I had the occassion to experiment with a number of TBH designs as a Peace 
Corps Volunteer in Paraguay.  In my experience, there was no discernable 
difference in the amount of comb attatchment to hive walls that were 
vertical vs. slightly sloping vs 60 degree slope.  
 
On a different subject: are there any other former Peace Corps beekeepers 
out there?
 
Peace,
 
Jordan C
 
On Thu, 14 Nov 1996, Joel Govostes wrote:
 
> ...
> >While I found it interesting and saw that it worked in their setting, I
> >observed that they had now way to transport frames of honey to central
> >extraction facilities.  I wonder how you do that with THBs also?
> >
> >Ed
> 
> With "transitional" or top-bar hives, you would transfer the crop into a
> container right in the yard.  The honey-combs are cut free from the top
> bars and dropped into a covered pail or other receptacle.  You can leave
> about 1/4" of comb on the top bar, to serve as a guide for the comb to be
> rebuilt. The bees will set right to work on the remnant of the comb,
> cleaning up the dripping honey and clustering to re-build the comb.
> 
> The tbh idea has roots in the ancient methods of Greek beekeeping.  There
> they have traditionally used tall woven (like wicker) baskets for the
> hives.  They lay bars across the basket for comb suspension.  Over all they
> use clay and a straw covering (hackles).
> 
> The combs - unlike those in simple box-hives - are removable by removing
> the bars.  The slight taper to the baskets is supposedly why the combs are
> not attached to the sides.  Evidently somewhere along the line somebody
> learned that if the bars were a certain distance apart, the bees would
> build one single comb on each.  The honey-combs could be removed for
> consumption, and also colonies could be divided by transferring half the
> bars/combs to a new basket, where they could raise a queen if they didn't
> have one.  A guy named Wheeler described these hives in the 17th (or 18th
> ?) century after a visit to Greece.  Bar hives were in use in North
> America, but the combs were usually fastened to the hive walls and needed
> to be cut out. It seems that use of removable bars with removable combs
> didn't get much attention in North America.  Langstroth discovered the bee
> space an� the frame idea, and that was a hit.
> 
> The drawback to the slightly tapered, basket-type Greek sort of hive is
> that the top is round, so the combs near the edges are alot smaller than
> the ones in the center. So - interchangeability of combs is not really
> ideal.  With the long, top-bar hive, all combs are the same width and so
> are more or less interchangeable.
> 
> Eva Crane's recent books (including Bees & Beekeeping and The Archaeology
> of Beekeeping) have an interesting overview of the development of
> transitional hives from Wheeler's description up to the Kenya design.
> 
> Incidentally, the Kenya top bar hive plan calls for inward sloping walls,
> supposedly to discourage comb attachment to the hive sides.  Clauss, in
> Tanzania (1983) and others (including our James Satterfield) have found
> that even with straight vertical sides, there is little comb attachment. At
> least not enough to go through the trouble of cutting the sides to slope.
> Might as well let them build a bigger comb that corresponds to a square or
> rectangular hive shape than decreasing the hive volume by having sloping
> sides.
> 
> It has been claimed by a number of experienced users that there is no less
> attachment in the vertical-sided box (Tanzanian tbh) than in the sloping
> sided box (Kenya tbh).  This being the case, it makes construction of the
> hive even simpler.  If the hive is too narrow perhaps the bees would be
> more apt to connect to the sides than if the hive is on the wide side, say
> the width of a Langstroth-sized comb.  The catenary hive I used had pretty
> much vertical sides toward the top, the curve shape starting down below
> a-ways.  There was virtually no comb attachment to the sides, even though
> the hive was small.
> 
> Clauss in the BEEKEEPING HANDBOOK (Tanzania) shows some great photos of the
> locals holding up big rectangular combs, still attached to the top bars,
> fat and heavy with capped honey.
> 
> Maybe someone else here has been able to compare sloping vs. vertical sided
> tbh's(?).
>