Keeping bees in Victoria is only permitted when they are kept in hives with removable frames. This allows frames to be removed for health inspection by an Apiary Inspector. Movable frames also allow frame replacement, the transfer to another hive and honey extraction without comb destruction. Langstroth hives made out of 8-frame boxes are commonly used here in Victoria; whilst 10-frame Langstroth hives are used in most other states of Australia.Designs can differ from country to country in many ways and hive boxes are used to fit 8, 9, 10, 11, 12, 13, 15 frames. In some countries other standards are used, like the British National or Modified National in Britain. Other countries use variants of the Dadant Hive which have deeper frames.However, the principle is the same:
The bottom box of a hive is the brood chamber, and a queen excluder can be used to separate it from the honey chambers above. These are called supers, because they are superimposed. The queen excluder is a metal or bamboo grid, or a flat plastic sheet perforated with slots. The width of the grid spacing or slots is large enough for the worker bees to pass through, but too small for the queen or drones.In practice the brood chamber may consist of two or even three boxes, and any number of supers can be used, but normally some are removed full of honey before the pile becomes too tall to operate conveniently.
In 1814 Swiss scientist François Huber, universally regarded as "the father of modern bee-science", published his discovery that there was a specific spatial measurement between the wax combs, which bees do not block with wax, but keep as a free passage.American Lorenzo Lorraine Langstroth was the first person to make practical use of Huber's earlier discovery and named it The Bee Space.Having determined this bee space (between 6 and 8 mm), Langstroth designed a series of wooden frames within a rectangular hive box, carefully maintaining the correct space between successive frames, and found that the bees would build parallel honeycombs in the box without bonding them to each other or to the hive walls.This enables the beekeeper to slide any frame out of the hive for inspection, without harming the bees or the comb, protecting the brood contained within the cells. It also meant that combs containing honey could be gently removed and the honey extracted without destroying the comb. The emptied honey combs (Stickies) could then be returned to the bees intact for refilling.Langstroth's book, The Hive and Honey-bee, published in 1853, describes his rediscovery of the bee space and the development of his patent movable comb hive. Read this book online http://www.gutenberg.org/ebooks/24583
In order that the movable frames can be removed individually from the hive, the frames must be precisely positioned on all sides, by the runners and by spacers that fix the lateral distance between frames, so that the "bee space" (about 6-8 mm) is maintained all round. The bee space has been incorporated in movable-frame hive designs since the design of the Langstroth Hive in 1851.Bees will use wax and/or propolis to close up any gap beyond a comb that is smaller than 6mm, attaching the comb to the adjacent surface. Gaps wider than 8mm will be utilised by the bees for building extra comb, mostly for drone cells, but also for honey.In particular when stacking boxes on top of each other, maintaining the bee space between the top of frames in the lower box and the bottom of frames in the top box is critical.When using the frames and boxes commonly available from beekeeping supply stores in Australia you will find that the gap between the frames in boxes stacked on top of each other is far too wide. As a result bees build comb in between the boxes, which gets broken apart when separating the boxes during hive inspection.
Whoever is using the "standard" frames and boxes as sold has surely been in the situation to look in discomfort at the broken burr comb, revealing white drone larvae or honey dripping out of the broken comb. If the broken comb does not get removed before the the super with frames is stacked back on again, bees cleaning up the mess are getting crushed in between - more discomfort and pain, not just for the bees.
The photo shows the result of ignoring, i.e. exceeding the required "bee space".
We are not the first and only ones who have made this discovery; it has been well documented in "The Australasian Beekeeper, December 2010" under "In the Apiary - Do your bees have too much space?" and in "The New Zealand Beekeeper, April 2010".However, the suppliers of hive boxes still supply box kits with fairly liberal measurements.
The height of hive boxes sold as "standard" in beekeeping supply stores in Australia measures between 243 and 248mm. Using frames and boxes as sold results in a gap of 10-18 mm instead of the 6-8mm bee space.What to do?Trim all boxes to the correct height of 239 mm before painting them. *This allows a 6-9mm gap between the frames in the bottom box and the frames in the top box.Luckily the length of the boxes is measuring correctly.With regards to accuracy, quality and consistency of locally available beekeeping timber products, like frames and hive boxes, there is a great potential for improvement.* To make matters worse, the standard height of 230-233 mm for wooden frames sometimes measures 235 mm. Measure frame and box height from your supplier and adjust accordingly.The following figure and associated table below illustrate a cross section through a Langstroth hive with two boxes stacked onto each other, showing the critical dimensions and the required "bee space".
|"standard" as sold||Box Height trimmed|
|BH = Box Height||242-248 mm||239 mm|
|oFH = Frame Height||230-233 mm||230-233 mm|
|BH - oFH (max gap)||18 mm||9 mm|
|BH - oFH (min gap)||9 mm||6 mm|
|gap > bee space||gap = bee space|
|"standard" as sold|
|iBL = inner Box Length||464-465 mm|
|oFL = outer Frame Length||448-452 mm|
|iBL - oFL (max gap)||17 mm|
|iBL - oFL (min gap)||12 mm|
|gap = bee space on each end|