Mine Warfare in Command – Part II: Mine-sweeping

August 22, 2012 · Posted in Command

In our previous video we demonstrated how mining operations work in Command; creating mining missions and assigning suitable assets to them makes an otherwise tedious undertaking very straightforward to accomplish.This time we take a look at the flip side of the coin – finding and removing these mines.

So once more side "Red" has created a mine barrier on the entrance to the straits of Hormuz, and side "Blue" has to neutralize it by clearing at least part of it to create a safe transit lane. Blue has access to two Avenger-class and one Osprey-class mine-warfare ships (MCM), plus a dozen MH-53E Sea Dragon helicopters at nearby airfield "Base 1", fitted with the Mk105 mine-countermeasures equipment.

First, we take a peek "behind the scenes" by briefly enabling "God’s Eye" view, to see what Blue is up against. The minefield looks pretty thick (around 3000-4000 mines). Normally Blue does not have access to this information.

Switching back to normal view, we define an area for the safe transit corridor we want to open. Using the created reference points, we create a new mine-clearing mission and assign all available assets to it, enabling the 1/3rd rule (more on this later). Then we sit back and watch them get to work: The ships activate their HF sonars and plot a course towards the area, and some of the helicopters begin their air ops procedures for taking off. This is going to take a while, so time acceleration is widely used.

Some observations:

* Zooming on the MCM ships and helicopters shows their mine-sweep coverage (the blue triangles). Once one or more mines are detected, the vessels manouver in such a way as to place the target mine inside this coverage area in order to trigger it. (The odds of this happening depend on the tech levels of the sweep gear and the mine being prodded; an old mine is much easier to sweep with modern equipment and vice-versa). If no mines are detected the units will still patrol inside the designated area, aiming to set-off undetected mines (hopefully without being damaged by them).

* Helicopters are much more efficient than ships at sweeps against detected mines thanks to their speed (and reduced vulnerability) but are less effective at detecting the mines in the first place. Ships on the other hand have the sensors suitable for detecting mines en-masse but are less effective at clearing them, and more vulnerable. As is obvious in this example, ships and helicopters are most effective in this mission when cooperating to maximize their strengths.

* All ships (including MCMs) try as much as possible to avoid passing too close to detected mines (the pathfinding code takes known mines into account when plotting a course). The "minimum safe distance" is estimated based on the ship’s own signature characteristics (magnetic, noise etc.) and whatever information is available about the mine contact. Smaller ships have a smaller keep-out distance and MCM ships have a big advantage thanks to their special signature-suppression techniques (non-metallic hulls & structure, enhanced degaussing, low-noise motors, reduced pressure etc.). This enables them to manouver much closer to mines than other ship types in order to sweep or hunt them.

* Despite these measures however, all 3 ships progressively suffer blast damage. (MCM vessels are designed with the assumption that they will suffer multiple proximity blasts during their lifetime, much more intense than for frontline warships). Even the best MCM ships are vulnerable to this; during the mine-clearing operations off Inchon in 1950, multiple MCM ships and destroyers were lost. Normally the ships would withdraw after a certain damage threshold and return to a tender or naval base for repairs, rotating with others. Command does not currently support this feature but probably will at some point in the future.

* Midway through the operation one of the helicopters is destroyed by fragments from a surface mine detonation. This is not a bug; helicopters occasionaly do get damaged or lost while detonating nearby mines (the USN lost two helicopters this way while clearing the Haiphong harbor in 1973). One factor we would like to improve here is to make the damage more graceful so that the helo is not destroyed by the smallest fragment damage but has a chance to limp back. This is related to our under-development aircraft damage model.

* At 8:53 we enter the mission editor and deactivate the mission’s "1/3rd rule". This option dictates that hosted aircraft & ships will depart for their missions in 1/3 increments rather than all together, in order to rotate and thus provide continous coverage of the patrol/mission area. Disabling this option allows us to perform a "surge": All available assets tasked to the mission are immediately launched, providing temporarily a significant increase of on-station assets at the cost of reduced coverage in the long term. This is one of the typical trade-off decisions that the player must make.

Towards the end of the video, we pause the scenario and activate "God’s Eye" once more, to witness if the sweep team has made a difference. As can be seen, a very obvious dent has been made on the mine barrier; there is still much work, but the safe-transit corridor is beginning to take form. There is also something else noteworthy: Some mines close to the sweep team have not been detected at all. Such is the uncertain nature of mine operations.

This example was presented under favorable conditions for the sweep team: No unsweepable mines were included, and these do exist (Command’s databases currently have 3 mine types with fuses that are virtually sweep-proof). Other mine types can be swept but are really hard to detect in the first place. Sweeping in general is efficient but bound to miss some here and there; a hard proposition for the forces that have to pass through the supposedly sanitized area. Thus sweeping is typically complemented by active mine-hunting operations; we will take a look at them in Part III.

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