Internal Structure

Equipment Overview Standard Structure  Equipment Type: Structure  Critical Slots: 0

Equipment Overview Endo-Steel Structure  Equipment Type: Structure  Critical Slots: 14

Overview

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The Internal Structure of a BattleMech forms the skeletal structure of the 'Mech to which all components are mounted.

Standard Internal Structure

The Standard Internal Structure of a 'Mech weighs 10% of its max. tonnage (i.e. on a 100 ton Atlas the internal structure weighs 10 tons).

It is the least bulky structure and does not take up any critical hit slots. It is also the least expensive and converting a 'Mech to it costs the 'Mechs maximum tonnage x 5,000 (on an Atlas, it would cost 500,000 ).

Endo-Steel Internal Structure

The Endo-Steel Internal Structure of a 'Mech weighs only 5% of its max. tonnage (i.e. on a 100 ton Atlas, it would only take up 5 tons), or half as much as Standard Internal Structure, but it requires 14 Critical Slots on Inner Sphere 'Mechs and 7 slots on Clan 'Mechs.

However, converting to Endo-Steel costs the 'Mechs max. tonnage x 10,000 (on an Atlas, it would cost 1,000,000 .

Internal Structure Health

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Depending on the 'Mechs tonnage, each of its locations has a certain amount of internal health, equal to 1/2 of the maximum amount of armor that can be mounted in that component. The one exception is the Head, which receives 18 internal hit points. (Note: The total health of the head component is somewhat disputed as some users claim to be able to "headshot" or "one-shot" 'Mechs with only a 35 point alpha strike. The maximum suggested here is 36, and could be less depending on the amount of armor allocated to the Head component.)

Number of equipable internal hit points with different 'Mech weights:

Tonnage	Internal Structure
'Mech	total	HD	RA + LA	RL + LL	RT	CT	LT
20	78	18	6	8	10	12	10
25	98	18	8	12	12	16	12
30	114	18	10	14	14	20	14
35	128	18	12	16	16	22	16
40	146	18	12	20	20	24	20
45	162	18	14	22	22	28	22
50	178	18	16	24	24	32	24
55	194	18	18	26	26	36	26
60	210	18	20	28	28	40	28
65	220	18	20	30	30	42	30
70	226	18	22	30	30	44	30
75	240	18	24	32	32	46	32
80	256	18	26	34	34	50	34
85	272	18	28	36	36	54	36
90	288	18	30	38	38	58	38
95	302	18	32	40	40	60	40
100	316	18	34	42	42	62	42

Note:

• Each arm and leg has the given amount of internal hit points.
• Each torso does not split internal hit points front/rear is they do for armor allocation.

Regarding Standard vs. Endo-Steel:

A 'Mechs maximum amount of internal health is independent of the type of internal structure equipped.

Different types of internal structure result in a different weight (tons) with equal health.

The trade-in for weight saving comes in the consumption of Critical Slots.

Taking Damage

When a battlemech's armour has been destroyed the battlemech starts to take damage to its internal structure, weapons systems and other equipment. When the internal structure of a battlemech's head, center torso or both legs are destroyed, the battlemech is destroyed. If an XL engine is fitted to the battlemech, the destruction of a side torso will also destroy the battlemech.

Savings

Compared to the weight saving of Armor, switching to an advanced internal structure provides a greater saving, i.e.:

Commando (25 t): Armor (Standard : Ferro Fibrous) 8.06 : 7.47 t vs. Structure (Standard : Endo Steel) 2.5 : 1.5 t = armor 0.59 t vs. structure 1 t

Cicada (40 t): Armor 12.56 : 11.65 t vs. structure 4 : 2 t = armor 0.91 t vs. structure 2 t

Hunchback or Centurion (50 t): Armor 15.57 : 14.44 t vs. structure 5 : 2.5 t = armor 1.13 t vs. structure 2.5 t

Cataphract (70 t): Armor 20.56 : 19.11 t vs. structure 7 : 3.5 t = armor 1.45 t vs. structure 3.5 t

Atlas (100 t): Armor 29.19 : 27.13 t vs. structure 10 : 5 t = armor 2.06 t vs. structure 5 t

Upgrading the Structure

To switch between Standard and Endo-Steel Internal Structure, use the Upgrades tab in the Mech Lab and choose structure.

• Switching to Endo-Steel requires that you have enough money and Critical Spaces available on your 'Mech.
• Switching to Standard Structure requires that you have enough money and tonnage available.