I am flying SQ into LHR T3 in Y, and then I have a long layover before departing T1 on UA in Biz class. From any research I can find, there really isn't a good "arrivals" option for *A into T3 in Y class, even if you are *G or 1K. I'm thinking of transferring to T1 after arrival in T3, leaving my bags for the day at the small T1 bag keep near the entrance of the arrivals lounge in T1, and spending 5 or 6 hours in London via Heathrow Express. I have a 10 hour layover lol. The ? is, can I get into the T1 arrivals lounge on a DEPARTING biz class ticket?(since I'm arriving on SQ in Y)-- OR is it better to just go back through security after i pick up my bags from the day bag check and then I would use the Star Alliance lounge in T1 past security AFTER I've been in London all day....does the *A lounge have showers? Any thoughts? I've researched a bunch and broken it down to that...any help/experience appreciated.