I have a top bar hive, and it is set up similar to many "Long" hives; That is, it is the size of three Langstroth deep bodies set side by side.  The enterances to my hive are on one of the short ends, and the bees like to keep the brood nest within a frame or two of the end with the enterance.
When Harvesting honey, I slide the telescoping lid forward, exposing the frames at the "back" of the hive, and smoke them lightly.  If it is cool, thre are few bees in the back of the hive.  This job is best done very early in the morning, when it is cool, or at other times when you are less likely to be mobbed by robbing bees.   As I lift individual full combs out of the hive, I brush the bees off with a standard nylon brush, and then place the combs in a covered container.  With a TBH, a twist of the wrist breaks the combs off into a bucket or pan, but if you have standard frames, you will want to have an empty hive body or box to place them in.
The removed combs are replaced with empty combs or top bars, and the hive is closed up again.  The bees in the brood nest are not disturbed, and I have harvested honey on a cool day in autumn without using any brush, smoke or chemicals whatsoever.  When the bees are clustered snugly up in the brood nest, they are reluctant to move- if you move gently, you will scarcely disturb them at all.
I know of no plans for long hives on the net, but James Satterfields Top Bar Hive website has lots of Plans for long TBH's.  If you want to do a langstroth version, just find a plan for a langstroth hive body, and triple the length of the ends where the frames rest.  These become the side panels of a long hive.  If you calculate your dimensions right, you can just use three standard inner lids laid side by side, but I do recommend making one big telescoping cover so that it is as weathertight as possible.  (It cost me about $40 to have my giant plywood lid covered with sheet metal, but it looks really nice!)  You can just slide the telescoping cover back from the front, remove the first inner cover, and place supers over the brood nest area if you really want to make comb honey in rounds or casettes or something.  (A brick or two keeps the lid from tipping, and the slant actually runs rainwater away from where the lid is butted up aginst the super.)
I have been using a set up similar to this to allow my TBH to clean up hive scrapings and cappings for me this summer.  I slid back the lid as descibed above, placed a queen excluder over the notched top bars to act as a shelf, and covered it with an old hive body and lid.  All my scrapings and stuff go into this to get cleaned up- by my next visit the wax is clean and ready for the melter, and I have avoided robbing problems. (And have a lot fewer ants in my solar wax melter!)   An old dish pan of cappings set in the empty "Back" of the TBH is also quickly cleaned up by the bees with no muss or fuss- and it's easier to get the dry wax out of the dishpan than to scrape it off of a queen excluder!
Using this hive as "Clean up Crew" has saved me quite a bit of mess, stickiness, and robbing problems this year!
Ellen in Michigan
  waldig <[log in to unmask]> wrote: Ahlert,

Would you know if there are photos of this design on the web ? This system
makes a lot of sense. My only question is: since there are no honey supers
in this setup, how do you remove the frames for extracting honey ?