The Marathon Internal Engineering Documents are a set of documentation about the UESC Marathon. Below is an excerpt. == Section 1-c appendix H == Subject: Doors By: Estasia Orestes, Dominick I. Plackar, and Ursa Simbalzi Date:<2402.03.23.16.42> There are five basic door designs to be used on the Marathon: 1. Outer Bulkhead Doors 2. Airlock Doors 3. Inner Bulkhead Doors 4. Tertiary or Inner Sealed Non-Vacuum Safe Doors 5. Quaternary or Inner Powered Automatic Opening Doors Direct control of all doors except the Tertiary and Quaternary doors will be given to Durandal with indirect control of all other doors going to Durandal. The difference between direct and indirect control primarily has to do with the manner of opening the doors. Durandal will only open a directly controlled door when h