David Junker's bentwood and reeds trough hive

The hive was kindly presented to me by David Junker. His own web page for his hive is here.

Construction

The wooden body frame is made from ash bent after heating in a steam chamber and clamped on formers until fully cooled. Between the inner and outer 'U'-shaped members of the frame is sandwiched a reed mat stabilised with stainless steel wire. Such mats, 5, 100, 200 cm in size, can be bought from ecological building materials suppliers. The inner 'U'-shaped end boards comprise 20 mm softwood inside, clad with 25 mm compressed cork board. The hive is designed for warm-way operation with a 40 mm diameter entrance tunnel in softwood at one end. The 15 ash frames, detailed below, are fitted with comb supports made of bamboo and spacers. The semicircular spacers on the frames give 35 mm between frame centres. An additional frame, analogous to a dummy board or division board, is fitted with an acrylic sheet to enable comb development monitoring without disturbing the brood nest. The top-bars are covered with an organic linen cloth, topped with a 25 mm thick sheet of fibreboard for insulation. On this rests the curved wood-framed aluminium roof, which, like the Warré hive roof, is designed for ventilation of the loft cavity. The roof overhang is 140 mm at the front and back, and 70 mm at the sides.  

The hive has remarkable similarities to an inverted skep with easily inspectable combs.

Matthäus Junker has provided calculations (in German) showing that the heat loss from David Junker's reed hive is less than half that of a hive with all softwood walls of 25 mm thickness and the same surface area. Note that the calculations take into account the thermal resistance of the inside and outside surfaces, as well as that of the wall material. A PDF of the calculations, together with hygrological considerations is downloadable here.

Cloaming

The hive arrived fully built apart from the roof and stand which were easy to assemble, but David Junker advised cloaming the exposed reeds in the traditional manner used for skeps. I used Matthias Thun's cloam recipe comprising clay (1 part), fresh cow manure (1 part), sieved wood ash (1/2 part) and whey as required. The clay was dug from a local outcrop and required much kneading with water before it was soft enough to use.

Bentwood and reeds trough with cork-lined ends and entrance hole

Below left: cloam ingredients                               Centre: mixing cloam                  Right: applying cloam

   

Below: partly cloamed hive

Below left: inside of roof                                          Below right: a frame showing spacers and comb supports

The roof is a curved piece of aluminium on a curved frame comprising a bentwood batten at each end joined by five rafters dowel-jointed to the ends, and with a rectangular frame attached below forming eaves that loosely enclose the hive body's top.

The whole comb area on the partly semicircular frame is estimated by dividing the inside of the frame into a rectangle 120 x 420 mm at the top with a near-semicircle of 210 mm radius below it. This gives 1196 cm2 per frame, 17,740 cm2 for 15 frames and 35,880 cm2 for both sides of each comb. By comparison, an 11-frame British National brood box has 14,234 cm2, and a 22-frame Einraumbeute (golden hive) 50,138 cm2. Volumes occupied by fully built comb in all three hives are: reed trough 62.8 litres, National 24.9 litres, ERB 87.7 litres.

Below left: 4 frames and the acrylic division board in place                                     Below right: 25 mm fibreboard in place

 

Below left: the complete hive                                  Below right: bait hive

  

14 June 2021 -- populating the hive with a swarm

Swarming normally starts here at the beginning of May and reaches its first peak around 20 May. It was a 6-week wait before the first swarm became available when it entered the bait hive on the front porch of our house (see photo above right). Unfortunately it weighed only 0.75 kg. One around 2 kg would have given a better start. But with the paucity of swarms so far this season, it seemed best to make use of it. It could be united with another at a later date if one becomes available. The swarm was run in at dusk up a board positioned at the reed hive entrance. This proved very slow because, unlike with Warré and other hives with separate floors, the entrance, 40 mm diameter, could not be enlarged for the run-in. Shaking the swarm in would have been much quicker and will be the method used in future. To minimise bees rushing out in the morning and returning to the bait hive site which is only about 250 metres away, loose grass was piled in front of the entrance hole so that bees emerging would have to push their way through it and likely take note of the changed circumstances.

15 June 2021

 By the next morning the swarm was clustered on the front wall of the hive below frames 1-3.

16 June 2021

A neat cluster had formed centrally under the first frames. The day began with rain, which was forecast to continue all day, so it was felt necessary to feed. The bee chamber was reduced from 8 to 5 frames and 2 kg of sugar as 2:1 syrup was given in a tub positioned beyond the acrylic follower board. The tub was covered with wine corks to prevent drowning, and sticks were inserted to ease access from the hive walls. About 3 dozen bees returned to the site of the bait hive. These were collected into a portable vacuum cleaner and shaken onto the top of the feed tub immediately before replacing the linen top-bar cover cloth, insulation board and roof.

 

 

References

Thun, M. K. Die Biene -- Haltung & Pflege.  M. Thun Verlag, 6th edition, 2015.

 

David Heaf's index page