An offlink is different from regular . Andaman never got P7 as regular link for your info. I have seen Andaman many times. It came with P5 recently , LGD P7 and RPM P7 but they are very very rare. RPM WAP4/ RPM WAP1 is the link for that train. Apart from GT , none other long distance train got nominated from RPM to get P7 link. Initially RPM WAP7 was regularised with TN express for a while later it was discontinued.