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Line Item Updates To VehicleMaker

I'm trying to point out specific changes to the VehicleMaker rules such that the outcomes match the other game rules in terms of expectations and have at least a passing familiarity with reality.

Thus: The base line submarine construction can not make a depth of 50m safely according to the dept rules on p253. Suggestion: Increase the armor on the sub slightly, which allows it to sink to that depth, and return to the surface.

The VehicleMaker rules allow building a vehicle with AV:90, but requires adding several layers of armor to do so. Hence difficult and expensive. This would allow a safe dive depth of 150m (depth 3).

The VehicleMaker rules do not allow building vehicles (at least according to my interpretation of the rules, which seems to be generally wrong) with AV:300. Thus, you can not build with VehicleMaker a submarine capable of making 500m depth safely.

I am simply reading the table as presented. If the values are wrong, please make better recommendations in the T5 09 Errata thread.

Where in Vehicle Maker are these covered? I have been spending a lot of time looking for them and not finding them.
 
Nope. I can't devise a motorcycle, either. Using Vehicle Extensions you could get it. But if you want to get one this way, I think we'd either need another vehicle classification, or shrink one of the existing ones.

I don't think shrinking one of the others is very useful but a new category of "Bike" can be used from muscle powered to grav.

Then we could get from the velocipede to the speeder-bikes of Star Wars.

[And then, think of Sons of Anarchy in the Far Far Future...]
 
Where in Vehicle Maker are these covered? I have been spending a lot of time looking for them and not finding them.

Depths table in 5.09 is on page 253. At the bottom of the table is a description of damage from pressure.

On the Watercraft and Enhancers table, the column titles "Armor" has the armor values (AV)

Armor values for subs are:
- Sub Type has Armor 20 as a base, 100 tons, 1,000 KCr
- Patrol mission gives x2 armor = 40
- VHeavy build gives x3 armor = 120, 300 tons, 9,000KCr
- Advanced design +20 armor = 140, -2 tons, 9,040KCr
- Alt Armored gives +60 armor = 200, +2 tons, 9,090KCr

That's as much armor as we can add. Unless you can add more armor by adding Alt Armored twice or more. But the rules are unclear on that subject.

Even with my suggestion to increase the base armor on submarines to 30 still won't allow Armor 300.
 
Depths table in 5.09 is on page 253. At the bottom of the table is a description of damage from pressure.

On the Watercraft and Enhancers table, the column titles "Armor" has the armor values (AV)

Armor values for subs are:
- Sub Type has Armor 20 as a base, 100 tons, 1,000 KCr
- Patrol mission gives x2 armor = 40
- VHeavy build gives x3 armor = 120, 300 tons, 9,000KCr
- Advanced design +20 armor = 140, -2 tons, 9,040KCr
- Alt Armored gives +60 armor = 200, +2 tons, 9,090KCr

That's as much armor as we can add. Unless you can add more armor by adding Alt Armored twice or more. But the rules are unclear on that subject.

Even with my suggestion to increase the base armor on submarines to 30 still won't allow Armor 300.

Thanks, Tjoneslo, I was starting to get the idea that was the case, but the added tonnage makes no sense at all for the Advanced and Alt Armor if you are talking about the pressure hull of a submarine. That is why I was not seeing it.

Back on page 640, there are the Armor equivalents for a variety of materials. An Armor of 20 for the sub with a Steel Hull would equate to a thickness of just under 3 millimeters of steel plate.

20 ÷ 70 X 10 millimeters = 2.86 millimeters of steel plate.

That, to put it simply, is totally ridiculous. NO, repeat NO, repeat NO sub is going to have a hull thickness of less 3 millimeters of steel. So, to begin with, throw that value out, and add the Armor values on page 640 to the discard without regret pile, and simply state, here is the hull thickness required to reach a given depth.

To reach a depth of 150 meters, and do not worry about hull damage, as this will be half of probable crush depth, your submarine needs a hull thickness of 0.875 inches or approximately 2.25 centimeters of high-tensile strength steel, either the vanadium alloy used in World War 2 or HY-65, and to be really safe, you could use HY-80 steel. Now, that is going to cost more than standard steel, for HY-65 you might get away with an extra 50% to cost. For HY-80, and allowing for the X-Raying of all welds, cost should go up by at least a factor of 3, but that would give you a really big safety factor. The vanadium alloy used in World War 2 was not significantly more expensive than the high-tensile strength steel that it replaced.

The reason that I say you need to toss the Armor Values and limits in Vehicle Maker is actual Armor thicknesses used.

Armor Thickness on front superstructure of German WW2 JagdTiger self-propelled anti-tank gun was 250 millimeters. So 25 centimeters X 70 (the armor value of 1 centimeter of steel) equals an Armor Value of 1750. That Armor value might be higher, as that may have been Face-Hardened Plate, which would add about 15% to the Armor value.

The Armor Thickness on the front plate of the British Churchill World War 2 Infantry Tank was 6 inches or 152 millimeters. That comes out to 1064 for Armor Value.

The Armor Thickness on the HMS Inflexible of 1880 was a sandwich of 24 inches of Wrought Iron Armor and 16 inches of Teak mounted on 1.5 inch Wrought Iron Hull Plating. So 61 centimeters of Armor Plate, 40 centimeters of Teak, and an additional 3.8 centimeters of hull plating formed the Belt Armor on the Ship. Multiplied out, 3050 for the Wrought Iron Plating, 160 for the Teak, and 190 for the hull plating adds up to an Armor Value of 3400.

Given that the Tank in Vehicle Maker starts with an Armor Value of 50, or less than 10 millimeters of Steel, it looks like the best you can do in Vehicle Maker is maybe 300 for Armor Value for the tank, or a thickness of 43 millimeters of plating.

For a ship, you start with an Armor Value for your hull of 10 for a 1000 Traveller dTon or 13,500 water displacement ton ship. That equates to 2 millimeters of Wrought Iron or 1.43 millimeters of Steel. A ship with that thickness of hull plating might not survive being built, and definitely will break up when launched, once you add the weight of the propulsion system. It looks like if you put everything on in additional armor that you can, you can get up to 180 for an Armor Value. That would give you a hull thickness of 36 millimeters of Wrought Iron Plate, or 25.7 millimeters of Steel Plate. Your ship will now not break up, and if properly framed and designed, should survive a North Atlantic Winter. It is by no stretch of the imagination an Armored Vessel, but one that meets current building standards for a commercial cargo ship.

One final comment on wooden ships. Wood is given an Armor Value of 4, so the hull thickness for a wooden ship would be 2.5 centimeters or about one inch of wood. That will work for small boats, like a rowing launch or a whale boat. For a larger, cargo or passenger carrying vessel, it will not work, and most definitely will not work for a 13,500 water displacement ton ship.
 
Something odd in the output of your VehicleMaker tool Rob; all the Military Vehicles end up with a decimal Speed that ends in .03


[EDIT] and actually while playing around with Endurance the above seems to be affecting it and giving an out put of: $speed x 17

Half fixed.
 
Armor Thickness on front superstructure of German WW2 JagdTiger self-propelled anti-tank gun was 250 millimeters. So 25 centimeters X 70 (the armor value of 1 centimeter of steel) equals an Armor Value of 1750. That Armor value might be higher, as that may have been Face-Hardened Plate, which would add about 15% to the Armor value.

From the game perspective when you start having Armor Numbers over 300 you run into two problems. The first is you need weapons that can do that sort of damage through, to break through the armor and destroy the tank.

GURPS "solved" this problem by letting weapon damages range as high as they wanted. So you would have weapons with damage ratings of "6Dx80" (roll 6D, multiply sum by 80). There is a similar set of rules on p. 672 called Many Dice.

This introduces the second problem, which I've seen called the "eggshell problem". GURPS, like T5, uses the armor stops all damage unless damage is greater than armor value. So the weapon above will either do no damage to the vehicle (and it's crew/passengers) or it will puree them. Neither of which adds to the drama of the combat situation.

I think there has been a deliberate effort on the part of Marc and the other T5 designers/playtesters not to have their armor/weapon damages exceed AV100 or 30D of damage, and it may be lower than that.

If you accept that as a starting point, the linear interpretation of AV to mm of armor (e.g. AV1 = 2.8mm steel, so AV10 = 28mm of steel) is wrong. It really needs to be a log scaled thing, where each x2 to Armor is a 10x to thickness. Or some such relationship.

I think the pressure damages need to be rethought significantly anyways. Pressure at 50m is 5D, which implies unprotected humans (e.g. scuba divers) can't reach 50m either. Which is also bogus and wrong.
 
From the game perspective when you start having Armor Numbers over 300 you run into two problems. The first is you need weapons that can do that sort of damage through, to break through the armor and destroy the tank.

GURPS "solved" this problem by letting weapon damages range as high as they wanted. So you would have weapons with damage ratings of "6Dx80" (roll 6D, multiply sum by 80). There is a similar set of rules on p. 672 called Many Dice.

I do not have GURPS, so I have no idea as to what that does. I have played miniatures, with AP tables for armor and guns, but also hit location as well. If you hit the tracks/suspension, the tank no longer moves and is a nice stationary target. If you hit the engine compartment and penetrate, normally not that difficult, the tank catches fire and the crew exits in a bit of a hurry. Neither require weapons capable of penetrating the front armor, but I guess I fail to see the problem. If the players are basically playing a miniature armor warfare game, use those type of rules. I know that is what I would do. I would not bother with the overly complex combat rules of Traveller. If needed, I will get out my Ogre rules for the Grav Vehicles.

They did have the heavy weapons in MegaTraveller, and do have them in Mongoose.

This introduces the second problem, which I've seen called the "eggshell problem". GURPS, like T5, uses the armor stops all damage unless damage is greater than armor value. So the weapon above will either do no damage to the vehicle (and it's crew/passengers) or it will puree them. Neither of which adds to the drama of the combat situation.

See above comment. I fail to see the issue. You want to play in a tank, you deal with the problems that being in one has. It is like the game is bending over backward to avoid killing the player's character. What is the drama in knowing that you are never going to die?

I think there has been a deliberate effort on the part of Marc and the other T5 designers/playtesters not to have their armor/weapon damages exceed AV100 or 30D of damage, and it may be lower than that.

I take it that they do not want to inflict severe harm on the player's characters. One reason why I have players run more than one character is that if one of the characters is killed, he/she can keep playing. Plus it cuts down on the number of NPC that I have to role-play. I have never had an NPC run by me take out one of the player's characters, but I have come close a couple of times.

If you accept that as a starting point, the linear interpretation of AV to mm of armor (e.g. AV1 = 2.8mm steel, so AV10 = 28mm of steel) is wrong. It really needs to be a log scaled thing, where each x2 to Armor is a 10x to thickness. Or some such relationship.

I thought that you were looking to keep some semblance of reality to the game.

I think the pressure damages need to be rethought significantly anyways. Pressure at 50m is 5D, which implies unprotected humans (e.g. scuba divers) can't reach 50m either. Which is also bogus and wrong.

Actually, given the new gas mixtures, you have divers going to 150 meters fairly regularly.
 
Problem with Beast Power and Speed

I will give you another headache, this time with the Beast Power chart in Vehicle Maker.

I put the Paul R. Tregurtha, currently the largest bulk carrier on the Great Lakes through it just for the Beast Power needed. The Tregurtha is 308.91 meters long, with a beam of 32 meters, and a depth of hull of 17.07 meters. I am not including the volume of the crew superstructure aft, figuring that not counting that compensates for the taper of the bow and stern, as the rest of the hull is a long rectangle. Multiplying that out gives me a volume of 168,738.8 cubic meters, and then dividing by 13.5 cubic meters to get to Traveller dTons, I get 12,499.185 Traveller Tons, so call it 12,500. Her top speed is 25 kilometers per hour. As Beast Power is Tons X Speed(Cubed), that would give me 12,500 X 3.5(Cubed), or 535,937.5 Beast Power to move the ship at 25 kilometers per hour. I used 3.5 as 25 kilometers is halfway between 3 and 4. The actual horsepower needed is 2 Diesel engines supplying 16,080 Horsepower.

The problem is that for ships, what is critical is the velocity of the ship compared to its length. The ratio used is Velocity in Knots divided by the Square Root of the Length in feet, V/L(0.5). The Tregurtha is a 1,000 feet long, so the square root is 31.62, and the top speed in knots is 13.5. So her speed-length ratio is is 0.4269. Anything under 0.5 indicates a very moderate and economical speed, so less required horsepower. The closer the speed-length ratio is to 1, the greater the horsepower needed, with the power curve bending up very sharply if you go beyond a speed-length ratio of 1.

For a more detailed discussion of this subject, I would suggest anyone interested read Chapter 21 in the following work from archives.org.

https://archive.org/details/warships00attwrich

You would have precisely the same problem if you could build railroad trains, given that some are easily a kilometer or so long, traveling at 100 kilometers an hour.
 
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Neither require weapons capable of penetrating the front armor, but I guess I fail to see the problem. If the players are basically playing a miniature armor warfare game, use those type of rules. I know that is what I would do. I would not bother with the overly complex combat rules of Traveller. If needed, I will get out my Ogre rules for the Grav Vehicles.

The problem is we have a personal level (and scale) combat system which needs to include some vehicles. You are correct, if the referee and players want to run a complete vehicle combat, there are better rules for doing so.

The pain of this is the designers have been willing to sacrifice every level of mapping to reality to make the build process simple and integration with the combat system easy. While keeping it a personal combat system and not a vehicle level one.
 
I think the pressure damages need to be rethought significantly anyways. Pressure at 50m is 5D, which implies unprotected humans (e.g. scuba divers) can't reach 50m either. Which is also bogus and wrong.

Please add that to the errata.
 
I've started testing updates to the Stage, Option, and Environmental descriptors in my online code. I created an experimental directory and put them there. Having little to go on I based changes on basic vehicles, and converted volume and cost changes to percentages instead of flat changes.

I suspect the same sort of thing will happen with armor and load as well, but for now I'm looking at the other two data.

The code is here:

http://eaglestone.pocketempires.com/vehicles-experimental/omni_vehicle_maker.html
 
I've started testing updates to the Stage, Option, and Environmental descriptors in my online code. I created an experimental directory and put them there. Having little to go on I based changes on basic vehicles, and converted volume and cost changes to percentages instead of flat changes.

I suspect the same sort of thing will happen with armor and load as well, but for now I'm looking at the other two data.

The code is here:

http://eaglestone.pocketempires.com/vehicles-experimental/omni_vehicle_maker.html

Is this a replacement for Vehicle Maker or simply your own version?
 
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