# Relationship history for MSHA mine 4800155

Current hierarchy: **Tata Chemicals Ltd → Tata Chemicals Soda Ash Partners LLC → Tata Chemicals Mine**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** General Chemical Corp → Tata Chemicals Mine; 1950-01-01 to 1989-06-30; source msha-controller-operator-history
- **controller_controls_mine:** Allied-Signal Inc → Tata Chemicals Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Allied-Signal Inc → General Chemical Corp; 1950-01-01 to 1989-06-30; source msha-controller-operator-history
- **operator_operates_mine:** Tata Chemicals Soda Ash Partners LLC → Tata Chemicals Mine; 1989-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** General Chemical  et al → Tata Chemicals Mine; 1989-07-01 to 2008-03-31; source msha-controller-operator-history
- **controller_controls_operator:** General Chemical  et al → Tata Chemicals Soda Ash Partners LLC; 1989-07-01 to 2008-03-31; source msha-controller-operator-history
- **controller_controls_operator:** Andover Group  et al → Tata Chemicals Soda Ash Partners LLC; 1989-07-01 to 2008-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Tata Chemicals Ltd → Tata Chemicals Mine; 2008-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Tata Chemicals Ltd → Tata Chemicals Soda Ash Partners LLC; 2008-04-01 to current/open; source msha-controller-operator-history