Steve,

make sure to arrive at the airport on time after the busy day, otherwise they could rebook you on KLM

Serious though, the lounges at FRA are normally pretty smoky and a seat is tough to get at certain times ( comparable to KLM at Schiphol early morning )

Based on that the shower list can be pretty full as well, make sure to contact housekeeping at the entrance of the bathroom and write down your name in the appropiate list.You will be called by the lounge agents, if it is your turn, like at Schiphol.

Showers at FRA are lala, but still in better shape than at AMS and more important you will have warm water.Next time make sure to fly via MUC, the Senator showers there are really awesome, maybe somebody can post a link to a picture, but I was really impressed the first time there.

Here is a terminal map of FRA, however I never flew into FRA from the UK or to HKG, so I can only assume which gates will be used.
There is a SEN lounge in the non Schengen part of the A concourse ( close to A 51 ) , which is small and another one close to the security check in the B concourse.You are likely to arrive in the non Schengen part of the A concourse, if your flight gets a terminal position and no bus gate.

Be aware that there is also a United Red Carpet Club, close to the C concourse of T1, this club is open until 10 p.m. , but is deserted after all guests for th last UAL flight to the US leave after 4.30 !! Food selection is inferior to the LH Sen lounges, but you have much more space there at certain times !!

http://www.frankfurt-airport.de/cms/...sichtsplan.htm