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Old 10-23-2018, 05:14 AM   #21
Luke Bunyip
 
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Default Re: [AtE] Wasteland vehicle improvised weaponry

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Originally Posted by mlangsdorf View Post
A Ford F-350 Supercab Longbed is 21' long, 6.7' wide, and about 5.5' tall from the bottom of the cabin to the roof. The bed is 8' long, so the hood and cab take up 13' - call them 5.5' long and 7.5' long, respectively. The height to the windows is about 3.5'.

If you want to armor the hood and and doors of the cab, but not the bed, you're looking at 6.7 * 3.5 + 2 * 13 * 3.5 + 5.5 * 6.7 = 151 sqft of armor plate. That 2400+ lbs right there.

The windows are 2 * 7.5 * 2 + 6.7 * 3.5 (ish, the front windshield is curved and angled, but you'd want gaps to see through it...) = 60 sqft of armor plate, and another 1000 lbs.
This is all straight flat sided plate? What if the front upper and lower plates over the engine compartment were angled? Would there be a DR/wt benefit?


Player suggested ripping the IC motor out, sticking some scavenged wheel hub EC motors, as well as a couple of motor car battery packs in the floor of the tray (the void between the chassis frame?). Recharged by deploying folding PV panels, and/or a trailer mounted gassifer/EC generator with a stash of charcoal.

If the front radiator and engine block are removed, the front armour only needs to cover the suspension and whatever else is in the former engine compartment. And can be angled like a wedge.

Or... am I missing something.


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A radio controlled/dumb/kamikaze go-kart loaded with improvised explosives would make an erratic but potentially devastating weapon.
Oh, my... so need to spring that on the PCs.
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Old 10-23-2018, 07:25 AM   #22
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Default Re: [AtE] Wasteland vehicle improvised weaponry

Sloping your armour, the way the frontal armour of tanks often is, is only advantageous if the stuff inside can fill the sloped shape efficiently, or if sloping would mean less framing to support the armour. If it can't, you gain little or nothing.

Removing the engine and having a simple wedge plus wheel guards might well work. OTOH, you might need that volume for more batteries, as there's likely less free space under the tray than you think.

Oh, and having a trailer to carry extra fuel, etc., has not gone well in the past for armoured vehicles.
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Old 10-23-2018, 08:15 AM   #23
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Default Re: [AtE] Wasteland vehicle improvised weaponry

[QUOTE=Rupert;2217857] Sloping your armour, the way the frontal armour of tanks often is, is only advantageous if the stuff inside can fill the sloped shape efficiently, or if sloping would mean less framing to support the armour. If it can't, you gain little or nothing. [QUOTE]

Should gain quite a bit from it actually if only increasing dramatically the number of shots that glance off due to not archiving a decent impact angle. It should however be considerably more difficult to build and likely heavier when not able to design the vehicle from ground up for sloped armor. Might still be something for the front of some vehicles.

One thing with armoring up a vehicle this way however is that I'd guess that some parts you really want to armor up like windows and especially radiators don't really work well if you do so and under extra strain I'm guessing heat will be a big problem. That's without going into all the problems the weight put on the body I guess breakdowns of a wide variation of drivetrain and suspension parts will be regular business.
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Old 10-23-2018, 12:07 PM   #24
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Default Re: [AtE] Wasteland vehicle improvised weaponry

A PIAT or other spigot mortar would be pretty easy to cobble together with various warheads. Black powder, napalm, harpoon, etc. Imagine something like a wheeled Ontos with a half dozen PIATs.

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Originally Posted by Verjigorm View Post
You can save a lot of weight by only armoring the important bits. For a pick up truck, I would armor the engine compartment(complete with a cow catcher grille) and the drivers seat. The rest would be a "fighting platform" for my warriors, and it doesn't need a lot of armor. Roll cages are still a generally good idea.
Very much this. I wouldn't armor the bed of a pickup, for instance. That's where your tripod-mounted weapon is, but it fires over the cab, so just armor the cab. Heck, just armor the grille and windshield. Maybe the doors.

Last edited by acrosome; 10-23-2018 at 12:14 PM.
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Old 10-23-2018, 05:33 PM   #25
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Default Re: [AtE] Wasteland vehicle improvised weaponry

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... I wouldn't armor the bed of a pickup, for instance. ... Heck, just armor the grille and windshield. Maybe the doors.
That was my thought. From the sounds of it, it would take a truck prime mover to carry the weight of full armour, presuming that fuel can be found on which to run it (presuming one stays with an IC engine).

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Originally Posted by acrosome View Post
That's where your tripod-mounted weapon is, but it fires over the cab....
Now, you're just being technical...

Seriously, my setting is an AtE Australia. Automatic weaponry is rare down here. A motorised repeating arbalest, or a pneumatically powered harpoon or spud gun is as good as any of my players PCs are going to have access to.
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Old 10-23-2018, 08:59 PM   #26
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Default Re: [AtE] Wasteland vehicle improvised weaponry

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Originally Posted by Luke Bunyip View Post
This is all straight flat sided plate? What if the front upper and lower plates over the engine compartment were angled? Would there be a DR/wt benefit?
Sloping armor plate increases the relative thickness, which is good, but also increases the area that you need to armor, which is bad.

Take the front grill of that F-350: it's normally 6.7' * 3.5' at 90 to the ground. Incline it back to 60 degrees, and it's a 4' plate to reach the same height, plus you need to add some triangles to cover the gaps. You can use thinner plate to make up the weight - I think it works out to 8.5mm thickness at an inclide has the same protection as 10mm at right angles - if you can guarantee that no one is going to shoot at your car from a higher elevation.

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Originally Posted by Luke Bunyip View Post
Player suggested ripping the IC motor out, sticking some scavenged wheel hub EC motors, as well as a couple of motor car battery packs in the floor of the tray (the void between the chassis frame?). Recharged by deploying folding PV panels, and/or a trailer mounted gassifer/EC generator with a stash of charcoal.
As it just so happens, I am currently overly familiar with the performance characteristics of electric motors and PV panels for another project I'm working on. Best case is you're replacing a roughly 300 kW engine with roughly 200 kW motors that are running at 90% efficiency and you're getting equivalent performance because you're not taking transmission losses and that's super generous. So you need 220 kW of PV production, and modern panels under ideal conditions generate 0.25 kW per square meter - so 880 square meters of panels, roughly 30m x 30m if you want to operate continuously in daylight.

Charcoal has an energy density of 1.4 MJ/L, petroleum about 35 MJ/L. They've both got about the same specific gravity, or near enough. So for every 20L of petrol you had in the F-350's tank, you need to provide 500L of charcoal bunkerage to get the equivalent range, not counting the extra weight of 480L of charcoal (~360 kg if I'm doing the math right).

Gassifiers and charcoal engines are mostly renewable, while petroleum mostly isn't. If the choice was between a charcoal gassifer and walking or riding a horse, I'd go with the gassifier. But I'd be extremely loathe to rip out a perfectly functional petroleum engine and replace with anything else until I had completely exhausted the expected supply of petroleum in the reasonable scavenging area.
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Old 10-23-2018, 09:04 PM   #27
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Default Re: [AtE] Wasteland vehicle improvised weaponry

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Originally Posted by exalted View Post
One thing with armoring up a vehicle this way however is that I'd guess that some parts you really want to armor up like windows and especially radiators don't really work well if you do so and under extra strain I'm guessing heat will be a big problem. That's without going into all the problems the weight put on the body I guess breakdowns of a wide variation of drivetrain and suspension parts will be regular business.
F-350s are rated for nearly 10 tons gross vehicle weight and can tow another 6 tons at full load. Dropping a couple of tons of armor on it will cut into the cargo capacity but not affect the structure.

I wouldn't try up armoring a sedan in the same way - it takes nearly as much armor and most cars are not built to carry 4+ tons.

Armoring the radiator is a little tricky but airscoops are a possibility.
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Old 10-24-2018, 11:37 AM   #28
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Default Re: [AtE] Wasteland vehicle improvised weaponry

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Originally Posted by exalted View Post
Should gain quite a bit from it actually if only increasing dramatically the number of shots that glance off due to not archiving a decent impact angle. It should however be considerably more difficult to build and likely heavier when not able to design the vehicle from ground up for sloped armor. Might still be something for the front of some vehicles.
If the metal used for the armour is hardened, maybe. However, if it's not, then in my experience shooting rifles at steel plates, even highly sloped plates will get quite deep gouges put in them, deep enough that if the plate is thin it'll get penetrated.

Now, the slope will allow a thinner plate to stop a bullet than having it square on. However, sloping it also means you need more area of plate, and this cancels out. That leaves you relying on the odds of 'bouncing' bullets to give added protection, and in my experience without hardening it's not really a thing except at extreme angles.
Quote:
One thing with armoring up a vehicle this way however is that I'd guess that some parts you really want to armor up like windows and especially radiators don't really work well if you do so and under extra strain I'm guessing heat will be a big problem. That's without going into all the problems the weight put on the body I guess breakdowns of a wide variation of drivetrain and suspension parts will be regular business.
Louvres will work for the radiator, giving decent protection from most angles. However, the windows are an issue, and most improvised armoured cars and trucks end up with very thin vision slits, and hoping that nobody gets a lucky hit. Were I the driver I'd be wearing heavy goggles as well, in case of bits of bullet coming in from near-misses.

The added weight of armour on these vehicles was always a problem, as it increased wear and tear, increased fuel consumption, impaired speed and handling, and massive reduced the payload they could carry.
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Old 10-24-2018, 11:45 AM   #29
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Default Re: [AtE] Wasteland vehicle improvised weaponry

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Originally Posted by Luke Bunyip View Post
Common cartridges in the setting are 22LR, .223R, and .308/7.62x51mm.
So... what would be the thickest armour an aspiring road warrior would require to protect themselves against 7d pi?
If we assume 'protect' to mean the GURPS standard of 'stop the average damage roll', 7d requires DR24.

Assuming your standard mild steel, at DR56/inch (B558-559), this means about 0.43" (say 11mm) of plate. A half-inch plate (12.7mm) gives DR28 and is quite good protection from 7d, and near-complete protection from the 5d damage of .223/5.56mm rounds (or the 5d+1 of 7.62x39mm bullets).

As a rule of thumb, a plate one inch thick weighs 40 pounds per square foot - serious armour gets heavy very quickly.
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Old 10-24-2018, 11:56 AM   #30
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Default Re: [AtE] Wasteland vehicle improvised weaponry

I'm really amused at how some people want to make this sound impossible (that is, improvised vehicle armor) when people have been doing it effectively for about a century. The original Rolls Royce armored car was built on requisitioned Silver Ghost chassis, and was actually pretty awesome for the era. A number of others were similar. And, no, you don't end up with the equivalent of an MBT, but you do end up with better small arms and fragmentation protection, which does count for a lot. (Especially in an AtE setting where you're hardly going to encounter RPGs behind every bush.) So now, just as when we all posted links to Khyber Pass copies to refute the people who thought it was impossible to build a functioning firearm yourself, here we go:

The Kurds have made quite a few impressive examples recently.

Other interesting stuff has come out pf the Syrian Civil War, too. Some look suspiciously like an A7V, built on construction-machinery chassis. In the video you can see them obviously being used en mass with combined arms tactics.

Drug cartels are getting into the act as well.

The Poles in WWII.

If you have some organization you can make pretty decent examples, like the Soviets did in WWII in some besieged cities. Though, those were almost official types, frankly.

So don't think so much about bolting plates onto an F-350. Instead, think of stripping the entire body off of the F-350, leaving only the chassis and powertrain. Then you can get a lot more creative and effective in your armored body design, including incorporating some slope. Or even better use a 10-wheeled dump truck or Caterpillar D7 or D9 dozer instead of the F-350. For inspiration, look what the British and Serbians did with the Caterpillars. The Israeli D9R at the top is even more impressive, though again that was more of an official type standard.

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