Alternative Warré hTBH

Last Sunday we held a very successful training day on the management of horizontal Top Bar Hives and our thanks go to Gareth John for sharing his extensive knowledge.

Gareth John's
hTBH training session
(click any picture to enlarge)

Those present learned how to inspect a neglected hTBH hive and how to perform a split. The hive used for the training was a biobees style Kenyan hTBH.

The need for a new hTBH

At the wash-up session at the end of the training the discussion turned to adaptations to the hive design to minimise the problems encountered when working with horizontal hives. Whilst no absolute conclusions were reached the group agreed that the straight sided Tanzanian hive offered less problems than the angled catenary shaped Kenyan hive.

In addition, because at YABeeP we err on the more natural side of 'natural beekeeping', we generally favour the Warré hive over the hTBH because of its minimising disturbance on the bees. One benefit of the hTBH is the ease with which splits can be made to raise further colonies. However, because of it's size and shape, splits raised from a Kenyan hTBH with a wider top and sloping sides cannot be easily transferred to a Warré. Garth reported that Quentin had been experimenting making a hTBH using Warré comb dimensions. This news provided one of those 'eureka' moment for the group - why had we not thought of this before?

Typical Kenyan style hTBH (biobees
model) note sloping sides resulting
in wide top bars - 430mm

Making a horizontal hive, using the Warré dimensions, would make usable breeding hives from which to make splits to go into Warré hives. It would also create a simpler to manage horizontal hive for those 'hands-on' beekeepers who like the horizontal style - in case you were not aware the surface area of Warré combs are a near match for the comb size on a Biobees hTBH which is probably the main hTBH of choice used in the UK. It

An additional bonus for a group like YABeeP would be that the frames/bars would then be interchangeable between hTBH and Warré hive types should emergency action be necessary e.g. providing emergency queens, etc.

The model
Fired by enthusiasm I have been experimenting with a design that would facilitate this and have arrived at this model which is simple and heap to make using the same seasoned untreated 25mm timber we used at the recent Warré hive building day.

This is not necessarily the best design, but it is simple to make, easier that the biobees model due to the 90 degree angles, and is constructed using glue & screw technology or glue & dowels for those non-metal converts.

The full 3D model of this hive can be viewed and downloaded here in Google Sketchup . (Google Sketchup is an excellent free 3d modelling programme which you an download here).

Showing roof and floor open

Roof and floor closed
(roof cover omitted for clarity)

Note: Warré hive body dimensions

Width 300mm + (25mm x 2) / Depth 210mm + 25mm

presumes 25mm timber used

Standard Warré rebates
to hold top bars

Side bottom panels (shown in yellow) glued
& screwed to provide bottom re-enforcement
and prevent sides warping

Version with windows
Left open; right closed
(click to enlarge)

Observations:

Internal height/width = 210mm x 300mm - pp Warré design
Length = variable as dictated by timber but a suggested minimum of 1,000mm
Sides rebated 10mm x 10mm to hold Warré top bars (see below for info' on top bars for this hive)
Top re-enforcing = 25mm x 40mm strip around top end/sides set 20mm below side walls. As well as re-enforcing to prevent warping this recess keeps rain out of top section and provides an anchor from which to hinge the lid.
Bottom re-enforcing provided by 2 glued & screwed base pieces - shown in yellow in above illustration.
Lid hinged to hive body - no lifting/storage required. Hinge stops provided by pieces of nylon strapping screwed one end to hive body the other end to lid.
Follower board used as per other hTBHs
Entrance holes in both ends plus centre and each end of non-opening side. Other than user selected entrance these are all plugged but provide alternative options. (Author suggests use of end rather than central entrances for less experienced beekeepers).
Single 35mm entrance hole used rather than 2/3 smaller entrances at each point as bees naturally choose and control a single entrance.
Opening base to give beekeeper access options in an emergency
No varroa screen but varroa can be counted using hinged central floor piece - an optional varroa tray and draw can be added below this base opening if required
Space above top bars for insulation and storage.
Requires less inspections as attached combs are more easily cut with a short straight side - especially if using half frame top bars - see below. This allows bees to naturally attach their comb to the hive sides so they an more easily control their hive atmosphere (Nestduftwärmebindung).

Half Frame Top Bars

The top bars used in a standard Warré hive provide both an anchor for the bees to build comb in that box plus a space to allow them to pass vertically from box to box. This hive however is operated horizontally so a different technique is required.

The suggested solution is to use standard sized Warré top bars (W24mm x D10mm x L320mm) with comb guides - either a short vertical bar or a truncated triangle added below - see illustration below. As with other hTBHs this encourages the bees to build along the bar to prevent cross-combing. The 12mm space between each bar is then filled with a 12mm shim - see the following illustrations.

This not only allows bars to be transferred to a standard Warré if you are making breeding splits, but it also allows more flexibility those choosing to operate this as a stand-alone hTBH as shim sizes can be varied to accommodate comb different width between brood and honey storage areas.

Top bars types
Left: with bar - Centre: standard Warré - Right: with triangle

Showing top bars with shims (in yellow) between

Finally, Quentin & Gareth are also experimenting with half sided frames to their top bars to a) make them easier to remove without damaging comb and b) provide a more robust anchor for the new comb. Remember in the hTBH arrangement, unlike in a standard Warré, the combs are occasionally inspected and moved. New honey comb can prove weak and break under load, especially if cut or moved.

Their design provides dowels at each end as shown in Quentin's photos below. These dowels fit fairly tight to the sides of the hive so the bees can propilise them to the sides to control hive atmosphere. The beekeeper therefore needs to cut the propolis between the dowel and hive to free them.