Product: Merkava Mk IVm 1.0
by The Omega Concern
Modeler, Scripter, etc: April Heaney
Support Address: This email address is being protected from spambots. You need JavaScript enabled to view it.
Product Revision Date: 2018-06-22
Manual Revision Date: 2018-06-22

Thank you and congratulations on your purchase of The Omega Concern's Merkava Mk IVm Main Battle Tank. Please read this manual before driving your enemies back across the desert.

The Omega Concern is dedicated to producing quality work at affordable prices, and we support everything we sell. All of our products are designed with the balance of impact on sim performance and ease of use in mind. If you find one of our products to be causing lag, behaving in unexpected ways, or otherwise being a pest, we need to know so we can correct it.

You are eligible for all upgrades on this version, being version 1. Also, your feedback is valued! If there's something you love, hate, or just think would be better if it were just a little different, we want to know. Your input directly influences the course of development and future features of Omega Concern products.

There is a technical support pass phrase in this manual, which you are strongly advised to use when first contacting support about this product. We do this because other people (not you!) don't bother reading the manual which contains the answers to their questions, thus taking our time and attention away from thoughtful questions not answered in the manual, such as yours. As always, emailing the support address above is preferable to offline IMs and notecards, both of which too easily get lost in the shuffle.

About the Merkava

The Omega Concern's Merkava Mk IVm "Windbreaker" is a model and simulation of the main battle tank designed by MANTAK for the Israel Defense Forces (IDF). The Merkava Mark IV is a third generation tank, and the variant known as the "Windbreaker" is equipped with the Trophy active protection system (APS). The Merkava is used exclusively by the IDF.

The Omega Concern is not affiliated with, nor endorsed by MANTAK, IMI, Urdan, Soltam, or any other company involved in the design, production or manufacture of the Merkava series or its weapon systems. All trademarks and copyrights are and remain the property of their respective owners.

  1. Unpacking and Setup

    1. Package Contents

      The Merkava comes in a mathematically legitimate box, completely free of imagnary or irrational numbers. You will need to rez it and select "Open".

      Press the button "Copy To Inventory", and you will now have a new folder in your inventory named "Merkava Mk IVm 1.0 (Boxed)" (or similar) which will contain the items from the box.

    2. Rezzing the Merkava

      The Merkava is a mesh model, which means you will need a viewer capable of displaying mesh. The standard SL viewer is one such option, as are several others on the Third Party Viewer Directory.

      To rez this tank, simply drag the object named "Merkava Mk IVm 1.0" from the folder in your inventory to an open area, bearing in mind that the vehicle has a footprint of about 11 by 5 meters, and you will need 217 prims free on the parcel. This vehicle uses no avatar attachments with the exception of the on-screen head-up display.

      It is best to rez a new copy of the vehicle from inventory for each use and deleting it when done, as opposed to taking one in-world back into inventory and reusing it.

  2. Driver/Commander and Gunner Roles

    1. Driver/Commander

      The driver/commander is primarily interested in driving the tank, maneuvering in response to threats, and setting up the vehicle such that the weapons can be utilized against targets. In the case of a single operator of the Merkava, the driver/commander will also assume gunner duties.

    2. Gunner

      The gunner operates the 120mm MG253 smoothbore cannon and 12.7mm coaxial machine gun.

    3. Driver-Gunner Handoff

      The driver (being the owner of the vehicle) can assume gunner control, or in the case of a two-person crew, can assign it to or withdraw it from the gunner, as described below in Operation 3.3.7.

  3. Operation

    1. Getting in and out

      1. Driver/Commander: The driver/commander boards the Merkava by right-clicking on the vehicle body and selecting "Board" (Some viewers may simply show "Sit Here" which serves the same function).

      2. Gunner: The gunner follows the same procedure as described for the driver/commander, but must get into the vehicle after the driver/commander has, and must do so before the driver/commander has started the engine.

        Getting back out of the tank may be accomplished by simply hitting the "Stand up" button, but everyone will laugh at you and call you a noob. Use the "EGRESS" button on the HUD, which is explained below.

    2. The HUD/MPD

      All of the vehicle's systems are controlled by the HUD/MPD (Head-up Display/Multi-Purpose Display) which is also used to convey information about the vehicle. If you don't already have it attached, fear not, as the Merkava will happily pass you one. If you have a gunner, they will similarly be passed a HUD. Simply locate the HUD in your inventory (the "Recent Items" tab is made for this) and right click and select "Wear" from the menu. It will attach to your bottom screen position. If you have a Merkava HUD still attached, it will function without issue, and the tank won't try to pass you another.  When you get back out of the tank, it will hide itself from view. To detach, simply locate it in your inventory, right-click and detach.

      Merkava HUD Overview

      Merkava HUD Data Entry Keypad

    3. You've Got Buttons

      1. ENGINE
        Starts and stops the engine, and indicates if the engine is running (green) or stopped (red).

      2. SMOKE
        Deploys smoke in an arc centered on the direction in which the turret is facing. The number just to the right of this button indicates how many sets of smoke grenades you have available.

      3. EGRESS
        Allows you to egress gracefully from the vehicle, as opposed to simply standing up, which is graceless, embarrassing to those who have to witness it, and may kill you if you're using an OCS HUD.

      4. REJECT
        Reject is not the question. "Do you want to get rid of your annoying and/or unwanted gunner?" is the question. Reject is the answer.

      5. OCS Mode Indicator/Options Menu
        When orange, indicates the vehicle is in OCS mode. (i.e. if the crew is wearing active OCS HUDs) Pressing this brings up the Options menu. From this menu, you may turn on/off the headlights, change the camouflage scheme, adjust your main gun ammunition loadout (as explained below), or toggle the self-delete function.

        1. Setting the MG253 Shell Loadout
          You may only select the loadout option before the tank has been started or any weapons have been used. After that, this option is locked out.

          The Merkava can carry 42 shells for the main gun, and while this defaults to 18 each of the M829A3 and M830A1 and 6 of the M1028, you can adjust the balance of shells as you like, while remaining within the 42 shell total.

          To use the loadout feature, select the Options menu. From this menu, select "Loadout." You will be presented with a menu of the following options:

          M829A3, M830A1, M1028 +/- : You'll first have to remove some shells from one of these slots, which will show in the "Free" count. You may then add any shells shown in the Free count to whichever slot you please.

          Done: When you're happy with your loadout, press this. This will commit your changes, but they can be changed until the tank is started, or you arm the weapon systems. After either of these events, you may not change the loadout on the current tank.

          Reset: Resets the loadout to the default 18/18/6.

          Discard: Dismisses the loadout menu and does not commit your changes.

          The loadout you decide to keep will become the default ammo levels for this tank. Meaning if you rearm/repair this tank, the weapons will be restocked to this level.A newly rezzed tank will have the default ammo levels.

        2. The Self-Delete Function
          By default, if you abandon the Merkava on land you do not own (As in are the actual landowner), it will delete itself after a short time to prevent littering. The "AutoDel" button on the Options Menu will toggle this feature on or off, so if you want to keep it parked on rented land, this will facilitate that.

      6. CAM
        Cycles the driver's camera between the default 'loose follow', rigid 'driving', overhead and drive-by camera modes.

      7. GUNNER
        In the case of a single driver/commander/gunner, this will toggle control of the weapon systems and turret tracking. With a two-person crew, on first press this will give control to the driver/commander, a second press will hand off weapon control to the gunner, and a third will deactivate gunner control entirely.

      8. FCS
        Toggles the Fire Control System for both the main gun and coaxial machine gun.

        With FCS off, you may manually set the range.To manually rangefind a target you may use the default "R" gesture, or chat command "/5 ranging" and the range that is returned will automatically be used by the coax to calculate windage and bullet drop.

      9. APS
        Toggles on and off the Active Protection System (APS).

        The APS uses an explosive charge to detonate or deflect incoming anti-tank munitions. There are two charges on the port (left) and starboard (right) side of the turret. The symbols resembling paranthesis on the HUD - ( and ) - indicate the number of charges left by colour: Green means two charges, yellow means one, and red means there are no charges left on that side.

      10. COAX
        Selects the 12.7mm coaxial machine gun.

      11. MG253
        Selects the 120mm MG253 cannon.

        1. Loading Status
          After firing, the MG253 will be reloaded with the same shell type as was just fired, assuming there are any available. The loading status has three phases, in which the "LOADING" indicator will turn from red to yellow, and then the blue "ARMED" indicator will appear when the cannon is reloaded and ready to again be fired. You will also hear the sound of the breach being opened, loaded and locked as an auditory cue to loading and arming status.

          As autoloaders are actually slower to reload a tank's main gun than a live crew member is, using the Merkava with another player as your gunner will reduce the MG253's reloading time by about 16%.

        2. M829A3
          Loads a M829A3 sabot shell into the main gun.

        3. M830A1
          Loads a M830A1 High Explosive shell into the main gun.

        4. M1028
          Loads a M1028 canister (a.k.a. "beehive") anti-personnel shell into the main gun.

        5. MODE
          When using the M830A1 shells, this toggles the fuzing mode between impact and ranged fuzing.

      12. MORTAR
        Selects the 60mm turret-mounted mortar.

        1. HE
          Loads a high explosive round into the mortar tube.

        2. ILLUM
          Loads an illumination round into the mortar tube.

        3. SMOKE
          Loads a high explosive round into the mortar tube.

      13. KPAD
        Tapping the "KPAD" buttons causes the data entry keypad to pop out. From here, you may enter the fuzing range for M830A1 shells. Simply tap the appropriate numbers, and your entry will appear while you enter it in the digital display beside the "MG253" button. Press the green enter key when done. The valid range is 75 to 500 meters. If you make a mistake during entry, press the red delete key. Pressing the delete key again will cancel the data entry operation and fold the keypad. Also, pressing the delete key without having entered any data will fold the keypad.

    4. Going Mobile

      1. Driving Controls
        Merkava WASD Controls

        The Merkava uses the arrow keys or WASD keys for gear selection and steering/pivoting control. The WASD keys will be used for the examples here.

        W and S control the tank gearing, shifting forward and backwards respectively. You do not have to hold down W to drive forward, simply tapping the key will increase your gearing, which will increase power to the drivetrain, which will move the tank forward. The Merkava has four forward speeds, neutral, and two reverse.

        A and D turn the tank left and right, or pivot it around when it is sitting still.

        The C or Page Down key will reset your throttle to zero and apply full brakes, stopping the tank.

        The E or Page Up key cycles the driver's camera between the default 'loose follow', rigid 'driving', overhead and drive-by camera modes.

      2. Starting

        Starting the Merkava after you've boarded is done by hitting the Engine Power Switch (ENGINE). Allow the engine a second or two to start, and then tap the W key once or twice to get moving.

      3. Maneuvering

        The A and D keys rotate the tank left or right respectively, and used in combination with the W and S keys to control gearing, the Merkava can get up inclines of over 45 degrees and over most any object lower than its nose and forward track wheels. If you happen to roll the tank onto its side, you will lose mobility.

      4. Fording Water

        The Merkava has a maximum fording depth of approximately 2.0 meters. Attempting to cross water deeper than this can result in water entering the engine intake, the engine being inundated with water and a complete loss of power and mobility. Bear in mind also that crews with OCS HUDs active will also drown in deep water if steps are not taken to abandon the vehicle and get ashore in an expeditious manner.

      5. Stopping

        You can stop the Merkava by either deicrementing the throttle (S key) until you have reached neutral, or by pressing the C key while either in a forward or a reverse gear and you will brake to a stop. If you wish to disembark, press the Engine Power Switch (ENGINE) and then the EGRESS button.

  4. Weapons

    Before you can select and take control of any of the Merkava's weapon systems, you must be the active gunner. As the driver/commander, clicking the GUNNR button will toggle control of the weapon system. When the button appears green, you are the "active gunner" and as such, have control over all weapons systems.

    In addition to causing appropriate OCS damage (impact and blast) the weapons on the Merkava also deliver 100% damage in Linden Damage enabled areas.

    1. 120 mm MG253 Smoothbore Cannon

      This is the tank's main gun. It is aimed in mouselook, and is fired by pressing the left mouse button. The turret will rotate at a rate of 30 degrees per second in the direction the gunner is looking, and the gunner must wait for the turret to fully traverse to aim at the target, or the shot will probably not go where you want. Its range of lateral motion is 360 degrees, to maximum depression and elevation of -9 to +20 degrees, relative to the tank body.

      By default, the MG253 functions under a Fire Control System (FCS) in an automatic rangefinding mode. Normally this will mean after pressing the left mouse button, there will normally be a slight pause (or a longer pause for shots traversing sim borders) and then the gun will fire.

      The FCS calculates a three-dimensional, asymptotic targeting solution taking into account the following:

      Shell selection
      Your tank's motion
      Target range, elevation and velocity
      Wind deflection

      If you fire against a target that is in motion, the shot will be calculated to meet the target at the precise point the target will be when the shell arrives. When using the M830A1 High Explosive shells, they will be fuzed for the distance to the target, so in the event the shot is not a direct hit, the shell will still detonate near to the intended target. When fired in rangefinding mode, the FCS will give you feedback about the firing solution, which will look similar to this:

      RNG: 241 @ 106 T: 1.40 s VC: 2.75 @ 200 WC: 1.81 @ 090

      This means the target is 142 meters away at a bearing of 106 degrees. Time for the shot to travel to the target is 1.40 seconds. This is a moving target, so it is compensating for that (Velocity Compensation) by leading (aiming ahead) 2.75 meters at a bearing of 200 degrees. Also, to compensate for wind deflection, it is adding 1.81 meters at a bearing of 90 degrees to the solution. As an approximate (and not to scale) kinematic diagram, it would look something like this:

      1. M829A3
        The M829A3 sabot round is a kinetic energy weapon and is best suited for armored targets. As it is a non-explosive round, blast damage is minimal, making it a poor choice for anti-personnel engagements.

      2. M830A1
        The M830A1 is a high explosive round for use against dismounted infantry, light armored vehicles, helicopters and structures. In addition to the local blast effect of the high explosive, this shell will throw shrapnel for a considerable distance which can be lethal to anyone not under cover.

        1. Impact Mode
          The default fuzing mode for the M830A1 is impact, simply meaning it blows up on contact with a solid object. When used in conjuction with the FCS, the round will be fuzed for the distance to the target, so in the event the shot is not a direct hit, the shell will still detonate near to the intended target.

        2. Fuzing Mode
          Proximity fuzing sets a distance from the tank at which the shell will detonate. This is useful against aircraft, infantry behind cover,and other soft targets which are susceptible to shrapnel damage. The proximity distance can be set from 75 meters to 500 meters. The FCS (if enabled) will aim at a virtual target in the direction you are aiming, at the distance speficied by the fuzing range, compensating for shell drop and windage to detonate the shell at the location you are aiming with high precision.

      3. M1028
        The M1028 Canister round (also called a "beehive round" for the sound that 1,150 high-speed, marble-sized tungsten steel balls makes) can be thought of as a very large shotgun shell. While it has limited effectiveness against any type of armored vehicle or fortified structure, it is highly lethal against infantry out to a range of approximately 115 meters, encompassing an arc of 30 degrees, with the damage inflicted falling off as the range increases.

    2. 60mm MORTAR

      The Merkava's 60mm has a range from 35 meters to 105 meters, and fires high explosive, illumination or smoke rounds, and clicking the HE, ILLUM or SMOKE buttons will select them respectively.

      Range is set by clicking on the up and down chevrons in the mortar section on the HUD. The number shown between the chevrons is the current range. Aiming is done in mouselook, just like the main gun or coaxal machine gun, and the mortar is fired the same way, by clicking the left mouse button. The mortar will launch in a high arc along the forward axis of the turret, to land at the selected distance.

      High explosive and Smoke rounds will detonate upon impact. Illumination rounds will deploy at 25 meters above the target.

    3. 12.7 mm coaxial machine gun

      This machine gun is a moderate rate of fire (600 rounds per minute) weapon aimed by the gunner in mouselook. Sustained or high-density fire may result in the barrel overheating. You will be able to again fire the weapon after several seconds to allow the barrel to cool down. It has a capacity of 600 rounds.

      In its default mode, the coaxial will use the Merkava's Fire Control System (FCS) to determine the range of the target at which you are aiming, and will compensate for windage and bullet drop to put the rounds accurately on your target. With FCS off, you must do this manually. If FCS is off and you manually rangefind a target (via the default "R" gesture, or "/5 ranging") the range that is returned will automatically be used by the coax to calculate windage and bullet drop.

  5. Gestures and Chat Control

    The Merkava will accept from the crew chat controls on channel 5, so commands can be given in the form of "/5 command" such as "/5 engine" (without the quotes, of course). Commands which are accepted on channel 5 are:

    engine: Starts/stops the engine.
    gunner: Toggles/hands off gunner control.
    lights: Toggles the headlights
    options: Pops up the options menu
    eject: Given by the driver/commander, ejects the gunner.
    coax: Arms the coaxial machine gun.
    mg253 : Arms the MG253 main cannon. The MG253 can also take additional subcommands for selecting shells: MG253&m829a3, MG253&m830a1, and MG253&m1028.
    ranging: Measures the range to a target in mouselook.
    fcs: Toggles the Fire Control System.
    smoke: Deploys smoke canisters

    Included in the kit are several gestures you can activate and use for most functions. The gestures use suggested key bindings, but feel free to reassign them to whatever works best for you. However, if you are not using a viewer that allows you to bind gestures to the keys these are, editing the existing gestures will not allow you to save with the current letter and number key bindings.

    Do note that you may have other gestures using the same keys as the ones included in this package. To locate and correct these conflicts, press control - G in your viewer and click on the"Key" column header to sort by key assignment.

  6. Taking Damage

    1. Compartmentalized Damage Model

      The Merkava simulates seven separate systems, each of which can take damage and experience degraded performance and/or failure. Damage to a component is determined by where on the body the vehicle was hit, with possible damage to nearby systems. The 'core' of the tank is its last reserve of hit points, which if depleted will result in its destruction. As a general rule, if you have to get hit by an anti-tank weapon, taking it to the front of the body is your best bet, as this is where the armor is strongest and where the Merkava is least susceptible to catastrophic damage.

    2. Vehicle Status Display

      This display is a pictogram of the vehicle systems, color coded from green to red to indicate the 'health' - better to worse, respectively - of each system from good to disabled, respectively. If a component suffers a failure or critical damage, it will turn red and you will hear an alert.

  7. Troubleshooting

    1. The Merkava has been extensively tested and is free of any known bugs. If you believe you have discovered a bug, please contact This email address is being protected from spambots. You need JavaScript enabled to view it. and provide, with as much detail as you can, step-by-step instructions for reproducing it. Things don't get fixed if we don't know what needs fixing. :)

      Your support phrase is 'Oi Vey!'

    2. To rez the Merkava, the parcel in which you are doing this needs to have at least 217 prims/prim equivalent free.

    3. If things aren't rezzing for you, such as the gun rounds or missiles, check your group tag and the group tag of the vehicle to make sure it is harmonious with the area you are in. Some viewers give the option of always creating objects under the group to which the land is set, which may cause you issues if you aren't expecting it and travel to another parcel that requires a different group.

    4. If you seem to be doing no damage in OCS, first make sure you are wearing an OCS HUD. The OCS logo near the bottom of the Merkava HUD will appear orange when OCS is engaged and working.

    5. You may have other gestures using the same keys as the ones included in this package. To locate and correct these conflicts, press control - G in your viewer and click on the"Key" column header to sort by key assignment. The keys are merely suggested key bindings, feel free to reassign them to whatever works best for you. If you are not using a viewer that allows you to bind gestures to the keys these are, editing the existing gestures will not allow you to save with the current letter and number key bindings.

    6. Sounds, and not being able to hear them: If you're using a Viewer 2 or 3 based viewer, the default sound settings cause sounds to carry a few meters at most, then be unable to be heard. If not already showing, press Control-Alt-Shift-D and make the Advanced Menu appear. From that menu, select "Show Debug Settings," or if you're using the Firestorm viewer, press Control-Alt-Shift-S. In the box, enter or locate "AudioLevelRolloff" and try setting it between 0.040 and 0.200 for better hearing.

    7. Asset corruption happens. Rarely, a copy of something will become corrupt and behave in very strange ways. The first thing to try is to unpack a fresh copy of the item from the box in which it came. If that doesn't solve the issue, you can have another box of the same item sent to you via the service kiosk at The Omega Concern's main store. Failing that, contact the support address and request a new box be sent to you and you will receive it as soon as possible.

  8. The End

    First, a heartfelt thank you to all The Omega Concern's customers over the years. You guys gave me the sweetest gig in the world, and I love you all for it. I do this all for you.

    A big thank you to Eddison Campbell, Eric Sheppard, and Caete Chevalier for these years of friendship and beta-testing, in that order.

    As it always has been, and always will be: Fun is the whole point. Do go have some. :)