# Which length is best for a Top Bar Hive? 3 or 4 feet?



## BobRagsdale (Nov 23, 2014)

Quite often I see discussions pop up regarding one hive length or another, and which is best. My hives, based on Wyatt Mangum's design, are three feet in length. I see that a lot of other people advocate Michael Bush's recommendation of a 4 foot hive, 

As I was reviewing posts to see if there was "best" length I realized that even hives of differing lengths may have very different volumes due to the height and widths of their ends. When I did the calculations I found that most of the recommended hives have pretty similar volumes despite their difference in length.

By my calculations

A 3 foot Wyatt Mangum design has 72 liters of volume.
A 4 foot Michael Bush design has 74.3 liters of volume.
So while there is a 25% difference in length, there is only a 3% difference in volume.

I ran the numbers on several other noted top bar beekeepers and found that nearly all of the recommended hive dimensions yielded a volume somewhere between 72 and 80 liters - only an 11% difference between the smallest and largest. Now when I build my hives I keep them in that range.

I have made two Top Bar Hive Volume Calculators in a Google Spreadsheet that you can try. 

The first tab in the workbook is rather involved but it allows you to do a volume comparison of hives of your dimensions to the recommended dimensions of Mangum, Chandler and Bush.
The second tab is a simple volume calculator for one hive.
Please note that the spreadsheet is "protected" to ensure that the formulas remain intact. When you open it there will be gray diagonal bars over all of the cells that you can not enter data in. They can be distracting. To turn them off go to the menu, click "View" and click the "Protected ranges" checkmark.

As I note on the spreadsheets, all dimensions for Mangum, Chandler and Bush hives are based on my personal interpretation of each author's guidance for constructing a top bar hive. My interpretation may not be exactly as each author intended so the resultant dimension and volume calculations should be used as a general, relative guide, not as an absolute comparison tool. And that I may have gotten all of this horribly wrong so please use of this information is at your own risk/discretion. 

Let me know if these are of any help to you and if you have any recommendations on how I might improve them.


----------



## jwcarlson (Feb 14, 2014)

4 feet or 5 feet.

The bigger the combs the harder they will be to keep straight and easier to break off. Mine are Les Crowder's footprint 4 footers. Combs are shallow and easy to keep straight.


----------



## b2bnz (Apr 5, 2009)

When I made my TBH I wanted the bars to be the same length as a Langstroph hive so I could start my bars in a Lang if I wanted to and then transfer to a TBH or visa versa if the hive was failing. With long bars there was the possibility of comb breaking off along the bar, so I added a 'T' piece of 200 mm in length to the center of the bar, effectively dividing the comb on the bar into two equal triangles. This solved all the problems and works a treat.


----------



## Apismellifera (Oct 12, 2014)

It's a bit of work to bevel the top bars, but I think that edge helps to make a strong attachment and straight comb better than any other method.

Nice work on the calcs, Bob!


----------



## BobRagsdale (Nov 23, 2014)

jwcarlson said:


> 4 feet or 5 feet.
> 
> The bigger the combs the harder they will be to keep straight and easier to break off. Mine are Les Crowder's footprint 4 footers. Combs are shallow and easy to keep straight.


Yes, I have heard that a lot of people like and have had success with the Les Crowder design. As I read it his dimensions are:
- Top 20.25"
- Bottom 9.5"
- Side 10"
- Which would yield and approximate height of 8" to 8.5"
And a volume of between 76 and 80 liters - again, in the same volume range of generally recommended top bar hives.


----------



## BobRagsdale (Nov 23, 2014)

b2bnz said:


> When I made my TBH I wanted the bars to be the same length as a Langstroph hive so I could start my bars in a Lang if I wanted to


@b2bnz - I do the same. My bars are 19" in length. The thing I didn't realize initially however was that the ends need to be the same thickness as the ends of the frames that go in the Langstroth - 1/4". Now when I make my bars I mill the ends to be 1/4" thick so they are interchangeable with my Langs. I do end up switching them back and forth more than I would have initially expected.


----------



## TheGeneralsBees (Feb 17, 2013)

Apismellifera said:


> Nice work on the calcs, Bob!


Thank you. Suggestions on how to improve them and on other calculators that may be of use are always welcome.


----------



## jwcarlson (Feb 14, 2014)

BobRagsdale said:


> Yes, I have heard that a lot of people like and have had success with the Les Crowder design. As I read it his dimensions are:
> - Top 20.25"
> - Bottom 9.5"
> - Side 10"
> ...


I would say 5 foot would be better than 4 for a Crowder hive, my first year packages were only fed for a couple weeks lightly and they filled them nearly 3/4 of the way. At that length it might get a bit difficult for them to use the whole thing?


----------



## Michael Bush (Aug 2, 2002)

I agree with many of the comments. I think the real question is 4 feet or 5 feet...


----------



## Cabin (Nov 30, 2014)

I like Les' logic. Build the hive to fit the transport you may be using. I am still in the planning stages to get started this spring, I plan on making 2 or 3 trap hives at 24 inches to catch a swarm or two and a few at 51 inches that will fit in the truck if I have to move them(not planning on it but you never know).


----------



## shannonswyatt (May 7, 2012)

I make mine just under 4 foot, but that is so I don't have a bunch of waste wood when building them. Since most of the wood I get is in 8 foot lengths anything over 4 foot means I will have waste. My top covers are made from a four foot sheet of coroplast now, so that drives the size more or less.


----------



## Oldtimer (Jul 4, 2010)

BobRagsdale said:


> By my calculations
> 
> A 3 foot Wyatt Mangum design has 72 liters of volume.
> A 4 foot Michael Bush design has 74.3 liters of volume.
> So while there is a 25% difference in length, there is only a 3% difference in volume.


Good observation there BobRagsdale.

Watching what bees do naturally if allowed, they like their cluster to be roundish, or in fact, egg shaped. Long thin and sideways is not their preference. So as you have observed the volume in these various designs is very similar, the shorter length will suit the bees better. 

I have even seen bees in longer thinner designed TBH's swarm rather than build comb all the way to the end.

It's a trade off though. If you have a shorter hive with longer or deeper frames, it becomes more difficult to manage it the way you want as pointed out by JWCarlson. So like pretty much all hive designs there is some compromise between what works for the bees and what works for the beekeeper.

My ultimate TBH would be short and deep, and I would possibly have some kind of reinforcing in the combs to avoid damage of the larger combs when handling. Reinforcing is not at all unnatural, I have often seen wild hives with twigs etc going through the combs the bees just use them to help the structure.


----------



## Apismellifera (Oct 12, 2014)

Hmmm... I have a vision of rods that are glued into holes drilled in the bar, longer in the middle and shorter on the sides, of course. Would be preferable to drill for the rods before beveling the bar. Chopsticks? Bamboo skewers? Repurposed metal rods from something?

If you drilled all the way through the bar you could use a circlip on the top to hold them, easily removable to replace if necessary, as opposed to glued.

How far apart would be optimal spacing?


----------



## shannonswyatt (May 7, 2012)

I think the the idea of improving the bars in a TBH ultimately leads to just using Lang frames. But that is just me.


----------



## Kamon A. Reynolds (Apr 15, 2012)

You can make slide in dividers to shrink the space if needed. I like 5 feet. Great colonies will need the space for honey production.


----------



## Silverbackotter (Feb 23, 2013)

4-5 feet. 

Some of my fours don't have enough room in the summer, but five can be a pain to move. Both will flex in the middle if the legs are on end and they are full. 

I have some 3' and consider them nucs in my cold climate. 


I think the best bar length is Crowder's as you can cut out and go back and forth to deep langs with some effort.


----------



## BobRagsdale (Nov 23, 2014)

Oldtimer said:


> Watching what bees do naturally if allowed, they like their cluster to be roundish, or in fact, egg shaped.


I have been thinking about that exact thing and have been playing the idea of arched top-bars. I am not sure how practical they would be to make and manage (certainly wouldn't be simple like the straight bars - which defeats the simplicity angle of the top-bar hive) but it would be very stable as the top of the comb would be supported on three sides. I suspect that by springtime I will have come up with something and we can watch and see if it is a disaster or success.


----------



## jwcarlson (Feb 14, 2014)

shannonswyatt said:


> I think the the idea of improving the bars in a TBH ultimately leads to just using Lang frames. But that is just me.


I agree entirely, I like our top bar hives. Super easy to inspect and it does seem like having less of the hive exposed at one time results in relatively calmer bees. But I doubt I will expand our TBHs beyond what we have 4x 4' and 4x 12 bar nucs. All of the same Les Crowder footprint for interchangeability. 

I could see myself migrating out of them in the next few years, but we'll see. Interested to see how everything winters first. The idea of a long Lang to harness a some of the TBH advantages makes sense to me.


----------



## onesojourner (Jan 9, 2014)

I want to say my first hive was pretty close to 100 liters. That one got 3/4 filled with comb on the first year of a package. My second one I added about 5 inches to the length so it is 4' 5" or so and about an inch deeper. It was populated by a small swarm, they only got to about the 9th bar.


----------

