[HOW TO] Mortars

[Karate Pyjamas]

A small topic about Mortars

This video of mine explains the following methods of zeroing in a mortar:

• Calculation
• Range table

 

It also features:

• Using map-grid for target acquisition
• Terrain Elevation
• Map tools (Mills, bearing, distance)

 

Why you want this:

• More precise control
• Low angle and High angle attack
• ETA to impact
• Precise Bearing and Elevation numbers
• Allows for blind firing
• So you're no longer an artillery computer scrub

 

Download the Artillery Sheet here:

Spoiler

https://docs.google.com/spreadsheets/d/1DY8QMsdrfdnZ49WqZTLV63lrqPfg23YQXwPFHX3HCT0/export?format=xlsx&id=1DY8QMsdrfdnZ49WqZTLV63lrqPfg23YQXwPFHX3HCT0

 

The video explains it all:

Map techniques are interwoven with the methods.

• 0:47 - 6:52 Artillery Sheet method (Map Grid + GPS + Contour Levels)
• 6:52 - 9:12 82mm Range table Method (Maptools)

UPDATE 1-1-2016 Fire Mission Routine:

When operating in the some of the cramped environments like we tend to do at times, it's important to follow proper Fire Discipline to avoid friendly casualties when firing artillery shells. It takes time for shells to impact at the designated location so make sure you give friendlies enough time to retreat or prevent them from moving up when shells are danger close.

 

Spoiler

 

Proper Fire Discipline:
FO - Forward Observer
AB - Artillery Battery

FO: "*AB Callsign* this is *FO Callsign*, request fire mission, over"

AB: "*FO Callsign* this is *AB Callsign*, request fire mission, over"
FO: "Grid *xxxx* *yyyy* *zzz*, over" (Send the 4x, 4y digit coordinate of the target and its height.)
AB: "Grid *xxxx* *yyyy* *zzz*, over"
FO: "Target *type of target and surroundings*, (Optional1: *Shell Type* when not specified, AB decides shell type, Optional2: "*Number of Shells* Rounds", when not specified AB will select a suitable amount of rounds Optional3:"Danger Close"), over" 
AB: "*Repeat Full Target line including Optional1 and Optional2*, out" 

When AB decides the type and number of shells he will state which shells and how many will be fired!

AB: Prepares guns for fire mission and shoots

AB: "Fire for effect, over"
FO: "Fire for effect, out"
AB: "Splash, over"  

It is crucial the AB knows the Time to Impact, 5 seconds before impact he will send this message so the OB can orient his focus on the target
FO: "Splash, out"
*

**
FO: "*AB Callsign*, this is *FO Callsign*, End of mission: *target* destroyed, over"
AB: "*FO Callsign*, this is *AB Callsign*, End of mission, *target* destroyed, out"

*Optional Adjustment

If the rounds land of target, the FO will call out the adjustments needed and request for another barrage of shells
 

FO:"Adjust Fire, Add/Drop *xx meters to the target* Left/Right *yy meters to the target*" 

Add is when the rounds fall short of the target, drop when target is overshot. Left and right is pretty explanatory. Just remember you correct TOWARDS the target not how far they have missed from the target!
AB:"*Repeats FO message*"
 

From now the regular routine ressumes, AB corrects the guns and fires and informs when they fired and when they splash, FO always repsonds to the AB in the correct way untill mission is complete.

 

**Repeat Fire
If the target wasn't fully destroyed the FO can call in for a seconds strike to obliterate the target.

 

FO:"Repeat, over"
AB:"Repeat, out"

From now on the regular routine ressumes, AB fires the same volley of shots as before and lets the FO know when they are shot and when they are to splash.

It must be noted that before calling in a fire mission it is absolutely crucial the FO already knows the target coordinates, the same can be assumed from the AB that they know their own exact coordinates.

If for any reason the fire mission needs to be aborted (target moved, other complications) either of the parties involved can say:
AB/FO:"Break Break, Abort Fire Mission, over" 
AB/FO:"Fire mission Aborted, out"

If a message was incorrectly repeated:
AB/FO:"Negative, *repeat correct message*"
AB/FO:"*repeat message*"
 

 

10

Here's an example fire mission that includes all the options (adjust, repeat):

Spoiler

FO callsign: EAGLE
AB callsign: VAMPIRE

 

FO:"VAMPIRE, this is EAGLE, request fire mission, over"
AB:"EAGLE, this is VAMPIRE, request fire mission, over"
FO:"Grid 1545 0157 64, over"
AB:"Grid, 1545 0157 64, over"
FO:"Target, 2 times BMP, 10 times infantry dismounted, in the open, over"
AB:"Target, 2 times BMP. 10 times infantry dismounted, in the open, HE 5 rounds, out"
The target is out in the open so there is no point for special penetration rounds, HE will suffice as a shell type and VAMPIRE decides 5 rounds will scatter enough that it will destroy the target.
AB:*Prepares the guns*

AB:*Fire the guns*
AB:"Fire for effect, over"
FO:"Fire for effect, over"
AB:"Splash, over"
FO:"Splash, out"
The shells miss the target, they fall short and are to the left of the target
FO:"Adjust fire, add 20, right 10, over"
AB:"Adjust fire, add 20, right 10, out"

AB:*Adjusts their guns*

AB:*Fire the guns*
AB:"Fire for effect, over"

FO:"Fire for effect, out"
AB:"Splash, over"
FO:"Splash, out"
Bad luck, the 5 shells on target didn't scatter enough to take out all the infantry and one of the BMP's remained undamaged
FO:"Repeat, over"
AB:"Repeat, out"
AB:*readies their guns for another volley*

AB:*Fire the guns*
AB:"Fire for effect, over"
FO:"Fire for effect, out"
AB:"Splash, over"
FO:"Splash, out"
This time the targets don't get away and the mortar shells obliterate the target wiping out all the infantry and permanently disable the BMP's
FO:"VAMPIRE, this is EAGLE, End of mission: Target 2 times BMP, 10 times infantry destroyed, over"
AB:"EAGLE, this VAMPIRE, End of mission: Target 2 times BMP, 10 times infantry destroyed, out"

 

Update 23-12-2017 Mortar Trajectory Explained:
 

With this update I've included 4 plots that explain how the mortar trajectory works and how one should compensate the trajectory for uphill and downhill shooting.

First we look at the angle the mortar fires at. Increasing the elevation we can fire at things closer to us. If we lower the elevation we can get a bit more distance out of the mortar.



We now look at how the charge of the mortar affects its trajectory. A bigger charge allows us to reach out further when we keep the elevation constant. We can also use this to our advantage. For example, if there is a really big mountain in the way perhaps it's wise to select a bigger charge so you know you will clear the mountain.

Now lets look at the theory behind shooting a target above or below you. First we tackle a target above the mortar:

When we use the maptools we can get a range to the target of dx. However, since the target is above us we can see that if we were to dial in the mortar for that distance dx we would shoot the red trajectory and hit in front of the target. Therefore we need to adjust our elevation downwards so we can hit the target. The range table gives an adjustment in 100m height difference intervals. If there is only a 50-meter difference feel free to just divide the adjustment given by the range table in half or interpolate for other differences. However, a height difference of 10 to 20 meters relative to your own height shouldn't really cause any issues, and adjustment is considered optional.

Downhill shooting is very similar to uphill shooting. However, instead of lowering our elevation we increase our elevation as shown in the following diagram. The indicated numbers on the range table for adjusting the mortar work similarly, but instead we now adjust in the other direction.


Understanding the trajectory of your mortar shells is very important to minimize civilian/blufor casualties and to get pinpoint accuracy. That said, the further your target is away the larger the deviations will be, so don't expect pin-point accuracy on targets beyond 1.5km

[TheToxicPixels]

Great Work Dude!

[Guest]

Nice this should get pinned!

[maxxykang312]

Im gonna start using mortars now, really helpful post!!!

[Eggmuffin]

The mumbling made it really tricky to follow, but other than that, it's a good guide. I'll definitely try it out.

[Karate Pyjamas]

Yeah, it wasn't the best night I recorded this. I couldn't find my LAV mic, my room mate was being noisy as fuck so I had to re-do so many segments. I do speak a bit fast (which I will keep in mind next time) and I had a slight cold at that time.

 

I wish I had a better PC so I could actually record it instead of making a slide show, that would make things a lot clearer too. I decided to use some sound effects to make it clear when something new appeared on screen. (Pen noises and slide clicking.)

[Chon]

Well that calc. sheet dosent work properly anymore, rounds goes halv way or so. Dont know if BIS change the velocity or something on the Mortar.

[Karate Pyjamas]

Well that calc. sheet dosent work properly anymore, rounds goes halv way or so. Dont know if BIS change the velocity or something on the Mortar.

Is it on flat ground? Did you select the right charge? Did you select the right angle of attack?

[Karate Pyjamas]

1-1-2016: Updated with fire mission routine

[Karate Pyjamas]

5-2-2017: Artillery sheet has been fixed because of a slight calculation error. Updated with 3CB M6 (60mm "handheld" mortar) Muzzle Velocities!

[GhostDragon]

(there is a built in range table on the m6 handheld mortar) this is accessable through ctrl + B

[Karate Pyjamas]

1 minute ago, GhostDragon said:

(there is a built in range table on the m6 handheld mortar) this is accessable through ctrl + B

I know, I've added it to the spreadsheet too for those who want to use that. I actually had to reverse engineer that table to get the correct muzzle velocities.

[Karate Pyjamas]

23-12-2017: Updated original post with mortar trajectory plots, including an explanation how to compensate for high or low targets.