they can lay people off in seniority order, before they lay people off, they start at the top and work there way threw seniority asking if anyone wants to leave. Can't you request to leave in your seniority order? meaning if someone with less seniority leaves before you, don't you have the right to take there place, and go instead of with less seniority.
I already know what your Sup. will say when you pose that question to him. he's going to say" but your the only person trained to do it." your respones should be "it's not my job to have have someone else trained to do my job. thats your job. what if i called in sick, or was unable to work that day what would you do?"