I built a 3/4-scale catenary hive according to Mr. Bielby's book.  It was
basically for a model, but I made the bee spaces regular size, and hived a
small swarm in it.  They did great all through that season, gradually
building up a fine brood nest, and eventually filled an additional 6"
"super" about halfway with goldenrod/aster honey.  (The super combs were
natural, suspended from wax-coated dowels nailed across (inside) the top of
the box).
 
The experimental colony actually overwintered like this, much to my
astonishment, and the next spring I allowed them to work up into a regular
brood box and removed the catenary hive below.
 
It was quite a success, and I found the hive very cheap and simple to make.
The top-bars were 2-piece, with a 2" strip of brood foundation pinched
between and nailed through.  Spacing of the bars was accomplished by small
nails driven into the ends of the bars, to the appropriate depth.  The
"curve" part of the hive was actually formed, not with 1/8" plywood (as per
Bielby), which I couldn't find, but leftover formica sheet like is used to
cover kitchen countertops. It was a bargain at the local hardware store. It
is very flexible but smooth and plenty strong.  I also stapled roofing
paper around the hive, packing fiberglass insulation scraps around the
curve-wall. This was probably not really needed. The whole thing is painted
a shade of brown.  Someday I'll make a couple of full-size ones, I think,
as it was interesting and enjoyable project.  The combs the bees made were
extremely even and straight, mostly worker comb.  As the season went on
they became surprisingly strong, and I didn't have to worry about them
breaking at all during inspections.
 
BTW a fine queen excluder for this hive is just a sheet of heavy
utility-plastic, as used to cover outside windows in wintertime.  Hardware
dealers sell it in inexpensive rolls.  Just cut a piece to lay across the
brood comb bars, with an inch and a half or so space left all around. The
bees will carry the honey up around the edges, and the queen will be kept
down by the plastic.  Another benefit is the plastic prevents the natural
surplus-combs in the "super" above from being connected to the brood-comb
bars.  (So you can remove the honey super without cutting the combs free).
Give it a try sometime...                             JWG Freeville, NY