Hovercrafts and mines

[McPerth]

As here there are many people quite more knowledgeable than myself on those issues, I'd wish to ask a question that arised in a game I play (but could also in T2K, 2300AC and even Traveller, even while ACV have limited use when gravitics exist):

How do mines affect hovercrafts?

I mean, I understand most mines (be them antipersonnel or antitank) are activated by presure, but would a hovercraft produce enough presure to activate them?

Thanks in advance for any answer.

 

[BackworldTraveller]

That would be a definite maybe.

You do have pressure (divide the mass by the entire area enclosed by the skirt) but you also have gusting. So if your mine is using thin wires to find the moment to explode then you may get it to trigger. Otherwise, not much.

If you have a proximity mine with ultrasonic movement detector - quite possibly. Magnetic mine? Could be. Chemical sniffer? Who knows! Joe Bloggs triggering by remote observation - depends if Joe Bloggs spots you and react in a timely fashion. Tripwires - probably.

It's 40 years since I helped build my dad's hovercraft - but it was definitely very low ground pressure.

 

[Spinward Flow]

would a hovercraft produce enough presure to activate them?

Short answer: NO.

Additionally, even if the mine is detonated by remote command trigger ("push the button, Max!") ... most hovercraft will suffer relatively little damage from a buried ground mine detonating. Large hovercraft will be 1-2 meters off the ground (or more) which will do a lot to reduce the "power" of the explosive charge at that distance.

Small personal (1 man) hovercraft will ride lower to the ground (0.5 meters?) and might get overturned by an unexpected detonation below the vehicle.

Wheeled and Tracked vehicles have ground pressure rated in tons per m².
Air Cushion vehicles have ground pressure rated in kilograms per m².

Or if you want a more authoritative CT source, there's always CT Striker book 3, p10:

C. Ground Pressure: Grav vehicles and ACVs have no ground pressure.

 

[Condottiere]

By simple pressure, probably not.

However, if the military is expecting these types of vehicles, sensors that feed environmental data to an app programmed to figure out if a hovercraft is overhead.

And regarding height, the mine could be connected to a spring and become a Bouncing Betty.

 

[Grav_Moped]

My hovercraft is full of eels.

(It's either a defensive measure against magnetic-influence mines, or a bad translation -- I'm not sure which.)

 

[mike wightman]

Google says:
"For example, the average human being when standing on a beach exerts a pressure of some 3lbs per square inch underfoot, rising locally to 25lbs per square inch when walking. The average hovercraft by comparison, exerts a pressure of only 0.33lb per square inch on the surface regardless of speed."

Your maths problem for today is to convert it to the units of your choice.

 

[gchuck]

IIRC The 'Hammers Slammers' books/short stories do go into some amount of detail regarding anti-vehicle mines versus hovercraft.
Not specifically helpful, but an observation.

I do seem to recall that AT mines have a 'pressure' switch, but also have a stake/lever/whisker that protrudes from the mine above ground several inches, that would activate the mine while not requiring it to be directly run over.

 

[kilemall]

Magnetic detectors or air pressure…

The latter could be vulnerable to detonation by storm…

 

[Condottiere]

A tank is a large dense collection of steel.

But current events is allowing a great deal of reconsideration, including that mines tend to have different rate of temperature changes than the surrounding soil.

 

[Spinward Flow]

A tank is a large dense collection of steel.

Well ... until its armor is made out of composite laminates instead due to advancing technologies.
Eventually they'll be made out of crystaliron, superdense and bonded superdense armors.

Steel is just an early tech phase.

 

[McPerth]

FIrst of all ,thanks for all your answers.

So, I understand it would be easy (or at leat possible) to make mines against hovercraft, but the current ones would not bee too effective against them (I guess because they are so little used in military that no one has seen it as worthy)...

 

[kilemall]

FIrst of all ,thanks for all your answers.

So, I understand it would be easy (or at leat possible) to make mines against hovercraft, but the current ones would not bee too effective against them (I guess because they are so little used in military that no one has seen it as worthy)...

Generally speaking in RL they are fragile enough that just autocannons, guns or missiles will do.

Do Ogre style armored GEVs and it might be worth the effort.

 

[McPerth]

Generally speaking in RL they are fragile enough that just autocannons, guns or missiles will do.

Sure, but this needs you to detect them...

Let's imagine you think your flank to be (relatively) secure due to your minefields, and then suddenly a unit mounted on ACVs moves through them. If the minefields are not effective, you may be in trouble before you can bring your guns to bear...

Do Ogre style armored GEVs and it might be worth the effort.

Also 2300AD (among other games) use hovertanks...

In fact they seem to be in use in most games where grav is not available

 

[Condottiere]

Armoured trucks are not going away.

But cost benefit has to be carefully adjusted, because survivability is going to require massive investment in combined arms and additional defensive systems.

Basically, we're entering the dreadnought phase.

 

[BackworldTraveller]

FIrst of all ,thanks for all your answers.

So, I understand it would be easy (or at least possible) to make mines against hovercraft, but the current ones would not be too effective against them (I guess because they are so little used in military that no one has seen it as worthy)...

Self-forging rounds that work like some current IEDs would probably work.

Triggers based on magnetic signature would be possible - fusion bottles seem likely to have a noticeable signature even if the hull weren't, itself, magnetic.

 

[Condottiere]

Speaking of which, I heard that mines are now constructed to create a blast to the side of the tank.

Also, I think, as in an urban environment, mines might be set above the height of a vehicle.

 

[Timerover51]

The military has large shaped charges for blasting holes into the ground to set ammonium nitrate cratering charges in roads. As a field expedient, said large shaped charges can be set in a bank on the side of a road on their side, and used against vehicles, armored or un-armored. There are large charges with a long jet of metal. Set upside down with a detonator, they would work nicely against hovercraft. For that matter, a row of cratering charges with command detonation would also work nicely. Several hundred pounds of ammonium nitrate going off under a hovercraft would very likely flip it onto its back, aside from wreaking absolute havoc to the fans. If you know that your opponent is using hovercraft, you make preparations to welcome him properly.

 

[Rigel Stardin]

Really all that need is a pressure switch attuned to the down force of any hovercraft. Once the down force is detected, a projectile is fired upward. It can be armor piercing or high explosive. Remember, large intakes are required to move the air need for lift. All the mine has to do is destroy the 'skirt or fan' to make it immobile. The same applies to high tech version as well. Jet engines, repulsor lift and even my 'thruster based' systems are applying downward force to keep the craft off the ground.

 

[Dragoner]

All one needs is the tiny proximity sensor buds, often magnetic, also seen in car bumpers, and as mentioned above, an EFP style IED.

 

[Enoki]

If hovercraft were a serious threat, then I could see mines set off by magnetic signature, optical sensor (it goes dark over the mine as the hovercraft passes), air pressure, or any of several other options. A low-tech version might use feeler antennae on the mine. Couple that with say a "bouncing" or jumping mine that launches upwards then radially fragments or uses expanding rod to tear the hovercraft skirt to shreds immobilizing it if you don't want or think you can outright kill it. If a gas turbine is used, you might add in a chemical that when ingested into the engine, causes it to die by extinguishing the burners like a chemical fire extinguisher.