EMP-proof Defender

chris snell

Administrator
Callsign: NW5W
Staff member
I've been thinking about doomsday scenarios lately--not seriously or with any kind of fear--more as a thought exercise. I really love my 300Tdi-powered 110 because of how little it takes to run it aside from fuel. Thinking of potential weaknesses of the truck in an EMP situation, the only thing I can think of is perhaps the fuel cut-off solenoid coil. Does somebody make a purely hand-operated solenoid replacement for our the Bosch IP? Aside from the silly and hypothetical Dr. Strangelove EMP scenario, there's the more realistic broken-solenoid-way-out-in-the-desert scenario. Aside from carrying a spare solenoid (which I do), how can you work around this?
 

javelinadave

Administrator
Staff member
You could always remove the plunger and shut the motor off by dumping the clutch while holding the brake.
 

JimC

Well-known member
I believe to EMP harden you just need to have your equipment off during a strike. Your alternator could of course be fried and maybe the battery. In addition to the solenoid over-ride I think a compressed-air powered starter would be advisable.
 

xplorutah

Well-known member
Pfft... roll start in a nuclear apocalypse? You know how thick that ash gets?
Remembering to park nose down hill is a pain and never mind pushing with lawless post EMP types running around? I am sure you would have "security systems' but still, pushing a 110 with only one hand?
 
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JimC

Well-known member
Roll-start it.
Always? Also, you probably moved to a defilade, hull-down, or other protective position in the run-up to the strike. Even if you moved to an expedient cover location, you might not have had time to tactical park or choose a location conducive to compression starting.
 

Adam

Well-known member
Lucky! They took our nikes away (less than ten miles from my house) - but we have other worthwhile targets nearby.

 

SARTech

Well-known member
Good question. Is the fuel pump solenoid energized to allow fuel flow and de-energized to stop fuel flow or is it fail safe and de-energived to allow flow?
 

red64chevelle

Active member
I am going on my limited knowledge of EMP's, but I thought they mainly destroyed electronic devices, not all electrical things. Being that a fuel stop solenoid is electrical, and does not have any solid-state components in it, I think the 300TDI as built is EMP proof. You might end up with a problem with the alternator, as the voltage regulator and rectifier have solid-state components in them (rectifying diodes and Zener diodes). If you were concerned with it, I would carry a spare fuel stop solenoid and alternator. They could be kept in an old ammo box that would act as a faraday cage. "The MOD was concerned that the electronics of the Td5 would be susceptible to EMP weapons, so the 300Tdi was continued to be produced for the export market." https://www.landroverexpedition.com/articles/110-sw-300tdi-row-lhd/
 

UnfrozenCaveman

Well-known member
The 4bd1 in the Petentie uses a pull to stop cable. Sure, in its o.e. configuration theres a clockwork motor that pulls the cable but it's not unheard of to use a tractor control when the clockwork motor fails.
 

Napalm00

Well-known member
When the starter went on my 200tdi I was absolutely amazed how easy it was to push start the truck. If you're on a flat space in the middle of nowhere one guy could totally do it and then lightly jog to hop in.

I found it easy to push start it in reverse by just pushing on the bullbar
 

TravelinLight

Well-known member
I have been morbidly curious about the same topic. The 200 TDI is rather easy to push start as noted. The weak link would be the alternator as mentioned above. You could also always remove the stop ball from the cut off solenoid in an emergency dessert situation and dump the clutch as mentioned. Limp home mode.
 

RBBailey

NAS-ROW Addict
Callsign: KF7KFZ
I’m not smart, but I would bet that theoretically an EMP can destroy even the electrics in a caveman’s Defender. It would depend on the strength of the current/pulse when it hits. It would be like having a very large flood of amps suddenly hitting the wires and traveling to whatever component is at the end of the wire, causing massive melts and shorts. And you don’t have to have the power on to get damage. Who knows, maybe some of us would see our diesel truck spring to life while just sitting in the garage!

On a sort of related note, back in the ‘90s before cable TV was an option for us, my wife could tell when I was getting close to home in the ‘65 IIa because there was a particular interference static that would show up on the TV!
 

pmatusov

Founding Member
I've been following this with some degree of curiosity.

There's no such a thing as "EMP proof" or not "EMP proof;" it's a matter of just how much voltage or current is induced by electric and magnetic field in EMP. It can be bad enough to evaporate aluminum panels (after all, that's how about one-half of Aluminum is produced). Or it can be benign enough to affect open electric lines of communications but not affect a vehicle's electronics at all.
FWIW, it is relatively easy to improve the "EMP-proof-ness" of all automotive electronics - shield what you can, use resistors and fly-back diodes on the sensitive circuits feeding into any computer. In a nuclear strike terms, it may decrease the distance from the blast to your vehicle at which EMP would kill critical electrical components - if that's what you're looking for.
But on a grand scheme of things - imagine an apocalyptic scenario where 99% of the vehicles on the road become dead and yours is/are not. Are you prepared to defend them from whoever wants to take them?

There's a book on this subject, strangely given to me by my kids - "One Second After" - that is all explicitly about what our world would look like after an EMP strike.
 

pmatusov

Founding Member
Speaking of technical details - the most-EMP-susceptible circuits are those with long unshielded wires going to them. Basically, any wiring harness going through the length of the inner body (and, say, not through a framerail). If you're concerned, put it into a conducting jacket like this.
 
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