Total mech tonnage - calculation

[MasterBLB]

Hi fellow MechModders

I'm continuing developing my Mech Designer, and I've encountered something I'd like to ask you about.
How total mech weight is calculated? Based on example of Hunchback 4P, it is:
"InitialTonnage": 18.5 from chassis_def*.json
+ stock armor weight (MechStatisticsConstants.json, where there is "ARMOR_PER_STEP" and "TONNAGE_PER_ARMOR_POINT", as well as several allocationratio entries)
+ stock stuff weight (there it is easy, each item has "tonnage" entry in .json)
= should be 50t
Am I right?

 

[Hopalong]

That sounds right for the PC game, the 31.5 is what we the players customize a Mech with. The PC game tends to ignore all the tabletop stuff “inside” of a Mech.

Here is a stock TT HBK-4P:

Type/Model:    Hunchback HBK-4P
Mass:          50 tons

Equipment:                                 Crits    Mass
Int. Struct.:  83 pts Standard               0      5.00
Engine:        200 Fusion                    6      8.50
   Walking MP:   4
   Running MP:   6
   Jumping MP:   0
Heat Sinks:     23 Single                   15     13.00
 (Heat Sink Loc: 7 LT, 2 RT, 2 CT, 2 LL, 2 RL)
Gyro:                                        4      2.00
Cockpit, Life Supt., Sensors:                5      3.00
Actuators: L: Sh+UA+LA+H    R: Sh+UA+LA+H   16       .00
Armor Factor:  160 pts Standard              0     10.00

                          Internal    Armor
                          Structure   Value
   Head:                      3          9 
   Center Torso:             16         26 
   Center Torso (Rear):                  5 
   L/R Side Torso:           12      20/20 
   L/R Side Torso (Rear):              4/4 
   L/R Arm:                   8      16/16 
   L/R Leg:                  12      20/20 

Weapons and Equipment    Loc  Heat  Ammo   Crits    Mass
--------------------------------------------------------
6 Medium Lasers          RT     18           6      6.00
1 Medium Laser           RA      3           1      1.00
1 Medium Laser           LA      3           1      1.00
1 Small Laser            HD      1           1       .50
--------------------------------------------------------
TOTALS:                         25          55     50.00
Crits & Tons Left:                          23       .00

And the TT HBK-4P without armor, HS, weapons:

Type/Model:    Hunchback HBK-4P
Mass:          50 tons

Equipment:                                 Crits    Mass
Int. Struct.:  83 pts Standard               0      5.00
Engine:        200 Fusion                    6      8.50
   Walking MP:   4
   Running MP:   6
   Jumping MP:   0
Heat Sinks:     10 Single                    2       .00
 (Heat Sink Loc: 2 CT)
Gyro:                                        4      2.00
Cockpit, Life Supt., Sensors:                5      3.00
Actuators: L: Sh+UA+LA+H    R: Sh+UA+LA+H   16       .00
Armor Factor:    0 pts Standard              0       .00

                          Internal    Armor
                          Structure   Value
   Head:                      3          0 
   Center Torso:             16          0 
   Center Torso (Rear):                  0 
   L/R Side Torso:           12        0/0 
   L/R Side Torso (Rear):              0/0 
   L/R Arm:                   8        0/0 
   L/R Leg:                  12        0/0 

Weapons and Equipment    Loc  Heat  Ammo   Crits    Mass
--------------------------------------------------------
--------------------------------------------------------
TOTALS:                          0          33     18.50
Crits & Tons Left:                          45     31.50

 

[MasterBLB]

Thank you very much, seems that's it what I needed.

 

[Hopalong]

Just a FYI, I can think of 7 Mechs where the tonnage “doesn’t add up”:

The 4 SL Mechs in the game, they have a artificial lower "InitialTonnage" so that the HBS Devs could add heat sinks to them.

The mechdef_panther1b_PNT-9R and mechdef_shadowhawk1b_SHD-2D have missing jump jets, so they are underweight.

The UrbanMech got a speed boost and didn’t have to pay any tonnage for a larger engine.

 

[MasterBLB]

Looks like all is fine, at least for Battletech the game standards: