Hive Temperatures while working the TBH

[Scot Mc Pherson]

I have a few biotherms used for temping food while cooking. They are a probe stype thermometer that you stab a steak with or poultry and it gives you the temp at the tip of the probe. I have been using these to take temperature reading of the hives throughout the day and also while working the TBHs.

Lets start with a little background info. The optimum temperature within a hive is 96 Degrees F. +/- 13 degrees being acceptable for brood rearing.

So, during these last hot few weeks I have been leaving the probes in the hive at the entrance and also sticking them between top bars. The temps are the same in all places I can put the probe, so I now only temp at the entrance since all temps are the same and that is where the air is being drawn out of the hive it should be the hottest anyway if it were different.

When I temp the hives at night, the ambient temperatures outside the hive being in the 90s somewhere, the inside of the hives is always between 98-100 degrees at night. During the noonday to afternoon sun, the temps seem to peak at about 102 degrees no matter how much the bees are working, so I think they are successfully keeping thing cool if at this temp this is when they start fanning and recruit more fanners if the temp "tries" to go higher.

When I open the hives, I can feel the windtunnel effect of the bees drawing air out the entrance. Bees also find the "new" entrance between the top bars and man its like a fan is blowing in my face sometimes. With a few minutes the temp of the probe reads lower at 100 degrees, and by the time I work through the hive and reassemble everything, the temps of the hive have been reduced to between 98-100 Degrees F. 2-4 degrees less then when the hive remains untouched through the whole week.

What am I saying? It had been presented that perhaps many of the comb failures that TBH beekeepers were experiencign were because we disturbed the airflow of the hive when we were working them and that the hive got HOT as a result making the combs weaker. I no longer agree that this is one of the reasons. Working the hive if anything as reduced the temps inside the hive.

Now having said that, there is one thing that does happen when working a TBH hive. While working the hive, the sun by necessity is beating directly on the top bars and warming them. When I take the covers of of my hives, I feel the top bars and they are as cool as a peice of wood should be if left in the shade. This is good, it means my cover is doing its job well. But the tops of the bars get warm as they are exposed. This means that heat can slowly readiate through the wood until the undersurface of the top bar gets warm. Its true that this can happen, but I have been paying attention to this. I have also tried and experiment testing this as well. In the heat of the sun, if I expose a peice of wood to noon day sun for 1 hr, the underside of the wood remains cool, it takes a long time for the heat stored in the top of the top bar to travel through the insular qualities of 3/4" worth of pine wood. So I don't think the bottom fo the bar is getting hot after the cover has been off for 15-30 minutes of working the hives (which is what I try to limit my sessions to).

Further, when the top bars of a hive are replaced and the last top bar is put on in the back "closing" the hive up, the bees are venting the hive at the entrance in vaccuum fashion as they normally do trying to pull the air out of the hive. The effect this causes is a depression in air pressure in the hive, and air starts to be pulled though the cracks of the hive and that includes the MANY cracks between the top bars. This pulling of air between the top bars cools them relatively quickly, and so I am further convinced that working the hives in the sun is NOT the cuase of comb failure.

I have become convinced that comb failure is 100% attributable to two factors. Hive design and comb handling technique and skill. If they combs are built too largely so they require support on the sides, then the support on the side IS required or the bees wouldn't have put it there. When we remove these attachments, the honey is no longer supported as much as before, couple this with perhaps poor handling of the combs, not carefully cradling the top bar in one's fingers weakening the while structure. When we move honey comb top bars, we must be careful how we handle the comb. Its the heaviest comb found in the hive, not only because of WHAT is in the comb, but also because the combs themselves are often thicker than brood combs, so these combs can get REALLY HEAVY. IN my top bar hives, I estimate from handling that my heaviest combs are somewhere aound 8-10 Lbs. This much weigth being supported by only the top bar is a lot of weight to support.

Some of us have devised some device or another in order to be able to detach combs from teh walls without causing strees to the comb. I think this isn't the best idea. If you design your hives so that the bees don't have to attach combs to the walls, which they only seem to do if its necessary to do so, then you find you won't hav eto detach combs. In my hives, I still get small attachment which I can break safely by just sliding the comb back and forth against its neghbor slowly and careful and this breaks the attachment without tugging on the main comb at all. SInce they are small attachments, they aren't lending any mechanical support at all to the honey and so the honey is safely supported by the top bar. I haven't had any comb failures so far during our hot spell in florida, and I have about 6 or 7 full combs of capped or mostly capped honey stores at the back of my two best hives.

Also I have found something else interesting. If the attachments are small and you removed them and scrap them from teh hive wall, teh bees dont' seem to replace the attachments. But if the bees have had need to place the attachments and they are significant (as they are in a couple of my NUCs which are of differnet design), then the bees will try to quickly replace the supports.

Just some thoughts and I would like to hear everyone's input.

------------------
Scot Mc Pherson
Foundationless Small Cell Top Bar Hives
BeeWiki: http://linuxfromscratch.org/~scot/beewiki/

[Oxankle]

I am too new at this to discuss comb structure and top bar length--I will only say that in a hive of Crowder design I have perfect combs without a single attachment anywhere. Of course these combs are only about 8 inches deep by 18 long. That same hive has no cover. I have yet to either build a telescoping top or find a piece of sheet metal to cover it, so it is covered by a couple of garbage sacks. The wood under them gets quite warm in the morning sun. Fortunately it is shaded from late morning on. I will have to cover it before long now.
Ox

[Scot Mc Pherson]

I am betting one of the reasons for this is because your hive is in the shade. If your hive were in full sun or when you weather gets hot, I am betting attachments would develop.

[Oxankle]

Scott:
That is one of the things we ought to be alert to as we continue to learn about TBH's. If this hive develops attachmnet points as summer progresses I'll advise.

Right now I see perfect comb, shallow but long.
Ox

[topbarguy]

Hi Scot and Everyone,

In regards to tbh heating, location is everything. The intensity of the sun in Florida is much less in the summer than it is Wyoming. Differences in elevation and latitude make alot of difference here.

For me, solar intensity and the fragility of new comb are the most critical. Daytime temps are very hot. But night time temps are cool with a 40 degree temperature swing.

Comb, whether in a frame on or a topbar, can quickly melt in my conditions. When examining a standard hive here, it's a standard practice to place the few combs removed from a super in the shade or they will quickly melt.

So maximum daytime temps aren't a large factor like they would be in hotter areas like Texas, Arizona or Florida.

Handling new comb in hot weather isn't an easy task. Mishandling that new comb will gaurentee comb failure in hot weather. Caution is advised.

The most striking evidence in my comb failure was the difference between the comb that had been worked and that which was being worked. I had removed and photographed about 6 frames of comb starting at the rear of the hive with temps in the high 90s. Each comb was carefully cut loose. The bees were brushed off and then the comb was set in a frame on top of the hive. Three photos were taken and the comb returned to the free space toward the rear of the hive. I estimate the process took less than 5 minutes per frame, probably closer to 3 minutes.

Less than 30 minutes into this process, the first comb failure occured in the worked combs toward the back of the hive. The comb fell and remained somewhat upright. I immediately attempted to pick it up to prevent bees and maybe the queen from being killed. I couldn't pick it up. It was a slumped pile of mush. I ended up using my hivetool as a spatula and scrapping it to the rear of the hive where I thought the bees could work it and clean up the mess, which was a mistake.

At the same time, the comb that I was working on toward the front of the hive was firm and stiff. The attachments required cutting. The comb could be brushed free of bees. And the comb could be handled enough to photograph it and return it to the hive.

After photographing another comb, the next comb failure occured in the worked combs toward the rear of the hive. This comb gently slumped to the floor and the mush just barely touched an adjacent worked comb. It failed instantly.

Now, my sun baked brain realized this hive was in big trouble :> ) I had really goofed up. But I didn't know the half of it. I took a quick shot. Scooping the collapsed comb to the rear of the hive and closed them up. You can see a picture of my tbh at this stage at:
http://fire.prohosting.com/topbargu/preca.htm

It's not a pretty sight. I left the yard with my heart in my stomach. Comb toward the front of the hive, where the bees rather than the beekeeper were still in control, was cool and firm. I figured the bees would get the situation under control.

And they would have had I not created a big disaster by trying to salvage a few combs.

I returned the next day to find almost all the bees clustered outside the hive with honey flowing out the entrance. Inside the combs had gradually failed starting at the rear of the hive and progressing toward the front. The failure had been gradual enough to allow most of the bees, including the queen, to escape outside.

I had photographed each comb at weekly intervals since placing bees in the tbh without any significant problems. But handling comb the same way in hotter weather resulted in comb failure.

Moral of a long, sad story. Be careful. Be aware and forewarned. The same comb handling technique used when the comb is light and conditions are favorable can let you down when conditons change. Don't just focus on the comb stength/conditions toward the front of the hive. And always carry a clean bucket for comb. I didn't.

I now know it's better to throw failed comb on the ground than disrupt hive ventilation. And it's better yet to not disrupt the hive at all under some conditions.

Tbh beekeepers need to be smarter about handling comb. I can imagine some situations where some tbh configurations wouldn't be as desirable as others. But I've seen pictures of abandoned feral combs outside of Tucson, Az. They were over two foot long. And located in shade in some rocks with few attachments other than at the top. It hadn't failed. But then it hadn't been worked by beekeepers either. :> )

Regards
Dennis

[Scot Mc Pherson]

Top bar length isn't the most critical dimension as far as comb integrirty is concerned. THe most important is height. Since your comb is 8 inches, that should help a lot.

[Oxankle]

Scott, Topbar:
I think that the lessons from experiences recounted on this board are that (1) successful top bar designs are limited and (2)the beekeeper had better keep his hands off fresh comb unless he is harvesting it.

The Hardison hive is over ten inches deep. The Crowder hive less than nine. Both are successful in New Mexico. People on this board are experimenting with Tanzanian models and no telling how many of their own ideas.

As for me, the honeyflow is about over here and the bees will be on their own now until soybeans (if there is a flow there) and the fall flowers. The temperature can be expected to be 90 to l00 or more degrees from now until the end of August or even mid-September. I do not propose to poke my nose inside a TBH again until then. I have material on hand to build more Crowder "short hives" for pollination and packages, but they will have to wait on suitable weather for filling.
Ox

[Scot Mc Pherson]

Dennis,
There is a big difference in your hive design than the designs that many of us have determined are safer. Your top bar is 20" long and the combs are 15" high. I don't understand how you can blame the heat and sun for this. There are design considerations that involve verticle weight, catenary curve (both for bee preference AND for mechanical support), and several others. There is a reason why I came up with the designs that I use, and its not because someone else did. My designs are by chance similar to other people's but they are distinctly different, and so far I haven't a bad thing to say about my design.

15-16" top bar
9-10 inches in height
25-30degree slope
6-8" bottom board

And a good cover design that shades the hive, which provides the bees with the sense they have more than 1/4" of wood above their heads and still provides adequate ventilation to allow the attic born heat to blow away.

Dennis, try a hive with those dimensions and take a look at the pics at http://linuxfromscratch.org/~scot/pics/bees to see how I put it all together. The only difference between my older hives and my newer hives is I now rip 2 top bars from a 2x4 instead of 3 top bars.

I really don't think yoru comb failure is strictly heat related, but coupled with the comb being way to darned big. Fine for brood comb which is light as a feather, honey comb though is FAR FAR heavier, not only because of WHAT the comb is bearing, but becuse the combs are sometimes 2x as thick too.

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Scot Mc Pherson
Foundationless Small Cell Top Bar Hives
BeeWiki: http://linuxfromscratch.org/~scot/beewiki/

[Scot Mc Pherson]

Ox,
Although you will probably curtail comb failure by not messing with your hives during the summer, you will never find out whether the hive was designed well because your comb will never be "tested". You also stand a good chance of the hive developing into a real mess when you don't look into it. Combs could be built anywhere and every where and attached all over.

Work you hives, and if they fail you know you have something to think about.

------------------
Scot Mc Pherson
Foundationless Small Cell Top Bar Hives
BeeWiki: http://linuxfromscratch.org/~scot/beewiki/

[topbarguy]

Hi Scot,

>I really don't think yoru comb failure is >strictly heat related, but coupled with >the comb being way to darned big.

Could be, but my combs are actually very small compared with feral comb. Check out:
http://www.bee-l.com/biobeefiles/dennis/index.htm

This feral comb pictured at the bottom of the page is inside a very poorly ventilated space. It has almost no burr or brace comb. And it's at least 2 ft longer than the picture shows. It has obviously been both hot and heavy in the wall. Yet it hasn't failed. If height of comb were the major factor, this comb should be mush.

One big difference exists. That comb hasn't been worked by a beekeeper. What in our management/manipulation would cause a realitively small comb like mine to fail and a really big one, like in the photo, to stand?

Reducing comb height certianly reduces the stress. No regard for any comb handling other than no horizontal cutting is required for 3" comb. :> ).

So why not build very shallow hives? I know that although bees have a horizontal focus in their behavior/broodnest construction, the vertical element is also very important. It is especially important as the bees prepare for and overwinter in the broodnest. At that time their focus is primarily vertical.

Bees when given unrestricted comb building space tend to build comb that is heigher than it is wide. It appears they attempt to get a broodnest with a maximum amount of volume and mininum surface area with some vertical flexibility.

Bees in standard equipment seem to overwinter in an optimal cluster size. In my climate that's about 12 deep frames of bees spread into two deep boxes. I know it's alot less than that down south.

I have designed my tbhs with these factors in mind. And have approached the comb failure as a management failure rather than a design failure.

I will certainly let you guys know if I am wrong.

Regards
Dennis

[topbarguy]

Greetings Everyone,

I think flexibility is one of the greatest advantages of running a tbh and also one of its greatest pleasures. This flexibility allows the beekeeper to design and build a hive that is optimumized for his own purposes.

As such, all tbhs are local and very individual. The real test of a tbh is whether it suits the purposes of its builder and his management style. Everthing else concerning its evaluation is irrelevant as the bees don't care whether they live in our empty boxes or any other cavity.

When I raised queens, I was into the hives every three days rain or shine. My beekeeping has changed. I now want hives that can function on their own without my intervention for months. They must be stable, wind tight and able to overwinter in my environment without any intervention. Enough room must exist to store a honey crop and enough vertical flexibility must for the bees to develop lots of small cell sized comb so I won't need to treat for mites.

These are my priorities, but I doubt they are anyone elses. So how would my hive/management be different than if my priorities/location were different?

What do you think?

Regards
Dennis

[This message has been edited by topbarguy (edited June 13, 2004).]

[Oxankle]

Scott:
The honeyflow is over. Unless the fall flowers or soybeans produce a good crop there will be no more comb-building until spring in the TBH's.

In the meantime, the bees will raise a couple of generations of brood, store fall flower nectar and in general "toughen up" the comb.

As for the bee's preference in brood nest shapes, I suspect that has more to do with what is available to them than with preference. A hollow tree is round and high. A gasoline tank on an abandoned auto is long and low. The interior of a frame wall is wide, high and narrow all at once. All three serve the bees' purposes.

In time we will have the collective experience of the board to guide us. At the moment I am sticking with what the pro's have shown to work.

I really dislike the limited depth and volume of the Crowder hive. It is too shallow to put anything other than a frame feeder in place--the Hardison hive accepts a half gallon detergent bottle made into a feeder. Nevertheless, it is the Crowder hive that is producing perfect comb without my intervention. Volume is not important if you can harvest combs at any time they are completed just by lifting them out, breaking them off and replacing the top bar.
All that is needed is enough stores to make the winter where you are.

I am further convinced of the probable success of the two older designs by the fact that at least one user shakes package bees from his hives. You cannot do that with fragile or overloaded comb.
Ox

[Scot Mc Pherson]

Ox,
When the bees can choose the shape of their combs they build the catenary curve. That is a fact and is irrefutable. The curve itself is defined by the natural curve of free space honey combs. Why would there not be a preference if the bees follow the pattern repeatedly over thousands of years of recorded history? Sure they CAN build comb in a gas can, but you think its their best choice?

Our flows are pretty much all year with a 6-8 week dearth in july-august where 2ndary flowers are the only things available. The rest of the year is continuous and overlapping flows, even in the winter which is when our most well known flow runs. Citrus blossom.

Dennis,
Bees prefer different sizes and shaped of hive cavities. Refer to Eva Crane "Archeology of beekeeping" if you want some 'credible' reference instead of just my banter.

And yes Management technique has a whole lot to do with comb failure. Hive design IS a part of management technique as well. And also handling combs at all is part of management. The fact that bees can build combs 2 ft long unsupported does not change the fact that we as beekeepers keeping bees in hives that we have to inspect and manipulate requires that we design hives that we will be able to do so. TO build a hive that one must refrain from touching is IMO a silly thing to do.

This comb doesn't match the criteria for being a model for top bar hives. It IS supported in several places. This comb appear to have been mostly empty when the wall was torn off, not bearing very much weight at the moment. The comb is supported all up and down the length of both sides, and is not freely hanging from the top. I could build frames that were 2ft deep and they'd work too, but we are designing TBHs and managing free hanging combs.

Experiment all you want, but I encourage you to experiment with designs other than extreme ones. The designs I put together will do you well even in your "wyoming sun". Which I am afraid I can't agree that your sun is stronger than the sun here in the sub-tropics. The ground during a dry spell is too hot to walk on barefoot already.

[Michael Bush]

>Which I am afraid I can't agree that your sun is stronger than the sun here in the sub-tropics.

If you spent much time at 7200 feet and much time at sea level you'd realize it IS much stronger in WY because there is less atmosphere to filter out the suns rays. You get a sunburn three times as fast at high altitudes.

[chemistbert]

My TBH is about 9" deep with 15 degree sides. 19" Tb and I have very little attachment. About the catenary shape I sort of have to disagree. My bees built a shape that mimics my hive dimensions. Rather odd looking but it is the way they wanted it. All I know is that they are doing very well and I am having a blast working them. My langs are work, my TBH is pleasure. My 2 cents.

[topbarguy]

Hi Scot,

You have a tbh design that works for you. It suits your purposes/climate and is therefore a great design. You are having fun observing and exploring nature with your bees. What more could anyone want? Congradulations.

My criteria for a tbh are somewhat different than yours.

I want removable comb but not free hanging comb in my hives. Free hanging comb would be a disaster here with the wind, open range cattle and the migratory nature of beekeeping in Wyoming. So comb attachments are an advantage, not a disadvantage.

Summers are short here and I've spent most of them poking into thousands of beehives. Now, I'd like to spend more time doing other things. My hives must be self sustaining.

Northern beekeeping is very different than that in the south. Hives are intentionally not disturbed for months on end. No benefit is gained by poking around in the hive. In fact it can be very detrimental. Determining when not to mess with a hive is as important as knowing when to mess with them here.

And my hives must survive a very long, nasty fall, winter, spring. First nectar--end of April. Last nectar--first of September.

By Florida standards there might not be any nectar until the end of May. And after two weeks, none until the end of July. By the second week in August it's done! :> )

Honey flows here are intense but sporadic with no nectar in between. Surplus honey is made during a three week period at the end of July.

So I would suspect my tbhs might be somewhat different than yours. But I do appreciate everyone sharing their thoughts and ideas. It allows me to choose those ideas that would suit my needs. Some work great and some don't. I guess that's what makes my tbhs a work in progress, much like my beekeeping. :> )

Regards
Dennis

[Scot Mc Pherson]

Michael,
I agree that altitude effects sunlight intensity, but I also know that so does latitude. When one live at 45-50 degrees North latitude, the sunlight is travelling diagonally through the atmosphere. This increases the amount of atmosphere the sunlight travels through by a great deal.

Yes I live at see level, but right now the sun is directly overhead and travells straight down through the atmosphere.

Both tropical latitudes and altitude reduce the amount of atmosphere the sunlight travels through. But when above the 45Lat line, the sun is travelling at an angle such that only the highest of altitudes can offset the amount of atmospheric filtering.
7200 ft might have an effect, but consider the atmospheric limit (where atmosphere ends and stratosphere begins) is something like 50,000-60,000 ft. When you consider this, latitude has a greater impact of sun intensity. Its why when you go to the carribean for 2 weeks, you can come back almost darker than your african neighbors. Its why sun poisoning is a more prevelent problem in Florida than in Wyoming.

Dennis,
Its fine that you don't have to touch your hives for several months. It still doesn't make sense to design a hive that will cause you frustration because of comb collapse. I am not saying that you should use my design, or anyone else's in particular, I just think its defeating to design a hive to the more extreme limits. My hives still developed attachments with any new comb built, and the longer you leave the hives without inspecting them, the larger the attachments become. The only difference between your hives and mine, is that when I do a thorough hive inspection, I don't have to worry about the honey dropping from the top bars.

------------------
Scot Mc Pherson
Foundationless Small Cell Top Bar Hives
BeeWiki: http://linuxfromscratch.org/~scot/beewiki/

[topbarguy]

Hi Chemist Bert,

I worked my hives today and have the same experience. The tbhs are pure joy, even though I need to cut some comb occasionally.

The Lang hives are just more work. Maybe it's the novelty of the tbhs or the fact that I have been working thousands of Langs since the late 60's.

Or it could be the gentle, undisturbed nature of the bees when working a tbh compared to a Lang. But the difference is real.

It's so real I have given away all but two of my small cell Lang hives. Once I understand and can work with the wintering dynamics of a tbh, then I will get rid of the remaining two.

About that time I will be moving to Florida and starting all over again. Scot will have to teach all about Florida beekeeping. ;> )

Regards
Dennis
Short or Tall, I like em all. Tbhs that is. :> )

[Scot Mc Pherson]

I most definately agree. TopBarHives make beekeeping a genuine joy.

Dennis, I am certainly not any authority on "florida beekeeping" This is my first year keeping bees in Florida. All of my prior beekeeping experience has been rooted in New Jersey and Connecticut. You are more than welcome to come and visit me when you have the opportunity. Probably the most important aspects of Florida beekeeping are heat management and dealing with the july-august dearth where only 2ndary flora is available to the bees. Otherwise honey flows all year. I haven't had 1st hand knwoledge of this summer dearth though. My bees have just begun washboarding again and I am now pretty sure that this means that a new flow has been discovered (mangrove is the new flow here).

[Oxankle]

Hi, Guys:

I want to inject a little thought here. First, Bert: Your l5 degree hive is very close to the l3 degree Hardison hive, a proven design. Bottom board width? In both the Hardison and Crowder designs the design is such that it makes use of all the wood in a standard board; A 1 x 12 in the Hardison, a 1 x 10 in the Crowder. Crowder has angled his hive steeply to use a Lang-length top bar. Hardison uses less slope to use a shorter bar and get depth. Both work. My point is that there were more than "bee" considerations that entered into these designs.

Now you, Scott: With all due respect I think that the catenary curve theory may be a pile of crud. By its very nature, a catenary curve is what results when you pull on a cord, either spiderweb or bridge cable. The shape changes when you put weight at any given point on that stressed cord. The stresses in any point on a comb will change as the shape of the comb changes but the pull on the cord will never exceed bee strength. That is what governs shape of the curve.

Now; how do bees build comb? When building downward they grasp each other and form a chain, just as they do when swarming. That chain sags. The bees are busily building comb, placing wax in spots all along that chain. When they start the base of the comb may be small and the stressed cord results in a tiny comb that may resemble part of an egg. When the comb reaches an attachment point at the end or ends, that point follows the object to which attached. In a properly built TBH the comb mimics the shape of the hive, like Bert's. Offered unlimited bottom space, such as when built on the soffit of a house, the bottom ends as a form of catenary, often elongated in the middle combs.

In short, I submit that bees might not prefer the catenary curve, it just might be that they are powerless to do anything else when building descending comb. Only when they reach the limits of their descent will they build in very small segments to fill out the bottom of the comb.

I would be interested to know how the researchers you speak of offered the bees an opportunity to choose anything other than a catenary curve when this research was done.

Now, as to management; Not entering a hive for a period of time is manqagement just as entering a hive daily. These things are judgement calls. A beekeeper should enter his hives when NEEDED. Anything more is interference, not management. Of course the hobby beekeeper is expected to play with his bees, and I do, but nevertheless the principle holds.

Like Topbar, I have a one-flow season. It begins in late April and is over by mid- June. If I am to get a honey crop, that is it. The bees are worked on warm days in Jan to check feed, same for late Feb and perhaps more than once in March. By April they are on their own unless trouble is spotted. All they get in May and June is fogging and supering, again barring trouble. Honey comes off in July, around July 4th. The bees are watched to see if they find a soybean crop and they may get supers if they do. Other than that they get only fogging until they are checked in the fall for winter stores and put to bed.

All of this may be altered by combining, re-queening, splits, anything we do. Even so, the bees are best left alone unless they need us. In the case of my TBH's, if the little nerds build some crooked or cross comb they will have to do it over next spring.
Ox

[chemistbert]

Oxankle, My bottom board is whatever it is. Meaning the TB is 19" and the angle 15 degrees with a 1x10 being the side length. I made the bottom out of floor laminate and trimmed with a flush cutter on my router. I don't really know what size it is. I suppose one could do the math but I am far to lazy for that. You bring up an very interesting point about the catenary shape. I would be interested to see what shape bees would buil in microgravity, but that's not really feasible as how would they forage? I suppose you could take some bees and keep them shut in a box with feed. Oh the mental exercise... http://www.beesource.com/ubb/smile.gif Einstein would have loved having bees. (Especially TBH's)

[Michael Bush]

I have concluded from my experience, that the slope is important to the strength of the comb. Mostly that the corners of a square unsupported comb cause undue stress. Whether a curve is any better than a straight slope I couldn't say, but if you hold the comb anything other than perfectly perpendicular and the top bar anything other than perfectly horizontal the corners are what pulls the comb more out of shape.

I am doing a medium depth hive with square coners because the amount the corners affect it seem related to how deep the comb is. In other words a lot of weight a long ways down has more leverage when you move the comb.

We'll see how they both do.

[Scot Mc Pherson]

The catenary curve of comb really has nothing to do with the way a cord hangs. They are very different models of engineering and weight distribution.

The bees do not run a chain and build from the chain. They cluster, but the cluster isn't governed by anything so simple. A cluster can hang nearly compressed to the top of the hive, and it can also hang right down the middle in almost like a vertically hanging rope. The comb when started will be first built here, but once the "foundation" has been laid, the bees build comb where they think they need it, not necessarily following this "chain". The curve of comb is a choice of evolution through millions of years of natural selection based on survival and fitness. The natural cruve of comb is by its nature a stronger structure and a choice the bees make because the bees that have made that choice are the ones still around.

Bees do not always build down, sometimes they build sideways or even up. To use your eves example, comb can sometimes extend several horizontal inches beyond the eves into free space and even build up and above the eves. Its still a catenery curve. Want picture?
http://photos.groups.yahoo.com/group/FloridaBeekeepers/lst

The catenary curve of comb is a mechanical structure. When the bees have a place to attach at the side, but still in freespace elsewhere, the curve can be seen drawn from that point. It is similar looking to the cord being suspended from two points, but is distinct in that the cord is supported by only two points, the comb on the otherhand is suspended and weight distributed across the top attachment, and any other points of attachment are supports, but not an evenly distributed weight bearing point.

Since the curve of unsupported comb is what is seen in nature, then it makes sense to produce a hive that as closely as feasible emmulates this shape. The comb built will not likely develop attachments because the comb is closely shaped to a freespace comb, and the bees end up closely respecting the beespace. With the angle selected its amazing how straight a line the edges are, being a perfect row of cells at the top, bottom and also the sides since the angle is the same.

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Scot Mc Pherson
Foundationless Small Cell Top Bar Hives
BeeWiki: http://linuxfromscratch.org/~scot/beewiki/

[chemistbert]

My 15 degree hive has very little attachments. Perhaps the bees think it is close to this catenary shape? I don't think so but I'm also not making the comb either.

[Michael Bush]

Actually my standard medium sized (three box long) TBH hive also has very few attachements. But the comb seems easier to support on the 22 degree slope on the KTBH.

[Oxankle]

It will be very interesting to see which hives are still in favor two years from now. I am completely open minded about this, but my gut tells me to go with a proven design and change when someone shows a better way.

What I find interesting is that the proven TBH designs are low-volume boxes. Those of the top bar prof. in Virginia are only 60 CM long and seem to be made on a Hardison design or something very similar. The article I found noted that this hive was too small for a healthy colony in the springtime and so he shook package bees from them to prevent overcrowding.

We will learn much about TBH management as we go along.
Ox

[Scot Mc Pherson]

Mine have roughly the volume of 3 deep supers. My hives are 4 ft long. Its not small volume, its a smaller cutaway that makes the difference, volume is easily modified by simply changing the length of the hive body. I have hives that are 6 bars, 10 bars, and 37 bars in length. The rest of the dimensions are identical. Universal design is critical to interchangeability to ease management.

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Scot Mc Pherson
Foundationless Small Cell Top Bar Hives
BeeWiki: http://linuxfromscratch.org/~scot/beewiki/

[Michael Bush]

It does seem like as the hive gets long it takes some managment to keep them storing honey and not swarming. Juggling bars around so they fill them all is still an easy thing to do, but does seem to require some managment.

But making the combs smaller and the hive longer seems to be the only way to get combs that don't collapse and a volume large enough for a productive hive.

[chemistbert]

Has anyone used deep TBHs in the shade. My hive is about 9" deep and the comb seems very strong. But they are partially shaded during the day. They really only get good strong morning sun. Interestingly enough they are out foraging before my Langs right beside them. Any thoughts about that?

[Michael Bush]

>Has anyone used deep TBHs in the shade.

All my TBH's have been in the shade until my recent medium one that I am trying in the sun.

>My hive is about 9" deep and the comb seems very strong.

Mine was a standard 9 5/8" box on a 3/4" bottom board so from the top of the box to the bottom of the botom board was 10 3/8". The comb collapsed. On a brand new drawn comb full of nectar the comb is like Jello hanging from a bar. It does not look very strong. By the time it's capped it seems MUCH stronger, but when it collapsed every single comb fell off. It looked like it went down like a row of dominoes. One of the back combs fell and fell into the next and so on.

>But they are partially shaded during the day.

Mine was full shade all day.

>They really only get good strong morning sun. Interestingly enough they are out foraging before my Langs right beside them. Any thoughts about that?

I think it really only matters much when night time temps get below 50 F. Then the morning sun gets them warmed up enough to break cluster sooner. Some bees are out sooner because of race. Darker bees seem to get out earlier when it's cold out (which I assume it's not any more).

[Scot Mc Pherson]

If you design a good cover, then sun nor shade will matter much in the overall temperature of the hive. My covers are peaked 15 degrees and overhang the sides and edge of the hive so that even on an open plain, the sun only hits the ends of the hive early morning or late afternoon. The hive body itself is entirely under shade from teh cover, but the hive has the benefit of being out and surrounded by sun all day.

I believe pests such as SHB and friends might not "enjoy" being in the sun, and therefore are restricted during the day in their ability to enter the hive. Which at night is more difficult because the hive is PACKED with bees. During the day most of the bees are out foraging, and so if the hive is in a wooded area for instance, shade/dark dwelling pests have an easier time finding your hive. At least that's what my evidence looks like.

Further I should mention that the "Attic space" above th top bars is ventilated to prevent hot air from gathering too much above the top bars, and also to help cool the bottom of the cover so it doesn't radiate heat onto the top bars. When bees vent their hives, they create a depression between their hive and the outside. Air gets sucked into the hive from any crack or crevice, and this includes the cracks between your TopBars and the heated air above them. If you look at the pics of my hives, you can see how my cover is supported above the top bars creating a drafty condition. Also this was my first roof design and you can see that I sealed the peaks of my covers. I no longer do that. I still use a cap to cover the crack, but I leave that crack wider and let the hot air run upwards and out the ends in case there is no draught to push/pull the hot air out from under the eves of the cover.
http://linuxfromscratch.org/~scot/pics/bees/

[This message has been edited by Scot Mc Pherson (edited June 16, 2004).]

[chemistbert]

Mr. Bush. You say your hives were in the shade all day and yet you had failures? Are we talking about more than one hive? Could it have been a fluke? I have seen feral hives with alot more that a foot of comb suspended. Maybe I have super bees! http://www.beesource.com/ubb/biggrin.gif All this is very curious.

[Scot Mc Pherson]

The bees generate heat too. Ambient temperature being high makes it impossible for the bees to cool their hives without the aid of evaporation. Sun is just the icing on the cake, not the baker as it were.

With heat management, sun makes things worse, but its not the root cause in most cases.

[Michael Bush]

>Mr. Bush. You say your hives were in the shade all day and yet you had failures?

Yes

>Are we talking about more than one hive?

No, but more than one failure in the same hive.

>Could it have been a fluke?

Anything can be a fluke, but I concluded that it's too deep of a comb to be manipulated.

>I have seen feral hives with alot more that a foot of comb suspended.

Yes, and no beekeeper moving them around. The stress of just gently lifting it out is huge compared to just haning there and you break any bridge comb which not only removes the strength of the bridge but causes stress on the comb in the process.

>Maybe I have super bees! All this is very curious.

Mine did fine from April until July. In July it collapsed.

[chemistbert]

Oh oh then... I guees I will see then won't I? I get what you are saying about the feral comb. Well if it does collapse then it has been a learning experience.