铜

copper (chemistry) / see also 紅銅|红铜[hong2 tong2] / CL:塊|块[kuai4]

铜 = 同 + 钅 : Tommy Turtle (tu) runs a copper (铜) mine in the engine's kitchen ((e)ng2). He managed to force two twins (同) to work for him and mine the copper using golden harpoons (钅).

铜 character breakdown

铜
- 同
  - 冂
    - 丨
    - ㇆
      - 一
      - 亅
  - 𠮛
    - 一
    - 口
- 钅

同

tóng = tu + (e)ng2

like / same / similar / together / alike / with

同 = 冂 + 𠮛 : Tommy Turtle (tu) is stapling (冂) a magical scroll (𠮛) to the wall of the engine's kitchen ((e)ng2). On it he wrote that he's looking for two twins (mnemonic symbol for 同).

同

衕

tòng = tu + (e)ng4

see 衚衕|胡同[hu2 tong4]

钅

Character component without intrinsic meaning

Mnemonic symbol: a golden harpoon.