You are Alfred(Phrédo)Robrtson, an elictrical engineer who helped to construct the Aperture power-grid as well as wire GLaDOS into it. Kept on-site in case of emergency you were forgotten by the now deceased employees as well as GLaDOS*. You are woken up by your containment unit in its final moments of back-up battery life and you alone explore and escape while finding clues piece by piece about the past and present of Aperture Science. You are the Escapist.
Texture is a test, it'll be more Aperture-like soon. That's also not where it goes.
Black Mesa in Aperture Science...
That those look a lot like a black mesa rail train...
Why would aperture Science use rail train? They have stable portals... A whole bunch a multifunction "there's nothing it doesn't do" transport tubes...
Though I'm not against a crowbar a tool... And maybe the little device of Alyx (the device she use for opening doors...) It would fit for a technician...
In all honesty, I wouldn't go to work each day with a device being tested in the research facility. Especially with the warnings GLaDOS reads to you. The aperture train will be re-textured though to look more like it belongs, and the crowbar skin will be changed too. Also, you will use more than the portal gun but no one tool will be the most useful.