span>

<span style='color:orange'>3. 8x4 and 8x8 driveline option</span>

<span style='color:orange'>4. M-17 driver's periscopes (x3)</span>

Rear Gunner Station - ICV_M2 and ICV_Mk19

<span style='color:orange'>1. M240 pintel mount (100xY rounds 7.62mm)</span>

<span style='color:orange'>2. Reload / fire turned out only</span>

Cargo Station

<span style='color:green'>1. GetIn / GetOut with rear ramp lowered only</span>

<span style='color:orange'>2. Eight cargo (if 9th is Rear Gunner) positions for ICV_M2 and ICV_Mk19</span>

<span style='color:orange'>3. Four cargo positions for ATGM</span>

Electronics

<span style='color:orange'>1. Ability for occupants to have other Stryker locations auto marked and updated on map (15 second interval) while inside vehicle due to FBCB2 system</span>

<span style='color:orange'>2. GPS mapping for Stryker despite server settings</span>

<span style='color:orange'>3. Friendly forces position updates via LOS IR beacons (forward arc only)</span>

Visual / Model changes

<span style='color:blue'>1. Edit model to remove front deck item in driver's vision</span>

<span style='color:orange'>2. Edit model to add rucksacks, spare drive shaft, etc to exterior</span>

<span style='color:orange'>3. Re skin hull Army solid green color hull</span>

<span style='color:brown'>4. Re skin tires</span>

<span style='color:orange'>5. Re skin unique damaged tires</span>

AI / Editor / Technical changes

<span style='color:green'>1. Re designate vehicles "M1126 (M2)", "M1126 (Mk19)", and "M1134"</span>

<span style='color:blue'>2. Use config class names 4IB_StrykerBase, 4IB_Stryker_ICV_M2, 4IB_Stryker_ICV_Mk19, 4IB_Stryker_TOW</span>

<span style='color:blue'>3. Increase damage at which AI eject from vehicle</span>

<span style='color:blue'>4. Reduce IR signature</span>

Sound

<span style='color:green'>1. Correct M151 traverse audio (quieter)</span>

[opteryx 1562]

WHOA!!! This is what I've been dreaming of!

[-Puma- 2]

when the shoot from vehicle mod is finished, u could add watchout/machine gunner position in stryker, wich they have in

IRL (stryker squad MG/AR are supporting thru the hatch in cargo bay)

take my words back seems that u got it covered allready, NICE JOB!!!

+no more smoke on the tow trail, wich makes it impossible to steer

now if only we could get these addons in 1 pack to use 'em in MP

[MehMan 0]

Nice plan! I really hope you'll be able to do all that's on there, finally it'll make the stryker more usefull.

Do you plan to add slat armor once it's possible?

[VIPER SHIVA 0]

Do you have any plans to add the 105mm MGS, and medical variants? Would be very cool...

The rest of your project sounds spot on, I'm looking forward to seeing your work.

okthnxbi

[wolfsblut_ 0]

The project sounds sensational.

[Krabsworth 0]

the strykers need to be pretty much invincible to RPG's. I just read a book written by a guy who was a gunner on one in Iraq, and he said on dangerous patrols as many as 4-5 RPG's would hit his Stryker and they hardly dented it

[sakura_chan 9]

I think I can help with the drivetrain performance section. I have a series of scripts from my player realism upgrade project that deals with gforce/acceleration/speed checking. Here is what I found for the Arma stryker:

----------------------------------

Max Speed flat road: 97.42 km/h

Max Speed flat terrain: 44.92 km/h

---------------------------------

1/4 mile time road: 16.2 - 17.1 seconds

1/4 mile time terrain: 30 seconds

---------------------------------

Max braking deceleration: -52.77 m/s

Max Accel road (E key): 34 m/s

Max Accel road (W key): 25.46 m/s

Max Accel road (Q key): 9.8 m/s

Max Accel terrain (E key): 26.9 m/s

Max Accel terrain (W key): 17.45 m/s

Max Accel terrain (Q key): 7.88 m/s

[max power 21]

You calculated acceleration to m/s^2, right, not m/s?

34 m/s^2 is 34 m/s per second. 34 m/s is 122 km/h. So, that means that an ArmA stryker would accellerate an additional 122km/h every second of accelleration. If its maximum speed is 90, that means it should reach its top speed in .77 seconds if the accelleration is linear. I think that it certainly isn't, but those figures seem wrong to me. I don't have the data to disprove them, though. I just want to make sure that you are correct, given your typos and the sorts of figures you're sharing.

[frederf 0]

So far it's going well. Total armor will will going up enough that an RPG hit makes your ears ring but you don't get 11 guys going up in flames in an instant.

A small "when damage < x" script can be run to give folks enough time to bail out when hit by weak munitions

The maxspeed is already set at 100 kmph in game so that is done and done. I haven't found an obvious "acceleration" figure or "horsepower" figure but overall I doubt that the straight line acceleration needs to be changed.

One major concern is having the MGs only reloadable while exposed only, plus having a manual reload action instead of the automatic when at 0 rounds kind. I'm pretty sure the manual reload is possible after reading the existing configs. The exposed only might be more problematic. There is no precedence for a vehicle weapon in OFP or ArmA that can only be fired from _inside_ the vehicle and can only be reloaded from _outside_ the vehicle. Also I have never seen a manual reload vehicle weapon but I have confidence that can be done.

After seeing how BIS has made the Stryker P3D models themselves I have to express disappointment. The M2, Mk19, and TOW variants have the majority of their models/textures in common yet use three distinct files. I am hoping to use hidden selections to combine all variants to one model (or at least one ICV model and one ATGM model). It may prove to be more trouble than it's worth to combine the ATGM and the ICV models due to the major differences in the static weapon mounts, hatches, and interiors. It should be a simple matter to make an "open back" model exposing the interior to view and add on a seperate "hatch" which is tied to the animation later.

I would also definitely like to add a small flat hidden selection in the front and skin it with a separate texture file. This way I can include 12 different ICV_M2s with only different bumper numbers, having a tiny increase in file size but manyfold increase in uniqueness of the units.

I'm currently working on the gunner daytime TV optics w/o blackwhite filter and fields of view (zoom levels). It should be a simple texture replacement and small config edit. I am slightly concerned that a realistic sight in a Stryker (long range) would probably having an automatic adjustment based on the laser range finder reading. Without something that sophisticated bullet drop at long range will be similar to a BIS M1A1 in not being anywhere near the crosshair. If I can get a laser rangefinder feedback loop from the script to automatically adjust the 2D optic for range then I will (theoretically possible) then I will attempt it but it's complex and low priority.

One complete unknown is how actions work in vehicles such as getin/getout. Are they simple scripts defined somewhere or are they more usual beasts? Hopefully if they are normal type scripts all manner of functionality regarding getin/getout and reload can be done such as:

Preventing reload unless turned out

Prevent embarking is rear ramp is up

Preventing disembarking if rear ramp is up

Allowing only driver to operate ramp

Adding delay if using eject to escape crew compartment (there are emergency hatches on the sides of the Stryker)

A weapon turret concern is if all turrets have to be stabilized by design in ArmA. In a real stryker engaging with the RWS station while the vehicle is moving and turning is difficult. I think the Mapfact AH-64 laser designator might be of the unstabilized variety.

The 4x8 and 8x8 transfer case, a silly idea, would be used to lower top speed in 8x8 mode but with a benefit to the climbing power of the vehicle. I think using a "writable" mode for the config may allow the config.bin values for the Stryker2 to be changed during game time.

The second gunner on the Stryker with the M240 should be easily possible.

I have yet to find where the animations are stored to adjust, for example, the front hatch of the Stryker driver.

Stryker MGS is definitely a much-desired AddOn and will likely be forthcoming once the model is prepared. The unit is a relatively simple tank-like object. I have already made a kind of half-arse Stryker MEV addon already. It has no ammo for the M2, medicine ability on the stryker (like M113amb), and red cross panels on 3 sides. In real life the differences between the MEV and the ICV are simply air conditioning and a bigger generator.

Ultimately I would love to make a Strkyer MC variant with a bolted on 120mm mortar. Aiming would have to be done via some kind of of mortar system.

[Col. Faulkner 0]

I haven't found an obvious "acceleration" figure or "horsepower" figure

Stryker has a 350 horsepower engine.

[CameronMcDonald 146]

Sounds like a nice project, keep it up!

[Scrub 0]

Now that the sights are not tied to barrels, is it possible to have an animated sight proxy (or dummy, or vector, or whatever you call them here)? One that follows a controller, or a set of values calculated from outside of the model? Just an idea. Nice job

[rstratton 0]

now that right there kicks alot of ass i sure hope u plan to take on the tanks next

[frederf 0]

I haven't found an obvious "acceleration" figure or "horsepower" figure

Stryker has a 350 horsepower engine.

I didn't mean a real life power figure (I already knew the 350 HP) but I haven't seen any CONFIG parameter that would let me alter the horsepower or acceleration at all. I think it's just "back calculated" based on the max speed.

Quote[/b] ]Now that the sights are not tied to barrels, is it possible to have an animated sight proxy (or dummy, or vector, or whatever you call them here)? One that follows a controller, or a set of values calculated from outside of the model? Just an idea. Nice job

Currently the sights are tied to the barrel still, but in a fixed relationship that can be whatever you want. I don't quite understand what you mean by "follows a controller"

[HamishUK 0]

the strykers need to be pretty much invincible to RPG's. I just read a book written by a guy who was a gunner on one in Iraq, and he said on dangerous patrols as many as 4-5 RPG's would hit his Stryker and they hardly dented it

I would agree on improved survivability. But near invincibility is a tall order.

Excelletn news about the mod though!

[mickuzy 0]

the strykers need to be pretty much invincible to RPG's. I just read a book written by a guy who was a gunner on one in Iraq, and he said on dangerous patrols as many as 4-5 RPG's would hit his Stryker and they hardly dented it

is that My War by Coloby Buzzel. that has some pretty good descriptions of strykers in them. for the free version of his book(well half the book) go to MY WAR goes to his early blog posts, thats where most of his iraq stuff is.