No, typically crematories do not perform two cremations simultaneously in the same cremation chamber. There are several reasons for this:

1. Identification and Integrity: The foremost reason is to ensure the integrity and proper identification of the remains. Mixing remains would be ethically and morally problematic and could lead to significant distress for families.

2. Equipment Design: Cremation chambers (also known as retorts) are designed to accommodate one body at a time. Combusting more than one body simultaneously could lead to operational challenges and might not allow for complete and efficient cremation of both bodies.

3. Legal Regulations: In many jurisdictions, legal regulations prohibit the cremation of more than one body at a time in the same chamber to ensure the accurate return of remains to the respective families.

4. Religious and Cultural Sensitivities: Many religious and cultural practices have specific rituals and beliefs related to death and cremation. Simultaneous cremation could go against these beliefs and customs.

However, there are some exceptions, mainly related to the cremation of very small remains:

1. Infants and Parents: In some cases, especially the tragic scenario where both an infant and a parent pass away, some crematories might allow for simultaneous cremation if the family requests it and if it's legally permissible.

2. Multiple Infants: Some crematories may have specialized equipment to accommodate the cremation of multiple infants simultaneously, but this would be under specific conditions and with the families' explicit consent.

3. Pets and Owners: There are occasional stories of owners wishing to be cremated with their beloved pets. However, the majority of jurisdictions have regulations against the co-cremation of humans and animals. If this is a desire, it's essential to discuss it with the funeral director or crematory to understand the legal and logistical implications.

In any case where simultaneous cremation might be considered, it's crucial to ensure transparency, consent from all involved parties, and adherence to any applicable laws and regulations.