Author Topic: Design request: minimalist rocket truck  (Read 4683 times)

Siegfried Marcus

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Design request: minimalist rocket truck
« on: 09 April 2017, 12:57:05 »
I have an Excel sheet, but I don't quite trust it.  Does someone want to design me a C-tech truck around 2-5 tons?  I want it to go at least 6/9 and have minimal crew (no more than 3).  It needs to be armed with rockets, basic fire control would be nice, armor is optional. 
Here is my AU story set in the Free Rasalhague Republic.
http://bg.battletech.com/forums/index.php?topic=52953.0

Daryk

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Re: Design request: minimalist rocket truck
« Reply #1 on: 09 April 2017, 13:11:59 »
6/9?  Here's a turbocharged version from Foxhaven Motors:

Code: [Select]
Fast Rocket Truck
3,000 Total
  621 kg Chassis (Wheeled, Off-Road, TL C)
  600 kg Engine (ICE, 6/9)
  225 kg Seats (3 Crew: Driver/Gunners)
  280 kg Armor (7 points of TL C BAR 5, 2/2/2/1)
1,000 kg 2 RL-10s
   50 kg Basic Fire Control (+1 to hit)
  104 kg Cargo
  120 kg Fuel (2,000 km range)

gomiville

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Re: Design request: minimalist rocket truck
« Reply #2 on: 09 April 2017, 14:53:42 »
You didn't specify how many rockets you wanted it to carry, so...

The smallest I could make is this:
Code: [Select]
1350kg Small Wheeled SV, Tech C
Chassis (Tech C, Off-Road): 280kg
Engine (6/9, Tech C ICE): 270kg
Fuel (1050km range): 29kg
Armor (6pts Tech C BAR 2, 3/1/1): 96kg
Crew (1 driver, 1 gunner, basic seats): 150kg
Basic Fire Control: 25kg
RL10 (Front): 500kg
Cost: 18,564cb

Scaling up slightly, we have:
Code: [Select]
2300kg Small Wheeled SV, Tech C
Chassis (Tech C, Off-Road): 477kg
Engine (6/9, Tech C ICE): 460kg
Fuel (750km range): 35kg
Armor (8pts Tech C BAR 2, 2/2/2): 128kg
Crew (1 driver, 1 gunner, basic seats): 150kg
Basic Fire Control: 50kg
2xRL10 (Front): 1000kg (changing this to an RL15 is the same mass and cost)
Cost: 36,243cb

Next up is this:
Code: [Select]
3400kg Small Wheeled SV, Tech C
Chassis (Tech C, Off-Road): 704kg
Engine (6/9, Tech C ICE): 680kg
Fuel (750km range): 51kg
Armor (10pts Tech C BAR 3, 4/2/2): 240kg
Crew (1 driver, 1 gunner, basic seats): 150kg
Basic Fire Control: 75kg
3xRL10 (Front): 1500kg (changing this to an RL20 is the same mass and cost)
Cost: 54,879cb

And, at the top end is this:
Code: [Select]
4650kg Small Wheeled SV, Tech C
Chassis (Tech C, Off-Road): 963kg
Engine (6/9, Tech C ICE): 930kg
Fuel (970km range): 91kg
Armor (13pts Tech C BAR 4, 4/3/3): 416kg
Crew (1 driver, 1 gunner, basic seats): 150kg
Basic Fire Control: 100kg
4xRL10 (Front): 2000kg (changing this to 2xRL15 is the same mass and cost)
Cost: 74,379cb

That's the smallest possible with each weapon configuration with maximum armor for that mass, and using fuel to soak up all extra mass (because cargo would take up space).  The heaviest design maxes out the possible spaces for the vehicle size, so it can't carry cargo (which would take up more space). 

And you can't fit another RL10 in, even if you up the mass and lower fuel and armor.  Small support vehicles have only 5 spaces, and seating for the crew takes up one space, so that's 4 spaces for weapons/equipment/cargo.  Each RL10 is one space, so that's 4xRL10, max.

By the way, if you wanted it tracked, for that halftrack/crawler kind of feel, the speed requirements really start to hurt:
Code: [Select]
4900kg Small Tracked SV, Tech C
Chassis (Tech C): 733kg
Engine (6/9, Tech C ICE): 2352kg
Fuel (845km range): 199kg
Armor (13pts Tech C BAR 4, 4/3/3): 416kg
Crew (1 driver, 1 gunner, basic seats): 150kg
Basic Fire Control: 50kg
2xRL10 (Front): 1000kg (changing this to an RL15 is the same mass and cost)
Cost: 47,635cb
« Last Edit: 09 April 2017, 14:59:49 by gomiville »

Daryk

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Re: Design request: minimalist rocket truck
« Reply #3 on: 09 April 2017, 15:04:24 »
I think the max armor for 1 ton vehicles is 5 points, 6 for 2 tons, and 7 for tons (the table says round down).  Also, unless I'm reading it wrong, each weapon requires a gunner, which is why I limited mine to two RL-10s (he wanted no more than three crew).

gomiville

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Re: Design request: minimalist rocket truck
« Reply #4 on: 09 April 2017, 15:23:46 »
I think the max armor for 1 ton vehicles is 5 points, 6 for 2 tons, and 7 for tons (the table says round down).
Max armor factor is 4+2 per ton, round down.  So, a 4.999t truck can have 13pts.  That's 4.999*2 = 9.998, round down to 9, plus 4, is 13.

Quote
Also, unless I'm reading it wrong, each weapon requires a gunner, which is why I limited mine to two RL-10s (he wanted no more than three crew).
Yea, you have a point about that.  I was adding the total weapon mass together, then dividing it by 3 for basic fire control.  By that interpretation, that's up to 3 tons of weapon for each gunner. (I prefer this interpretation.)

However, it does say "per heavy weapon" at the start of that line.  So, for a 0.5t weapon, that's 0.1667 gunners needed, per weapon, rounded up to 1 gunner per weapon.  (Which seems stupid to me, for things like rocket racks, where the gunner is basically just targeting and pushing a button, as opposed to cannons or rifles, which require reloading and such.  Having two rocket racks or one, the weapon operations requirements shouldn't really double, when they're all slaved to fire at the same target.  These crew requirements are like the space requirements for artillery and such, penalizing armed support vehicles.)

So, my heaviest version would be two RL15:
Code: [Select]
4750kg Small Wheeled SV, Tech C
Chassis (Tech C, Off-Road): 984kg
Engine (6/9, Tech C ICE): 950kg
Fuel (780km range): 75kg
Armor (13pts Tech C BAR 4, 4/3/3): 416kg
Crew (1 driver, 2 gunner, basic seats): 225kg
Basic Fire Control: 100kg
2xRL15 (Front): 2000kg
Cost: 74,685cb

A dual RL10 version would be:
Code: [Select]
2600kg Small Wheeled SV, Tech C
Chassis (Tech C, Off-Road): 539kg
Engine (6/9, Tech C ICE): 520kg
Fuel (950km range): 50kg
Armor (9pts Tech C BAR 3, 3/2/2): 216kg
Crew (1 driver, 2 gunner, basic seats): 225kg
Basic Fire Control: 50kg
2xRL10 (Front): 1000kg
Cost: 37,397cb

The single RL10 version I posted above would still work with only one gunner.

A slightly adjusted tracked version would be:
Code: [Select]
4900kg Small Tracked SV, Tech C
Chassis (Tech C): 733kg
Engine (6/9, Tech C ICE): 2352kg
Fuel (525km range): 124kg
Armor (13pts Tech C BAR 4, 4/3/3): 416kg
Crew (1 driver, 2 gunner, basic seats): 225kg
Basic Fire Control: 50kg
2xRL10 (Front): 1000kg
Cost: 47,740cb
« Last Edit: 09 April 2017, 15:37:05 by gomiville »

Daryk

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Re: Design request: minimalist rocket truck
« Reply #5 on: 09 April 2017, 15:35:21 »
That's what I get for reading tables on insufficient sleep... :P

I think the point of the gunner rules is to drive you to use proper combat vehicles.  I'm also not fond of how they're written, but I think we're reading it right.

gomiville

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Re: Design request: minimalist rocket truck
« Reply #6 on: 09 April 2017, 15:42:12 »
Wait, hang on, just looked in the errata.

Quote
Medium/Heavy: Total Weapon Tonnage ÷ 2† Total Weapon Tonnage ÷ 3† Total Weapon Tonnage ÷ 4†/††
Single dagger is "Round up" and double dagger is "Tech E Chassis SVs use Tonnage ÷ 5; Tech F Chassis SVs use Tonnage ÷ 6 to determine gunners."

So, according to that, it's not per weapon, but all weapons, added together, then divided by 3 for basic fire control.  Back to 1 gunner for up to 3 tons of weapons.

My first proposals all work.

Daryk

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Re: Design request: minimalist rocket truck
« Reply #7 on: 09 April 2017, 15:53:01 »
Cool... glad to know it got fixed.  I don't normally do Support Vehicles, so I'm not surprised to not be getting this right...

gomiville

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Re: Design request: minimalist rocket truck
« Reply #8 on: 09 April 2017, 15:56:11 »
Cool... glad to know it got fixed.  I don't normally do Support Vehicles, so I'm not surprised to not be getting this right...
I built a massive spreadsheet for this, a while back, so I probably researched it at some point, to get the values right.  Don't remember.

Daryk

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Re: Design request: minimalist rocket truck
« Reply #9 on: 09 April 2017, 16:13:07 »
Yours might be the spreadsheet I dimly remember seeing back in the day.  Either way, I've updated the SVs for Liam's thread too.  Thanks again!

Speaking of which, there's still room for a few more Baronies...

Siegfried Marcus

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Re: Design request: minimalist rocket truck
« Reply #10 on: 09 April 2017, 17:00:16 »
Thanks guys.  The gunnery crew was exactly what I was worried about.  The 40 rocket version is the clear winner in terms of lives risked/payload.  The 20 rocket version is nice too because it means the enemy has to hit two trucks to take out the same number of rockets.  Just for fun I made a combat vehicle version in SAW.  It's c-bill price is only slightly higher, but I like to imagine that level C tech makes the support version much more attainable.  Follow up, what's the fastest <5 ton truck we can get with 20 rockets?
Here is my AU story set in the Free Rasalhague Republic.
http://bg.battletech.com/forums/index.php?topic=52953.0

Daryk

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Re: Design request: minimalist rocket truck
« Reply #11 on: 09 April 2017, 17:13:43 »
Hmmm... Fastest with 2 RL-10s...

Fixed tonnage:
RL-10s: 1,000 kg
Fire Control (Basic): 50 kg
Seats: 150 kg
Armor: 64 kg (4 points BAR 2 TL C)

First guess at 3,000 kg:
621 kg Chassis
yields 8/12

Second guess at 4,999:
1,035 kg chassis
yields 10/15

Detailed 4,999 version:
Code: [Select]
1,035 kg chassis
2,600 kg engine (10/15, TL C ICE)
   150 kg crew seating
    50 kg Basic Fire Control
1,000 kg 2 RL-10s
    64 kg 4 points TL C BAR 2 armor
  100 kg fuel (385 km range, not much)

gomiville

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Re: Design request: minimalist rocket truck
« Reply #12 on: 09 April 2017, 17:36:50 »
Something just under 5t moving 10/15 is the best I can come up with too.  I might tweak the armor and fuel values, but basically the same thing.

If you switch to a fuel cell, you can get it up to 13/20, at the expense of logistics.

Siegfried Marcus

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Re: Design request: minimalist rocket truck
« Reply #13 on: 09 April 2017, 18:12:09 »
It would probably be more practical to drop to 9/14.  That's a 2,125 kg engine by my numbers.  That saves 475 kg, which is almost enough for another RL10.  If it's for city defense, one could probably accept even shorter range.  I think I would stick with 20 rockets and improve range and armor.  I want it to be able to make a wide sweep around a flank and come cruising in (no psr, better to hit) at 97 km/h to deliver its strike.
Here is my AU story set in the Free Rasalhague Republic.
http://bg.battletech.com/forums/index.php?topic=52953.0

gomiville

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Re: Design request: minimalist rocket truck
« Reply #14 on: 09 April 2017, 22:03:41 »
Like this?
Code: [Select]
4500kg Small Wheeled SV, Tech C
Chassis (Tech C, Off-Road): 932kg
Engine (9/14, Tech C ICE): 1913kg
Fuel (745km range): 143kg
Armor (13pts Tech C BAR 3, 4/3/3): 312kg
Crew (1 driver, 1 gunner, basic seats): 150kg
Basic Fire Control: 50kg
2xRL10 (Front): 1000kg (changing this to an RL15 is the same mass and cost)
Cost: 46,382cb

Or, since I've been doing all of mine with the Offroad chassis mod, you could drop that for the extra RL, for a little extra mass:
Code: [Select]
4900kg Small Wheeled SV, Tech C
Chassis (Tech C,): 677kg
Engine (9/14, Tech C ICE): 2083kg
Fuel (490km range): 103kg
Armor (13pts Tech C BAR 3, 4/3/3): 312kg
Crew (1 driver, 1 gunner, basic seats): 150kg
Basic Fire Control: 75kg
3xRL10 (Front): 1500kg (changing this to an RL20 is the same mass and cost)
Cost: 60,615cb
« Last Edit: 09 April 2017, 22:07:39 by gomiville »